Abstract: An AM/FM radio system for a vehicle that is selectively impedance matched to the particular tuned frequency of interest so that noise received by other frequencies does not affect the received signal. The radio system includes an HMI allowing a user to select an AM or FM radio station and a radio tuner responsive to a signal from the HMI identifying the selected radio station. The tuner tunes the radio system to the radio station, and provides a signal to the HMI identifying the radio station. The HMI places a message on a vehicle bus identifying the radio station that the radio tuner is tuned to. An antenna controller receives the message from the vehicle bus to selectively control an impedance matrix to provide impedance matching for the selected radio station frequency. The antenna controller also selectively tunes antenna radiating elements to the particular tuned frequency.

Abstract: An antenna capable of receiving both left-hand circularly polarized (LHCP) signals and right-hand circularly polarized (RHCP) signals, and outputting both signals on a single feed. The antenna includes two coplanar concentric patches. The inner patch is substantially square. The outer patch surrounds the inner patch to define a gap therebetween. A resonant parallel inductive/LC circuit interconnects the two patches. The circuit includes a plurality of printed traces within the gap and interconnecting the concentric patches. The gap and each trace function as an LC circuit.