Abstract: A thin film antenna for a vehicle antenna is described. The principal element of the antenna is formed of a thin transparent film of conducting material having a horizontally elongate generally rectangular shape. The principal element is supported on or within the upper region of a vehicle window and is electrically fed with respect to a ground point on the vehicle body to effect coupling with the metallic structure of the vehicle and enhance antenna performance. An optional auxiliary element can be attached to the principal element to provide a means for tuning the impedance of the antenna.

Abstract: A slot antenna is disclosed for a horizontal dielectric vehicle door in which the ground plane of the antenna sheet does not connect with or overlap the surrounding electrically conducting vehicle body panels but which nevertheless maintains significant RF currents at FM frequencies through the vertical roof pillars of the vehicle. This is accomplished by the formation of a parasitic slot surrounding the antenna slot in the gap between the sheet and the surrounding sheet metal at the trunk opening. The parasitic slot has a first portion of length substantially the same as that of the antenna slot and a similar width and a second portion of a greater width effective to comprise an open circuit for currents. Thus the total effective length of the parasitic slot is equal to that of the antenna slot for similar resulting current flow from the decklid area through the vertical roof pillars; and the desirable FM performance is preserved.

Abstract: An FM antenna for a vehicle with a ground plane comprising a horizontal roof having supporting pillars at the front and rear corners comprises a side fed, looped, annular slot antenna in the roof of loop length substantially one wavelength in the commercial FM broadcasting band, the slot antenna being displaced from the center of the roof toward one of the front and rear of the roof.