Browse Prior Art Database

GSM Noise Reducer

IP.com Disclosure Number: IPCOM000009832D
Original Publication Date: 2002-Sep-20
Included in the Prior Art Database: 2002-Sep-20
Document File: 5 page(s) / 438K

Publishing Venue

Motorola

Related People

Authors:
Chason Carroll

Abstract

In today's world, mobile accessories are becoming much more complex. A recent problem that has plagued many audio accessories is that of GSM noise or "buzz." The buzz consists of a transmission signal of 217 Hz with a duty cycle of 12.5%. This frequency causes audible noise in the voice band (300 -3k Hz). This invention addresses two problems that effect the audio signal originating in a cell phone and progressing to an accessory: ground shifting and RF GSM buzz. These problems originate from the method the phone extracts power from its power source, i.e. battery, power supply, accessory. The phone draws current from the power source in order to transmit and receive audio. This current produces spikes (at 217Hz) that are converted into noise by the audio accessory. The objective of this invention is to rid the system of the noise spikes so that they are not heard by the end user.