JPS5683147A - Switching system for diversity reception - Google Patents

Abstract

PURPOSE:To prevent the production of discontinuous points of output level variance at diversity reception and to suppress the deterioration in the frequency characteristics in short time, by setting the time when two signal change-over switches are turned on at the same time at signal switching, with a monostable multivibrator. CONSTITUTION:An input reception signal from reception antennas 1, 2, is converted into IF signal at reception converting sections RX1, 2 with the signal from reception conversion local oscillator LOs 1, 2. The IF signal converted at the conversion sections RXs 1, 2 is phase-detected at the phase detector PD at the phase synthesis section PSC, control is made at PLL operation so that the same phase can be obtained at all times, and the amplitude of two IF signals is discriminated at a level comparator A. The signal discriminated at the comparator A is fed to a monostable multivibrator MM controlling the signal switches SW1, SW2, the time simultaneously turning on the switches SW1, SW2 is determined with the multivibrator MM, the production of discontinuous points of output level variance is prevented, and the deterioration in the frequency characteristics can be suppressed in a short time.