Motorola Corporation

General Dynamics Corporation

Hugh Robert Malone

Dean Lawrence Cook

Monty W Bai

James R Phillips

Ronald Dee Fuller

Deborah Sue Dendy

Keith A Kingston

Michael Dydyk

Richard S Kommrusch

Craig L Fullerton

Frank P Blatter

Chad Scott Bergstrom

James E Mitzlaff

Jeffery Scott Chuprun

Douglas J Mathews

Michael Lee Fraser

Lyle A Fajen

Ronald F Kielmeyer

John L Leicht

Richard M Dougherty

Bernhard A Ziegner

Donald W Forst

Steve Henry Arneson

Beth A Longbrake

John D Goshinska, Jr

Scott D Munier

Vernon R Scott

Paul L Brownlee

Richard J Christensen

John G Doggett, Jr

Michael L Matson

Michele G Oehlerking

Earl R Yingling

Pineabrim McCullough, Jr

Ronald P Vidano

Methods and apparatus are provided for distributed polyphase spread spectrum communication and non-contiguous spectrum underlay. The method includes polyphase channelizing a direct sequence spread spectrum (DSSS) signal, determining available spectrum in an observed frequency range having a noise floor based on detection of polyphase users below the noise floor, distributing the polyphase channelized signal among the available spectrum, and interference mitigation using a combination of standard signal detection and cyclostationary feature detection methods. The apparatus includes: a first processor adapted to polyphase channelize a code division multiple access (CDMA) spectrum and a digitized RF bandwidth containing a discontiguous polyphase waveform distribution; a second processor adapted to detect occupied bands, interferers and polyphase users in a spectrum and determine discontiguous frequency opportunities based on the detected interferers and polyphase users; and a third processor adapted to allocate the polyphase channelized CDMA spectrum among available spectrum based on the discontiguous frequency opportunities.

Method and apparatus for distributed polyphase spread spectrum communications

The present invention provides two approaches for eliminating a keyhole problem associated with an azimuth-elevation gimbal antenna which is a problem that occurs when the antennae is tracking a satellite vehicle that is substantially directly overhead, i.e., the satellite vehicle is near the zenith position. At such a point, the azimuth motor of the gimbal antenna must turn very rapidly when the satellite passes through such near zenith position. A first approach involves tilting up one of the elevation axis joints when the antenna points at or near its zenith position such that the pointing angle may be altered by a predetermined angle, for example around 0.5&deg; to 1&deg;, from the zenith position. A second approach involves tilting the secondary reflector of the cassegrain antenna such that the pointing direction of the antenna may be altered by a predetermined angle.

Method and apparatus for eliminating keyhole problem of an azimuth-elevation gimbal antenna

Waveguide phase shifter (,FIG.,and,FIG.,) uses piezoelectric ceramics to implement a voltage variable actuator (,) for moving at least one dielectric vane (,) relative to a reference surface (,) in a waveguide cavity (,). In this manner, the phase shift in waveguide phase shifters (,) is controlled. In one embodiment, actuator (,) comprises first piezoelectric wafer (,), second piezoelectric wafer (,), first metallic layer (,), second metallic layer (,), third metallic layer (,), mating surface (,) and spacer (,). Actuator (,) uses a stack of piezoelectric materials to establish a lever arm mechanism to establish vertical movement (,) and move dielectric vane (,). Actuator (,) uses a stack of piezoelectric materials to establish vertical movement (,) and move dielectric vane (,). Waveguide phase shifters (,) are used in phased array antenna (,) operating at microwave frequencies.

Stacked piezoelectric actuators to control waveguide phase shifters and method of manufacture thereof

An antenna system (,) capable of transmitting electromagnetic radiation using the technique of combining two quadrature signals for either right hand circular polarization or left hand circular polarization using a circularly polarized antenna (,), or alternately, either horizontal or vertical polarization using a linearly polarized antenna (,) while incorporating feedback for automatically correcting for amplitude and phase variations in the quadrature paths using a switch (,) which selects the sense of the polarization and electronic optimization of the transmit antenna (,). The antenna system includes a control circuit having a polarization switch (,) for receiving a transmission signal. The switch (,) generates first and second output signals which are substantially similar to the transmission signal, and determines whether to apply the transmission signal to one of a first or a second switch output. A coupler (,) receives the first and second switch outputs and generates first and second output signals having a predetermined phase difference. A variable detector (,) detects and adjusts a relative amplitude and phase of the respective first and second output signals. An error correction circuit (,) determines an adjustment to the variable phase detector to vary the phase and amplitude of the first and second output signals in accordance with the relative amplitude and phase of the respective first and second output signals.

Method for efficiently generating selectable antenna polarization

An array (100) of voltage variable capacitors (110) is provided in which voltage variable capacitors (110) are fabricated with piezoelectric displacement devices (150). Voltage variable capacitors (110) have first plates (120) which are coupled to displacement devices (150). First plates (120) are dielectrically coupled to second plates (130). Displacement device (150) has a stack of metallic layers (154), voltage variable material blocks (152), and voltage supply terminals (170) and (180). Voltage differences are established across voltage variable material blocks (152) using voltage supply terminals (170) and (180). A voltage difference causes a voltage variable material layer to change thickness, and this causes first plate (120) to move relative to second plate (130). Voltage variable material is selected from a group of piezoelectric ceramics, which can include lead-titanate (PbTiO.sub.3), lead-zirconate (PbZrO.sub.3), barium-titanate (BaTiO.sub.3), and lead-zirconate-titanate (PbZr.sub.x Ti.sub.1-x O.sub.3), where x varies from zero to one.

