Abstract: A diode network includes a series branch coupled between two signal ports and a shunt branch coupled between a node in the series branch and ground and connected in parallel with a transistor of a latching circuit that is further coupled to supply forward bias to the shunt branch and reverse bias to the series branch when the transistor is conductive for blocking RF signal flow between the ports. The bias applied to the branches is reversed when the latch transistor is non-conductive thereby enabling RF signal flow between the ports. The transistor provides plural functions of establishing positive feedback for the latch, supplying forward and reverse bias to the shunt and series branches, respectively, and enhancing the attenuation of the shunt branch when conductive.

Abstract: In a radio frequency switch, a pair of diodes is coupled in series with polarities opposed between input and output ports. A shunt diode is coupled between the junction point of the pair of diodes and a point of reference potential. A transistor has its main conduction path coupled between the junction point and the point of reference potential. When the switch is to couple a signal between the input and output ports, a control arrangement applies bias tending to forward bias the pair of diodes, to reverse bias the shunt diode and cut off conduction through the transistor.

Abstract: A switching system for connecting a plurality of input signals to a pluray of selected outputs. A plurality of input signals are connected to a crosspoint matrix through a buffer circuit. The crosspoint switching matrix is comprised of a plurality of CMOS crosspoint switch integrated circuits and switching is controlled by a microprocessor which provides the desired connections for selected outputs. A built-in-test circuit (BITE) is provided for testing each circuit path in the switching system.