Title:
PHASE SYNCHRONIZING DEVICE
Document Type and Number:
Japanese Patent JP3399017
Kind Code:
B2
Abstract:
PURPOSE: To provide the phase synchronizing device which is used in, for example, a direct conversion FM receiver to improve the phase comparison sensitivity.
CONSTITUTION: A reception signal is converted to base band orthogonal signals based on a frequency signal subjected to 90° phase shift by mixers 111 and 112. The signals are up converted by mixers 151 and 152 and have the frequency converted to the frequency of a local oscillator 17 by an adder 18 and a subtractor 19. The output from the subtractor 19 is supplied to a demodulating circuit 20 to obtain a demodulated signal. Outputs from the adder 18 and the substractor 19 are amplified by limiter amplifiers 211 and 212 and the phases are compared with each other by a phase comparator 22, and the phase difference is integrated by a loop filter 23 to control a VCO 12. The oscillation signal of this VCO 12 has the phase shifted by a 90° phase shifter 13 and is supplied to mixers 111 and 112 to synchronize the VCO 12 with the reception signal.
Inventors:
Tadao Suzuki
Application Number:
JP10556893A
Publication Date:
April 21, 2003
Filing Date:
May 06, 1993
Export Citation:
Assignee:
株式会社デンソー
International Classes:
H04B14/00; H03D7/18; H04L27/14; (IPC1-7): H04L27/14; H03D7/18; H04B14/00
Domestic Patent References:
| JP479546A | ||||
| JP677737A | ||||
| JP6472626A | ||||
| JP583038B2 | ||||
| JP535491B2 | ||||
| JP6347313B1 |
Other References:
【文献】特許2964573(JP,B2)
Attorney, Agent or Firm:
Takehiko Suzue
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