Abstract: A matching network for coupling an OEM vehicle antenna to communications equipment operating at two different frequencies without any physical modification of the antenna mast and base. The network comprises a first transmission line section connected at one end to the antenna, a first stub tuner connected to the opposite end of the first transmission line section, a second transmission line section connected at one end to the junction of the first transmission line section and the first stub tuner, a second stub tuner connected to the opposite end of the second transmission line section, and a feedline connected to the junction of the second transmission line section and the second stub tuner for connection to the communications equipment operating at the two different frequencies.

Abstract: An antenna system characterized by decoupling the antenna mast for multiple bands by use of a quarter wave decoupling stub or by the use of a frequency relative trap. As a result the antenna has multiple resonances simultaneously. The foregoing also can be accomplished by selecting antenna mast lengths that are harmonically related to provide a single element with multiple resonances without external devices. A diplexer comprising the combination of high and low pass filters and a broadcast coupler can be connected to the antenna feed point with transceivers operating in the different bands being connected to the high and low pass filters. The simultaneous multiple resonances ensure a matched impedance at the antenna feed point so that when a communications device is connected by a length of coax to the antenna feed point the matched impedance will be maintained at the feed point regardless of the length of the coax.

Abstract: A broadcast coupler which couples both a broadcast radio receiver and communications equipment in a vehicle to the existing OEM vehicle antenna wherein no physical modifications are made to either the antenna mast or the antenna base or the antenna feed line. The broadcast coupler has a built-in tuner capability which permits the existing OEM supplied antenna to function as a low standing wave ratio (SAR) communications antenna. The broadcast coupler tunes the existing OEM antenna and provides the necessary isolation to permit the communications equipment, i.e., transmitter, receiver or transceiver, to function without detection by the operator of the vehicle. Since the existing OEM antenna is tuned by the broadcast coupler, the vehicle does not have to be modified and a new antenna does not have to be purchased.

Abstract: A disguised broadband antenna system for use with a broadcast radio receiver and communications apparatus in a vehicle wherein the antenna system comprises a standard broadcast antenna mounted to the vehicle by means of a base, a distributed matching network for coupling the antenna to the broadcast receiver and the communications equipment in the vehicle and a broadcast coupler connected between the matching network and the broadcast receiver and communications equipment for providing isolation between the broadcast receiver and communications equipment. The distributed nature of the matching network provides the broadband frequency response required while at the same time providing the highest Q factor available in a limited size and spreads any power dissipation over a relatively larger area. A series reactive element is connected electrically to the antenna through the base to cause the antenna to operate closer to resonance through the broadband frequency range of interest.