James S Proctor

US Patent:

58983384, Apr 27, 1999

Filed:

Sep 20, 1996

Appl. No.:

8/717500

Inventors:

James A. Proctor - Los Gatos CA
Lance Todd Mucenieks - Boulder Creek CA

Assignee:

Spectrian - Sunnyvale CA

International Classification:

H03F 126

US Classification:

330149

Abstract:

A digitally implemented, look-up table-based, predistortion and feed-forward correction signal processing mechanism compensates for distortion generated in the RF power amplifier. The input signal to the RF amplifier is stored for comparison with the measured the RF output. In each of predistortion and feed-forward signal processing paths, the magnitude of the complex waveform of the input signal is extracted to derive a read-out address to a dual-port RAM which stores weights to be multiplied by the input signal. In the predistortion signal processing path, the product is coupled to the RF power amplifier. In the feed-forward correction loop, the product is amplified by an auxiliary feed-forward RF amplifier and coupled into the amplified output signal path of the RF power amplifier.

US Patent:

59492830, Sep 7, 1999

Filed:

Jun 29, 1998

Appl. No.:

9/106167

Inventors:

James A. Proctor - Los Gatos CA
Lance Todd Mucenieks - Boulder Creek CA

Assignee:

Spectrian - Sunnyvale CA

International Classification:

H03F 126

US Classification:

330149

Abstract:

A digitally implemented, look-up table-based, predistortion and feed-forward correction signal processing mechanism compensates for distortion generated in the RF power amplifier. The input signal to the RF amplifier is stored for comparison with the measured the RF output. In each of predistortion and feed-forward signal processing paths, the magnitude of the complex waveform of the input signal is extracted to derive a read-out address to a dual-port RAM which stores weights to be multiplied by the input signal. In the predistortion signal processing path, the product is coupled to the RF power amplifier. In the feed-forward correction loop, the product is amplified by an auxiliary feed-forward RF amplifier and coupled into the amplified output signal path of the RF power amplifier.

US Patent:

59297042, Jul 27, 1999

Filed:

Feb 20, 1998

Appl. No.:

9/026925

Inventors:

James Arthur Proctor - Los Gatos CA
Lance Todd Mucenieks - Boulder Creek CA

Assignee:

Spectrian - Sunnyvale CA

International Classification:

H03F 126

US Classification:

330149

Abstract:

An RF power amplifier has an RF input port to which an RF input signal is coupled, an RF output port from which an amplified RF output signal is derived. An RF carrier cancellation combiner has a first input coupled to the RF input port and a second input coupled to the RF output port. The carrier cancellation combiner produces an RF error signal representative of RF distortion of a signal flow path through the RF amplifier between the RF input port and the RF output port. To reduce a residual carrier signal in the RF error signal, a wideband autocalibrating correlator correlates a reference signal, representative of the RF input signal, with the RF error signal, producing a control signal, which is coupled to a vector modulator to modify the signal flow path through the RF amplifier. A digital signal processor within the correlator measures DC distortion associated with the multiplier components of the correlator and controllably removes DC distortion from the control signal, so that modification of the signal flow path through the RF amplifier by the vector modulator is controlled with a higher precision, providing maximal carrier cancellation.

US Patent:

59600470, Sep 28, 1999

Filed:

Nov 12, 1997

Appl. No.:

8/968214

Inventors:

James Arthur Proctor - Los Gatos CA
James Carl Otto - Melbourne FL

Assignee:

Harris Corporation - Melbourne FL

International Classification:

H04B 710
H04L 102

US Classification:

375347

Abstract:

A system and method for transmitting information in which a relatively narrowband signal is transmitted followed by the transmission of a relatively wideband signal. The narrowband signal may be used by the receiver to alert the receiver to the upcoming wideband signal. In a system in which the transmissions occur asynchronously to the receiver, the receiver may be less complicated because the receiver is provided with an indication of the time and/or the center frequency of the wideband signal. Either the narrowband signal or the wideband signal may be used to transmit information from the transmitting device to the receiver. The system and method find particular advantage in tracking and locating systems in which a plurality of tags asynchronously transmit information and/or location information to a receiver or a set of receivers.

US Patent:

60782161, Jun 20, 2000

Filed:

Mar 31, 1998

Appl. No.:

9/053529

Inventors:

James Arthur Proctor - Los Gatos CA

Assignee:

Spectrian Corporation - Sunnyvale CA

International Classification:

H03F 132

US Classification:

330151

Abstract:

A digital signal processor-resident RF power amplifier performance monitor generates and updates signals for controlling each of an adaptive predistortion unit and a vector modulator of a preamplification signal processing loop, and a vector modulator of a feed-forward error extraction and reinjection loop. A performance monitoring routine subjects monitored aliased data to a window function and determines the spectrum of the data. The spectral data is applied to a sensitivity mask, which masks the data in accordance with a carrier--intermodulation distortion function associated with the operation of the amplifier. The output of the mask is processed to derive a measure of intermodulation distortion power. The intermodulation distortion power is subjected to an error minimization operator, such as a perturbational gradient search, that adjusts each of the control signals for the components of the loops, in such a manner as to maximally cancel intermodulation distortion products.