Circuit and Method for Image Frequency Rejection

摘要

A circuit and method for image frequency rejection is provided that includes an analog dual-quadrature mixer device whose signal inputs for an in-phase-signal and a quadrature-phase signal are connected to an input circuit in the signal path and whose oscillator inputs for an in-phase oscillator signal and a quadrature-phase oscillator signal are connected to a local oscillator device, having an analog adder-amplifier device, which has a number of transistor pairs, in which in each case both transistors of each transistor pair are connected to the same load resistor for the addition of the signals applied at the control inputs of both transistors, and in which the control inputs of both transistors are connected downstream of the outputs of analog dual-quadrature mixer device, and having a multistage analog polyphase filter whose inputs are connected to outputs of the adder-amplifier device.

主权项

1. A circuit for image frequency rejection, the circuit comprising:
an analog dual-quadrature mixer device having signal inputs for an in-phase-signal and a quadrature-phase signal that are connectable to an input circuit in a signal path, the analog dual quadrature mixer device having oscillator inputs for an in-phase oscillator signal and a quadrature-phase oscillator signal that are connectable to a local oscillator device; an analog adder-amplifier device having a plurality of transistor pairs, both transistors of each transistor pair being connectable to the same load resistor for the addition of the in-phase signal and the quadrature-phase signal applied at control inputs of both transistors, the control inputs of both transistors being connectable downstream of the outputs of the analog dual-quadrature mixer device; and a multistage analog polyphase filter having inputs that are connectable to outputs of the adder-amplifier device.