Mixer circuit with image frequency rejection, in particular for an RF receiver with zero or low intermediate frequency

摘要

A mixer circuit with image frequency rejection includes a quadrature phase splitter 30 with an input which is connected to the input (Fi) of the mixer circuit and two outputs which deliver respectively two phase quadrature signals which are applied respectively to two simple mixers 31, 32. Two inputs of a quadrature phase and frequency splitter 33 having a frequency division ratio of DIV are connected respectively to the respective outputs of the two simple mixers 31, 32 and a further two inputs receive respectively quadrature signals derived from the output F0 of the mixer. The mixer is useful in GHz radio receiver of zero of quasi-zero intermediate frequency to supply baseband quadrature signals to the demodulator.