Kevin J Gamble

US Patent:

7939989, May 10, 2011

Filed:

Sep 22, 2009

Appl. No.:

12/564305

Inventors:

Marc Solal - Longwood FL, US
Julien Gratier - Newton MA, US
Robert Aigner - Ocoee FL, US
Kevin Gamble - Apopka FL, US

Assignee:

Triquint Semiconductor, Inc. - Orlando FL

International Classification:

H03H 9/25

US Classification:

310313B, 310313 C

Abstract:

An interdigital transducer includes an edge gap length between ends of electrodes and the opposing busbar increased sufficiently for reducing or even eliminating tunneling effects through the gap. As a result, a wave velocity of the acoustic wave within the longitudinally extending edge regions is less than the wave velocity within the transducer center region, and the wave velocity within the opposing gap regions is greater than a velocity in the transducer center region, thus an essentially flat propagation mode results within the aperture of the transducer. A SAW transducer or a SAW resonator on a high coupling substrate will thus guide the energy in the transducer region without a need for apodization. Higher equivalent coupling factors as well as lower losses are obtained.

US Patent:

8138858, Mar 20, 2012

Filed:

Oct 29, 2008

Appl. No.:

12/260703

Inventors:

Jayanti Jaganatha Rao - Jamestown NC, US
Aleh Loseu - Greensboro NC, US
Kevin J. Gamble - Huntsville AL, US

Assignee:

RF Micro Devices, Inc. - Greensboro NC

International Classification:

H03H 9/64

US Classification:

333195, 310313 D, 333193

Abstract:

The present invention relates to dual-mode SAW devices (DMSDs), which may allow for clean layouts of SAW device elements and provide low impedance with reduced insertion loss, and may increase broadband rejection by improving parasitic characteristics. In one embodiment of the present invention, a parallel set of DMSDs is cascaded with another parallel set of DMSDs. Internal connections between the four DMSDs may be electrically floating, which may further improve parasitic characteristics. With electrically floating internal connections, the parallel set of DMSDs may share a common grating structure, thereby reducing the size and complexity of a DMSD, which may further improve parasitic characteristics. The DMSDs may be used in radio frequency (RF) applications, such as SAW filters.

US Patent:

20120161577, Jun 28, 2012

Filed:

Mar 7, 2011

Appl. No.:

13/041653

Inventors:

Benjamin P. Abbott - Maitland FL, US
Robert Aigner - Ocoee FL, US
Alan S. Chen - Windermere FL, US
Kevin Gamble - Apopka FL, US
Julien Gratier - Watertown MA, US
Taeho Kook - Orlando FL, US
Marc Solal - Longwood FL, US
Kurt G. Steiner - Orlando FL, US

International Classification:

H03H 9/25
H02K 15/00
H01L 41/18

US Classification:

310313 C, 29596

Abstract:

An acoustic wave device operable as a piston mode wave guide includes electrodes forming an interdigital transducer on a surface of the piezoelectric substrate, wherein each of the plurality of electrodes is defined as having a transversely extending center region and transversely opposing edge regions for guiding an acoustic wave longitudinally through the transducer. A Silicon Oxide overcoat covers the transducer and a Silicon Nitride layer covers the Silicon Oxide overcoat within only the center and edge regions. The thickness of the Silicon Nitride layer is sufficient for providing a frequency modification to the acoustic wave within the center region and is optimized with a positioning of a Titanium strip within each of the opposing edge regions. The Titanium strip reduces the acoustic wave velocity within the edge regions with the velocity in the edge regions being less than the wave velocity within the transducer center region.