HIGH FREQUENCY SIGNAL SOURCE RECOVERY DEPHASES OF 90O

摘要

The invention relates to a source of signals mutually phase-shifted by 90 DEG which forms an electronic circuit which forms, at corresponding outputs, a source of two signals having the same frequency and same amplitudes and a constant value of the mutual phase shift which is approximately 90 DEG within a wide frequency band. The circuit according to the invention contains, in one of the transmission lines of the input signal, a wide-band phase shifter (4) in the form of a current source (5) which is controlled by means of the input signal and is connected to a reactive load (6), the output of which is supplied to a first wideband amplifier (8) with automatic wideband gain control. The signal at the output (2) of this line is phase-shifted by 90 DEG compared with the signal at the output (3) of the second line containing a second wideband amplifier (9). For the purpose of the independence of the amplitude changes at the input signal, the wideband amplifiers (8, 9) are equipped with automatic wideband gain control in both lines. The wideband amplifiers with automatic wideband gain control (8, 9) each contain a controllable amplifier (10, 13) in the form of differential amplifiers with current source. The circuit according to the invention for the generation of voltage signals phase-shifted by 90 DEG is mainly used in compensated mixers in superheterodyne receivers with mirror frequency suppression. IMAGE