RXM-900-HP3-PPO_技术文档

HIGH-PERFORMANCE

RF MODULE

RXM-900-HP3-xxx

WIRELESS MADE SIMPLE ^®

HP3 SERIES RECEIVER MODULE DATA GUIDE

DESCRIPTION

1.940"

The HP3 RF receiver module offers complete

compatibility and numerous enhancements

over previous generations. The HP3 is

HP SERIES RF RECEIVER

0.780"

RXM-900-HP3-SP*

LOT 10000

designed for the cost-effective, high-

Pin Spacing: 0.1"

performance wireless transfer of analog or

0.236"

digital information in the popular 902-928MHz

SIP Style

band. All HP3 Series modules feature eight

1.950"

parallel selectable channels, but versions are

also available which add serial selection of 100

channels. To ensure reliable performance, the

HP SERIES RF RECEIVER

0.750"

RXM-900-HP3-SP*

LOT 10000

receiver employs FM / FSK demodulation and

0.190"

an advanced dual-conversion microprocessor-

controlled synthesized architecture. The

receiver is pin- and footprint-compatible with all

SMD Style

Figure 1: Package Dimensions

previous generations, but its overall physical size has been reduced. Both SMD and

pinned packages are available. When paired with an HP3 transmitter, a reliable link

is created for transferring analog and digital information up to 1,000 feet. (under

optimal conditions). As with all Linx modules, the HP3 requires no tuning or additional

RF components (except an antenna), making integration straightforward even for

engineers without prior RF experience.

FEATURES

APPLICATIONS INCLUDE

Wireless Networks / Data Transfer

Wireless Analog / Audio

Home / Industrial Automation

Remote Access / Control

Remote Monitoring / Telemetry

Long-Range RFID

8 parallel / 100 serial (PS Versions)

user-selectable channels

FM / FSK demodulation for outstanding

performance and noise immunity

Exceptional sensitivity (-100dBm typical)

Wide-range analog capability including

audio (50Hz to 28kHz)

RSSI and Power-down lines

Precision frequency

MIDI Links

Voice / Music / Intercom Links

ORDERING INFORMATION

synthesized architecture

No external RF

PART #

DESCRIPTION

components required

Compatible with previous

HP Series modules

RXM-900-HP3-PPO

HP3 Receiver (SIP 8 CH only)

RXM-900-HP3-PPS

HP3 Receiver (SIP 8p / 100s CH)

HP3 Receiver (SMD 8 CH only)

HP3 Receiver (SMD 8p / 100s CH)

HP3 Development Kit (Pinned Pkg.)

HP3 Development Kit (SMD Pkg.)

RXM-900-HP3-SPO

High data rate

RXM-900-HP3-SPS

(up to 56kbps)

Wide supply range

(2.8 to 13.0VDC)

Direct serial interface

Pinned and SMD packages

Wide temperature range

(-30°C to +85°C)

MDEV-900-HP3-PPS-USB

MDEV-900-HP3-PPS-RS232

MDEV-900-HP3-SPS-USB

MDEV-900-HP3-SPS-RS232

Receivers are supplied in tubes of 10 pcs.

Revised 1/28/08

ELECTRICAL SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

Parameter

Designation

Min.

Typical

Max.

Units

Notes

Supply Voltage V_CC

-0.3

to

+18.0

V_CC

+85

VDC

°C

POWER SUPPLY

Operating Voltage

Supply Current

Any Input or Output Pin

Operating Temperature

Storage Temperature

Soldering Temperature

-0.3

-30

-45

V_CC

I_CC

2.8

16.0

–

3.0

19.0

5.6

13.0

21.0

10.0

VDC

mA

µA

–

1

2

+85

°C

+260°C for 10 seconds

Power-Down Current

RECEIVE SECTION

Receive Frequency Range

Center Frequency Accuracy

Channel Spacing

First IF Frequency

Second IF Frequency

Noise Bandwidth

Data Rate

I_PDN

*NOTE* Exceeding any of the limits of this section may lead to permanent

damage to the device. Furthermore, extended operation at these maximum

ratings may reduce the life of this device.

F_C

–

902.62

-50

–

927.62

MHz

kHz

MHz

kHz

bps

3

+50

250

34.7

10.7

280

–

3

4

–

4

5

–

PERFORMANCE DATA

–

N_3DB

–

These performance parameters

are based on module operation at

25°C from a 3.0VDC supply unless

ANT

GND

NC

–

100

50

0.8

56,000

28,000

2.0

Analog / Audio Bandwidth

Analog / Audio Output Level

Data Output:

–

Hz

GND

1.1

VAC

otherwise

illustrates

necessary

noted.

the

for

Figure

connections

testing and

2

GND

NC

CS0

Logic Low

–

0.0

–

0.5

V_CC

–

VDC

6

Logic High

V_CC-0.3

PC

operation. It is recommended all

ground pins be connected to the

ground plane. The pins marked NC

have no electrical connection.

CS1 / SS CLOCK

CS2 / SS DATA

PDN

Output Impedance

Data Output Source Current

Receiver Sensitivity

RSSI:

–

17

kohms

–

230

-100

–

µA

7

5VDC

PC

RSSI

MODE

VCC

-94

-107

dBm

8,9

AUDIO

DATA

Dynamic Range

60

–

70

24

–

80

–

dB

mV/dB

V

4

Figure 2: Test / Basic Application Circuit

Gain

Voltage With No Carrier

Spurious Emissions

Interference Rejection:

–

1.6

–

TYPICAL PERFORMANCE GRAPHS

–

-57

dBm

F

1MHz

5MHz

–

54

57

–

dB

4

3.0

C

PDN

C

2.5

ANTENNA PORT

RF Input Impedance

TIMING

R_OUT

–

50

–

Ω

4

2.0

1

RX DATA

Receiver Turn-On Time:

via V_CC

1.5

T4

T3

T2

–

7.0

3.0

1.5

20

mSec

4

2

1.0

-110

via PDN

-100

-90

-80

-70

-60

-50

-40

RF INPUT (dBm)

Channel Change Time

Max time between transitions

ENVIRONMENTAL

Operating Temperature Range

CH1 1.00V

CH2 2.00V

500uS

Delta 1.920mS

T

1

Figure 3: RX Enabled to Valid Data

Figure 4: Receiver RSSI

10^-6

–

-30

–

+85

°C

4

Table 1: HP3 Series Receiver Specifications

10^-5

Notes

BER

10^-4

1. Over the entire operating voltage range.

2. With the PDN pin low.

3. Serial mode.

4. Characterized, but not tested.

5. With 1kHz sine wave @ 115kHz transmitter deviation

6. No load.

7. With 1V output drop.

8. For 10^-5@ 9,600bps.

10^-3

-92 -93 -94 -95 -96 -97 -98 -99 -100 -101 -102

1

PIN (dBm)