Voltage variable capacitor array and method of manufacture thereof

Antenna structure

Azimuth-elevation gimbal antenna

A phased array antenna (1000) is formed using a number of independently controllable piezoelectric phase shifters (1300) which results in a low cost phased array antenna that is functional at microwave and/or millimeter wave frequencies. In addition, the independently controllable piezoelectric phase shifters (1300) have sufficient phase range to allow a single antenna to be steered over a wide angle field of view. Piezoelectric phase shifters (1300) comprise at least one-voltage variable capacitor (1310, 1320, FIG. 2). Typically, the piezoelectric material used in the voltage variable capacitors is selected from a group consisting of lead-titanate (PbTiO.sub.3), lead-zirconate (PbZrO.sub.3), barium-titanate (BaTiO.sub.3), and lead-zirconate-titanate (PbZr.sub.x Ti.sub.1-x O.sub.3), where x varies from zero to one.

Phased array antenna using piezoelectric actuators in variable

A complimentary switched amplifier transceiver (10) is provided which offers performance advantages and reduces system complexity over conventional half-duplex transceivers by using complimentary switched amplifiers for eliminating switches. Power output to a channel transition (31) from a transmit amplifier (26) is not degraded by a switch insertion loss in a transmit mode. Receiver noise figure is not degraded due to the switch insertion loss from the channel transition (31) to a receive amplifier (27). Switch devices and their associated control lines are eliminated, reducing circuit complexity for complimentary switched amplifier circuits such as a combined amplifier switch (12) and a first bi-directional amplifier (22).

Complimentary switched amplifier transceiver system

A microwave monolithic integrated circuit (MMIC) RF-generated bias circuit and method includes an input for receiving an RF signal. A rectifier coupled to the input and to electrical ground produces a rectified RF signal in response. A voltage divider coupled to the rectifier and to the electrical ground receives the rectified RF signal and produces a DC voltage therefrom. An output is coupled to the voltage divider for applying the DC voltage to a MMIC field effect transistor (FET) for biasing. No separate bias battery is required, and efficiency is optimized because the generated bias voltage increases to the point where the amplifier voltage begins to decrease, which in turn reduces the generated bias voltage. The derived bias voltage may be used to control other circuits (e.g., other amplifiers, oscillators, mixers, etc.) which require detection of RF presence.

MMIC bias apparatus and method

A digital adjustable phase modulator and method includes a first circuit path and a second circuit path for a signal. A fixed bias voltage is coupled to the first circuit path and to the second circuit path which respectively include first and second active variable reactance components such as varactor diodes. The first circuit path and the second circuit path further include chip capacitors to provide a DC block for first and second MMIC single pole double throw switches, and transmission lines for the signal have a length of one-fourth of a wavelength of the signal to provide an RF short. A control voltage is coupled to the first and second varactor diodes such that the capacitances across the first and second varactor diodes changes, resulting in a phase difference between the signal traversing the first circuit path relative to the signal traversing the second circuit path.

Digital adjustable phase modulator and method

Microwave parallel coupled line filters with direct taps having improved rejection of undesired signals near the pass-band are disclosed. Improved rejection is achieved by controlling the transmission zeros created by the input and output direct taps. Performance is comparable to parallel coupled line filters having substantially more coupling sections. The method involves shifting the transmission zeros by changing the position of the direct taps along the resonator or changing the impedance of the open-circuited stub associated with each tap. Impedance transformers can be used to match back to the source and load impedances.

Coupled line filter with improved out-of-band rejection

An apparatus for providing electronically tunable biphase modulation including an input and a first switch having a first output, a second output and a first input coupled to the input. The first switch couples the first input to either the first output or to the second output in response to a modulating signal. The apparatus also includes a first signal path having a first phase shift and a second signal path having a second phase shift different than the first phase shift. The first signal path is coupled to the first output and the second signal path is coupled to the second output. The apparatus also includes a second switch having a first input coupled to the first signal path, a second input coupled to the second signal path and a terminal output.

MMIC tunable biphase modulator

A non-hermetic, three-dimensional, microwave semiconductor device carrier with integral waveguide couplers is disclosed. A molded plastic substrate having a suitable dielectric constant and varying thicknesses comprises plated conductors and locations for receiving GaAs MMIC's. MMIC's are mounted to a metal backplate and die bonded to the plated conductors. The waveguide couplers are integrally molded as part of the carrier substrate, and comprise plated through cylindrical members. Signals from a waveguide cavity are coupled to the MMIC's by inserting the waveguide couplers into a waveguide port. The carrier and integral waveguide coupler together with a plated molded cover forms a non-hermetic package providing pseudo-shielding cavities about the resident multiple semiconductor GaAs die. Transmission line impedance control is enhanced varying the substrate thickness on a per conductor basis. Frequency of operation exceeds 12 gigahertz.

Three-dimensional microwave circuit carrier and integral waveguide

Inductorless bias networks include a bias circuit having a bias return path which is coupled to and biases a variable impedance device in a relatively nonconductive state. Another bias circuit including a FET renders the variable impedance device relatively conductive in response to control signals so that one port is coupled to another port, for instance.

Broad band microwave biasing networks suitable for being provided in

Growing community of inventors

Phoenix, AZ, United States of America

Hugh Robert Malone