摘要 |
A low cost glass mount vehicle antenna system utilizes, in a preferred embodiment, an over-coupled quasi-TEM mode transmission line coupler having two simple stamped or printed plates stacked over an L shape internal ground plane. The two conductive plates are located on opposite sides of the glass. With proper open circuit terminations on two of the four coupler ports, the backwards and forward coupling signals are redirected/combined and are effectively fed diagonally between the other two ports, thereby achieving through-glass coupling. The over-coupling achieves this efficient through-glass coupling effect at two spaced-apart frequencies (e.g. 800 MHz and 1800 MHz). The coupler is of a low impedance type and can be used with a variety of collinear array and elevated-feed antennas. It features high efficiency, low backwards radiation, and mechanical simplicity.
|