CH1 500mV

1mS

Delta 4.080mS

Figure 5: Worst Case RSSI Response Time

Figure 6: BER vs. Input Power (typical)

Page 3

9. At specified center frequency.

Page 2

PIN ASSIGNMENTS

PIN DESCRIPTIONS

Pinned Receiver

Surface-Mount Receiver

Pin #

Name

Equivalent Circuit

Description

RF In

1

2

3

4

5

6

7

8

9

ANT

GND

NC

NC 36

NC 35

NC 34

NC 33

NC 32

NC 31

NC 30

NC 29

NC 28

NC 27

NC 26

NC 25

NC 24

NC 23

1

ANT

50-ohm RF Input

50Ω

2-8

GND

NC

Analog Ground

No Connection

9

10 CS0

25k

10

11

12

CS0

Channel Select 0

11 CS1 / SS CLOCK

12 CS2 / SS DATA

13 PDN

µ

CS0

CS1

CS2

14 RSSI

Channel Select 1 /

Serial Select Clock

CS1 /

SS CLOCK

25k

15 MODE

NC

22

21

20

19

µ

16 VCC

17 AUDIO

18 DATA

Channel Select 2 /

Serial Select Data

CS2 /

SS DATA

25k

µ

Figure 7: HP3 Series Receiver Pinout

V_CC

470k

Pin # Name

Description

Power Down

(Active Low)

13

14

PDN

1

2-8

9

ANT

GND

NC

50-ohm RF Input

Analog Ground

No Connection

Channel Select 0

RSSI

10

CS0

Received Signal

Strength Indicator

RSSI

Channel Select 1 / Serial Select Clock. Channel Select 1

when in parallel channel selection mode, clock input for

serial channel selection mode.

CS1 / SS

CLOCK

11

12

13

14

15

Channel Select 1 / Serial Select Data. Channel Select 2

when in parallel channel selection mode, data input for

serial channel selection mode.

Power Down. Pulling this line low will place the receiver

into a low-current state. The module will not be able to

receive a signal in this state.

Received Signal Strength Indicator. This line will supply an

analog voltage that is proportional to the strength of the

received signal.

CS2 / SS

DATA

25k

15

16

MODE

V_CC

Mode Select

µ

V_CC

Voltage Input 2.8-13V

PDN

RSSI

1V_P-PAnalog Output

17

AUDIO

Mode Select. GND for parallel channel selection, V_CCfor

serial channel selection

MODE

4.7k

18

DATA

NC

Digital Data Output

No Connection

V_CC

16

17

Supply Voltage

AUDIO

Recovered Analog Output

19-36

SMD Only

Digital Data Output. This line will output the demodulated

digital data.

18

DATA

NC

Figure 8: Pin Functions and Equivalent Circuits

19-36

No Connection (SMD only)

Page 4

Page 5

THEORY OF OPERATION

POWER-UP SEQUENCE

The HP3 is a high-performance multi-channel, dual-conversion superhet

receiver capable of recovering both analog (FM) and digital (FSK) information

from a matching HP Series transmitter. FM / FSK modulation offers significant

advantages over AM or OOK modulation methods, including increased noise

immunity and the receiver’s ability to capture in the presence of multiple signals.

This is especially helpful in crowded bands, like that in which the HP3 operates.

As previously mentioned, the HP3 is controlled

by an on-board microprocessor. When power

is applied, the microprocessor executes the

receiver start-up sequence, after which the

receiver is ready to receive valid data.

POWER ON

Squelch Data

Output Pin

Parallel Mode

Serial Mode

Determine Mode

Read Channel

Selection Inputs

Program Freq. Synth

To Default CH. 50

The adjacent figure shows the start-up

sequence. This sequence is executed when

power is applied to the V_CCline or when the

MODE

CS0

Program Frequency

Synthesizer

Crystal Oscillator

Begins to Operate

24MHz

Crystal

PLL

Channel

Select

4MHz

Int. Osc.

RSSI

CS1

CS2

PDN line is taken high.

{

10.7MHz

Crystal Oscillator

Begins to Work

Ready for

Serial Data Input

BPF

On power-up, the microprocessor reads the

external channel selection lines and sets the

frequency synthesizer to the appropriate

channel. Once the frequency synthesizer has

stabilized, the receiver is ready to accept data.

Digital

Data

VCO

Quad

Determine Squelch

State Data Output Pin

Determine Squelch

State Data Output Pin

Analog

Data

IF

Amp

34.7M

BPF

SAW BPF

Cycle Here Until More

Data Input

or Mode Change

Cycle Here Until

Channel

or Mode Change

LNA

10.7M

BPF

10.7M

Discriminator

Limiter

Figure 10: Start-Up Sequence

Figure 9: HP3 Series Receiver Block Diagram

POWER SUPPLY

The single-ended RF port is matched to 50-ohms to support commonly available

antennas, such as those manufactured by Linx. The RF signal coming in from

the antenna is filtered by a Surface Acoustic Wave (SAW) filter to attenuate

unwanted RF energy. A SAW filter provides significantly higher performance

than other filter types, such as an LC bandpass filter.

The HP3 incorporates a precision, low-dropout

regulator on-board, which allows operation over an

input voltage range of 2.8 to 13 volts DC. Despite this

regulator, it is still important to provide a supply that

is free of noise. Power supply noise can significantly

affect the receiver sensitivity; therefore, providing a

clean power supply for the module should be a high

priority during design.

Vcc TO

MODULE

10Ω

Vcc IN

+

10μF

Once filtered, the signal is amplified by a Low Noise Amplifier (LNA) to increase

the receiver sensitivity and lower the overall noise figure of the receiver. After the

LNA, the signal is mixed with a synthesized local oscillator operating 34.7MHz

below the incoming transmission frequency to produce the first Intermediate

Frequency (IF).

Figure 11: Supply Filter

A 10Ω resistor in series with the supply followed by a

10µF tantalum capacitor from V_CCto ground will help in cases where the quality

The second conversion and FM demodulation is achieved by a high-

performance IF strip that mixes the 34.7MHz first conversion frequency with

24.0MHz from a precision crystal oscillator. The resulting second IF of 10.7MHz

is then highly amplified in preparation for demodulation.

of supply power is poor. This filter should be placed close to the module’s supply

lines. These values may need to be adjusted depending on the noise present on

the supply line.

USING THE PDN PIN

A quadrature demodulator is used to recover the baseband signal from the

carrier. The demodulated waveform is filtered, after which it closely resembles

the original signal. The signal is routed to the analog output pin and the data

slicer stage, which provides squared digital output via the data output pin. A key

feature of the HP3 is the transparency of its digital output, which does not impose

balancing or duty-cycle requirements within a range of 100bps to 56kbps.

