Patent ID: 6167121
Filing Date: 2000-12-26
Classification: H04L,H04M

Abstract:
A modem apparatus which performs modulation and demodulation between a telephone circuit and a terminal apparatus, comprising:a modem circuit;a codec circuit performing conversion between an analog signal and a digital signal;plural capacitors provided between said modem circuit and said codec circuit;a first converter converting a first digital signal supplied from one of said terminal apparatus and said telephone circuit after being converted from an analog signal, using a second digital signal, into a third digital signal, the frequency of the second digital signal being higher than the frequency of the first digital signal and the frequency of the third digital signal being equal to or higher than the frequency of the second digital signal;a second converter reproducing the first digital signal from the third digital signal using the second digital signal; anda digital signal supplied from said terminal apparatus and a digital signal supplied from said codec circuit being supplied to said modem circuit, and an analog signal supplied from said telephone circuit and a digital signal supplied from said modem circuit being supplied to said codec circuit, one of said capacitors is provided between said first and second converters.