Title:
MODULATION CIRCUIT
Document Type and Number:
WIPO Patent Application WO/2009/004934
Kind Code:
A1
Abstract:
Provided a modulation circuit comprising a switch (13) for switching a Q-signal
and a QX-signal, which are frequency-offset at a frequency offset unit (23),
and a controller (18) for controlling a PC (32) to switch a local oscillation frequency
and for controlling the switch (13) to interchange and feed the Q-signal and the
QX-signal to a mixer unit (14). In case a local oscillation frequency (Flo) substantially
coincident to the frequency of a jamming signal due to a digital signal component
is set according to a desired frequency (Fdes) relating to the selection of a user,
the local oscillation frequency is changed to leave far the frequency of the jamming
signal, thereby to avoid the generation of a beat noise due to the jamming signal
and to switch the phase at the time when the frequency mixing is made at the mixer
unit (14), so that the frequency position of the image cancellation is changed
to a position different from the frequency position of a desired wave signal.
More Like This:
| JP3751424 | Intrusion transmitter |
| JP4633037 | Transmitter / receiver |
Inventors:
MIYAGI HIROSHI (JP)
KARASUDANI MUNEHIRO (JP)
KARASUDANI MUNEHIRO (JP)
Application Number:
PCT/JP2008/061281
Publication Date:
January 08, 2009
Filing Date:
June 13, 2008
Export Citation:
Assignee:
NIIGATA SEIMITSU CO LTD (JP)
MIYAGI HIROSHI (JP)
KARASUDANI MUNEHIRO (JP)
MIYAGI HIROSHI (JP)
KARASUDANI MUNEHIRO (JP)
International Classes:
H04B1/04; H03D7/18
Domestic Patent References:
| WO2005125022A1 | 2005-12-29 |
Foreign References:
| JP2007096694A | 2007-04-12 | |||
| JPH02143704A | 1990-06-01 | |||
| JP2005252861A | 2005-09-15 |
Attorney, Agent or Firm:
TACHIBANA, Kazuyuki (1-4 Kojimach, Chiyoda-ku Tokyo, JP)
Download PDF: