Title: Pulling-free LO generation system and method
Application Number: 200580013639 Application Date: 2005.04.25
Publication Number: 1985436 Publication Date: 2007.06.20
Approval Pub. Date: Granted Pub. Date:
International Classifi-cation: H03B19/00;H03B27/00
Applicant(s) Name: Koninkl Philips Electronics NV Address:
Inventor(s) Name: Frambach Johannes Petrus Anton;Zeijl Paulus Thomas
Attorney & Agent: chengtian zheng chenjing jun
Abstract:
    A system and method for generating an LO signal for an RF transmitter is provided that eliminates the risk of LO-pulling. A filtering technique is employed to select the desired harmonic of a VCO signal, usually the third. The required in-phase and quadrature LO signals can be derived by means of dividers. Any harmonic relation is avoided between the transmit signal and the VCO frequency, without generation of intermediate signals close to the VCO frequency, thus circumventing pulling of the VCO.
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