 |
|
The TX1 and RX1 form a miniature VHF
radio transmitter/receiver pair designed for PCB mounting
and suitable for extended range data links at speeds
up to 10kbps. Link ranges of 10km+ are achievable with
suitable choice of data rate and antennas.
|
TX1-173.250-10 and RX1-173.250-10
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Features
- CE Certified by independent Notified
Body
- Verified to comply with harmonised radio
standard ETSI EN 300 220-3 by accredited Test Laboratory
- Verified to comply with harmonised EMC
standard ETSI EN 301 489-3 by accredited Test Laboratory
- Frequencies available as standard: 173.225MHz,
173.250MHz
- Other frequencies from 151.300MHz to
173.250MHz available to order
- Data rates up to 10 kbps with 25kHz
channel spacing
- Usable range to 10km+
- Screened construction
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|
Available for licence-exempt operation in the UK 173MHz bands,
the TX1 & RX1 modules combine effective screening with
internal filtering to minimise spurious radiation and susceptibility
thereby ensuring EMC compliance. They are particularly suitable
for one-to-one and multi-node wireless links where longer
ranges are required at low to moderate data rates. Applications
include building security, EPOS and inventory tracking, remote
industrial process monitoring and data networks. Because of
their small size and low power consumption, both modules are
ideal for use in battery-powered portable applications such
as handheld terminals.
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Technical Summary
Transmitter
- 2 stage crystal controlled, NBFM modulated at up to 10
kb/s
- Operation from 2.2V to 12V @ 9.5mA
- Built-in regulator for improved stability and supply noise
rejection
- Exceptional power efficiency, typically 35% DC ® RF@ 3V supply
- +10dBm (10mW) RF output
- Harmonics typically -70dBc
- Enable facility
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|
Receiver
- Single conversion NBFM superhet
- Image rejection >50dB
- Operating from 2.7V to 12V @ 12mA
- Built-in regulator for improved stability
and supply noise rejection
- 10kbps max, -116dBm sensitivity @ 1ppm
BER
- RSSI output with >80dBm range
- Enable facility
|
| Evaluation Platform:
Universal
Evaluation kit or Narrow
Band Evaluation Kit |
| |
 |
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Functional description
The TX1 transmitter module is a two stage
crystal controlled NBFM transmitter operating between 2.2V
and 12V at a current of 9.5mA. At 3V supply it delivers nominally
+10dBm RF output. The SIL style TX1 measures 32 x 12 x 3.8
mm excluding the pins.
The RX1 module is a single conversion NBFM
superhet receiver capable of handling data rates of up to
10kb/s. It will operate from a supply of 2.7V to 12V and draws
12mA when receiving. A signal strength (RSSI) output with
greater than 80dB of range is provided. The SIL style RX1
measures 48 x 17.5 x 5.5 mm excluding the pins.
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| |
TX1 transmitter
Figure
1: TX1 block diagram
|
Figure
2: TX1 physical dimension
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|

|
| |
| Pin description - TX1 |
| RF GND |
Pins 1 & 3 |
RF ground, internally
connected to the module screen and pin 6 (0V). These pins
should be directly connected to the RF return path - e.g.
coax braid, main PCB ground plane etc. |
| RF out |
Pin 2 |
50W RF output to antenna.
Internally DC-isolated. See antenna section of applications
notes for details of suitable antennas / feeds. |
| En |
Pin 4 |
Tx enable. £0.15V
or open-circuit on this pin disables module (current <1mA),
³1.7V enables module. Input
impedance 1MW approx. Observe slew rate requirements
(see applications note). |
| Vcc |
Pin 5 |
DC +ve supply. Max ripple
content 0.1Vp-p. Decoupling is not generally
required. |
| 0 V |
Pin 6 |
DC supply ground. Internally
connected to pins 1, 3 and module screen. |
| TXD |
Pin 7 |
DC-coupled
modulation input. Accepts serial digital data at 0V to
3V levels. Input impedance 100kW nominal. |
|
|
RX1 receiver
Figure
3: RX1 block diagram
|
Figure
4: RX1 physical dimension
|
 |
| |
| Pin description RX1 |
| RF in |
Pin 1 |
50W
RF input from antenna. Internally DC-isolated. See antenna
section of applications notes for suggested antennas and
feeds. |
| RF GND |
Pins 2& 3 |
RF ground, internally
connected to the module screen and pin 6 (0V). These pins
should be directly connected to the RF return path - e.g.
coax braid, main PCB ground plane etc. |
| En |
Pin 4 |
RX enable.
