Automatic control of gain and phase deviations in a dual-branch receiver

A method of deriving the error signals for correcting the gain and phase deviations in a dual-branch receiver is described. This is based on separating the wanted signal and image signal components with an offset frequency between the transmitted carrier and the frequency of the first local oscillator. The correction process is adaptive and it operates continuously in the presence of modulation. A specific FM receiver architecture with remodulation has been chosen for illustration. However, the scheme described is also applicable for AM and single-sideband demodulation. The operation of the proposed scheme has been confirmed both by computer simulations and by experiments using a laboratory breadboard received