发明名称 |
Radio receiving apparatus for receiving communication signals of different bandwidths |
摘要 |
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.
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申请公布号 |
US6307897(B1) |
申请公布日期 |
2001.10.23 |
申请号 |
US19990456469 |
申请日期 |
1999.12.08 |
申请人 |
MATSUSHITA ELECTRIC INDUSTIRAL CO., LTD. |
发明人 |
OHTA GEN-ICHIRO;INOGAI KAZUNORI;SUDO HIROAKI;SASAKI FUJIO |
分类号 |
H04B1/16;H03D3/00;H04B1/26;H04B1/30;(IPC1-7):H04L27/22 |
主分类号 |
H04B1/16 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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