Motorola Corporation

William J Turney

Paul H Gailus

Lawrence F Cygan

Francis R Yester, Jr

Michael H Baker

Steven C Jasper

William J Martin

Terry K Mansfield

Edward T Clark

Nicholas Evangelos Buris

Joshua E Dorevitch

Gregory Hubert Piesinger

Mark A Gannon

Ronald H Chapman

Richard Stanley Rachwalski

Ross J Lillie

Umesh D Navsariwala

Robert V Janc

Edward C Porrett

Lester A Longley

Katherine L Zebrose

A passive repeater includes: a connecting transmission circuit having first and second opposing ends and made of a flexible material for substantially conforming to a portion of a structure, the structure having first and second opposing sides; first and second antenna elements respectively coupled to the first and second opposing ends of the connecting transmission element; and first and second affixing elements respectively coupled to the first and second antenna elements for attaching the first and second antenna elements to the first and second opposing sides of the structure, wherein the first and second antenna elements are operable to transfer a signal from the first opposing side of the structure to the second opposing side of the structure via the connecting transmission circuit.

Passive repeater for radio frequency communications

A material properties detection system (). The system can include an antenna () that is tuned for operation within a frequency band over which the antenna transmits. The system also can include a transmitter () that generates electromagnetic energy across the frequency band and forwards the electromagnetic energy to the antenna. An impedance measurement circuit () can be provided. The impedance measurement circuit can measure an input impedance of the antenna over the frequency band and generate measured impedance data (). The system can include a material characterization application () that processes the measured impedance data to generate a material characterization for a structure () to which the antenna is proximate. The material characterization can include a dielectric constant, a permittivity, a loss tangent and/or a permeability.

Portable system for rapid characterization of electrical properties of a material

A wireless communication unit provides () a first signal as received from a first portion () of a single antenna and provides () a second signal as received from a second portion of the antenna, which in a preferred embodiment can comprise a feedline (). The two signals contain information that is cross-coupled with respect to one another as a function, at least in part, of the structure of the antenna. A digital processing platform () de-couples () these signals to permit recovery of the original payloads. In one embodiment similar approaches are used to facilitate cross-coupling of signals and transmission of such cross-coupled signals from different portions of a single antenna structure. In another embodiment, both transmission and reception are facilitated by a common platform.

Antenna method and apparatus

A linear transmitter includes an amplifier feedback loop for amplifying an input signal at a power amplifier. The feedback loop is operated in an open loop mode when the power amplifier is operating at a first operating point and is operated in a closed loop mode when the power amplifier is operating at a second operating point. The transmitter further includes an auxiliary loop coupled to the amplifier feedback loop that provides phase training for the feedback loop and power leveling when the feedback loop is operating open loop. Open loop phase training and power leveling is done during open loop transmission, without an associated training signal or training period. Stable closed loop operation can commence subsequently providing the higher power amplifier efficiency associated with the second operating point and maintaining off channel interference requirements.

Dual open and closed loop linear transmitter

A method and apparatus is provided that amplitude modulates a modulated radio frequency (RF) signal ( ) by modulating the supply voltage of a power amplifier ( ). The method and apparatus further provides an impedance modulator ( ) that reduces output signal ( ) errors in response to an error signal generated by a feedback circuit ( ) that includes a quadrature modulator ( ), a limiter ( ), a comparator ( ), and a quadrature downconverter ( ). Intermodulation distortion generated in the feedback circuit ( ) by delay mismatches between amplitude and phase feedback paths, and non-linear effects of AM/PM conversion in a limiter ( ), are suppressed by placing limiter ( ) and quadrature downconverter ( ) in a forward path of the overall amplifier loop.

Method and apparatus for linear amplification of a radio frequency signal

An integrated sigma-delta radio frequency (RF) receiver subsystem ( ) and method utilizes a multi-mode sigma-delta analog-to-digital converter ( ) for providing a single and multi-bit output. A programmable decimation network ( ) for reducing the frequency of the in-phase and quadrature bit stream and a programmable formatting network ( ) are also used for organizing the in-phase and quadrature components from the decimation network ( ) for subsequent signal processing. The invention offers a highly integrated digital/analog RF receiver back-end which incorporates integrated filtering and a smart gain control that is compatible for use with other receiver systems and offering superior performance characteristics.

