Communications Satellite Corporation

Communications Satellite Corporation (comsat)

Arthur Frederick Standing

A low-power voltage and low-power current driver for use with PIN diode phase shifters is disclosed. The driver uses transistors which function as emitter followers for rapid switching of the voltage applied to the PIN diode and as a voltage or current source for the diode bias. The driver provides for separate control of the reverse bias voltage and forward bias current applied to the PIN diode.

Low-power voltage and current diode driver

A microwave stripline package provides symmetrical ground currents while permitting discrete components such as diodes, terminations, capacitors, etc.to be used. The package comprises a pair of face-to-face printed circuit boards, each of which is formed of a dielectric having a ground plane on one surface. The discrete components together with a printed circuit are assembled on one of the boards while a portion of the dielectric of the other board is cut away to provide mechanical clearance for the circuit components. Matching portions of the dielectrics on either side of the printed circuit are cut away to receive a pair of metal blocks which contact both the upper and lower ground planes in order to form a screened enclosure. The dimensions of the printed circuit within the screened enclosure are selected to provide impedance matching with the stripline outside the enclosure.

Symmetrical stripline package

A 4 phase PSK modulator is implemented using micro-strip printed circuit technology and produces a 4 phase PSK modulated carrier by direct modulation of an RF carrier. Implementation is by means of three strip-line hybrids and two semiconductor diode phase shifters. The RF carrier is applied to one input of the first hybrid, and the other input is terminated in its characteristic impedance. The outputs of the first hybrid are connected through the semiconductor diode phase shifters to the inputs of the second hybrid. The outputs of the second hybrid are directly coupled to the inputs of the third hybrid, and the 4 phase PSK output is available from each output of the third hybrid. The semiconductor diode phase shifters are controlled to produce either 0.degree. or 180.degree. phase shifts, and by changing the state of the diode phase shifters, a separate output phase is generated for each of the four possible diode states.

Growing community of inventors

Rockville, MD, United States of America

Arthur Frederick Standing