The Power Down (PDN) line can be used to power down the receiver without the

need for an external switch. This line has an internal pull-up, so when it is held

high or simply left floating, the module will be active.

When the PDN line is pulled to ground, the receiver will enter into a low-current

(<10µA) power-down mode. During this time the receiver is off and cannot

perform any function. It may be useful to note that the startup time coming out

An on-board microcontroller manages receiver functions and greatly simplifies

user interface. The microcontroller reads the channel selection lines and

programs the on-board synthesizer. This frees the designer from complex

programming requirements and allows for manual or software channel selection.

The microcontroller also monitors incoming signal strength and squelches the

data output when the signal is not strong enough for accurate data detection.

of power-down will be slightly less than when applying V_CC

.

The PDN line allows easy control of the receiver state from external

components, like a microcontroller. By periodically activating the receiver,

checking for data, then powering down, the receiver’s average current

consumption can be greatly reduced, saving power in battery-operated

applications.

Page 6

Page 7

THE DATA OUTPUT

TIMING CONSIDERATIONS

The DATA line outputs recovered digital data. It is an open collector output with

an internal 4.7kΩ pull-up. When an RF transmission is not present, or when the

received signal strength is too low to ensure proper demodulation, the data

output is squelched continuous high. This feature supports direct operation with

UARTs, which require their input to be continuously high. An HP3 transmitter and

receiver can be directly connected between two UARTs without the need for

buffering or logical inversion. It should be noted that the squelch level is set just

over the receiver’s internal noise threshold. Any external RF activity above that

threshold will “break squelch” and produce hashing on the line. While the DATA

line will be reliably squelched in low-noise environments, the designer should

always plan for the potential of hashing.

There are four major timing considerations to be aware of when designing with

the HP3 Series receiver. These are shown in the table below.

Parameter

Description

Max.

20.0mS

1.5mS

3.0mS

7.0mS

T1

T2

T3

T4

Time between DATA output transitions

Channel change time (time to valid data)

Receiver turn-on time via PDN

Receiver turn-on time via V_CC

T1 is the maximum amount of time that can elapse without a data transition. Data

must always be considered in both the analog and the digital domain. Because

the data stream is asynchronous and no particular format is imposed, it is

possible for the data to meet the receiver’s data rate requirement yet violate the

analog frequency requirements. For example, if a 255 (0FF hex) were sent

continuously, the receiver would view the data as a DC level. It would hold that

level until a transition was required to meet the minimum frequency specification.

If no transition occurred, data integrity could not be guaranteed. While no

particular structure or balancing requirement is imposed, the designer must

ensure that both analog and digital signals meet the transition specification.

AUDIO OUTPUT

The HP3 Series is optimized for the transmission of serial data; however, it can

also be used very effectively to send a variety of analog signals, including audio.

The ability of the HP3 to send combinations of audio and data opens new areas

of opportunity for creative design.

The analog output of the AUDIO line is valid from 50 Hz to 28 kHz, providing an

AC signal of about 1V peak-to-peak. This is a high impedance output and not

suitable for directly driving low-impedance loads, such as a speaker. In

applications where a low impedance load is to be driven, a buffer circuit should

always be used. For example, in the case of a speaker, a simple op-amp circuit

such as the one shown below can be used to act as an impedance converter.

T2 is the worst-case time needed for a powered-up module to switch between

channels after a valid channel selection. This time does not include external

overhead for loading a desired channel in the serial channel-selection mode.

T3 is the time to receiver readiness from the PDN line going high. Receiver

readiness is determined by valid data on the DATA line. This assumes an

incoming data stream and the presence of stable supply on V_CC

.

VCC

T4 is the time to receiver readiness from the application of V_CC. Receiver

readiness is determined by valid data on the DATA line. This assumes an

incoming data stream and the PDN line is high or open.

1uF

10k

6

4

2

3

HP Analog Out

–

+

250uF

RECEIVING DATA

5

Once an RF link has been established, the challenge becomes how to effectively

transfer data across it. While a properly designed RF link provides reliable data

transfer under most conditions, there are still distinct differences from a wired link

that must be addressed. Since the modules do not incorporate internal encoding

or decoding, the user has tremendous flexibility in how data is handled.

0.05uF

10 ohm

LM386

Figure 12: Audio Buffer Amplifier

It is important to separate the types of transmissions that are technically possible

from those that are legally allowed in the country of operation. Application Notes

AN-00126, AN-00140 and Part 15, Section 249 of the FCC rules should be

reviewed for details on acceptable transmission content in the U.S.

The transmitter’s modulation voltage is critical, since it determines the carrier

deviation and distortion. The transmitter input level should be adjusted to

achieve the optimum results for your application in your circuit. Please refer to

the transmitter data guide for full details.

If you want to transfer simple control or status signals (such as button presses)

and your product does not have a microprocessor or you wish to avoid protocol

development, consider using an encoder / decoder IC set. These chips are

available from several manufacturers, including Linx. They take care of all

encoding and decoding functions and provide a number of data lines to which

switches can be directly connected. Address bits are usually provided for

security and to allow the addressing of multiple receivers independently. These

ICs are an excellent way to bring basic remote control products to market quickly

and inexpensively. It is also a simple task to interface with inexpensive

microprocessors or one of many IR, remote control, DTMF, or modem ICs.

When used for audio, the analog output of the receiver should be filtered and

buffered to obtain maximum sound quality. For voice, a 3-4kHz low-pass filter is

often employed. For broader-range sources, such as music, a 12-17kHz cutoff

may be more appropriate. In applications that require high-quality audio, a

compandor may be used to further improve SNR. The HP3 is capable of

providing audio quality comparable to a radio or intercom. For applications where

true high fidelity audio is required, the HP3 will probably not be the best choice,

and a device optimized for audio should be utilized.

Page 8

Page 9

CHANNEL SELECTION

Parallel Selection

SERIAL CHANNEL SELECTION TABLE

CHANNEL TX FREQUENCY

RX LO

867.92

868.17

868.42

868.67

868.92

869.17

869.42

869.67

869.92

870.17

870.42

870.67

870.92

871.17

871.42

871.67

871.92

872.17

872.42

872.67

872.92

873.17

873.42

873.67

873.92

874.17

874.42

874.67

874.92

875.17

875.42

875.67

875.92

876.17

876.42

876.67

876.92

877.17

877.42

877.67

877.92

878.17

878.42

878.67

878.92

879.17

879.42

879.67

879.92

880.17

880.42

CHANNEL

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

TX FREQUENCY

915.37

915.62

915.87

916.12

916.37

916.62

916.87

917.12

917.37

917.62

917.87

918.12

918.37

918.62

918.87

919.12

919.37

919.62

919.87

920.12

920.37

920.62

920.87

921.12

921.37

921.62

921.87

922.12

922.37

922.62

922.87

923.12

923.37

923.62

923.87

924.12

924.37

924.62

924.87

925.12

925.37

925.62

925.87

926.12

926.37

926.62

926.87

927.12

927.37

927.62

RX LO

880.67

880.92

881.17

881.42

881.67

881.92

882.17

882.42

882.67

882.92

883.17

883.42

883.67

883.92

884.17

884.42

884.67

884.92

885.17

885.42

885.67

885.92

886.17

886.42

886.67

886.92

887.17

887.42

887.67

887.92

888.17

888.42

888.67

888.92

889.17

889.42

889.67

889.92

890.17

890.42

890.67

890.92

891.17

891.42

891.67

891.92

892.17

892.42

892.67

892.92

CS2

0

1

CS1

0

1

0

1

CS0

0

1

0

1

0

1

0

1

Channel

Frequency

903.37

906.37

907.87

909.37

912.37

915.37

919.87

921.37

0

1

2

3

4

5

6

7

902.62

902.87

903.12

903.37

903.62

903.87

904.12

904.37

904.62

904.87

905.12

905.37

905.62

905.87

906.12

906.37

906.62

906.87

907.12

907.37

907.62

907.87

908.12

908.37

908.62

908.87

909.12

909.37

909.62

909.87

910.12

910.37

910.62

910.87

911.12

911.37

911.62

911.87

912.12

912.37

912.62

912.87

913.12

913.37

913.62

913.87

914.12

914.37

914.62

914.87

915.12

0

1

2

3

4

5

6

7

All HP3 receiver models feature eight

parallel selectable channels. Parallel

Mode is selected by grounding the

MODE line. In this mode, channel

selection is determined by the logic

states of pins CS0, CS1, and CS2, as

shown in the adjacent table. A ‘0’

represents ground and a ‘1’ the positive supply. The on-board microprocessor

performs all PLL loading functions, eliminating external programming and

allowing channel selection via DIP switches or a product’s processor.

Table 2: Parallel Channel Selection Table

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50*

Serial Selection

In addition to the Parallel Mode, PS versions of the HP3 also feature 100 serially

selectable channels. The Serial Mode is entered when the MODE line is left open

or held high. In this condition, CS1 and CS2 become a synchronous serial port,

with CS1 serving as the clock line and CS2 as the data line. The module is easily

programmed by sending and latching the binary number (0 to 100) of the desired

channel (see the adjacent Serial Channel Selection Table). With no additional

effort, the module’s microprocessor handles the complex PLL loading functions.

The Serial Mode is

straightforward; however,

minimum timings and bit

order must be followed.

Loading is initiated by

taking the clock line high

and the data line low as

Variable Data

Note 2

Note 1

Data

1

2

3

4

5

6

7

8

Clock

T0

1ms

T3

Note 3

T4

5µs

8µs

T2

T1

25µs

5µs

shown.

The

eight-bit

1) Loading begins when clock line is high and data line is taken low

2) Ensure that edge is fully risen prior to high-clock transition

3) Both lines high triggers automatic latch

channel number is then

clocked-in one bit at a

time, with the LSB first.

(T0) Time between packets or prior to data startup ................................1mS min.

(T1) Data-LO / Clock-HI to Data-LO / Clock-LO.......................................25

(T2) Clock-LO to Clock-HI ...........................................................................5

(T3) Clock-HI to Clock-LO ...........................................................................8

(T4) Data-HI / Clock-HI .................................................................................5

Total Packet Time ......................................................................................157

µ

S min.

Figure 13: PLL Serial Data Timing

There is no maximum time for this process, only the minimum times that must be

observed. After the eighth bit, both the clock and data lines should be taken high

to trigger the automatic data latch. A typical software routine can complete the

loading sequence in under 200uS. Sample code is available on the Linx website.

NOTE: When the module is powered up in the Serial Mode, it will default to channel 50 until changed

by user software. This allows testing apart from external programming and prevents out-of-band

operation. When programmed properly, the dwell time on this default channel can be less than 200uS.

Channel 50 is not counted as a usable channel since data errors may occur as transmitters also default

to channel 50 on startup. If a loading error occurs, such as a channel number >100 or a timing problem,

the receiver will default to serial channel 0. This is useful for debugging as it verifies serial port activity.

= Also available in Parallel Mode

*See NOTE on previous page.

Page 10

Page 11

PROTOCOL GUIDELINES

TYPICAL APPLICATIONS

While many RF solutions impose data formatting and balancing requirements,

Linx RF modules do not encode or packetize the signal content in any manner.

The received signal will be affected by such factors as noise, edge jitter, and

interference, but it is not purposefully manipulated or altered by the modules.

This gives the designer tremendous flexibility for protocol design and interface.

The figure below shows a typical RS-232 circuit using the HP3 Series receiver

and a Maxim MAX232. The receiver outputs a serial data stream and the

MAX232 converts that to RS-232 compliant signals. The MODE line is grounded

so the channels are selected by the DIP switches.

VCC

Despite this transparency and ease of use, it must be recognized that there are

distinct differences between a wired and a wireless environment. Issues such as

interference and contention must be understood and allowed for in the design

process. To learn more about protocol considerations, we suggest you read Linx

Application Note AN-00160.

VCC

1

2

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

19

ANT

GND

NC

C1

4.7uF

+

C2

4.7uF

3

GND

4

GND

DB-9

5

6

1

6

2

7

3

+

1

2

3

4

5

6

7

8

16

15

14

13

12

11

10

9

GND

C3

4.7uF

C1+

V+

C1-

C2+

C2-

V-

VCC

GND

T1OUT

R1IN

R1OUT

T1IN

T2IN

GND

7

GND

NC

CS0

8

9

Errors from interference or changing signal conditions can cause corruption of

the data packet, so it is generally wise to structure the data being sent into small

packets. This allows errors to be managed without affecting large amounts of

data. A simple checksum or CRC could be used for basic error detection. Once

an error is detected, the protocol designer may wish to simply discard the corrupt

data or implement a more sophisticated scheme to correct it.

10

11

12

13

14

15

16

17

18

+

4

9

5

C4

4.7uF

CS1 / SS CLOCK

CS2 / SS DATA

PDN

T2OUT

R2IN

R2OUT

RSSI

MAX232

VCC

GND

MODE

VCC

C5

4.7uF

GND

AUDIO

DATA

GND

INTERFERENCE CONSIDERATIONS

Figure 14: HP3 Receiver and MAX232 IC

The RF spectrum is crowded and the potential for conflict with other unwanted

sources of RF is very real. While all RF products are at risk from interference, its

effects can be minimized by better understanding its characteristics.

