Unified frequency synthesizer for direct conversion receiver or transmitter

摘要

Method and system for direct conversion receiver (100), transmitter (200), or transceiver (300) device. The device includes a single frequency synthesizer (102) generating a frequency synthesizer output signal. At least one frequency divider (110n) is provided for generating a reduced frequency signal by selectively dividing the single frequency synthesizer output signal by an integer divisor value. Significantly, the device is configured to vary the reduced frequency signal so as to include every frequency the direct conversion communication device is designed to receive within a plurality of frequency bands by adjusting a frequency of the single synthesizer output signal and the divisor value.

主权项

1. A method for conversion of signals in a communication device, comprising:
generating a first signal Sfs using a frequency synthesizer having a predetermined synthesizer frequency tuning range which extends from about 1516 MHz to 2088 MHz; generating a second signal Sd within any one of a plurality of predetermined second frequency tuning ranges, by selectively performing a first frequency dividing operation on said first signal in accordance with any one of a plurality of predetermined divisor values; communicating the second signal Sd to a frequency conversion unit which includes a digital broadband phase splitter and a pair of mixers, including a first mixer and a second mixer; performing in said digital broadband phase splitter a second frequency dividing operation to produce first and second quadrature signals which have a phase offset of about 90°; communicating said first and second quadrature signals respectively to said first and second mixers; and using said first and second quadrature signals in each of said first and second mixer to modulate or demodulate a third signal by performing a frequency conversion operation on said third signal.