£0.15V
or open-circuit on this pin disables module (current <
1mA), ³1.7V
enables module. Input impedance 1MW
approx. Observe slew rate requirements (see application
note). |
| RSSI |
Pin 5 |
Received signal strength
indicator with >80dB range. See application notes for
typical characteristics. |
| 0 V |
Pin 6 |
DC supply ground. Internally
connected to pins 1, 3 and module screen. |
| Vcc |
Pin 7 |
DC +ve supply. Max ripple
content 0.1Vp-p. Decoupling is not generally
required. |
| AF |
Pin 8 |
Buffered and filtered
analogue output from the FM demodulator. It has a standing
DC bias of 1V and 400mVP-P baseband signal. Useful as
a test point or to drive external decoders (see applications
notes). External load should be >1kW
// <100pF. |
| RXD |
Pin 9 |
Digital output from internal
data slicer (squared version of the signal on pin 8).
It may be used to drive external decoders. The data is
true data, i.e. as fed to the transmitter. Output is "open-collector"
format with internal 10kW pullup
to Vcc (pin 7). |
|
|
| Absolute
maximum ratings
Exceeding the values given below may cause
permanent damage to the module.
| Operating temperature |
-20*C to +60*C |
| Storage temperature |
-40*C to +100*C |
| |
|
| TX1 |
|
| Vcc, TXD (pins 5, 7) |
-0.3V to +16.0V |
| En (pin 4) |
-0.3V to +Vcc |
| RF out (pin 2) |
±50V @ <10MHz,
+20dBm @ >10MHz |
| |
|
| RX1 |
|
| Vcc, RXD (pins 7, 9) |
-0.3V to +16.0V |
| En, RSSI, AF (pins 4,
5, 8)) |
-0.3V to +Vcc |
| RF in (pin 1) |
±50V @ <10MHz,
+13dBm @ >10MHz |
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 |
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Performance specification: TX1 transmitter
(Vcc = 3.0V / temperature = 20°C unless
stated)
|
| General |
pin |
min. |
typ. |
max. |
units |
notes |
| DC supply
|
|
|
|
|
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| Supply voltage |
5
|
2.2
|
3.0
|
12
|
V
|
|
| Supply current |
5
|
-
|
9.5
|
11
|
mA
|
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|
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|
| RF |
|
|
|
|
|
|
| RF power output
@ Vcc=2.2V |
2
|
+4.5
|
+6
|
+7.5
|
dBm
|
1
|
| RF power output @ Vcc
³
2.8V |
2
|
+8.5
|
+10
|
+11.5
|
dBm
|
1
|
| Spurious emissions |
2
|
-
|
-70
|
-55
|
dBc
|
2
|
| Frequency accuracy |
|
- 2.0
|
0
|
+2.0
|
kHz
|
3
|
| FM deviation (peak) |
|
±2.5
|
±3.0
|
±3.5
|
kHz
|
4
|
| |
|
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| Baseband |
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| Modulation bandwidth @
-3dB |
|
0
|
-
|
7
|
kHz
|
|
| Modulation distortion
(THD) |
|
-
|
10
|
15
|
%
|
7
|
| TXD input
level (logic low) |
7
|
-0.2
|
0
|
0.2
|
V
|
5, 7
|
| TXD input
level (logic high) |
7
|
2.8
|
3.0
|
3.2
|
V
|
5, 7
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| Dynamic timing |
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| Power-up time (En ® full RF) |
|
-
|
2
|
5
|
ms
|
6, 7
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|
Notes:
