AR57
RF Receiver Module
 

 
Features

The AR57 has been designed in accordance with ETS300-086 ( Voice ) and ETS300-113 ( Voice + Data ) regulations and operates in frequency modulation.

The modules are manufactured using Surface Mount Technology ( SMT ) and are therefore compact and reliable. The reception frequency is determined by a crystal which can be rapidly supplied by STE on the frequency required.

Special care has been devoted to the design of the radio frequency, demodulation and supply circuits by using highly selective double tuned circuits to make the module suitable to meet most requirements. Either FM ( linear frequency response ) or the PM ( 6dB / octave deemphasis ) modulation can be chosen and the cut-off frequency of the demodulator can be changed.

An audio output which is not blocked by the squelch circuit detects in-band or out-band pilot tones ( subaudio or superaudio tones ) as well as selective calling tones. A direct output from the discriminator ( DC coupled ) is available to demodulate complex digital signals as well as an RSSI output which helps measure the received signal intensity.

An open collector output controlled by the carrier detection and squelch circuit and a MUTE input to block the audio output are also implemented. The STB input allows to switch off the module supply ( for example during transmission ) whereas the audio circuit supply can be maintained ( to decrease the transmitting-receiving switching times in case of digital signal reception ).