QUADRATURE DEMODULATOR AND INTERROGATOR

Title:

QUADRATURE DEMODULATOR AND INTERROGATOR

Document Type and Number:

WIPO Patent Application WO/2007/097319

Kind Code:

A1

Abstract:

A quadrature demodulator for suppressing noise affections as much as possible even when the level of a received signal becomes small, thereby reducing the occurrences of erroneous reproduction of the received data. In the quadrature demodulator, an I-signal and a Q-signal are generated from a modulated received signal, a local signal and from a local signal having been phase-shifted by 90 degrees, and then the DC components of the I-signal and Q-signal are removed by capacitors (37,38). In addition, the frequency components higher than the frequencies of the I-signal and Q-signal are removed by lowpass filters (35,36). The I-signal having passed through the lowpass filter is squared by an I-signal squaring part (43), while the Q-signal having passed through the lowpass filter is squared by a Q-signal squaring part (44). The squared I-signal and Q-signal are then added together by an adding part (45). A comparator (18) then compares the level of a resultant added signal (S1) with a threshold value (T1), thereby providing a signal (S2). A data generating part (48) of a digital signal processing part (12) inverts the signal level in response to each rising edge of the signal (S2), thereby demodulating the received data.

More Like This:

WO/2005/034502	APPROXIMATOR APPARATUS, AND ASSOCIATED METHOD FOR APPROXIMATING AN N-DIMENSIONAL EUCLIDEAN NORM
JP3197955	ACCUMULATOR TYPE PHASE DIGITIZER
JP3086144	[Title of Invention] Burst demodulator

Inventors:

MUROFUSHI NOBUO (JP)
OISHI SADATOSHI (JP)

Application Number:

PCT/JP2007/053070

Publication Date:

August 30, 2007

Filing Date:

February 20, 2007

Export Citation:

Click for automatic bibliography generation Help

Assignee:

TOSHIBA TEC KK (JP)
MUROFUSHI NOBUO (JP)
OISHI SADATOSHI (JP)

International Classes:

H04L27/22; G06K17/00; H03D1/00; H04B1/30; H04B1/59; H04B5/02

Foreign References:

JP2004147016A	2004-05-20
JP2004140681A	2004-05-13
JPH08223230A	1996-08-30
JPH06244754A	1994-09-02
JPH0869583A	1996-03-12
JPH11298366A	1999-10-29

Attorney, Agent or Firm:

SUZUYE, Takehiko et al. (1-12-9 Toranomon, Minato-k, Tokyo 01, JP)

Download PDF:

View/Download PDF PDF Help

Previous Patent: 4-(3-BENZOYLAMINOPHENYL)-6,7-DIMETHOXY-2- METHYLAMINOQUINAZOLINE DERIVATIVE

Next Patent: TUBE WITH GROOVES FORMED IN INNER SURFACE THEREOF, METHOD OF PRODUCING THE TUBE, AND GROOVED PLUG