The figure below shows a circuit using the QS Series USB module. The QS

converts the data from the receiver into USB compliant signals to be sent to a

PC. The MODE line is high, so the module is in Serial Channel Select mode. The

RTS and DTR lines are used to load the channels. Application Note AN-00155

shows sample source code that can be adapted to use on a PC. The QS Series

Data Guide and Application Note AN-00200 discuss the hardware and software

set-up required for QS Series modules.

Interference may come from internal or external sources. The first step is to

eliminate interference from noise sources on the board. This means paying

careful attention to layout, grounding, filtering, and bypassing in order to

eliminate all radiated and conducted interference paths. For many products, this

is straightforward; however, products containing components such as switching

power supplies, motors, crystals, and other potential sources of noise must be

approached with care. Comparing your own design with a Linx evaluation board

can help to determine if and at what level design-specific interference is present.

1

2

36

35

34

33

32

31

30

29

28

27

26

25

24

23

22

21

20

19

ANT

GND

NC

3

GND

4

GND

USB-B

5

6

External interference can manifest itself in a variety of ways. Low-level

interference will produce noise and hashing on the output and reduce the link’s

overall range.

4

3

2

1

GND

1

2

3

4

5

6

7

8

16

15

USBDP

USBDM

GND

RI

DCD

GND

7

GND

NC

CS0

DAT -

5V

8

9

DSR

13

12

11

10

9

VCC

DATA_IN

10

11

12

13

14

SUSP_IND DATA_OUT

GND GND

High-level interference is caused by nearby products sharing the same

frequency or from near-band high-power devices. It can even come from your

own products if more than one transmitter is active in the same area. It is

important to remember that only one transmitter at a time can occupy a

frequency, regardless of the coding of the transmitted signal. This type of

interference is less common than those mentioned previously, but in severe

cases it can prevent all useful function of the affected device.

RX_IND

TX_IND

485_TX

RTS

CTS

DTR

CS1 / SS CLOCK

CS2 / SS DATA

PDN

VCC

RSSI

SDM-USB-QS

MODE

VCC

16

17

18

AUDIO

DATA

Figure 15: HP3 Receiver and Linx QS Series USB Module

The receiver can also be connected to a microcontroller, which will interpret the

data and take specific actions. A UART may be employed or an I / O line may be

used to continuously monitor the DATA line for a valid packet. The receiver may

be connected directly to the microcontroller without the need for buffering or

amplification.

Although technically it is not interference, multipath is also a factor to be

understood. Multipath is a term used to refer to the signal cancellation effects

that occur when RF waves arrive at the receiver in different phase relationships.

This effect is a particularly significant factor in interior environments where

objects provide many different signal reflection paths. Multipath cancellation

results in lowered signal levels at the receiver and, thus, shorter useful distances

for the link.

Page 12

Page 13

BOARD LAYOUT GUIDELINES

MICROSTRIP DETAILS

If you are at all familiar with RF devices, you may be concerned about

specialized board layout requirements. Fortunately, because of the care taken by

Linx in designing the modules, integrating them is very straightforward. Despite

this ease of application, it is still necessary to maintain respect for the RF stage

and exercise appropriate care in layout and application in order to maximize

performance and ensure reliable operation. The antenna can also be influenced

by layout choices. Please review this data guide in its entirety prior to beginning

your design. By adhering to good layout principles and observing some basic

design rules, you will be on the path to RF success.

A transmission line is a medium whereby RF energy is transferred from one

place to another with minimal loss. This is a critical factor, especially in high-

frequency products like Linx RF modules, because the trace leading to the

module’s antenna can effectively contribute to the length of the antenna,

changing its resonant bandwidth. In order to minimize loss and detuning, some

form of transmission line between the antenna and the module should be used,

unless the antenna can be placed very close (<1/8in.) to the module. One

common form of transmission line is a coax cable, another is the microstrip. This

term refers to a PCB trace running over a ground plane that is designed to serve

as a transmission line between the module and the antenna. The width is based

on the desired characteristic impedance of the line, the thickness of the PCB,

and the dielectric constant of the board material. For standard 0.062in thick FR-

4 board material, the trace width would be 111 mils. The correct trace width can

be calculated for other widths and materials using the information below. Handy

software for calculating microstrip lines is also available on the Linx website,

www.linxtechnologies.com.

The adjacent figure shows the suggested

GROUUNNDD PPLLAANNEE

PCB footprint for the module. The actual pad

dimensions are shown in the Pad Layout

section of this manual. A ground plane (as

large as possible) should be placed on a

lower layer of your PC board opposite the

module. This ground plane can also be critical

to the performance of your antenna, which will

be discussed later. There should not be any

ground or traces under the module on the

same layer as the module, just bare PCB.

ON LLOWWEERR LLAAYYEERR

Trace

Figure 16: Suggested PCB Layout

Board

During prototyping, the module should be soldered to a properly laid-out circuit

board. The use of prototyping or “perf” boards will result in horrible performance

and is strongly discouraged.

Ground plane

No conductive items should be placed within 0.15in of the module’s top or sides.

Do not route PCB traces directly under the module. The underside of the module

has numerous signal-bearing traces and vias that could short or couple to traces

on the product’s circuit board.

The module’s ground lines should each have their own via to the ground plane

and be as short as possible.

AM / OOK receivers are particularly subject to noise. The module should, as

much as reasonably possible, be isolated from other components on your PCB,

especially high-frequency circuitry such as crystal oscillators, switching power

supplies, and high-speed bus lines. Make sure internal wiring is routed away

from the module and antenna, and is secured to prevent displacement.

The power supply filter should be placed close to the module’s V_CCline.

In some instances, a designer may wish to encapsulate or “pot” the product.

Many Linx customers have done this successfully; however, there are a wide

variety of potting compounds with varying dielectric properties. Since such

compounds can considerably impact RF performance, it is the responsibility of

the designer to carefully evaluate and qualify the impact and suitability of such

materials.

Figure 17: Microstrip Formulas

Effective Dielectric

Constant

Characteristic

Impedance

Dielectric Constant Width/Height (W/d)

The trace from the module to the antenna should be kept as short as possible.

A simple trace is suitable for runs up to 1/8-inch for antennas with wide

bandwidth characteristics. For longer runs or to avoid detuning narrow bandwidth

antennas, such as a helical, use a 50-ohm coax or 50-ohm microstrip

transmission line as described in the following section.

4.80

4.00

2.55

1.8

2.0

3.0

3.59

3.07

2.12

50.0

51.0

48.0

Page 14

Page 15

PAD LAYOUT

AUTOMATED ASSEMBLY

The following pad layout diagram is designed to facilitate both hand and

automated assembly.

For high-volume assembly, most users will want to auto-place the modules. The

modules have been designed to maintain compatibility with reflow processing

techniques; however, due to the their hybrid nature, certain aspects of the

assembly process are far more critical than for other component types.

Pinned Receiver

Surface-Mount Receiver

0.065

Following are brief discussions of the three primary areas where caution must be

observed.

