Harris Corporation

Other

Imagine Communications Corp.

Timothy Wilfred Dittmer

George Cabrera

Dmitriy Borodulin

Zhiqun Hu

Gavin Martin Monson

Wayne Douglas Duello

Paul Thomas Moore

Peter John Poggi

Bryce A Robertson

Ralph L Mortimore

Wayne Douglas-Duello

Dale J Doyle

Systems and methods are provided for providing a hybrid signal having a reduced crest factor. A digital signal is generated that assumes one of a plurality of vector states at discrete sampling times, with each of the plurality of vector states having an associated phase. An analog signal is monitored to determine when a phase of the analog signal is aligned with the phase of a vector state assumed by the digital signal. A crest factor reduction is applied to the digital signal if the digital signal assumes a vector state having an associated phase aligned with the phase of the analog signal to provide a compressed digital signal. The compressed digital signal and the analog signal are combined to provide the hybrid signal. The analog signal is not altered prior to being combined with the compressed digital signal.

Composite crest factor reduction

Systems and methods are provided for generating dual outputs in a digital exciter system. A first signal path produces one of a frequency modulated audio signal, a digital information signal, and a signal comprising both frequency modulated audio and digital information. A second signal path produces one of a frequency modulated audio signal, a digital information signal, and a signal comprising both frequency modulated audio and digital information. A main exciter output provides one of the signal produced at the first signal path and the signal produced at the second signal path to an associated first signal destination. An auxiliary exciter output provides one of the signal produced at the first signal path and the signal produced at the auxiliary signal path to an associated second signal destination.

Dual output digital exciter

Systems and methods are provided for amplifying a composite input signal, comprising a drive signal and an envelope signal, at a power amplifier. A secondary modulation, representing a portion of the composite input signal falling outside of a frequency band associated with the envelope signal, is produced for the drive signal. The secondary modulation is applied to the drive signal. The drive signal is amplified at the power amplifier to produce an amplified signal. At least a portion of the envelope signal is employed to drive a supply terminal of the power amplifier.

Enhanced bandwidth envelope elimination and restoration

Systems and methods are provided for efficient amplification of a signal utilizing a modified Doherty amplifier system. A modified Doherty amplifier system includes a nonlinear main amplifier and a nonlinear auxiliary amplifier. An impedance-inverting network separates the main amplifier from an associated load. A second quarter wave transmission line separates the auxiliary amplifier from an associated signal source. The signal source has an associated minimum signal power, such that the signal power never drops below a predetermined percentage of a peak signal power.

Modified doherty amplifier

An RF wideband amplifier system is provided that includes an M way splitter for receiving an RF input signal and splitting same into M RF signals for respective application to M power amplifier modules PAM- to PAM-M that amplify the M signals and apply the amplified M signals to an M way combiner that applies an amplified RF signal to a load. A main controller provides an automatic level control reference signal, representative of the desired output power level of each of the power amplifier modules. Each power amplifier module includes an 2*N way balanced splitter that receives one of the M RF signals and splits the signal into 2*N signal portions; 2*N RF amplifiers that respectively receive the 2*N signal portions and amplify same and provide therefrom 2*N amplified signal portions; an 2*N way RF combiner that receives and combines the amplified RF signal portions and provides therefrom a combined amplified output RF signal; a power detector that provides a power signal representative of the level of the output power of the power amplifier module; a difference circuit that provides an attenuation control signal having a value in accordance with the difference in values of the power signal and the reference signal; and, a variable adjuster that adjusts the magnitude of the one of the M RF signals in accordance with the difference.

Broadband amplifier system having improved linearity and minimum loss

A directional coupler comprises a coupler circuit board which is mounted substantially perpendicular to the surface of a parent circuit board. First and second upper traces are disposed on the opposing surfaces of the coupler circuit board. The coupling between the upper electrically conductive traces determines the odd mode impedance of the coupler. First and second lower traces are also disposed on opposing surfaces and connected to ground. The upper and lower traces are arranged such that the even mode of the impedance is determined by the coupling between the first upper trace and the second lower trace and the coupling between the second upper trace and the first lower trace.

Surface mounted broadside directional coupler

A power amplifier system is presented for use in amplifying an RF input signal comprising N sub-power amplifiers are connected together in parallel with each receiving and amplifying a portion of the RF input signal. A combiner combines the amplified portions of the RF input signal to provide a combined output signal. Each sub-amplifier includes at least one transistor having an input port that receives a DC bias voltage and an output port, such that when the RF input signal is not present a quiescent current flows through the output port. A controller is operative when the RF signal is not present to check and adjust the magnitude of the quiescent current flowing in each of the sub-amplifier output ports in the sequence of 1 . . . N.

RF power amplifier transistor quiescent current checking and adjusting

A power amplifier system is presented for amplifying an RF input signal. The system includes a vector modulator for receiving and modifying an input signal and providing therefrom a modified signal. The system also includes at least one power amplifier the operation of which is monitored and the vector modulator is controlled in accordance with the monitoring.

Power amplifier having monitoring and circuit protection

An air-dielectric stripline is provided which includes top, intermediate and bottom planar dielectric layers spaced from each other in parallel planes with each layer having upper and lower oppositely directed faces. First and second electrically conductive planar ground planes are respectively attached to the lower surface of the top dielectric layer and the upper surface of the bottom dielectric layer. First and second planar dielectric spacer layers are respectively located between the top and intermediate dielectric layers and the intermediate and bottom dielectric layers for maintaining a given spacing therebetween. Each spacer layer has a channel formed therein to thereby define upper and lower air chambers on opposing faces of the intermediate layer. A conductive inner trace is attached to at least one face of the intermediate layer within one of the chambers and is spaced from an associated ground plane by the thickness of a spacer dielectric layer.

Air-dielectric stripline

An AC power amplifier is disclosed for amplifying an AC input signal while limiting the current drawn by the amplifier. The amplifier includes at least one transistor having an input circuit for receiving an AC input signal as well as a DC bias voltage and an output circuit connected to the DC voltage source for drawing current therefrom during conductive periods of the transistor. The transistor exhibits the characteristic of being nonconductive when the AC input signal together with the DC bias voltage are less positive than a DC threshold voltage level and is conductive when the AC input signal and the DC bias voltage are together more positive than the DC threshold voltage level whereupon DC current is drawn by the output circuit from the DC voltage source. The DC current is sensed and a sense signal is provided having a magnitude in accordance therewith. The sense signal is compared with a reference current level and a control signal is provided having a value which varies as a function of the comparison. The control signal is decreased in magnitude when the sense current exceeds the reference current level. The DC bias voltage is then decreased to thereby decrease the conductivity of the transistor and thereby limit the magnitude of the DC current to that of the reference current level.

AC power amplifier having current limit control

A polyphase divider/combiner is provided and which includes a common input/output port and a plurality of N output/input ports, wherein N is an even integer greater than two. N electrical signal transmission paths are provided with each extending from the common input/output port to a respective one of the N output/input ports. The N electrical signal transmission paths are of N different electrical lengths such that the output/input ports are out of phase relative to each other by 180/N degrees.

Growing community of inventors

Mason, OH, United States of America

Timothy Wilfred Dittmer