Advances in Concealed AM/FM Antenna System Design 930952
Whip antennas have been used for automotive AM/FM reception for many years. Although these systems typically offer very good reception performance, they suffer from other disadvantages including wind noise and aerodynamic drag, styling detraction, and the potential for mechanical damage. These limitations offer a significant incentive for developing concealed AM/FM antenna systems for the automobile.
The concept of using a concealed antenna system for AM/FM reception is not new. However, previous concealed antenna designs have suffered from poor EMC performance and lack of sufficient gain for reception of distant stations under weak field strength conditions. Recent advances in the design and test methodology for concealed antenna systems have resulted in subjective performance that is equivalent to, and under certain circumstances exceeds, the performance level of a traditional whip antenna.
This paper will discuss the system design considerations for an AM/FM concealed antenna system, objective performance data on several concealed antenna designs, an analysis on the signal-to-noise benefits of using a pre-amplifier for an FM antenna system, and the test methodology used to subjectively quantify the field performance of a concealed antenna system. Data will be presented that shows a carefully designed concealed antenna system can potentially offer the performance level that favorably competes with the existing whip antenna system.