Integrated multi-mode bandpass sigma-delta receiver subsystem with interference mitigation and method of using same

The present invention addresses the need for an apparatus and method for controlling the load of a PA, to improve PA efficiency in linear transmitters with isolator elimination (IE) circuitry, that does not require the use of high frequency RF circuitry. The present invention provides a PA load controller (,) that improves the efficiency of a PA (,) by adjusting the PA load using an AGC signal (,), a level set adjustment signal (,), and a signal strength indicator (,), these three signals are readily obtained from continuous gain and phase adjustment circuitry (e.g.,,). The load controller determines a phase of the PA load that minimizes the AGC signal and a phase of the PA load that maximizes the level set adjustment signal. From these determinations, the PA load controller determines a phase of the PA load that improves the efficiency of the PA and adjusts the PA load phase accordingly.

Power amplifier load controller and method for controlling a power amplifier load

An integrated multi-mode bandpass sigma-delta radio frequency receiver subsystem with interference mitigation includes a first intermediate frequency amplifier. At least one mixer for mixing the output of the first amplifier and an oscillator signal. A second IF amplifier for amplifying and filtering the output of the at least one mixer. A multi mode multi bandwidth sigma delta analog digital converter for providing digital output signals with high dynamic range. A digital mixer providing I and Q signals a decimation network providing I and Q signals at reduced programmable data and clock frequencies and a formatting network for arranging the I and Q signals into a predetermined format for use with a digital signal processor.

Integrated multi-mode bandpass sigma-delta receiver subsystem with

An amplifier structure (200) includes a main amplifier loop (203) for efficiently amplifying an input signal at a power amplifier (228) coupled to a load susceptible to impedance variations. The amplifier structure (200) includes a DC correction circuit (214) for detecting and correcting misadjustments in the amplifier (200) in order to eliminate DC offset associated therewith.

Digital DC correction circuit for a linear transmitter

An amplifier structure (200) includes a main amplifier loop (203) for efficiently amplifying an input signal at a power amplifier (228) coupled to a load susceptible to impedance variations. The amplifier loop (200) further includes an auxiliary loop (201) coupled to the main loop (201) for simultaneously preventing the power amplifier (228) from operating inefficiently or causing off-channel interference.

Method and apparatus for an improved linear transmitter

A zero-IF transmitter (200) has a DC offset, representative of a carrier feedthrough signal. A value to correct the DC offset is successively approximated (207). A summer (201) adds the value to a desired input to reduce the DC offset.

DC offset reduction in a zero-if transmitter

A linear transmitter (100), which utilizes closed loop feedback to maintain its linearity, employs a method for reducing off-channel interference produced by the linear transmitter (100). A dynamically alterable parameter source (DAPS, 126) is provided to the linear transmitter (100). The DAPS (126) is then used to adjust at least one loop parameter of the closed loop feedback such that off-channel interference is reduced.

Method and apparatus for reducing off-channel interference produced by a

A method and apparatus is provided for a transmitter (200) with a stable, linear response. The transmitter (200) includes an amplification stage (242), and a negative feedback correction loop (244) with a feedback signal (252). A reference signal (251) is combined with the feedback signal (252) to produce an error signal (253) for coupling to the amplification stage (242). Transmitter parameters are varied when a difference between the reference signal (251) and the error signal (253) exceeds a particular threshold.

Method and apparatus for a linear transmitter

In a radio transmitter (100) that includes a power amplifier (104) and an antenna (106), a method for enhancing an operating characteristic of the radio transmitter (100) can be accomplished in the following manner. The power amplifier (104) provides a signal (113) to a variable matching network (111), wherein the signal (113) comprises energy to be radiated by the antenna (106). The variable matching network (111) couples the signal (113) to a sampler (112) that is operably coupled to an output of the variable matching network (111 ) and the antenna (106). The sampler (112) samples a forward component (114) and a reflected component (115) of the signal (113). The radio transmitter (100) processes the sampled forward and reflected components (116, 118) to produce a feedback control signal (120). The feedback control signal (120) is used to adjust the variable matching network (111 ), such that an operating characteristic of the radio transmitter (100) is enhanced.

Method and apparatus for enhancing an operating characteristic of a

A transmitter that includes an amplifying element, an antenna, a gain stage, and a closed loop feedback may compensate for varying antenna loads without an isolator. This may be accomplished by determining the effects of the varying loading on overall loop gain. Knowing the effects, the transmitter adjusts the gain of the gain stage to maintain a constant overall loop gain, thus eliminating the need for an isolator.

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Schaumburg, IL, United States of America

William J Turney