Hartcran House, 231 Kenton Lane, Harrow, Middlesex, HA3 8RP, England Tel: +44 (0) 20 8909 9595, Fax: +44 (0) 20 8909 2233, www.radiometrix.com PRELIMINARY SAT3 Issue 1, 27 January 2012 869MHz Narrow Band FM Transmitter The SAT3 transmitter modules offer a 10mW RF output UHF data link in Radiometrix SIL standard pin-out and footprint. This makes the SAT3 ideally suited to low power applications using narrow band transmitters. Together with the matching SAR3 receiver a one-way radio data link can be achieved over a distance up to 1km+ with suitable choice of data rate and antennas. Features Conforms to EN 300 220-3 and EN 301 489-3 Standard frequency 869.2125MHz 25 kHz channel spacing Data rates up to 4kbps Usable range over 1km+ Fully screened Low power requirements Figure 1: SAT3 transmitter The SAT3 is a narrow band radio transmitter module for use in long range data transfer applications at ranges up to 1kilometre+ Applications Automatic meter reading (AMR) Car and building security Social alarms Industrial telemetry and telecommand In-building environmental monitoring and control EPOS and inventory tracking Technical Summary Size: 32 x 13.5 x 4.5mm Operating frequency: 869.2125MHz Supply range: 5v Current consumption: 45mA Max Data bit rate: 4kbps max. Transmit power: 10dBm (10mW) nominal Evaluation platforms: Universal Evaluation Kit, NBEK + SIL carrier Radiometrix Ltd., SAT3 transmitter data sheet Page 1 Figure 2: SAT3 Block diagram Functional description The SAT3 transmitter consists of a frequency modulated Voltage Controlled Temperature Controlled Crystal Oscillator (VCTCXO) feeding a frequency multiplier with two stage amplifier and RF filter. Operation can be controlled by the EN (Enable) line, the transmitter achieving full RF output typically within 1.5ms of this line being pulled high. The RF output is filtered to ensure compliance with the appropriate radio regulations and fed to the 50Ω antenna pin. User interface 4.5 mm 32 mm 12.0 mm 12.5 mm SAT3 Radiometrix PCB level 15.24 mm 1 2 3 4 5 6 7 1 = RF GND 2 = RF OUT 3 = RF GND 4 = En 5 = Vcc 6 = 0V 7 = TXD 7 holes, 0.7 mm dia, pin spacing 2.54 mm Figure 3: SAT3 pin-out and dimension ENT1L pin 1, 3 2 4 5 6 7 Name RFgnd RF out EN VCC 0V TXD Function RF Ground 50 RF input from the antenna Pull high to enable Transmitter (Note 1) 5V DC power supply Ground DC coupled input for 5V CMOS logic. Rin = 200kΩ NOTES: 1. EN pin should not be left floating Radiometrix Ltd., SAT3 transmitter data sheet Page 2 Absolute maximum ratings Exceeding the values given below may cause permanent damage to the module. Operating temperature Storage temperature -20°C to +60°C -30°C to +70°C RF in (pin 1) VCC (pin 5) EN (pin 4) All other pins ±50V @ <10MHz, +13dBm @ >10MHz -0.3V to +16V -0.3V to +16V -0.3V to +5.5V Performance specifications (Vcc = 5V / temperature = 25°C unless stated) General DC supply Supply voltage TX Supply current @ 10mW Antenna pin impedance RF centre frequency Channel spacing Number of channels RF RF power output Spurious emissions Adjacent channel TX power Frequency accuracy FM deviation (peak) Baseband Modulation bandwidth @ -3dB TXD input level (logic low) TXD input level (logic high) pin min. typ. max. units 5 5 2 3.1 5 38 50 869.2125 25 1 16 45 V mA +9 +10 +11 -2.5 ±2.5 > -40 0 ±3 +2.5 ±3.5 2 2 0 7 7 Dynamic timing TX select to full RF Notes: 1. 2. 3. 4. 5. notes MHz kHz 3 0 5 4.0 1.5 2 dBm dBm dBm kHz kHz 1 5 2 3 kHz V V 4 4 ms Measured into 50Ω resistive load. Total over full supply and temperature range. With 0V – 5.0V modulation input. To achieve specified FM deviation. Meets EN300-220 Radiometrix Ltd., SAT3 transmitter data sheet Page 3 Applications information Power supply requirements The SAT3 has a built-in regulator which delivers a constant 3V to the transmitter frequency control and RF circuitry when the external supply voltage is 3.1V or greater. This ensures constant frequency stability and removes the need for external supply decoupling except in cases where the supply rail is extremely poor (ripple/noise content >0.1Vp-p). TX modulation requirements The module is factory-set to produce the specified FM deviation with a TXD input to pin 14 of 5V amplitude, i.e. 0V “low”, 5V “high (other variants available on request) If the data input level is greater than 5V, a resistor must be added in series with the TXD input to limit the modulating input voltage to a maximum of 5V on pin 7. TXD input resistance is 200kΩ to ground. 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 1.2kbps Note: Tx antenna half-wave Rx antenna half-wave Environment rural/open Range 1000m + 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. The SAT3’s TXD input is normally driven directly by logic levels but will also accept analogue drive (e.g. 2tone signalling). In this case it is recommended that TXD (pin 14) be DC-biased to 2.5V approx. with the modulation ac-coupled and limited to a maximum of 5Vp-p to minimise distortion over the link. Although the modulation bandwidth of the SAT3 extends down to DC 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 receiver’s audio output. Module mounting considerations The modules may be mounted vertically or bent horizontal to the motherboard. Good RF layout practice should be observed. If the connection between module and antenna is more than about 20mm long use 50Ω 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 SAT3 transmitter is manufactured in the following variant as standard: SAT3-869.2125-3 (869.2125MHz) Matching Receiver: SAR3-869-8 Radiometrix Ltd., SAT3 transmitter data sheet Page 4 Radiometrix Ltd Hartcran House 231 Kenton Lane Harrow, Middlesex HA3 8RP ENGLAND Tel: +44 (0) 20 8909 9595 Fax: +44 (0) 20 8909 2233 [email protected] www.radiometrix.com Copyright notice This product data sheet is the original work and copyrighted property of Radiometrix Ltd. Reproduction in whole or in part must give clear acknowledgement to the copyright owner. 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: http://www.ofcom.org.uk/radiocomms/ifi/ Information Requests Ofcom Riverside House 2a Southwark Bridge Road London SE1 9HA Tel: +44 (0)845 456 3000 or 020 7981 3040 Fax: +44 (0)20 7783 4033 [email protected] European Radiocommunications Office (ERO) Peblingehus Nansensgade 19 DK 1366 Copenhagen Tel. +45 33896300 Fax +45 33896330 [email protected] www.ero.dk