Craig C Christensen

US Patent:

6711397, Mar 23, 2004

Filed:

Nov 20, 2000

Appl. No.:

09/716305

Inventors:

Andrei R. Petrov - Pocatello ID
Craig L. Christensen - Pocatello ID
Kenneth L. Reinhard - Pocatello ID

Assignee:

AMI Semiconductor, Inc. - Pocatello ID

International Classification:

H04B 126

US Classification:

455324, 455326, 455317, 455296, 375328, 375324

Abstract:

A direct conversion receiver is disclosed that converts RF signal into corresponding quadrature baseband signals without requiring conversion through an intermediate frequency. The direct conversion receiver abates local oscillator leakage, increases dynamic range and increases RF selectivity as compared to conventional direct conversion circuits. The circuit includes an in-phase branch and a quadrature-phase branch, each branch including two mixers instead of the conventional one. Each mixer is provided with balanced control signals that include a primary control signal and a complementary control signal. For each branch, the signals from the mixer pass through an operational amplifier and a low pass filter to extract the corresponding baseband signal component.

US Patent:

6744309, Jun 1, 2004

Filed:

Sep 30, 2002

Appl. No.:

10/262437

Inventors:

Andrei R. Petrov - Pocatello ID
Craig L. Christensen - Pocatello ID

Assignee:

AMI Semiconductor, Inc. - Pocatello ID

International Classification:

H03D 100

US Classification:

329347, 329358, 375320

Abstract:

Amplitude detection of a baseband electrical signal. The detection may be performed by performing full wave rectification on both an in-phase portion of the electrical signal, as on a quadrature-phase portion of the electrical signal. The output signal may be generated by summing the rectified in-phases signal and the rectified quadrature-phase signal. The peak amplitude of the output signal may then be used to determine the amplitude of the original baseband signal.

US Patent:

7006809, Feb 28, 2006

Filed:

May 6, 2003

Appl. No.:

10/430455

Inventors:

Andrei R. Petrov - Pocatello ID, US
Craig L. Christensen - Pocatello ID, US

Assignee:

AMI Semiconductor, Inc. - Pocatello ID

International Classification:

H04B 1/06

US Classification:

4552761, 4552772, 375347

Abstract:

A diversity receiver circuit that adaptively selects a variable number of one or more antennas for use in improving signal quality. Each antenna is provided its own receiver that each generates a representation of a received signal. This adaptive selection offers high dynamic adaptability in using the appropriate antennas and receivers at the appropriate time to thereby improving signal-to-noise ratio. The receivers may be direct conversion receivers that implement up-conversion of the baseband signal to reduce DC offset and 1/f noise characteristic of direct conversion architectures.

US Patent:

7197091, Mar 27, 2007

Filed:

May 6, 2003

Appl. No.:

10/430656

Inventors:

Andrei R. Petrov - Pocatello ID, US
Craig L. Christensen - Pocatello ID, US

Assignee:

AMI Semiconductor, Inc. - Pocatello ID

International Classification:

H03D 3/22
H04L 27/22

US Classification:

375332, 330332, 341118, 455130, 455131

Abstract:

A direct conversion circuit that includes an in-phase and quadrature-phase feedback path that reduces Direct Current (DC) offset. Each feedback path includes a compensating mixer that generates an error correction voltage that is passed through a loop gain circuit and an integrator. The integrated signal is applied to the output of a low pass filter that operates on the down-converted baseband signal. The direction conversion circuit may not only down convert the received modulated signal using a down-converting mixer into a baseband signal, but also, after performing a passive low pass filtering to remove higher-order components, performs up-conversion of the baseband signal using an up-converting mixer. This allows active elements operating on the up-converted signal to introduce less 1/f noise.

US Patent:

7375578, May 20, 2008

Filed:

Oct 29, 2004

Appl. No.:

10/977295

Inventors:

Shane B. Blanchard - Chubbuck ID, US
Craig L. Christensen - Pocatello ID, US

Assignee:

ON Semiconductor - Phoenix AZ

International Classification:

H03K 17/687

US Classification:

327427, 455 6711, 4551271, 327 58, 327 61, 327327, 327437

Abstract:

An RF envelope detection circuit that operations at low currents, high sensitivity, and high dynamic range. The circuit receives an AC signal at its input terminal and applies a signal on its output terminal that is a function of the envelope magnitude of the AC signal. To do so, a current source provides a current with an AC signal being superimposed thereon. A rectification circuit rectifies the AC component of this current. A voltage amplifier then amplifies the voltage for providing on the output terminal of the detection circuit. A current sink draws a current from the output terminal that has approximately the same magnitude as the current provided by the current source. A capacitor is coupled to the output terminal of the rectifier so as to store excess charge provided by the rectifier that is in excess of the magnitude of the current provided by the current source.

US Patent:

8248316, Aug 21, 2012

Filed:

Jan 31, 2008

Appl. No.:

12/023187

Inventors:

Craig L. Christensen - Pocatello ID, US

Assignee:

Semiconductor Components Industries, LLC - Phoenix AZ

International Classification:

H01Q 1/12

US Classification:

343718, 381323

Abstract:

Method and System for wireless communications is provided. The system includes an RF module, and a coupler. The coupler is coupled with the RF module. The coupler includes a member for conductive coupling with the user's body such that RF energy is coupled into and/or out of the user's body.

US Patent:

20100020994, Jan 28, 2010

Filed:

Oct 28, 2004

Appl. No.:

10/975914

Inventors:

Craig L. Christensen - Pocatello ID, US
Andrei R. Petrov - Pocatello ID, US

International Classification:

H04R 25/00

US Classification:

381315

Abstract:

A hearing aid that includes an antenna attached to the retrieval component. Since the retrieval component extends outside of the ear canal when the main body of the hearing aid is placed within the ear canal, the attached antenna also extends outside of the ear canal. Thus, much of any received wireless signals are not shield by the ear canal, but are received directly by the antenna. Furthermore, the antenna may transmit wireless signals externally to the ear, rather than having the signals be blocked by the ear canal. This enables more reliable wireless communication with the main body of the ear canal.

US Patent:

61632082, Dec 19, 2000

Filed:

Dec 15, 1998

Appl. No.:

9/211550

Inventors:

Craig L. Christensen - Pocatello ID
Kenneth L. Reinhard - Pocatello ID
Andrei Rudolfovich Petrov - Pocatello ID

Assignee:

Ga-Tek Inc. - Eastlake OH

International Classification:

H03D 318
H03D 300

US Classification:

329304

Abstract:

A phase shift keyed carrier recovery and demodulator circuit which includes a phase detector and subsequent feedback control loop circuitry which maintains an initial phase relationship. By comparing an incoming phase modulated carrier with the multiple phase outputs of a local oscillator, the circuit is able to generate a correcting signal which allows coherent phase tracking of the incoming phase modulated carrier. The phase detector produces a correction signal which allows the circuit to phase lock any two sequential phases of the locally generated phase outputs to phase positions on either side of the phase of the incoming phase modulated carrier. Once the circuit has obtained carrier phase lock, the multiple phases produced by the local oscillator will remain fixed (without phase change) relative to the initial detected phase of the incoming phase modulated carrier. Since the local oscillator is fixed (locked) to the phase of the incoming phase modulated carrier, demodulation can be accomplished simply by clocking one or more flip flops with respective phases of the local oscillator.