Hitachi, Ltd.

Hitachi Video and Information System, Inc.

Tomomi Matsumoto

Mitsutaka Hikita

Nobuhiko Shibagaki

Toshio Nagashima

Toyoji Tabuchi

Hiroshi Hatashita

Satoshi Wakamori

Takatoshi Akagi

Kiyoshi Amemiya

Yukitomi Kanai

In a high frequency circuit device, inductive circuit elements constituting a matching circuit are constructed of so-called helical coils having fine metal wires wound in a hollow solenoid form, which are disposed inside a package in which a high frequency circuit element such as a surface acoustic wave element or the like is mounted. The high frequency circuit device may be utilized in equipment such as wireless communication equipment for reducing the size as well as providing good high frequency characteristics.

High frequency circuit device

A receiver apparatus having a mixer circuit, an oscillator circuit and a tuner circuit is provided with a trap circuit, interposed between the tuner circuit and the mixer circuit, for removing disturbing mutual modulation waves generated by receiving two or more RF signals. Further, the mixer circuit employs a double balanced mixer structure to offset two or more disturbing mutual modulation waves.

Receiver apparatus

A television tuner comprises a VHF tuner section and a UHF tuner section and is configured in the two tuned modes of VHF high band and VHF low band between which the input tuning circuit of the VHF tuner section is switched by a diode in response to a source voltage. The television tuner further comprises a bias circuit for biasing said band-switching diode in reverse or forward direction by use of the UHF band source voltage during the receipt of UHF band.

Television tuner circuit

Growing community of inventors

Hiratsuka, Japan

Tomomi Matsumoto