Murata Manufacturing Co., Ltd.

Yoshihiro Kurokawa

Yukio Sakamoto

Hidetoshi Yamamoto

A noise elimination scheme is disclosed which enables the prior established telephones or telephone exchange modules linked thereto to eliminate high-frequency noises as applied from outside portable radiotelephone transceiver units. A choke coil (15) is arranged on a circuit board (2) of a telephone main body (1) at a respective one of several nodes for connection with external communication lines (5). Another choke coil (15) is provided at each interconnection node between the circuit board (2) and signal transmission lines (6) of a telephone handset (10). Respective choke coils (15) have a specific stray capacitance of 0.3 pF or below to insure successful elimination of high frequency noises of at or above 800 MHz.

Growing community of inventors

Yokohama, Japan

Yoshihiro Kurokawa