1. Measured into 50W resistive load.
2. Exceeds EN/EMC requirements at all frequencies.
3. Total over full supply and temperature range.
4. With 0V - 3.0V modulation input.
5. To achieve specified FM deviation.
6. Dependent upon TXD conditions during power-up
7. See applications information for further details. |
 |
| |
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Performance specification: RX1 receiver
(Vcc = 3.0V / temperature = 20°C unless
stated)
|
| General |
pin |
min. |
typ. |
max. |
units |
notes |
| DC supply
|
|
|
|
|
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| Supply voltage |
7
|
2.7
|
3.0
|
12
|
V
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| Supply current |
7
|
-
|
12
|
14
|
mV
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| RF/IF |
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| RF sensitivity
@ 10dB (S+N)/N |
1, 8
|
-
|
-119
|
-115
|
dBm
|
|
| RF sensitivity @ 1ppm
BER |
1, 9
|
-
|
-116
|
-112
|
dBm
|
|
| IP3
at RF input |
1
|
-
|
-28
|
-
|
dBm
|
|
| RSSI threshold |
1, 5
|
-
|
-127
|
-
|
dBm
|
1
|
| RSSI range |
1, 5
|
80
|
90
|
-
|
dB
|
1
|
| IF bandwidth |
|
-
|
15
|
-
|
kHz
|
|
| Image rejection |
1
|
50
|
55
|
-
|
dB
|
|
| Adjacent channel rejection
|
1
|
50
|
55/60
|
-
|
dB
|
2
|
| Spurious response rejection |
1
|
70
|
100
|
-
|
dB
|
|
| LO leakage, conducted |
1
|
-
|
-70
|
-65
|
dBm
|
3
|
| LO leakage, radiated |
|
-
|
-70
|
-60
|
dBm
|
3
|
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| Baseband |
|
|
|
|
|
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| Baseband bandwidth @ -3dB |
8
|
0.05
|
-
|
6
|
kHz
|
1, 4
|
| AF level |
8
|
-
|
400
|
-
|
mVp-p
|
5
|
| DC offset on AF out |
8
|
0.7
|
1.0
|
1.3
|
V
|
|
| Distortion
on recovered AF |
8
|
-
|
1
|
10
|
%
|
|
| Load capacitance, AF /
RXD |
8, 9
|
-
|
-
|
100
|
pF
|
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|
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|
|
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| Dynamic timing
|
|
|
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| Power up with signal
present |
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| Power up to valid RSSI |
4, 5
|
|
4
|
5
|
ms
|
|
| Power up to stable RXD
output |
4, 9
|
|
16
|
20
|
ms
|
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|
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|
|
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| Signal applied with
supply on |
|
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| Signal to valid RSSI |
1, 5
|
-
|
0.4
|
0.6
|
ms
|
|
| Signal to stable RXD output |
1, 9
|
-
|
4
|
12
|
ms
|
6
|
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|
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|
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| Time between
data transitions |
9
|
1.8
|
-
|
0.1
|
ms
|
7
|
| Mark : space ratio |
9
|
20
|
50
|
80
|
%
|
8
|
|
Notes:
1. See applications information for further details.
2. Typically 55dB @ +25kHz offset, 60dB @ -25kHz offset
3. Exceeds EN/EMC requirements at all frequencies.
4. Lower limit can be extended to DC if required, by means of
external circuitry.
5. For received signal with ±3kHz FM deviation.
6. Typically 4ms for signal at channel center, maximum 12ms
at ±4kHz RF offset
7. For 50:50 mark to space ratio (i.e. square wave).
8. Average over 50ms period at maximum bit rate. |
 |
| |
| Module test Circuit |
Figure
5: TX1 test circuit
|
Figure
6: RX1 test circuit
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Application Information
|
|
Power supply requirements
Both modules have built-in regulators which deliver a constant
2.85V to the module circuitry when the external supply voltage
is 2.9V or greater, with 40dB or more of supply ripple rejection.
This ensures constant performance up to the maximum permitted
rail and removes the need for external supply decoupling except
in cases where the supply rail is extremely poor (ripple/noise
content >0.1Vp-p).
Note, however, that for supply voltages lower than 2.85V
the regulator is effectively inoperative and supply ripple
rejection is considerably reduced. Under these conditions
the ripple/noise on the RX1 supply rail should be below 20mVp-p
to avoid problems.
If the quality of the supply is in doubt, it is recommended
that a 10mF tantalum or similar
capacitor be added between pin 7 of the module (Vcc) and ground
together with a 10W series feed
resistor between pin 7 and the supply rail.
The enable pin allows the module to be turned on or off under
logic control with a constant DC supply to the Vcc pin. The
module current in power down mode is less than 1mA.
NOTE: If this facility is used, the logic control signal
must have a slew rate of 40mV/ms or more. Slew rates less
than this value may cause erratic operation of the on board
regulator and therefore the module itself.
