Patent ID: 8855174

Claim:
A method, comprising: generating a first radio frequency digital signal; providing the first radio frequency digital signal to a radio frequency digital-to-analog converter operating at a sampling frequency, an output of the radio frequency digital-to-analog converter comprising a first carrier signal corresponding to the first radio frequency digital signal and having a first frequency below the sampling frequency and an image of the first carrier signal having a second frequency above the sampling frequency; filtering the output of the radio frequency digital-to-analog converter to select the image of the first carrier signal for transmission; generating a second radio frequency digital signal; mixing the first radio frequency digital signal with the second radio frequency digital signal; providing the mixed first radio frequency digital signal and second radio frequency digital signal to the radio frequency digital-to-analog converter, the output of the radio frequency digital-to-analog converter comprising the first carrier signal and a second carrier signal corresponding to the second radio frequency digital signal; and filtering the output of the radio frequency digital-to-analog converter to select the second carrier signal and the image of the first carrier signal for transmission.