VARIABLE BANDWIDTH HANDS FREE TELEPHONE USING SWITCHED CAPACITOR FILTERING

This invention is a technique for providing isolation between the two channels of a handsfree telephone subset without resorting to gain switching or gain variations in the transmission path. The invention involves separating the frequency spectrum into two portions and allowing the stronger signal to capture a major portion of that available spectrum. Switched capacitor filters are used to control the degree of frequency bandwidth allocated to each channel while the filters are clocked from a common source assuring no possibility of overlap in the frequency spectrum. The affect of varying the bandwidth is much less noticeable than varying the amplitude and, therefore, creates much less user irritation.