Optimizing antenna interface for automobile radio receivers

Abstract

An automatic signal optimizing interface for connection between the antenna of an automobile radio receiver and the receiver itself processes the RF signal received by the antenna and provides an improved output signal to the automobile receiver which is optimized for distortion free reception. The output signal is limited to the desired frequency band to eliminate interfering signals, and is maintained within the optimum dynamic range of the receiver, even under reception conditions in which the received antenna signal itself is excessively high or undesirably low. The interface therefore permits superior performance by the radio receiver by optimizing the signal supplied to the radio and by preventing intermodulation distortion which otherwise commonly results from overloading of the front end of the radio receiver by excessively strong received signals. The optimizing interface operates independent of the radio receiver, and therefore is amenable to after market or OEM use in conjunction with substantially all existing automobile radio receivers. Operation of the signal processing circuitry of the interface is automatic so that no user intervention or monitoring is required, and is sufficiently rapid and of sufficient range and resolution to compensate for nearly all adverse reception conditions encountered in both urban and rural areas.