To make the orthogonal detector suitable for circuit integration with immunity to a parasitic component of components even at a high frequency by giving each output signal from two phase shifters to each amplifier whose output amplitude is identical to each other and using a vector synthesis means to synthesize the outputs of the amplifiers.
A phase shifter 11 is a 45° lead phase shifter and a phase shifter 12 is a 45° lag phase shifter, but actually the 45° phase lead/lag is an approximate value close to 45° because of the effect of a parasitic component of shifter components. An output of an oscillator 10 whose output frequency is equal to a carrier frequency of a digital modulation wave is given to the phase shifters 11, 12, where the output receives nearly 45° phase lead/lag, then the signals are given to amplifiers 33, 34, in which they are amplified so as to have the identical amplitude to each other as the outputs. The amplifiers 13, 14 are, e.g. limiter amplifiers whose output amplitude is limited. The outputs from the amplifiers 13, 14 are given respectively to vector synthesizers 15, 16, in which they are synthesized in terms of vectors. Outputs 100, 101 of the synthesizers 15, 16 have a phase difference of 90° (e.g. a phase of the terminal 101 is led relatively by 90° than the phase of the terminal 101, that is taken as a reference phase (0°)).
JPS57166705 | DEMODULATOR FOR FREQUENCY MODULATION SIGNAL |
JPS5854118 | 【考案の名称】検波回路 |
YAMAMOTO AKIO
ADACHI SATOSHI