Spectrian Corporation

Other

Xemod, Inc.

Power System Management, Inc.

Brian L Baskin

Lance Todd Mucenieks

John Alan Eisenberg

David L Brubaker

Charles Stuart Robertson, Iii

Dieter Werner Statezni

David S Wisherd

Huong M Hang

Joseph M O'Reilly

The present invention encompasses a method of location comprising: using a plurality of signal receivers to receive one or more multiple frequency input signals, wherein said multiple frequency input signals are of unknown origin, and said signal receivers are of known physical location, finding a difference in time of the reception of the signals between each of the signal receivers, using the difference in time of reception to locate the origin of the signals, utilizing the signals locate a signal receiver of unknown location.

Method of location using signals of unknown origin

The present invention encompasses a high efficiency pulse width modulator comprising: a variable duty cycle oscillator for receiving an input signal and providing a low level switching signal; a source voltage differentiation dependant positive switching signal circuit for receiving the low level switching signal, a stable reference signal, a sample of a positive supply voltage signal, and an error signal and the providing a positive supply switching signal and a reference signal; a positive supply switching circuit for receiving the positive supply switching signal and providing an output signal to an inductive load; an output voltage dependant negative supply switching signal circuit for receiving the output signal and a negative supply voltage signal and providing a negative supply switching signal; a negative supply switching circuit for receiving the negative supply switching signal and providing clamping of the inductive load to the negative supply, an output sourced charge pump for receiving the output signal and the positive supply voltage signal and providing a high voltage power supply; an output comparison circuit for receiving a sample of the output signal and a reference signal from the positive supply switching circuit, comparing the output signal to the reference signal and turning off the positive supply switching circuit when the output signal is lower than the reference signal; and a timing circuit for receiving an error signal from the comparison circuit and providing a feedback signal to the error circuit.

Pulse width modulator

Linearity of an RF/microwave power amplifier is enhanced by an amplitude and phase distortion correction mechanism based upon signal envelope feedback, that operates directly on the RF signal passing through the power amplifier. A phase-amplitude controller responds to changes in gain and phase through the RF/microwave power amplifier signal path caused by changes in RF input power, DC power supply voltages, time, temperature and other variables, and controls the operation of a gain and phase adjustment circuit, so as to maintain constant gain and transmission phase through the RF/microwave power amplifier.

Polar envelope correction mechanism for enhancing linearity of RF/microwave power amplifier

The present invention encompasses an amplifier system comprising: an input signal port for providing an input signal; a modulating signal source for providing a modulating signal; a first feed forward loop coupled to the input signal port and the modulating signal source, the first feed forward loop modulating the input signal with the modulating signal, amplifying a first modulated input signal, outputting a first amplified modulated signal including distortion signals, and outputting a first difference signal; a first synchronous detection circuit coupled to the first feed forward loop and the modulating signal source, the first synchronous detection circuit outputting a first control signal in response to the first difference signal and the modulating signal, wherein the first control signal controls modulation of the input signal by the modulating signal such that the first difference signal consists of only distortion signals; a second feed forward loop coupled to the first feed forward loop, the second feed forward loop modulating the first difference signal, amplifying a second modulated input signal, and outputting a second amplified modulated signal; a second synchronous detection circuit coupled to the second feed forward loop and the modulating signal source, the second synchronous detection circuit outputting a second control signal in response to a second difference signal which represents a difference between the first amplified modulated signal and the second amplified modulated signal, wherein the second control signal controls modulation of the first difference signal in order to cancel the distortion signals in the first amplified modulated signal by the second amplified modulated signal; and an output signal port coupled to the first feed forward loop and the second feed forward loop, the output signal port outputting an output signal that is a function of the first amplified modulated signal and the second amplified modulated signal.

Closed loop feed forward system featuring carrier reutilization for

The apparatus and the method representing an improved power management system are disclosed. The apparatus incudes a feedback control system with a delay element. The delay element introduces the oscillation frequency outside the input frequency band into the feedback control system. Therefore, the apparatus emulates a very efficient pulse width modulator (PWM) with a feedback. The apparatus additionally includes a pulse shaper amplifier that squares the pulse of the output signal.

High efficiency pulse width modulator

A pre-post distortion amplifier is disclosed. The device comprises the four-cascade amplifier comprising two driver amplifiers and two power amplifiers. The pre-post distortion amplifier allows one to amplify at least two RF signals with almost full compensation of the distortion signal introduced by the propagation of input signals within the pre-post distortion amplifier. Each pair of driver-power amplifiers is scaled down in power output to achieve the optimum result.

Pre-post distortion amplifier

Polar envelope correction mechanism for enhancing linearity of

A first loop is provided to subtract a properly scaled and delayed sample of the amplifier's input spectrum from a scaled and phase shifted sample of its output spectrum which contains intermodulation distortion. The result of this subtraction (if the samples are maintained at the same amplitude and 180 degrees out of phase) is a signal rich in the intermodulation products of the amplifier. A feature of the invention is a differential phase-amplifier comparator which compares the signals prior to and after amplification and generates control signals for amplitude and phase trimmers for the signal prior to the amplifier and thus maintains the required equal amplitude and 180 degree phase relationship required for carrier cancellation. The signals before amplification and after amplification are subtracted leaving substantially the intermodulation products resulting from amplification. A second loop is provided to reduce intermodulation distortion when a plurality of signals are amplified, resulting in the intermodulation of the signals. The intermodulation products are then fed forward with suitable amplification by an error amplifier and phase shift to cancel the amplifier intermodulation products when added to the amplifier output.

Linear RF amplifier having reduced intermodulation distortion

A planar balun including first and second spaced parallel elongated conductors on one surface of a ceramic, plastic, polymer, synthetic fiber or a composite substrate and a third elongated conductor on a second surface of the substrate opposite from the first and second conductors. The spacing from an outer edge of each of the first and second conductors to an outer edge of the third conductor being greater than the thickness of the ceramic substrate, and the spacing between the two parallel elongated conductors being greater than ##EQU1## The substrate is mounted on a metallic support plate which provides a ground plane spaced from the third conductor by a distance t2 in an atmosphere comprising air with the distance t2 being greater than ##EQU2## An input of the balun is at one end of the first and second conductors and an output of the balun is at the other end of the first and second conductors. One end of the third elongated conductor on the second surface is grounded to force a balance at the two outputs.

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Cupertino, CA, United States of America

Brian L Baskin