Abstract: A radio frequency connector for coupling radio frequency energy into or out of an antenna apparatus includes a ground portion that is both capacitively and conductively coupled to a ground structure within the antenna apparatus. The connector is designed so that radio frequency (RF) signals within the operative frequency range of the antenna apparatus flow predominantly through the capacitive ground connection of the connector, rather than through the conductive ground connection of the connector. Direct current signals and other low frequency signals within the antenna apparatus, on the other hand, have a direct path to ground through the conductive ground connection. Because the RF signals flow predominantly through the capacitive ground connection, the likelihood that passive inter-modulation (PIM) products will be generated within the metal-to-metal junctions of the conductive ground connection is significantly reduced.

Abstract: A low profile or very low profile antenna having a finely tunable frequency response is provided. The antenna is easily tuned to have a precise frequency response while its protective radome is in place. The antenna generally includes a first antenna element, a second antenna element, a ground plane, and a tuning mechanism. The tuning mechanism may be accessed while the radome of the antenna is in place. The antenna is particularly well-suited for use in shipping applications, where a very low antenna profile is desirable.

Abstract: A receiver which is tunable to any of a plurality of modulated carrier signals, said receiver comprising a tuner local oscillator the frequency of which is determined by a control circuit responsive to a user input indicating the selection of a modulated carrier signal to which the receiver should tune, and a non-volatile memory connected to said control circuit for storing information, and a real time clock connected to said control circuit for providing current time, said control circuit being responsive to a user entered channel viewing matrix which is stored in said non-volatile memory and is compared to information provided by said real time clock, said user entered channel viewing matrix defining times of certain channels of which said control circuit will be prohibited from allowing said receiver to tune, said control circuit comprising a control means for automatically changing channels to the next valid channel if the current channel is or becomes invalid, and a data entry means for entering informat