Patent ID: 7212581

Claim:
Up conversion circuitry for use in a radio transceiver for up converting, in two stages, a base-band information signal to an RF information signal for transmission, wherein a first said stage converts said base band information signal to an IF information signal and a second said stage converts said IF information signal to said RF information signal, said up conversion circuitry comprising: (a) an image rejection mixer component configured for up converting said base band information signal to said IF information signal using an IF oscillator signal and achieving substantial image signal rejection; (b) a mixer component configured for up converting said IF information signal to said RF information signal using an RF oscillator signal; and, (c) a frequency synthesizer configured for generating each of said RF and IF oscillator signals wherein said IF oscillator signal is an integer (N) sub-harmonic of said RF oscillator signal and the frequency value of said IF oscillator signal is selected to be within the operating frequency band of said image rejection mixer component.