The Enable pin should be tied directly to the Vcc pin if
this facility is not required.
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TX modulation requirements
The module is factory-set to produce the specified FM deviation
with a TXD input to pin 7 of 3V amplitude, i.e. 0V "low",
3V "high". Reducing the amplitude of the data input
from this value (usually as a result of reducing the supply
voltage) reduces the transmitted FM deviation to typically
±2.5kHz at the lower extreme of 2.2V. The receiver
will cope with this quite happily and no significant degradation
of link performance should be observed as a result.
Where the module supply is greater than 3V a resistor must
be added in series with the TXD input to limit the modulation
amplitude to a maximum of 3V on pin 7. TXD input resistance
is 100kW to ground, giving typical
required resistor values as follows:
| Vcc
|
Series
resistor |
| <=3V |
- |
| 3.3V |
10kW |
| 5V |
68kW |
| 9V |
220kW |
|
| |
| It should be noted that conditions on TXD
have a significant effect on the startup time of the module,
i.e. the time between En (or En+Vcc) going high and full RF
output being produced. For fastest startup TXD should either
be low or fed with data (preamble etc) for a minimum of 3ms
after En has been asserted. Startup time under these conditions
is typically 50-70% of that obtained if TXD is held high over
the same period. |
 |
|
| Reducing the output
power of the TX1
If the TX1-173.250-10 is to be used for other than industrial/commercial
applications its output power must be reduced to 1mW to comply
with type approval requirements. This is done by inserting
a 10dB attenuator network between the module and the antenna
or feed, as follows:
|
 Figure
7: 10dB attenuator for TX1
|
| |
| Keep all tracking around the
attenuator network as short as possible, particularly ground
paths, and use matched 50W microstrip
lines for input and output connections (track width of 2.5mm
if using 1.6mm thick FR4 PCB). |
| |
| RX Received
Signal Strength Indicator (RSSI)
The RX1 receiver incorporates a wide range RSSI which measures
the strength of an incoming signal over a range of 80dB or
more. This allows assessment of link quality and available
margin and is useful when performing range tests.
Please note that the actual RSSI voltage at any given RF
input level varies somewhat between units. The RSSI facility
is intended as a relative indicator only - it is not designed
to be, or suitable as, an accurate and repeatable measure
of absolute signal level or transmitter-receiver distance.
The output on pin 5 of the module has a standing DC bias
of 0.15V-0.45V (0.25V typ.) with no signal, rising to 0.9-1.3V
(1.15V typ.) at maximum indication. Output impedance is 10kW.
Pin 5 can drive a 100µA meter directly, for simple monitoring.
Typical RSSI characteristic is shown below (this is for
indicative purposes only and is not a guarantee of actual
RSSI characteristics):
|
 Figure
8: Typical RSSI response curve
|
| |
| To ensure a reasonably fast response
the RSSI line has limited internal decoupling of 11nF to ground.
This results in a small amount of audio ripple on the DC output
at pin 5 of the module. If this is a problem further decoupling
may be added at the expense of response speed, in the form of
a capacitor from pin 5 to ground. For example, adding an extra
0.1mF on this pin will increase the
RSSI response time to around 4ms. |
 |
| |
|
Expected range
Predicting the range obtainable in any given situation is
notoriously difficult since there are many factors involved.
The main ones to consider are as follows:
- Type and location of antennas in use
- Type of terrain and degree of obstruction of the link
path
- Sources of interference affecting the receiver
- "Dead" spots caused by signal reflections from
nearby conductive objects
- Data rate and degree of filtering employed
|
| The following are typical examples - but
range tests should always be performed before assuming that
a particular range can be achieved in a given situation: |
| Data
rate |
TX
antenna |
RX
antenna |
Environment |
Range |
| 1.2kbps |
half-wave |
half-wave |
rural/open |
10-15km |
| 10kbps |
half-wave |
half-wave |
rural/open |
3-4km |
| 10kbps |
helical |
half-wave |
urban/obstructed |
500m-1km |
| 10kbps |
helical |
helical |
in-building |
100-200m |
|
| Note: The figure for 1.2kbps assumes
that the receiver bandwidth has been suitably reduced by utilising
an outboard sallen-key active audio filter and data slicer or
similar arrangement. |
| |
| Data formats and
range extension
The TX1 data input is normally driven directly by logic levels
but will also accept analogue drive (e.g. 2-tone signaling).
