发明名称 |
Method and apparatus for quadriphase-shift-key and linear phase modulation |
摘要 |
A submultiple (30Fl) of an S-band transmitter output frequency (240Fl) is divided equally between a linear phase modulation branch and a QPSK modulation branch. The linear modulation branch includes a multiplier (X7) to increase the carrier frequency to a level (210Fl) which, when combined with the carrier in the QPSK branch in an up-converter (utilizing a mixer at the input thereof followed by a bandpass filter), produces the transmitter output frequency. This allows the QPSK modulator to operate at one-eighth of the output frequency where repeatable and precisely controlled modulation can be easily achieved. This also allows linear phase modulation at one-eighth the output frequency where low modulator deviation and good linearity can be easily maintained.
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申请公布号 |
US4216542(A) |
申请公布日期 |
1980.08.05 |
申请号 |
US19790017890 |
申请日期 |
1979.03.06 |
申请人 |
U S OF AMERICA NASA ADMINISTRATOR |
发明人 |
HERMESMEYER, CHARLES E |
分类号 |
H04L27/20;(IPC1-7):H04L27/18 |
主分类号 |
H04L27/20 |
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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