William F Fabry

US Patent:

7130434, Oct 31, 2006

Filed:

Mar 26, 2003

Appl. No.:

10/400741

Inventors:

Alan W. Grattan - Santa Cruz CA, US
William F. Fabry - Felton CA, US

Assignee:

Plantronics, Inc. - Santa Cruz CA

International Classification:

H04R 3/00
H04R 31/00
H05K 1/14

US Classification:

381113, 381111, 381114, 381112, 381 941, 361794, 361793, 29594

Abstract:

The present invention provides a solution to the needs described above through a microphone PCB with an integrated filter. The invention provides for an electret microphone assembly. The microphone assembly includes a multilayer printed circuit board. A field effect transistor with a gate is coupled to the electret microphone. The field effect transistor drain is coupled to provide audio frequency output to an audio output node, and the field effect transistor source is coupled to a ground. A first end of a resistor is coupled to the drain of the field effect transistor and the second end is coupled to a filter. The filter attenuates unwanted electromagnetic interference associated with a radio frequency transmitter. The filter includes a filter capacitor made of a ground layer coupled to ground within the multilayer printed circuit board, an active layer within the multilayer printed circuit board coupled to the second end of the resistor, and a dielectric layer disposed between the ground layer and the active layer. The filter further includes a first and second inductor comprising vias coupled to the active layer within the printed circuit board.

US Patent:

39783286, Aug 31, 1976

Filed:

Apr 7, 1975

Appl. No.:

5/565807

Inventors:

William F. Fabry - Sunnyvale CA
Dennis C. Hersley - Cupertino CA

Assignee:

National Semiconductor Corporation - Santa Clara CA

International Classification:

G06F 738

US Classification:

235156

Abstract:

A pocket calculator includes a main frame which consists of a keyboard, a display and display drivers mounted on a printed circuit board, a case, and a connector for receiving one of a plurality of arithmetic or processor modules. Each processor module includes an arithmetic chip mounted in a package which is, in turn, mounted on a printed circuit board having an edge connector. The case of the calculator has an aperture for receiving each one of the modules. The connector on the printed circuit board of the main frame is mounted in registry with the aperture and is disposed for receiving the module, such that any one of the number of processor modules may be employed with the same calculator main frame.