Title:
ANALOG FRONT END CIRCUIT
Document Type and Number:
Japanese Patent JPH03283838
Kind Code:
A
Abstract:
PURPOSE: To reduce the circuit scale and to simplify the circuit constitution by providing a switch circuit which cascades a high group low-pass filter and a low group high-pass filter.
CONSTITUTION: An analog.front.end circuit 21 is built in a MODEM used for personal computer communication or the like. In this analog.front.end circuit 21, low group band-pass filters and high group band-pass filters 27 constitute a filter for full duplex communication, and a switch circuit 28 is provided, and a high group LPF 27a and a low group HPF 26b constitute a filter for half duplex communication. Thus, the analog.front.end circuit 21 requires only two systems of band-pass filters though three systems of band-pass filters are normally prepared.
Inventors:
OTAKE HISAO
OKAMOTO SEIJI
FUJII TERUJI
OKAMOTO SEIJI
FUJII TERUJI
Application Number:
JP8316390A
Publication Date:
December 13, 1991
Filing Date:
March 30, 1990
Export Citation:
Assignee:
OKI ELECTRIC IND CO LTD
International Classes:
H04L5/14; H03H7/46; (IPC1-7): H03H7/46; H04L5/14
Attorney, Agent or Firm:
Kakimoto Yasunari