0.090

0.060

0.100

Reflow Temperature Profile

0.060

0.750

The single most critical stage in the automated assembly process is the reflow

stage. The reflow profile below should not be exceeded, since excessive

temperatures or transport times during reflow will irreparably damage the

modules. Assembly personnel will need to pay careful attention to the oven’s

profile to ensure that it meets the requirements necessary to successfully reflow

all components while still remaining within the limits mandated by the modules.

The figure below shows the recommended reflow oven profile for the modules.

0.030 Dia. Finished

0.100

Figure 18: Recommended PCB Layout

PRODUCTION GUIDELINES

300

Recommended RoHS Profile

Max RoHS Profile

Recommended Non-RoHS Profile

The modules are housed in a hybrid SMD package that supports hand or

automated assembly techniques. Since the modules contain discrete

components internally, the assembly procedures are critical to ensuring the

reliable function of the modules. The following procedures should be reviewed

with and practiced by all assembly personnel.

255°C

250

200

150

100

50

235°C

217°C

185°C

180°C

HAND ASSEMBLY

Pads located on the bottom of the

module are the primary mounting

surface. Since these pads are

inaccessible during mounting,

castellations that run up the side of

the module have been provided to

facilitate solder wicking to the

module’s underside. This allows for

very quick hand soldering for

Soldering Iron

Tip

125°C

Solder

PCB Pads

0

30

60

90

120

150

Time (Seconds)

180

210

240

270

300

330

360

Castellations

prototyping and small volume

Figure 20: Maximum Reflow Profile

Figure 19: Soldering Technique

production.

If the recommended pad guidelines have been followed, the pads will protrude

slightly past the edge of the module. Use a fine soldering tip to heat the board

pad and the castellation, then introduce solder to the pad at the module’s edge.

The solder will wick underneath the module, providing reliable attachment. Tack

one module corner first and then work around the device, taking care not to

exceed the times listed below.

Shock During Reflow Transport

Since some internal module components may reflow along with the components

placed on the board being assembled, it is imperative that the modules not be

subjected to shock or vibration during the time solder is liquid. Should a shock

be applied, some internal components could be lifted from their pads, causing

the module to not function properly.

Washability

Absolute Maximum Solder Times

The modules are wash resistant, but are not hermetically sealed. Linx

recommends wash-free manufacturing; however, the modules can be subjected

to a wash cycle provided that a drying time is allowed prior to applying electrical

power to the modules. The drying time should be sufficient to allow any moisture

that may have migrated into the module to evaporate, thus eliminating the

potential for shorting damage during power-up or testing. If the wash contains

contaminants, the performance may be adversely affected, even after drying.

Hand-Solder Temp. TX +225°C for 10 Seconds

Hand-Solder Temp. RX +225°C for 10 Seconds

Recommended Solder Melting Point +180°C

Reflow Oven: +220°C Max. (See adjoining diagram)

Page 16

Page 17

ANTENNA CONSIDERATIONS

GENERAL ANTENNA RULES

The choice of antennas is a critical

The following general rules should help in maximizing antenna performance.

and

consideration.

often

overlooked

The

design

range,

1. Proximity to objects such as a user’s hand, body, or metal objects will cause an

antenna to detune. For this reason, the antenna shaft and tip should be

positioned as far away from such objects as possible.

performance, and legality of an RF link

are critically dependent upon the

antenna. While adequate antenna

performance can often be obtained by

trial and error methods, antenna

design and matching is a complex

2. Optimum performance will be obtained

from a 1/4- or 1/2-wave straight whip

mounted at a right angle to the ground

plane. In many cases, this isn’t desirable

OPTIMUM

for practical or ergonomic reasons, thus,

NOT RECOMMENDED

task.

A

professionally designed

Figure 21: Linx Antennas

USEABLE

an alternative antenna style such as a

helical, loop, or patch may be utilized

antenna, such as those from Linx, will

help ensure maximum performance and FCC compliance.

Figure 23: Ground Plane Orientation

and the corresponding sacrifice in performance accepted.

Linx transmitter modules typically have an output power that is slightly higher

than the legal limits. This allows the designer to use an inefficient antenna, such

as a loop trace or helical, to meet size, cost, or cosmetic requirements and still

achieve full legal output power for maximum range. If an efficient antenna is

used, then some attenuation of the output power will likely be needed. This can

easily be accomplished by using the LADJ line or a T-pad attenuator. For more

details on T-pad attenuator design, please see Application Note AN-00150.

3. If an internal antenna is to be used, keep it away from other metal components,

particularly large items like transformers, batteries, PCB tracks, and ground

planes. In many cases, the space around the antenna is as important as the

antenna itself. Objects in close proximity to the antenna can cause direct

detuning, while those farther away will alter the antenna’s symmetry.

4. In many antenna designs, particularly 1/4-wave

VERTICAL λ/4 GROUNDED

ANTENNA (MARCONI)

whips, the ground plane acts as a counterpoise,

forming, in essence, a 1/2-wave dipole. For this

reason, adequate ground plane area is essential.

A receiver antenna should be optimized for the frequency or band in which the

receiver operates and to minimize the reception of off-frequency signals. The

efficiency of the receiver’s antenna is critical to maximizing range performance.

Unlike the transmitter antenna, where legal operation may mandate attenuation

or a reduction in antenna efficiency, the receiver’s antenna should be optimized

as much as is practical.

E

DIPOLE

ELEMENT

λ/4

The ground plane can be a metal case or ground-fill

I

areas on a circuit board. Ideally, it should have a

surface area > the overall length of the 1/4-wave

radiating element. This is often not practical due to

size and configuration constraints. In these

instances, a designer must make the best use of the

area available to create as much ground plane as

GROUND

PLANE

VIRTUAL λ/4

DIPOLE

λ/4

It is usually best to utilize a basic quarter-wave whip until your prototype product

is operating satisfactorily. Other antennas can then be evaluated based on the

cost, size, and cosmetic requirements of the product. You may wish to review

Application Note AN-00500 “Antennas: Design, Application, Performance”

Figure 24: Dipole Antenna

possible in proximity to the base of the antenna. In cases where the antenna is

remotely located or the antenna is not in close proximity to a circuit board,

ground plane, or grounded metal case, a metal plate may be used to maximize

the antenna’s performance.