In this case it is recommended that TXD (pin 7) be DC-biased
to 1.2V approx. with the modulation ac-coupled and limited
to a maximum of 2Vp-p to minimise distortion over the link.
The varactor modulator in the TX1 introduces some 2nd harmonic
distortion which may be reduced if necessary by predistortion
of the analogue waveform. At the other end of the link the
RX1 AF output is used to drive an external decoder directly.
Although the modulation bandwidth of the TX1 extends down
to DC, as does the AF output of the RX1, it is not advisable
to use data containing a DC component. This is because frequency
errors and drifts between the transmitter and receiver occur
in normal operation, resulting in DC offset errors on the
RX1 audio output.
The RX1 in standard form incorporates a low pass filter with
a 6kHz nominal bandwidth. In conjunction with similar filtering
in the TX1 an overall system bandwidth of 5kHz is obtained.
This is suitable for transmission of data at raw bit rates
up to 10kb/s. A lower rolloff frequency of around 50Hz has
been chosen for the internal filter and data slicer in order
to keep receiver settling times reasonably fast. This results
in a lowest usable data speed of about 1kb/s for the standard
module.
In applications such as long range fixed links where data
speed is not of prime concern, a considerable increase in
range can be obtained by using the slowest possible data rate
together with filtering to reduce the receiver bandwidth to
the minimum necessary. The internal data slicer is not suitable
for data having longer than 1.8ms between transitions and
in such circumstances the RX1 audio output can be utilised
to drive an external filter and data slicer.
The RX1 produces an audio output of approximately 400mVp-p
at pin 8, but due to the internal filtering this exhibits
a rolloff at low frequencies giving a reduced output of some
100mVp-p as DC is approached. This rolloff can be eliminated
and a flat response to DC obtained by using an external RC
compensation network, as follows:
|
| |
Figure
9: Audio compensation network
|
| The output of the network will be flat from
DC to 5kHz+. It will have a standing DC bias of 1V approx. and
should not be significantly loaded (input impedance of following
stage should ideally be ³1MW). |
 |
| |
|
Antennas
The choice and positioning of transmitter and receiver antennas
is of the utmost importance and is the single most significant
factor in determining system range. The following notes are
intended to assist the user in choosing the most effective
antenna type for any given application.
Integral antennas
These are relatively inefficient compared to the larger externally-mounted
types and hence tend to be effective only over limited ranges.
They do however result in physically compact equipment and
for this reason are often preferred for portable applications.
Particular care is required with this type of antenna to achieve
optimum results and the following should be taken into account:
1. Nearby conducting objects such as a PCB or battery can
cause detuning or screening of the antenna which severely
reduces efficiency. Ideally the antenna should stick out from
the top of the product and be entirely in the clear, however
this is often not desirable for practical/ergonomic reasons
and a compromise may need to be reached. If an internal antenna
must be used try to keep it away from other metal components
and pay particular attention to the "hot" end (i.e.
the far end) as this is generally the most susceptible to
detuning. The space around the antenna is as important as
the antenna itself.
2. Microprocessors and microcontrollers tend to radiate significant
amounts of radio frequency hash which can cause desensitisation
of the receiver if its antenna is in close proximity. The
problem becomes worse as logic speeds increase, because fast
logic edges generate harmonics across the VHF range which
are then radiated effectively by the PCB tracking. In extreme
cases system range may be reduced by a factor of 5 or more.
To minimise any adverse effects situate antenna and module
as far as possible from any such circuitry and keep PCB track
lengths to the minimum possible. A ground plane can be highly
effective in cutting radiated interference and its use is
strongly recommended.
A simple test for interference is to monitor the receiver
RSSI output voltage, which should be the same regardless of
whether the microcontroller or other logic circuitry is running
or in reset.

The following types of integral antenna are in common
use:
Quarter-wave whip: This consists simply of a piece
of wire or rod connected to the module at one end. At 173MHz
the total length should be 410mm from module pin to antenna
tip including any interconnecting wire or tracking. Because
of the length of this antenna it is almost always external
to the product casing.
