Narrow band multi channel radio transmitter/receiver

Paul Boughton

Circuit Design Inc has developed and begun delivery of the CDP-TX-02E-R transmitter and CDP-RX-02E-R receiver as the successor models to the CDP-02 series industrial use radio modules. The new products comply with the RoHS Directive that comes into force in Europe from 1st July 2006.

The R&TTE compliant narrowband multi channel radio module CDP-02 series has been very well received in the marketplacewith a total of more than 150000 sets sold since the product went on sale.  

The shape and interface of the RoHS Directive compliant successor model maintains compatibility with the earlier modelsbut thanks to improvements made in basic performancereliability and stability have been enhanced.  

With the development of new circuits using TCXOthe minimum operating temperature has been expanded from -10o°C in the earlier models to -20°C. RF output complies with the European ISM band RF power limit *1and you can select either 10 mW or 1 mW. In this way the modules can be used in applications where continuous transmission is necessary in all 32 channels.

To maintain high reliability and stability even in a tough condition for radioCircuit Design has improved the blocking performance and selectivity of the receiverto achieve receiver class 1*2 classification as defined in EN300220.

The features of CDP-TX-02E-R/CDP-RX-02E-R include:

  • R&TTE and RoHS compliant radio modules.

  • Class 1 receiver supported by high reliability; Blocking or desensitisation: 84dB (All); Adjacent channel selectivity – in band: 60dB (25kHz channel spacing); Adjacent band selectivity: 60dB.

  • Achieves an operating temperature range from -20 to 60¢ªC using aTCXO-based temperature compensation circuit.

  • 1mW/10mW RF output selection.

  • A transmission circuit structure that is highly resistant to reflection.

  • 25kHz step 32 multi channels.

  • Improved shock and vibration resistance.

  • Uses a custom SAW filter to avoid radio interference from other radio equipment.

  • High receiver sensitivity using double superheterodyne receiver circuits:

-120dBm (12dB SINAD/BER 1percent).

Excerpt from EN300220: 4.1.1 Receiver classification: The receiver used in short range radio devices is divided into three classes of receiver (see Table 1) each having its own set of minimum performance criteria.

This classificationsays Circuit Designis based upon the impact on persons in case the equipment does not operate above the specified minimum performance level. 

Circuit Design Inc is based in NaganoJapan.