Patent ID: 7106805

Claim:
A transmitter for GSM and UMTS comprising an in-phase/quadrature up-converter for mixing in-phase and quadrature inputs with an intermediate frequency local oscillator signal; a GSM path including a phase locked loop; and a UMTS path; wherein a frequency generator is further provided to generate a first signal at a frequency F 1 , and the first signal is supplied as an input to an image reject mixer in the GSM path, to a mixer in the UMTS path, and as an input to divider which divides the first signal by three to create an intermediate frequency local oscillator signal which is supplied to the in-phase/quadrature up converter; and wherein the image reject mixer in the GSM path is controllable to select either an upper or lower side band such that the GSM path operates at either (1+⅓)F 1 or (1−⅓)F 1 ; and wherein the mixer in the UMTS path selects the upper side band so as to have a output at (1+⅓)F 1 .