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公开(公告)号:US5077546A
公开(公告)日:1991-12-31
申请号:US610108
申请日:1990-11-07
IPC分类号: H03B19/18
CPC分类号: H03B19/18
摘要: A low phase noise frequency multiplier is disclosed for multiplying a sine wave obtained from a low phase noise crystal oscillator to higher frequencies than can be directly obtained from a crystal oscillator. The multiplication occurs without the ordinary increase in phase noise. The multiplier, when tripling the frequency contains a low phase noise frequency doubler. The double and triple frequency terms in the tripler are synthesized from two orthogonally related derivatives of the same wave, which are then multiplied in a double balanced mixer. The process reinforces the desired harmonics while not reinforcing the short term random phase noise, and produces a substantial improvement in the single sideband phase noise ratio over conventional frequency multipliers.