TRANSCEIVER FOR SIMPLEX COMMUNICATION FROM ONE DEVICE TO SEVERAL DEVICES

摘要

PURPOSE: A transceiver for a simplex communication from one device to several devices is provided to allow a transmitter party to select one of receiver parties, by sending a signal to a selected receiver at a transmitter and alternatively scanning two channels at the selected receiver in order to receive data at a corresponding channel. CONSTITUTION: An amplifier(22) amplifies a signal received via an antenna(21). A mixer(23) demodulates the amplified signal from the amplifier(22). A filter(24) selects and passes a low frequency components of the demodulated signal from the mixer(23). An amplifier(25) amplifies the signal from the filter(24). A detection circuit(26) detects a received channel at the signal from the amplifier(25). A speaker(27) outputs a final signal from the detection circuit(26) as a voice signal. A channel selector(28) checks a channel for the signal transmitted by the transmitter. A voltage controlled oscillator(30) transfers the selected channel to the mixer(23) in order to apply it for a demodulation. A phase locked loop(29) locates between the channel selector(28) and voltage controlled oscillator(30).