WIRELESS TRANSMITTER HAVING A MODIFIED TRANSLATION LOOP ARCHITECTURE

摘要

A transmitter for a wireless handset having a modified translation loop architecture. The transmitter includes a VCO (308) that generates a modulated transmit signal having a frequency FTx, and a modulated signal source (318) that generates a modulated LO signal with a frequency FLO. A mixer (316) mixes the transmit signal with the LO signal to produce an IF signal having a frequency FIF. A first divider (310) divides the LO signal frequency FLO by an integer M to generate a first comparison signal having a frequency FCF. A second divider (312) divides the IF signal frequency FIF, after it is multiplied by an integer K, by an integer N to generate a second comparison signal having a frequency FCF. The transmit and LO signal frequencies have the relationship FTx = FLO (KM+/-N)/M. A phase detector (302) coupled to the first and second comparison signals compares the phases of the signals and outputs a control voltage to the VCO proportional to any phase differences between the signals.