发明名称 |
Phase-locked loop methods and structures for generating modulated communication signals with nonconstant envelopes |
摘要 |
Phase-locked loop methods and structures are provided for generating modulated communication signals with nonconstant envelopes. These methods and structures realize the improved communication performance of nonconstant-envelope modulations with the upconversion advantages of phase-locked loops. The structures include transmitters in which a phase-locked loop is augmented with first and second feedforward paths that substantially restore phase and amplitude information to a transmit signal that is generated by a voltage-controlled oscillator of the phase-locked loop. The first feedforward path is configured to realize a path transfer function of s/Kv wherein the voltage-controlled oscillator has a transfer function of Kv/s. The second feedforward path extracts an envelope-correction signal from the modulated intermediate-frequency signal and a variable-gain output amplifier amplifies the transmit signal with a gain that responds to the envelope-correction signal.
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申请公布号 |
US6693969(B1) |
申请公布日期 |
2004.02.17 |
申请号 |
US20000689288 |
申请日期 |
2000.10.11 |
申请人 |
ANALOG DEVICES, INC. |
发明人 |
MONTALVO ANTONIO J.;ATKINSON SIMON |
分类号 |
H03C3/09;H03C5/00;H03L7/185;H04L27/20;(IPC1-7):H04L27/00 |
主分类号 |
H03C3/09 |
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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