Patent ID: 6931233
Filing Date: 2005-08-16
Classification: G01S

Abstract:
1. A GPS RF Front End integrated within a wireless mobile terminal, the GPS RF Front End containing a Frequency Synthesizer comprising: a Voltage Controlled Oscillator (VCO) for producing a Local Oscillator (LO) signal, wherein the LO signal has a frequency at approximately 1566 MHz; a first fixed counter means, coupled to the VCO, for dividing the LO signal frequency by 41, to obtain a second signal with frequency of LO/41, wherein the second signal is an ACQCLK signal; a second fixed counter means, coupled to the VCO, for dividing the LO signal by 31-and- 8/9ths, to obtain a third signal with frequency of 9/7 times the frequency of the second signal, wherein the second signal is a GPSCLK signal, the second fixed counter means further comprising a first divide-by-4 counter, the first divide-by-4 counter having five outputs, each output having a frequency of LO/4; a second divide-by-4 counter, coupled to one of the five outputs of the first divide-by-4 counter; a first programmable count-down counter, coupled to the output of the second divide-by-4 counter; a second programmable count-down counter, coupled to a Reference Frequency Signal, the Reference Frequency Signal being used by the wireless mobile terminal; and a Phase Frequency Detector, coupled to the outputs of the first and second programmable count-down counters, for comparing the phase and frequency of the outputs of the first and second programmable count-down counters.