Abstract: A cordless telephone is described comprising a fixed part which includes a reception section for receiving exact reception channel frequencies lying in a predetermined frequency range at equal intervals apart and a transmission section for transmitting exact transmission channel frequencies lying at a predetermined duplex interval from the reception channel frequencies. The cordless telephone further comprises a mobile part which includes a reception section for receiving frequencies lying in the range of the transmission channel frequencies of the fixed part and a transmission part for transmitting frequencies lying in the range of the reception channel frequencies of the fixed part. The mobile part includes a frequency control loop which using the transmission channel frequency transmitted by the fixed part as reference frequency holds its reception section fixedly tuned to the received transmission channel frequency.

Abstract: A high frequency amplifier circuit comprising a gated field effect transistor operated in common gate configuration with one of the two gate electrodes connected to the substrate of the field effect transistor. Transistors using two insulated gates or having one insulated gate and either a Schottky barrier junction or a pn junction gate may be used. AGC amplifier and mixer circuit configurations are described. By use of the basic configuration described, high frequency stability of the amplifier is significantly improved.

Abstract: A variable gain RF input amplifier having an improved cross modulation characteristic using a field effect transistor. About the first 10 db of signal attenuation is effected by an AGC voltage applied to the transistor, following which supplementary attenuation is provided by an increasing reverse bias applied to a PIN-diode in the RF signal input path to the transistor, the diode bias being derived from the source circuit of the transistor.