Patent ID: 6061575
Filing Date: 2000-05-09
Classification: H03D,H03L

Abstract:
A radio frequency (RF) transceiver comprising:a first oscillating means for generating a first local oscillator (LO) signal that is hopped between two different frequencies for transmitting and receiving, respectively, said first oscillating means including:a main voltage controlled oscillator (VCO) for generating said first LO signal;a programmable frequency divider for dividing said first LO signal;a phase detector for comparing the output of said frequency divider to a reference frequency signal and for generating a tuning signal to said main VCO based on said comparison;a loop filter at the input of said main VCO for filtering said timing signal; andmeans for lowering the frequency of said first LO signal prior to being divided by said frequency divider such that the bandwidth of said loop filter can be selected so as to minimize the settling time of said main VCO without a concurrent increase in output noise when hopping the frequency of said first LO signal between the transmit and receive operations;a second oscillating means for generating a second LO signal;a first mixing means for combining said first LO signal with a received signal to produce a first intermediate frequency (IF) signal;a second mixing means for combining said first IF signal with said second LO signal to produce a second IF signal;frequency scaling means for scaling the frequency of said second LO signal to produce a transmit offset signal;modulation means for modulating said transmit offset signal with a data signal; anda third mixing means for combining said first LO signal with said data modulated signal to produce a transmit RF signal.