Helical: This is a more compact but slightly less
effective antenna formed from a coil of wire. It is very efficient
for its size, but because of its high Q it suffers badly from
detuning caused by proximity to nearby conductive objects
and needs to be carefully trimmed for best performance in
a given situation. The size shown is about the maximum commonly
used at 173MHz and appropriate scaling of length, diameter
and number of turns can make individual designs much smaller.
Loop: A loop of PCB track having an inside area as
large as possible (minimum about 5cm2),
tuned and matched with 2 capacitors. Loops are relatively
inefficient but have good immunity to proximity detuning,
so may be preferred in shorter range applications where high
component packing density is necessary.
|
| |
Figure
6: integral antenna configurations
|
| |
Integral antenna summary:
|
whip
|
helical
|
loop
|
| Ultimate performance |
***
|
**
|
*
|
| Ease of design set-up
|
***
|
**
|
*
|
| Size |
*
|
***
|
**
|
| Immunity to proximity
effects |
**
|
*
|
***
|
|
 |
| |
Tamperproof
integral antenna
Where the RX1 is used
in alarm applications it may sometimes be necessary to provide
a warning if any attempt is made to remove or disable its antenna.
A typical solution to this problem is as follows: |
Figure
7: Tamper-proof antenna arrangement
|
| In normal operation the output will have
a resistance to ground of R1+R2. If the antenna is shorted to
ground it will show R2 only, and if the antenna is cut it will
be open-circuit. R1 and R2 may be any value over 1kW.
All track lengths should be kept to a minimum and the output
may need to be decoupled in some cases to avoid noise being
injected into the antenna from the following circuitry. |
| |
| External antennas
These have several advantages if portability is not an issue,
and are essential for long range links. External antennas
can be optimised for individual circumstances and may be mounted
in relatively good RF locations away from sources of interference,
being connected to the equipment by coax feeder.
Helical: Of similar dimensions and performance to
the integral type mentioned above, commercially-available
helical antennas normally have the coil element protected
by a plastic moulding or sleeve and incorporate a coax connector
at one end (usually a straight or right-angle BNC type). These
are compact and simple to use as they come pre-tuned for a
given application, but are relatively inefficient and are
best suited to shorter ranges.
Quarter-wave whip: Again similar to the integral type,
the element usually consists of a stainless steel rod or a
wire contained within a semi-flexible moulded plastic jacket.
Various mounting options are available, from a simple BNC
connector to wall brackets, through-panel fixings and magnetic
mounts for temporary attachment to steel surfaces.
A significant improvement in performance is obtainable if
the whip is used in conjunction with a metal ground plane.
For best results this should extend all round the base of
the whip out to a radius of 300mm or more (under these conditions
performance approaches that of a half-wave dipole) but even
relatively small metal areas will produce a worthwhile improvement
over the whip alone. The ground plane should be electrically
connected to the coax outer at the base of the whip. Magnetic
mounts are slightly different in that they rely on capacitance
between the mount and the metal surface to achieve the same
result.
|
| A ground plane can also be simulated by
using 3 or 4 quarter-wave radials equally spaced around the
base of the whip, connected at their inner ends to the outer
of the coax feed. A better match to a 50W
coax feed can be achieved if the elements are angled downwards
at approximately 30-40° to the horizontal. |
| |
 Fig.
7: Quarter wave antenna / ground plane configurations
|
 |
| Half-wave: There are
two main variants of this antenna, both of which are very effective
and are recommended where long range and all-round coverage
are required:
1. The half-wave dipole consists of two quarter-wave whips
mounted in line vertically and fed in the center with coaxial
cable. The bottom whip takes the place of the ground plane
described previously. A variant is available using a helical
instead of a whip for the lower element, giving similar performance
with reduced overall length. This antenna is suitable for
mounting on walls etc. but for best results should be kept
well clear of surrounding conductive objects and structures
(ideally >1m separation).
2. The end-fed half wave is the same length as the dipole
but consists of a single rod or whip fed at the bottom via
a matching network. Mounting options are similar to those
for the quarter-wave whip. A ground plane is sometimes used
but is not essential. The end-fed arrangement is often preferred
over the center-fed dipole because it is easier to mount in
the clear and above surrounding obstructions.
Yagi: This antenna consists of two or more elements
mounted parallel to each other on a central boom. It is directional
and exhibits gain but tends to be large and unwieldy - for
these reasons the yagi is the ideal choice for links over
fixed paths where maximum range is desired.
