Radiometrix
Hartcran House, 231 Kenton Lane, Harrow, HA3 8RP, England
Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233
Issue 2, 01 November 2004
TX2 & RX2
UHF FM Data Transmitter and Receiver Modules
The TX2 and RX2 data link modules
are a miniature PCB mounting UHF
radio transmitter and receiver pair
which enable the simple imple-
mentation of a data link at upto 160
kbit/s at distances upto 75 metres in-
building and 300 metres open
ground
.
Features:
left: TX2 transmitter
right:RX2 receiver
CE certified by independent Notified Body
Verified to comply with harmonised radio standard EN 300 220-3 by accredited Test Laboratory
Verified to comply with harmonised EMC standard EN 301 489-3 by accredited Test Laboratory
Data rates up to 160 kbps
Usable range up to 300 m
433.92 MHz versions.
Fully screened
Available for operation at 433.92 MHz in Europe (including UK), both modules combine full screening
with extensive internal filtering to ensure EMC compliance by minimising spurious radiations and
susceptibilities. The TX2 and RX2 modules will suit one-to-one and multi-node wireless links in
applications including car and building security, EPOS and inventory tracking, remote industrial
process monitoring and computer networking. Because of their small size and low power requirements,
both modules are ideal for use in portable, battery-powered applications such as hand-held terminals.
Transmitter - TX2
2 stage SAW controlled, FM modulated at up to 160 kbps
Operation from 2.2V to 6V
+9dBm on 433.92MHz
High efficiency, >15%, DC RF
Improved frequency and deviation accuracy
2
nd
harmonic, < -60dBc
Receiver - RX2
Double conversion FM superhet
SAW front end filter, image rejection 50dB
Supply 3.0V to 6.0V @ 13mA
-96 dBm sensitivity @1ppm BER with 160kbps version
-100 dBm sensitivity @ 1ppm BER with 40kbps-version
-107 dBm sensitivity @ 1ppm BER with 14kbps-version
LO leakage, < -60 dBm
Radiometrix Ltd., TX2 & RX2 Data Sheet
page 1
Functional description:
The TX2 transmitter module is a two stage, SAW controlled FM transmitter operating between 2V and
6V and is available in 433.92MHz. The TX2 module is type approved to EN 300 220-3 for European use
and delivers nominally +9dBm from a 5V supply at 12mA. The module measures 32 x 12 x 3.8 mm.
The RX2 module is a double conversion FM superhet receiver capable of handling date rates of up to
160kbps. The SIL style RX2 receiver measures 48 x 17.5 x 4.5 mm. It will operate from a supply of 3-6V
and draws 14mA when receiving. A fast-acting carrier detect and a power-up enable time of less than
1ms. This allows effective duty cycle power saving and a -107 dBm sensitivity. This combined with a
SAW front-end filter results in an excellent RF performance and EMC conformance.
TX2 transmitter:
Vcc (3)
RF out (2)
433 MHz band
pass filter
buffer
100 kHz
nd
2 order LPF
TXD (5)
+10 dBm @ 5V
433.92MHz
SAW-stabilised
oscillator
100K
RF gnd (1)
0 VOLT (4)
Fig. 1: TX2 block diagram
Pin description:
RF GND
(pin
1)
RF ground pin, internally connected to the
module screen and pin 4 (0V). This pin should
be connected to the RF return path (e.g. coax
braid, main PCB ground plane etc.)
RF out
(pin 2)
50Ω RF output to the antenna, it is DC
isolated internally. (see antenna section for
suggested antenna/feeds).
Fig.2: physical dimensions
Vcc
(pin 3)
+ve supply pin. The module will generate RF when the Vcc supply is present. Maximum ripple content
0.1V
P-P
. A 100nF de-coupling ceramic capacitor is suggested.
0V
(pin
4)
Supply ground connection, connected to pin 1 and screen.
TXD
(pin
5)
This DC coupled modulation input will accept either serial digital data ( 0V to Vcc levels) or high level
linear signals. Input impedance is 100kΩ.
Radiometrix Ltd., TX2 & RX2 Data Sheet
page 2
RX2 receiver:
418 MHz SAW-
controlled
1st Local oscillator
Vcc (5)
2 local
oscillator
15.82 MHz
nd
2
µ
F
CD (3)
RF in (1)
433 MHz band
pass filter
pre -
amplifier
SAW band
pass filter
2 mixer
IF amlpifier
demodulator
1 mixer
st
nd
AF
91 kHz
buffer
adaptive data slicer
+
AF (6)
Data out (7)
-
RF gnd (2)
0 VOLT (4)
Fig. 3: RX2 block diagram
Pin description
RF in
(pin
1)
50Ω RF input from the antenna, it is
DC isolate internally. (see antenna
section for suggested antenna/feeds).
RF GND
(pin
2)
RF ground pin, internally connected to
the module screen and pin 4 (0V). This
pin should be connected to the RF
return path (e.g. coax braid, main
PCB ground plane etc.)
Fig. 4: physical dimensions
CD
(pin
3)
The Carrier Detect may be used to drive an external PNP transistor to obtain a logic level carrier detect
signal, see test circuit. If not required it should be connected to pin 5 (Vcc).
0 Volt
(pin 4)
Supply ground connection, connected to pin 1 and screen.
Vcc
(pin 5)
+ve supply pin. +3.0V to +6.0V @ <17mA . The supply must be clean < 2mV
P-P
ripple. A 10µF de-
coupling capacitor and 10Ω series resistor is recommended if a clean supply is not available.
