AM/FM antenna performance in the presence of wide-band noise using tunable high-Q structures

摘要

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.

主权项

1. An audio and/or visual system, said system comprising:
a human machine interface (HMI) allowing a user to select a station; a tuner responsive to a signal from the HMI identifying the selected station and tuning the system to the station, said tuner providing a signal to the HMI identifying the selected station; a bus responsive to a message from the HMI or tuner identifying the station that the tuner is tuned to; an antenna controller receiving the message from the bus; an impedance matching matrix receiving a control signal from the antenna controller identifying the station, said impedance matching matrix selecting an impedance circuit from a switch-selectable set of impedance circuits in the matrix for the station; and an antenna including a plurality of antenna elements separated by PIN switches, where the antenna receives control signals from the antenna controller and adjusts a length of the antenna by connecting a number of the antenna elements to tune the antenna to a frequency for the station.