Title:
FREQUENCY CONVERTER FOR RECEIVING SATELLITE BROADCASTING
Document Type and Number:
Japanese Patent JPS6490689
Kind Code:
A
Abstract:
PURPOSE:To obtain the complete quantity of controlling a gain even in a wide band by simultaneously driving two gain varying circuits by one control signal through one transistor control circuit. CONSTITUTION:A first gain varying circuit using an attenuator consisting of PIN junction diodes 32, 33, 34 is disposed in the prestage of a frequency mixer 24, a second gain varying circuit using the transistor TR 35 is disposed in the post-stage of the mixer 24 and a TR 36 for simultaneously driving the two gain varying circuits is provided. According to this constitution, a mutual modulating distortion is reduced according to a wide band gain control before the mixer 24 and an intermediate frequency gain control after the mixer 24 is applied, thereby, a complete control range is maintained. When these gain controls are simultaneously driven, the gain control range in the vicinity is individually set to an optimum AGC curve.
More Like This:
| JP2004530314 | Controlling data-on-demand client access |
| JPS6018024 | LOCAL OSCILLATION CIRCUIT |
| JP2000030366 | INFORMATION RECEIVER AND DOWNLOAD PROGRESS SITUATION DISPLAY METHOD |
Inventors:
ADACHI KENJI
YASUDA MASAKATSU
YASUDA MASAKATSU
Application Number:
JP24900687A
Publication Date:
April 07, 1989
Filing Date:
September 30, 1987
Export Citation:
Assignee:
MATSUSHITA ELECTRIC IND CO LTD
International Classes:
H04N7/20; (IPC1-7): H04N7/20
Domestic Patent References:
| JPS572110A | 1982-01-07 |
Attorney, Agent or Firm:
Yoshihiro Morimoto