AF
(pin 6)
This is a buffered and filtered analogue output from the FM demodulator. It has a standing DC bias of
1.2V and 400mV
P-P
base band signal. It is useful as a test point or to drive linear decoders. Load
impedance should be > 2kΩ and < 100pF.
RXD
(pin 7)
This digital output from the internal data slicer is a squared version of the signal on pin 6 (AF). It may
be used to drive external decoders. The data is true data, i.e. as fed to the transmitter. Load impedance
should be > 1kΩ and < 1nF
Radiometrix Ltd., TX2 & RX2 Data Sheet
page 3
Survival Maximums:
Operating temperature:
Storage temperature:
TX2, all variants
Vcc (pin 3)
Data input (pin 5)
RF out (pin 2)
RX2, all variants
Vcc (pin 5)
Data, CD & AF (pin 7,3,6)
RF input (pin 1)
note:
-10°C to +55°C
-40°C to +100°C
-0.1V to +10.0V
-0.1V to +10.0V
±50V
@ < 10MHz , +20dBm @ > 10MHz
-0.1V to +10.0V
-0.1V to + Vcc V
±50V
@ < 10MHz , +13dBm @ > 10MHz
Operation of the TX2 above 6V may cause the module to exceed the licensed power level.
E lectrical Performance: TX2 transmitter
pin
DC LE VE LS
supply voltage
supply voltage
CURRE NT & RF POWE R
TX2-433-3V
supply current @ Vcc = 3V
RF power
@ Vcc = 3V
TX2-433-5V
supply current @ Vcc = 5V
RF power
@ Vcc = 5V
RF
2
nd
harmonic
harmonics @ > 1GHz
initial frequency accuracy
overall frequency accuracy
FM deviation (+/-)
modulation bandwidth @ -3dB
modulation bandwidth @ -3dB
modulation distortion (THD)
power up time to full RF
3
2
3
2
2
2
-
-
-
-
-
-
4
0
7
+6
-
-
-30
-70
20
DC
DC
-
-
6
+4
10
+9
-65
-50
0
-
25
-
-
5
-
10
+6
14
+12
-54
-40
+30
+70
30
20
100
10
100
mA
dBm
mA
dBm
dBc
dBc
kHz
kHz
kHz
kHz
kHz
%
µs
3
3
min.
2.2
4.0
typ.
3.0
5.0
max.
4.0
6.0
units
V
V
notes
-3V version
-5V version
1
1
1
1
2
note:
1. Measured into a 50Ω load.
2. For 160kbps version
Radiometrix Ltd., TX2 & RX2 Data Sheet
page 4
E lectrical Performance: RX2 Receiver
Unless otherwise noted:
Figures apply to 5V versions unless noted otherwise
Vcc = 5.0V, temperature 20°C unless noted otherwise
pin
DC LE VE LS
supply voltage, Vcc standard
supply voltage, Vcc, 3V version
supply current
supply ripple
data output high, 100µA source
data output low, 100µA sink
load capacitance on AF / Data
RF
RF sensitivity for 10dB (S+N)/N
RF sensitivity for 10dB (S+N)/N
RF sensitivity for 10dB (S+N)/N
RF sensitivity for 1ppm BER
RF sensitivity for 1ppm BER
RF sensitivity for 1ppm BER
CD threshold
CD threshold
CD threshold
IF band width
initial frequency accuracy
E .M.C.
image rejection (2*F
IF
)
spurious responses upto 1GHz
LO leakage, conducted
LO leakage, radiated
AF BASE BAND
baseband bandwidth @ -3dB
baseband bandwidth @ -3dB
baseband bandwidth @ -3dB
AF level
DC offset on AF
distortion on recovered AF
ultimate (S+N)/N
ultimate (S+N)/N
DYNAMIC TIMING
Power up with signal present
power up to valid CD, T
PU-CD
power up to stable data, T
PU-DAT
power up to stable data, T
PU-DAT
power up to stable data, T
PU-DAT
power up to stable AF, T
PU-AF
power up to valid CD, T
PU-CD
-
-
-
-
-
-
-
-
-
-
-
-
1
20
5
3
0.6
0.7
-
-
-
-
-
-
ms
ms
ms
ms
ms
ms
5
5
5
5
7
7
6,7
1,6
1,6
1,6
1,6
1,6
1,6
1,3
1,3
1,3
-
1
1
1
1
-
6
6
6
6
6
6
6
6
min.
4.0
3.3
11
-
-
-
-
-107
-100
-
-100
-93
-
-97
-90
-
-
-30
-
-
-
-
0.006
0.060
0.250
-
0.8
-
35
-
typ.
5.0
3.5
13
-
Vcc-0.6
0.4
-
-113
-107
-96
-107
-100
-90
-107
-100
-104
250
0
-50
-70
-65
-70
-
-
-
450
1.2
0.5
45
28
Max.
6.0
4.0
17
2
-
-
100
-
-
-
-
-
-
-
-
-
-
+30
-
-
-
-
7
20
91
-
1.6
1
-
-
units
V
V
mA
mV
P-P
V
V
pF
dBm
dBm
dBm
dBm
dBm
dBm
dBm
dBm
dBm
kHz
kHz
dB
dB
dBm
dBm
kHz
kHz
kHz
mV
P-P
V
%
dB
dB
notes
1
14kbps version
40kbps version
160kbps version
14kbps version
40kbps version
160kbps version
14kbps version
40kbps version
160kbps version
2
2
14kbps version
40kbps version
160kbps version
160kbps version
14kbps version
40kbps version
160kbps version
160kbps version
160kbps version
Radiometrix Ltd., TX2 & RX2 Data Sheet
page 5