Title:
RECEIVER
Document Type and Number:
WIPO Patent Application WO/2003/063353
Kind Code:
A1
Abstract:
A receiver wherein a received signal inputted to an RF amplifier (3) is attenuated by an attenuating circuit (10), and a frequency band is detected in which the field strength of the attenuated signal is greater than a predetermined level. The attenuation of the received signal utilizes the tuning voltage of a local oscillator circuit (5) that increases with increasing received frequency and decreases with decreasing received frequency, thereby causing large currents to flow through diodes (D1,D2) to reduce the ON-resistance and increase the attenuation amount of the received signal for a higher frequency range, while causing small currents to flow through the diodes (D1,D2) to increase the ON-resistance and reduce the attenuation amount of the received signal for a lower frequency range. In this way, the difference in signal attenuation amount due to different received frequencies can be reduced.
Inventors:
OGASAWARA ATSUSHI (JP)
Application Number:
PCT/JP2003/000211
Publication Date:
July 31, 2003
Filing Date:
January 14, 2003
Export Citation:
Assignee:
NIIGATA SEIMITSU CO LTD (JP)
OGASAWARA ATSUSHI (JP)
OGASAWARA ATSUSHI (JP)
International Classes:
H03J7/18; H04B1/18; (IPC1-7): H03J7/18; H04B1/18
Foreign References:
| JPH066249A | 1994-01-14 | |||
| JPH0461525A | 1992-02-27 |
Attorney, Agent or Firm:
Tachibana, Kazuyuki (Oaza-Shimoshingashi Kawagoe-shi, Saitama, JP)
Download PDF: