Oscillators – Phase shift type
Reexamination Certificate
2008-08-01
2011-10-25
Kinkead, Arnold (Department: 2817)
Oscillators
Phase shift type
C331S016000, C331S137000, C331S182000, C455S075000, C455S085000, C455S086000
Reexamination Certificate
active
08044734
ABSTRACT:
Techniques for mitigating VCO pulling are described. In an aspect, VCO pulling may be mitigated by (i) injecting an oscillator signal, which is a version of a VCO signal from a VCO, into a transmitter and (ii) using coupling paths from the transmitter to the VCO to re-circulate the oscillator signal back to the VCO. In one design, an apparatus includes a VCO and a coupling circuit. The VCO generates a VCO signal at N times a desired output frequency. The coupling circuit receives an oscillator signal generated based on the VCO signal and injects the oscillator signal into a transmitter to mitigate pulling of the frequency of the VCO due to undesired coupling from the transmitter to the VCO. The apparatus may include a phase adjustment circuit that adjusts the phase of the oscillator signal and/or an amplitude adjustment circuit that adjusts the amplitude of the oscillator signal.
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International Search Report and the Written Opinion—PCT/US2009/052574, International Search Authority—European Patent Office—Oct. 6, 2009.
Kinkead Arnold
QUALCOMM Incorporated
Tan Richard
Vu Kenneth K.
LandOfFree
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