Radio receiving apparatus for receiving communication signals of different bandwidths
Number of patents in Portfolio can not be more than 2000
United States of America Patent
Stats
-
Aug 8, 2000
Issued Date -
N/A
app pub date -
Dec 8, 1999
filing date -
Mar 27, 1996
priority date (Note) -
Expired
status (Latency Note)
Importance
Abstract
A received signal obtained from an antenna is subjected to high-frequency amplification. The amplified signal is supplied to a first bandpass filter, which extracts only signals of all the channels of a communications system concerned while filtering out other radio signals. The extracted signals are frequency-converted by using a local oscillation frequency, and only a desired wave is passed by a second bandpass filter. The desired wave is supplied to a sample-and-hold circuit, which performs sampling according to the bandwidth-limiting sampling theorem. A resulting discrete signal is supplied to an I-axis-component and Q-axis-component separating circuits, where the polarity of sample values is inverted for every other clock pulse with respect to each of the I and Q axes to thereby effect Hilbert transform. Resulting two orthogonal components on a phase plane are supplied to a complex coefficient filter.
First Claim
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