General Electric Company

Lockheed Martin Corporation

Allen Robert Wolfe

John A Windyka

Ronald J Naster

Robert S Long

John C Lopacki

A single pole multiple-throw switch for switching an RF signal to one of a plurality of outputs includes coupling the signal to a throw junction, said junction having connected thereto a plurality of switch legs, each leg includes a high voltage shunt diode spaced one quarter-wavelength from the throw junction; each diode mounted at its cathode end to a capacitor and adapted to receive a bias; wherein a controller applies a first DC bias to a selected one of the diodes to cause the selected diode to operate in reverse bias mode, such that the selected diode mounted on the corresponding capacitor provides a low insertion loss to pass the RF signal from the transmission line through the selected leg and to one of the outputs; and applies a second DC bias to the other diodes to cause the other diodes to operate in forward bias mode such that the other diodes mounted onto the corresponding capacitor provides a high insertion loss for blocking the RF signal to the remaining outputs.

High power UHF single-pole multi-throw switch

A bidirectional continuously variable phase shifting element is described for incorporation in a monolithic microwave integrated circuit (a circuit which combines both passive and active circuit elements). The preferred active device for use in the phase shifting element is a variable resistance field effect transistor (MESFET), while the preferred passive circuit element is a short transmission line interconnecting the principal electrodes. A variable phase shift for an RF signal passing through the phase shifting element is obtained by adjusting the gate potential of the MESFET between full conduction and nonconduction. The change in conductivity of the MESFET causes the serial impedance of the phase shifting element to vary from a substantially resistive impedance to a substantially capacitively reactive impedance arrangement, which requires only a single active device, is applicable to frequencies generally above 1 GHz, and provides phase shifts up to 45.degree. with reasonable insertion loss and return loss.

Continuously variable phase shifting element comprised of interdigitated

The inverted microstrip phase shifter consists of a substrate having at least one diode and biasing circuitry connected to one side and at least one center conductor connected to its opposite side. The substrate side containing a center conductor is enclosed within a hollow case so as to form an rf transmission line. The parameters for the biasing circuitry are selected by performing a computer optimization of the chain matrix equivalent expression for the voltage transmission coefficient.

Inverted microstrip phase shifter

A.C. grounded termination networks having multi-octave bandwidth capacity are provided in printed rf circuit form (e.g., microstrip, stripline) by fabricating a distributed element network as a series of alternating resistor-conductor elements having different circuit parameters. The circuit parameters are computed using an 'exhaustive search' procedure involving computer optimization of the chain matrix equivalent expression of the voltage reflection coefficient for the network.

Printed broadband A. C. grounded microwave terminations

A printed broadband rf transmission line circuit is provided with a D.C. bias port in the form of a high impedance printed stub conductor connected between a ground point and the transmission line. Minimum attenuation of a broadband rf signal on the line is achieved by including in the transmission line a plurality of series-connected conductor segments having different line length and impedance values such that the transmission line and stub conductor configuration are tuned to provide a maximum voltage transmission coefficient across the D.C. bias port. The parameters for the series-connected transmission line segments and the stub conductor are selected by performing a computer optimization of the chain matrix equivalent expression of the voltage transmission coefficient for the series-connected transmission line segments together with the stub conductor.

Printed broadband rf bias circuits

A printed rf circuit switchable step attenuator for frequencies in the Gigahertz range employs PIN diodes for switching a pi network in and out of a transmission line. The A.C. grounded terminations of the pi network are constructed through the use of low impedance, open end stubs, eliminating the need for plated over-edge ground connections. D.C. bias potential for controlling the switching diodes is coupled to the rf portion of the circuit by means including high impedance grounded stub conductors connected to the transmission line. To achieve broadband operation the admittance of the stub conductors is tuned out by configuring the transmission line as a series of differing line length and impedance sections which are arranged symmetrically with respect to the point of intersection between the grounded stub conductors and the line.

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Sauquoit, NY, United States of America

Allen Robert Wolfe