Pioneer Electronic Corporation

Hideki Iwasaki

Toshihito Ichikawa

Tomohisa Yokogawa

Masanori Kurosaki

Nobuo Kanda

Tomohisa Yokokawa

A superheterodyne receiver in which unwanted lowering of the RF gain due to the presence of an interference signal outside the band of the desired signal is substantially eliminated. Levels of the outputs of both the RF amplifier and first mixer of the circuit are detected. The two level detection signals so produced are summed, and the sum signal applied to the gain control input terminal of the RF amplifier.

Superheterodyne receiver

A multi-bit program identification signal is transmitted in the audible band with a program signal, and a receiver detecting the program identification signal automatically sets a predetermined minimum volume for reproduction of the program information. The volume control circuitry at the receiver can be made responsive to any one of a plurality of different program identification signals.

Program identifier signal receiver

An antenna switching circuit which selectively transmits, to a receiver, RF signals from a plurality of antennas including RF signals of different frequency bands such as the VHF band and the MF band using a single output terminal. To prevent a level drop of RF signals of one of the frequency bands due to a common use of the output terminal, a unidirectional switching element is added to a switching circuit network by which the selection of RF signals from the different antennas is performed. A branching circuit for separating RF signals of different frequency bands is provided with an attenuation operation using a variable impedance characteristic of a semiconductor switching element which is basically on-off operated for the switching between the RF signals of the different frequency bands.

Growing community of inventors

Saitama, Japan

Hideki Iwasaki