Abstract: A mismatch detector is provided for determining whether or not a particular load impedance is matched or mismatched to the characteristic impedance of a transmission line. The detector is capable of determining if a particular load impedance has a value outside of an impedance threshold circle having a center at a location other than at the center of the Smith Chart. This flexibility enables the detector to be more selective in determining improper load conditions.

Abstract: A portable radio transceiver and mobile mount housing are disclosed which utilize a switchless connector for connecting the portable unit to an external antenna which is electrically coupled to the mobile mount. In the preferred embodiment, the portable radio is equipped with an internal antenna which is either coupled to an electrical contact on the exterior of the portable unit adaptable to making electrical contact with a similar contact on the inside of the mobile housing when the portable radio is inserted therein. The internal antenna in the portable unit is shielded by the metallic mobile mount housing which obviates the need to disconnect the same. In one embodiment the contact disposed on the portable unit exterior is connected to a predetermined point on the internal antenna for impedance matching with the external antenna when the portable unit is inserted into the mobile mount housing.

Abstract: An adaptive impedance mismatch detector system is provided for determining whether or not a particular load impedance is matched or mismatched to the characteristic impedance of a transmission line. The detector system is capable of determining if a particular load impedance has a value outside of an impedance threshold circle having a center at a location other than at the center of the Smith Chart. The system changes the radius and/or center of the threshold circle in response to changes in circuit operating conditions or parameters. This flexibility enables the detector to be more selective in determining improper load conditions.

Abstract: A high efficiency radio frequency amplifier is provided which includes stabilization circuitry which is selectively actuated during periods of time when undesired amplifier circuit operating conditions are present which tend to cause amplifier oscillation. Otherwise, the stabilization circuit remains in effect decoupled from the amplifier so as not to unnecessarily draw power from the amplifier circuit when its action is not required to prevent undesired oscillation of the amplifier.

Abstract: A hybrid filter comprising a plurality of removably mountable resonator modules, each constructed of nmicrostrip, and mounted parallel to each other and perpendicular to the substrate so as to isolate the resonators for single mode operation; the inter-resonator coupling is provided by adjustable capacitor coupling gaps on the host substrate.