Annular slot windshield antenna

This paper discusses the development of a conformal automobile antenna for the AM/FM band. It is implemented by using a heat reduction metal film imbedded in the windshield to create an annular gap or slot at the circumference. Impedance characteristics and gain patterns are shown. The antenna system is effective, inexpensive and invisible. In conjunction with the infrared heat reduction film, the overall system also improves vehicle performance and reduces air pollution by increasing vehicle mileage through reduced drag and reducing the power needed by the air conditioning system.<>