Please note: Using a Yagi or other gain antenna with the
TX1 will exceed the maximum radiated power permitted by UK
type approval regulations. It can be used in the UK only in
conjunction with the RX1 receiver.
For best range in UK fixed link applications use a half-wave
antenna on TX1 transmitter and a half-wave or Yagi on RX1
receiver, both mounted as high as possible and clear of obstructions.
|
| |
| The above antennas
may be obtained from several sources in the UK, for example:
R W Badland Ltd
Tel. +44 (0)1384 423160 / 892839, Fax +44 (0)1384 423958
/895051
Website: http://www.badland.co.uk
Renair Antennae Ltd
Tel. +44 (0)20 8965 3001, Fax +44 (0)20 8965 5773
Website: http://www.renair.co.uk
|
 |
| |
| Module mounting considerations
The module may be mounted vertically or bent horizontal to
the mother board. Note that the four components mounted on
the underside of the RX1 are relatively fragile - avoiud direct
mechanical contact between these and other parts of the equipment
if possible, particularly in situations where extreme mechanical
stress could routinely occur (as a result of equipment being
dropped in to the floor etc.)
Good RF layout practice should be observed. If the connection
between module and antenna is more than about 20mm long use
50W microstrip line or coax or
a combination of both. It is desirable (but not essential)
to fill all unused PCB area around the module with ground
plane.
|
| |
|
Variants and ordering information
The BiM1 transceiver is manufactured in the following variants
as standard:
|
For UK alarm applications on 173.225MHz:
TX1-173.225-10 Transmitter
RX1-173.225-10 Receiver
For UK general applications on
173.250MHz:
TX1-173.250-10 Transmitter
RX1-173.250-10 Receiver
|
| Other variants can be supplied to individual
customer requirements at frequencies from 120MHz to 180MHz and/or
epitomized for specific data speeds and formats. However these
are subject to minimum order quantity (MOQ) and long lead time.
Please consult the Sales Department for further information.
|
 |
|
Some of the non-standard frequencies readily available. i.e.
no MOQ or long lead time, are as follows:
Part number: TX1-xxx.xxx-10
and RX1-xxx.xxx-10 (where xxx.xxx is the operating frequency)
|
| Frequency
(MHz) |
Type approval |
Notes |
| 121.500 |
- |
1, 2, 3 |
| 138.125 |
- |
1, 2, 3 |
| 138.2375 |
- |
1, 2, 3 |
| 142.475 |
- |
1, 2, 3 |
| 143.175 |
- |
1, 2, 3 |
| 144.390 |
- |
1, 2, 3 |
| 144.800 |
- |
1, 2, 3 |
| 145.175 |
- |
1, 2, 3 |
| 149.170 |
- |
1, 2, 3 |
| 149.260 |
- |
1, 2, 3 |
| 150.750 |
- |
1, 2, 3 |
| 151.275 |
- |
1, 2, 3 |
| 151.300 |
Yes |
2, 3 |
| 151.600 |
Yes |
2, 3 |
| 151.775 |
Yes |
2, 3 |
| 152.175 |
Yes |
2, 3 |
| 152.500 |
Yes |
2, 3 |
| 152.575 |
Yes |
2, 3 |
| 152.650 |
Yes |
2, 3 |
| 152.850 |
Yes |
2, 3 |
| 152.8125 |
Yes |
2, 3 |
| 153.9125 |
Yes |
2, 3 |
| 153.925 |
Yes |
2, 3 |
| 154.46375 |
Yes |
2, 3 |
| 154.600 |
Yes |
2, 3 |
| 155.345 |
Yes |
2, 3 |
| 155.475 |
Yes |
2, 3 |
| 155.715 |
Yes |
2, 3 |
| 155.725 |
Yes |
2, 3 |
| 156.525 |
Yes |
2, 3 |
| 157.300 |
Yes |
2, 3 |
| 157.420 |
Yes |
2, 3 |
| 158.100 |
Yes |
2, 3 |
| 158.700 |
Yes |
2, 3 |
| 159.685 |
Yes |
2, 3 |
| 159.6875 |
Yes |
2, 3 |
| 161.975 |
Yes |
2, 3 |
| 162.025 |
Yes |
2, 3 |
| 162.975 |
Yes |
2, 3 |
| 163.000 |
Yes |
2, 3 |
| 164.525 |
Yes |
2, 3 |
| 167.420 |
Yes |
2, 3 |
| 167.790 |
Yes |
2, 3 |
| 168.360 |
Yes |
2, 3 |
| 169.4125 |
Yes |
2, 3 |
| 169.41875 |
Yes |
2, 3 |
| 169.435 |
Yes |
2, 3 |
| 169.4625 |
Yes |
2, 3 |
| 169.5625 |
Yes |
2, 3 |
| 169.625 |
Yes |
2, 3 |
| 169.650 |
Yes |
2, 3 |
| 169.975 |
Yes |
2, 3 |
| 171.900 |
Yes |
2, 3 |
| 172.420 |
Yes |
2, 3 |
| 172.420 |
Yes |
2, 3 |
| 173.075 |
Yes |
2, 3 |
| 173.175 |
Yes |
2, 3 |
| 173.200 |
Yes |
2, 3 |
| 173.560 |
- |
1, 2, 3 |
| 173.960 |
- |
1, 2, 3 |
| 180.175 |
- |
1,2, 3 |
| 183.550 |
- |
1,2, 3 |
|
|
|
|
|
Notes: 1.
