The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 08, 1981
Filed:
Nov. 27, 1979
Satoru Fujishima, Muko, JP;
Fumio Nakayama, Kyoto, JP;
Murata Manufacturing Co., Ltd., Kyoto, JP;
Abstract
A television tuner comprises a high frequency amplifier for receiving a high frequency signal received by an antenna, a local oscillator, and a mixer for mixing the high frequency signal from the high frequency amplifier and the oscillation frequency signal from the local oscillator for providing an intermediate frequency signal. The high frequency amplifier comprises a high frequency amplifying transistor, and a group of acoustic surface wave filter elements each exhibiting a high band pass characteristic corresponding to each of the television channels. The output of each filter in the filter group is transferred to the mixer through a corresponding switching device among a corresponding plurality of semconductor switching devices individually coupled between the corresponding output terminals of the filters and the ground by turning off the semiconductor switching device corresponding to a desired channel and turning on the remaining switching devices. These semiconductor switching devices are adapted to be on/off controlled individually in response to corresponding flip-flops adapted to be selectively set in response to a channel selection switch. The local oscillator comprises another group of acoustic surface wave resonators each exhibiting a resonance characteristic corresponding to a channel and a feedback loop. The respective resonators are selectively enabled or disabled by means of a corresponding plurality of semiconductor switching devices in the same manner as done in the above described filters.