초록 ▼

A compact, easy to manufacture quarter-wavelength microstrip element especially suited for use as a mobile radio antenna has performance which is equal to or better than conventional quarter wavelength whip-type mobile radio antennas. The antenna is not visible to a passerby observer when installed,

A compact, easy to manufacture quarter-wavelength microstrip element especially suited for use as a mobile radio antenna has performance which is equal to or better than conventional quarter wavelength whip-type mobile radio antennas. The antenna is not visible to a passerby observer when installed, since it is literally part of the vehicle. The microstrip radiating element is conformal to a passenger vehicle, and may, for example, be mounted under a plastic roof between the roof and the headliner.

대표청구항 ▼

A low-profile antenna structure consisting of: a first planar electrically conductive surface; a second planar electrically conductive surface substantially parallel to, opposing and spaced apart from said first surface, said first and second conductive surfaces being dimensioned to provide a quarte

A low-profile antenna structure consisting of: a first planar electrically conductive surface; a second planar electrically conductive surface substantially parallel to, opposing and spaced apart from said first surface, said first and second conductive surfaces being dimensioned to provide a quarter-wave resonant cavity therebetween; and transmission line means for coupling radio frequency signals to and/or form said first and second surfaces, wherein the spacing and dimensions of said first and second surfaces are selected to produce a radio frequency signal radiation pattern which is substantially isotopic, wherein said first and second electrically conductive surfaces have substantially equal dimensions, and said transmission line means is connected to said first surface at a point internal to the volume disposed between said first and second surfaces, and comprises an unbalanced transmission line directly connected between said first and second surfaces.