Space Systems/loral, LLC

Ford Aerospace Corporation

Andrew M Kennedy, Ii

Ming L Yung

Bernard M Albrecht, Jr

Camille A Lesko

William W Nelson

Vernon E Dunn

Elizabeth C Townley

A multifunction microwave modulator circuit has an input signal splitter to provide two equal amplitude signal components. A phase quadrature relationship between the two signal components is obtained by constructing the splitter as a Lange coupler. There is pair of circuit cells, each of which operates separately on one of the two signal components to electronically adjust a vector representation of the signal to provide a vector having a desired amplitude, ranging over both positive and negative values of amplitude, including zero amplitude. The signal vectors of the two cells are combined by means of a Wilkinson combiner to provide an output signal represented by a resultant vector which may have any direction within 360 degrees, and an amplitude scale factor which varies from unity to zero. Each circuit cell has a Lange coupler with output terminals terminated with an impedance, such as back-biased transistors, variable in response to a control voltage to reflect power via a second input terminal to the Wilkinson combiner. The circuit may be operated in reciprocal fashion by applying an input microwave signal to the Wilkinson combiner and extracting the output signal from the Lange coupler of the power splitter.

Microwave modulator having adjustable couplers

A time delay shifter imparts a constant time delay to an electromagnetic signal, preferably a signal at a microwave frequency, over a band of frequencies. The phase shift imparted to the signal is a linear function of frequency. The shifter comprises a finite number of delay units (1) each having four single-pole single-throw switches (11-14). Closure of the first and third switches (11, 13) causes the signal to traverse a first path (2) containing a preselected length of transmission line that imparts a fixed time delay to the signal. Closure of the second and fourth switches (12,14) causes the signal to traverse a minimum-delay path (3) which is shorter than the delay path (2). The paths (2,3) are fabricated of coplanar waveguide. Each switch (11-14) is resonated by an inductor (21-24) for purposes of increasing isolation. An attenuator (70) is inserted in each minimum-delay path (3).

Coplanar waveguide time delay shifter

Growing community of inventors

Oakland, CA, United States of America

Andrew M Kennedy, Ii