ANTENNA SHARING

In cases where a transmitter and receiver

module are combined to form a transceiver,

0.1μF

it is often advantageous to share a single

Module

V

DD

Transmitter

^0.1μF

Antenna

5. Remove the antenna as far as possible from potential interference sources. Any

frequency of sufficient amplitude to enter the receiver’s front end will reduce

system range and can even prevent reception entirely. Switching power

supplies, oscillators, or even relays can also be significant sources of potential

interference. The single best weapon against such problems is attention to

placement and layout. Filter the module’s power supply with a high-frequency

bypass capacitor. Place adequate ground plane under potential sources of noise

to shunt noise to ground and prevent it from coupling to the RF stage. Shield

noisy board areas whenever practical.

antenna. To accomplish this, an antenna

switch must be used to provide isolation

between the modules so that the full

^0.1μF

GND

^0.1μF

GND

Receiver

Module

transmitter output power is not put on the

^0.1μF

sensitive front end of the receiver. There

Select

are a wide variety of antenna switches that

are cost-effective and easy to use. Among

Figure 22: Typical Antenna Switch

the most popular are switches from Macom and NEC. Look for an antenna

switch that has high isolation and low loss at the desired frequency of operation.

Generally, the Tx or Rx status of a switch will be controlled by a product’s

microprocessor, but the user may also make the selection manually. In some

cases, where the characteristics of the Tx and Rx antennas need to be different

or antenna switch losses are unacceptable, it may be more appropriate to utilize

two discrete antennas.

6. In some applications, it is advantageous to

place the module and antenna away from the

CASE

main equipment. This can avoid interference

problems and allows the antenna to be

oriented for optimum performance. Always use

GROUND PLANE

NUT

(MAY BE NEEDED)

50Ω coax, like RG-174, for the remote feed.

Figure 25: Remote Ground Plane

Page 19

Page 18

COMMON ANTENNA STYLES

ONLINE RESOURCES

There are literally hundreds of antenna styles and variations that can be

employed with Linx RF modules. Following is a brief discussion of the styles

most commonly utilized. Additional antenna information can be found in Linx

Application Notes AN-00100, AN-00140, and AN-00500. Linx antennas and

connectors offer outstanding performance at a low price.

®

www.linxtechnologies.com

• Latest News

A whip-style antenna provides outstanding overall performance

Whip Style

and stability. A low-cost whip is can be easily fabricated from a

wire or rod, but most designers opt for the consistent

performance and cosmetic appeal of a professionally-made

model. To meet this need, Linx offers a wide variety of straight

and reduced-height whip-style antennas in permanent and

connectorized mounting styles.

• Data Guides

• Application Notes

• Knowledgebase

• Software Updates

The wavelength of the operational frequency determines an

antenna’s overall length. Since a full wavelength is often quite

If you have questions regarding any Linx product and have Internet access,

make www.linxtechnologies.com your first stop. Our website is organized in an

intuitive format to immediately give you the answers you need. Day or night, the

Linx website gives you instant access to the latest information regarding the

products and services of Linx. It’s all here: manual and software updates,

application notes, a comprehensive knowledgebase, FCC information, and much

more. Be sure to visit often!

long, a partial 1/2- or 1/4-wave antenna is normally employed.

Its size and natural radiation resistance make it well matched to

Linx modules. The proper length for a straight 1/4-wave can be

easily determined using the adjacent formula. It is also possible

to reduce the overall height of the antenna by using a helical

winding. This reduces the antenna’s bandwidth, but is a great

way to minimize the antenna’s physical size for compact

applications. This also means that the physical appearance is

not always an indicator of the antenna’s frequency.

234

L =

F

MHz

Where:

L

= length in feet of

quarter-wave length

F = operating frequency

in megahertz

Specialty Styles

Linx offers a wide variety of specialized antenna styles.

Many of these styles utilize helical elements to reduce the

overall antenna size while maintaining reasonable

performance. A helical antenna’s bandwidth is often quite

narrow and the antenna can detune in proximity to other

objects, so care must be exercised in layout and placement.

www.antennafactor.com

The Antenna Factor division of Linx offers

a diverse array of antenna styles, many of

which are optimized for use with our RF

modules. From innovative embeddable

antennas to low-cost whips, domes to

Yagis, and even GPS, Antenna Factor

likely has an antenna for you, or can

design one to meet your requirements.

A loop- or trace-style antenna is normally printed directly on a

product’s PCB. This makes it the most cost-effective of antenna

styles. The element can be made self-resonant or externally

resonated with discrete components, but its actual layout is

usually product specific. Despite the cost advantages, loop-style

antennas are generally inefficient and useful only for short-range

applications. They are also very sensitive to changes in layout and

PCB dielectric, which can cause consistency issues during

production. In addition, printed styles are difficult to engineer,

requiring the use of expensive equipment, including a network

analyzer. An improperly designed loop will have a high SWR at the

desired frequency, which can cause instability in the RF stage.

Loop Style

www.connectorcity.com

Through its Connector City division, Linx offers a wide

selection of high-quality RF connectors, including FCC-

compliant types such as RP-SMAs that are an ideal

match for our modules and antennas. Connector City

focuses on high-volume OEM requirements, which

allows standard and custom RF connectors to be offered

at a remarkably low cost.

Linx offers low-cost planar and chip antennas that mount directly

to a product’s PCB. These tiny antennas do not require testing and

provide excellent performance in light of their small size. They

offer a preferable alternative to the often-problematic “printed”

antenna.

Page 20

Page 21

LEGAL CONSIDERATIONS

ACHIEVING A SUCCESSFUL RF IMPLEMENTATION

Adding an RF stage brings an exciting new

DECIDE TO UTILIZE RF

NOTE: Linx RF modules are designed as component devices that require

external components to function. The modules are intended to allow for full Part

15 compliance; however, they are not approved by the FCC or any other agency

worldwide. The purchaser understands that approvals may be required prior to

the sale or operation of the device, and agrees to utilize the component in keeping

with all laws governing its use in the country of operation.

dimension to any product. It also means that

additional effort and commitment will be needed to

bring the product successfully to market. By utilizing

premade RF modules, such as the LR Series, the

design and approval process is greatly simplified. It

is still important, however, to have an objective view

of the steps necessary to ensure a successful RF

integration. Since the capabilities of each customer

vary widely, it is difficult to recommend one

particular design path, but most projects follow steps

similar to those shown at the right.

RESEARCH RF OPTIONS

ORDER EVALUATION KIT(S)

TEST MODULE(S) WITH

BASIC HOOKUP

CHOOSE LINX MODULE

When working with RF, a clear distinction must be made between what is technically

possible and what is legally acceptable in the country where operation is intended. Many

manufacturers have avoided incorporating RF into their products as a result of

uncertainty and even fear of the approval and certification process. Here at Linx, our

desire is not only to expedite the design process, but also to assist you in achieving a

clear idea of what is involved in obtaining the necessary approvals to legally market your

completed product.

INTERFACE TO CHOSEN

CIRCUIT AND DEBUG

CONSULT LINX REGARDING

ANTENNA OPTIONS AND DESIGN

LAY OUT BOARD

In reviewing this sample design path, you may

notice that Linx offers a variety of services (such as

antenna design and FCC prequalification) that are

unusual for a high-volume component manufacturer.