|
Complies
with the ETSI standards but NOT approved |
|
2.
|
For specialised application,
NOT for general purpose |
|
|
e.g: 121.500MHz is an
international distress frequency |
|
3.
|
NOT an European Harmonised
frequency. Consult local radio requlatory authority. |
|
 |
| Type approval
TX1 and RX1 are CE
Certified by independent Notified Body according to the
R&TTE Directive (1999/5/EC). They are verified to comply
with Radio standard ETSI EN 300 220-3 and EMC standard ETSI
EN 301 489-3 by UKAS accredited Test Laboratory.
The TX1 module is type approved to European
harmonized standard ETSI EN 300 220-3 for UK use within the
following categories:
(a) General applications in the band 173.2-173.35MHz
but excluding 173.225MHz.
(b) Industrial/commercial applications
at the same frequencies as category (a).
(c) Fixed/in-building alarm applications
at 173.225MHz.
(d) Medical/biological applications
(including airborne use for the tracking of birds) in the
band 173.7-174.0MHz.
|
| REQUIREMENTS FOR CONFORMANCE TO ETSI
EN 300 220-3:
1. Transmitted ERP (effective radiated
power) must not exceed the limit of 1mW (0dBm) for category
(a) or 10mW (+10dBm) for categories (b), (c) and (d). Equipment
in category (a) must include a 10dB attenuator between the
TX1 RF output pin and the antenna or feed, as specified on
page 7 of this leaflet.
2. Any type of antenna system may be employed
provided that the applicable ERP limit is not exceeded - i.e.
transmitting antenna structures which exhibit ERP gain (such
as yagis) are not permitted. See pages 10-13 of this leaflet
for details of suitable antennas.
3. The module must not be modified or used
outside its specification limits.
4. The module may only be used to
transmit digital or digitised data. Speech and/or music are
not permitted.
|
| OEMs incorporating the TX1 as a component
part of their product are authorised by Radiometrix Ltd to quote
our type approval provided that all conditions are complied
with. Breaching any of these conditions will invalidate
type approval. |
 |
|
Limitation of liability
The information furnished by Radiometrix
Ltd is believed to be accurate and reliable. Radiometrix Ltd
reserves the right to make changes or improvements in the
design, specification or manufacture of its subassembly products
without notice. Radiometrix Ltd does not assume any liability
arising from the application or use of any product or circuit
described herein, nor for any infringements of patents or
other rights of third parties which may result from the use
of its products. This data sheet neither states nor implies
warranty of any kind, including fitness for any particular
application. These radio devices may be subject to radio interference
and may not function as intended if interference is present.
We do NOT recommend their use for life critical applications.
The Intrastat commodity code for all our modules is: 8542
6000.
R&TTE Directive
After 7 April 2001 the manufacturer can
only place finished product on the market under the provisions
of the R&TTE Directive. Equipment within the scope of
the R&TTE Directive may demonstrate compliance to the
essential requirements specified in Article 3 of the Directive,
as appropriate to the particular equipment.
Further details are available on The Office of Communications
(Ofcom) web site:
Licensing
policy manual
|
 |