Tracy A Martin

US Patent:

7171171, Jan 30, 2007

Filed:

Jun 21, 2004

Appl. No.:

10/872660

Inventors:

Timothy K. Coffman - Chandler AZ, US
Tracy S. Martin - Phoenix AZ, US
Michael S. LaBelle - Phoenix AZ, US

Assignee:

RF Micro Devices, Inc. - Greensboro NC

International Classification:

H04B 1/04
H03G 3/20

US Classification:

455126, 4551271, 4551151, 455 91, 330140, 330129

Abstract:

A mobile terminal senses transmitted power in a Gallium Arsenide (GaAs) circuit. The GaAs circuit provides a steady reference voltage through the use of an operational amplifier and feedback circuit. The operational amplifier drives the bases of two transistors to create balanced signals that are then used by a detection circuit.

US Patent:

8130054, Mar 6, 2012

Filed:

Oct 14, 2009

Appl. No.:

12/578924

Inventors:

Tracy Scott Martin - Phoenix AZ, US
Ruediger Bauder - Feldkirchen-Westerham, DE
Erin Spivey - Chandler AZ, US

Assignee:

RF Micro Devices, Inc. - Greensboro NC

International Classification:

H01P 1/36
H01P 5/04

US Classification:

333 24R, 333 242, 333 11

Abstract:

The present invention relates to a frequency-adjustable radio frequency (RF) isolator that may operate as a bandpass filter when processing RF signals in a forward direction and may operate as a notch filter when processing RF signals in a reverse direction. The notch filter has a notch frequency, which is adjustable to provide adequate isolation from reflected signals at a specific operating frequency. The frequency-adjustable RF isolator may include an electro-magnetic gyrator coupled to a variable impedance circuit, which may present a variable impedance to the electro-magnetic gyrator. The notch frequency may be dependent on the variable impedance. The notch filter may be a single-notch filter or may be a multiple-notch filter.