These services, along with an exceptional level of

technical support, are offered because we recognize

that RF is a complex science requiring the highest

caliber of products and support. “Wireless Made

Simple” is more than just a motto, it’s our

commitment. By choosing Linx as your RF partner

and taking advantage of the resources we offer, you

SEND PRODUCTION-READY

PROTOTYPE TO LINX

FOR EMC PRESCREENING

OPTIMIZE USING RF SUMMARY

GENERATED BY LINX

In the United States, the approval process is actually quite straightforward. The

regulations governing RF devices and the enforcement of them are the responsibility of

the Federal Communications Commission (FCC). The regulations are contained in Title

47 of the Code of Federal Regulations (CFR). Title 47 is made up of numerous volumes;

however, all regulations applicable to this module are contained in Volume 0-19. It is

strongly recommended that a copy be obtained from the Government Printing Office in

Washington or from your local government bookstore. Excerpts of applicable sections are

included with Linx evaluation kits or may be obtained from the Linx Technologies website,

www.linxtechnologies.com. In brief, these rules require that any device that intentionally

radiates RF energy be approved, that is, tested for compliance and issued a unique

identification number. This is a relatively painless process. Linx offers full FCC pre-

screening, and final compliance testing is then performed by one of the many

independent testing laboratories across the country. Many labs can also provide other

certifications that the product may require at the same time, such as UL, Class A / B, etc.

Once your completed product has passed, you will be issued an ID number that is to be

clearly placed on each product manufactured.

SEND TO PART 15

TEST FACILITY

RECEIVE FCC ID #

COMMENCE SELLING PRODUCT

Typical Steps For

Implementing RF

will not only survive implementing RF, you may even find the process enjoyable.

HELPFUL APPLICATION NOTES FROM LINX

It is not the intention of this manual to address in depth many of the issues that

should be considered to ensure that the modules function correctly and deliver

the maximum possible performance. As you proceed with your design, you may

wish to obtain one or more of the following application notes, which address in

depth key areas of RF design and application of Linx products. These

applications notes are available online at www.linxtechnologies.com or by

contacting the Linx literature department.

Questions regarding interpretations of the Part 2 and Part 15 rules or measurement

procedures used to test intentional radiators, such as Linx RF modules, for compliance

with the technical standards of Part 15, should be addressed to:

Federal Communications Commission

Office of Engineering and Technology Laboratory Division

7435 Oakland Mills Road

NOTE

AN-00100

APPLICATION NOTE TITLE

RF 101: Information for the RF Challenged

Columbia, MD 21046-1609

Phone: (301) 362-3000 Fax: (301) 362-3290 E-Mail: labinfo@fcc.gov

International approvals are slightly more complex, although Linx modules are designed

to allow all international standards to be met. If you are considering the export of your

product abroad, you should contact Linx Technologies to determine the specific suitability

of the module to your application.

AN-00126

AN-00130

AN-00140

AN-00155

AN-00160

AN-00500

Considerations For Operation Within The 902-928MHz Band

Modulation Techniques For Low-Cost RF Data Links

The FCC Road: Part 15 From Concept To Approval

Serial Loading Techniques for the HP Series 3

All Linx modules are designed with the approval process in mind and thus much of the

frustration that is typically experienced with a discrete design is eliminated. Approval is

still dependent on many factors, such as the choice of antennas, correct use of the

frequency selected, and physical packaging. While some extra cost and design effort are

required to address these issues, the additional usefulness and profitability added to a

product by RF makes the effort more than worthwhile.

Considerations For Sending Data Over a Wireless Link

Antennas: Design, Application, Performance

Page 22

Page 23

WIRELESS MADE SIMPLE ^®

U.S. CORPORATE HEADQUARTERS

LINX TECHNOLOGIES, INC.

159 ORT LANE

MERLIN, OR 97532

PHONE: (541) 471-6256

FAX: (541) 471-6251

www.linxtechnologies.com

Disclaimer

Linx Technologies is continually striving to improve the quality and function of its products. For this reason,

we reserve the right to make changes to our products without notice. The information contained in this

Overview Guide is believed to be accurate as of the time of publication. Specifications are based on

representative lot samples. Values may vary from lot-to-lot and are not guaranteed. "Typical" parameters can

and do vary over lots and application. Linx Technologies makes no guarantee, warranty, or representation

regarding the suitability of any product for use in any specific application. It is the customer's responsibility

to verify the suitability of the part for the intended application. NO LINX PRODUCT IS INTENDED FOR USE

IN ANY APPLICATION WHERE THE SAFETY OF LIFE OR PROPERTY IS AT RISK.

Linx Technologies DISCLAIMS ALL WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A

PARTICULAR PURPOSE. IN NO EVENT SHALL LINX TECHNOLOGIES BE LIABLE FOR ANY OF

CUSTOMER'S INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING IN ANY WAY FROM ANY DEFECTIVE

OR NON-CONFORMING PRODUCTS OR FOR ANY OTHER BREACH OF CONTRACT BY LINX

TECHNOLOGIES. The limitations on Linx Technologies' liability are applicable to any and all claims or

theories of recovery asserted by Customer, including, without limitation, breach of contract, breach of

warranty, strict liability, or negligence. Customer assumes all liability (including, without limitation, liability

for injury to person or property, economic loss, or business interruption) for all claims, including claims

from third parties, arising from the use of the Products. The Customer will indemnify, defend, protect, and

hold harmless Linx Technologies and its officers, employees, subsidiaries, affiliates, distributors, and

representatives from and against all claims, damages, actions, suits, proceedings, demands, assessments,

adjustments, costs, and expenses incurred by Linx Technologies as a result of or arising from any Products

sold by Linx Technologies to Customer. Under no conditions will Linx Technologies be responsible for

losses arising from the use or failure of the device in any application, other than the repair, replacement, or

refund limited to the original product purchase price. Devices described in this publication may contain

proprietary, patented, or copyrighted techniques, components, or materials. Under no circumstances shall

any user be conveyed any license or right to the use or ownership of such items.

Linx, “Wireless Made Simple”, CipherLinx, and the stylized

CL logo are the trademarks of Linx Technologies, Inc.

Printed in U.S.A.


型号：	RXM-900-HP3-PPO
厂家：	ETC
描述：	HP3 SERIES RECEIVER MODULE DATA HP3系列接收器模块数据
文件：	总13页 (文件大小：403K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

RXM-900-HP3-PPO [ETC]

相关型号：

RXM-900-HP3-PPS

RXM-900-HP3-SPO

RXM-900-HP3-SPS

RXM-916-ES

RXM-UHF

RXM0EID0

RXM0EID8

RXM0SIDH

RXM0SIDL

RXM1EID0

RXM1EID8

RXM1SIDH