A method of generating variable frequency signals (113a, 113b), comprising: performing complex tuning on a first digital baseband signal to produce a first complex tuned digital signal translated in the frequency domain, wherein performing complex tuning on the first digital baseband signal comprises controlling a first phase parameter; performing complex tuning on a second digital baseband signal to produce a second complex tuned digital signal translated in the frequency domain; interpolating the first complex tuned digital signal by a first integer factor N to create N equally spaced images (105 a) in the frequency domain, one of the N images corresponding to a first desired frequency; interpolating the second complex tuned digital signal by a second integer factor M to create M equally spaced images in the frequency domain, one of the M images corresponding to a second desired frequency; isolating the one of the N images of the first complex tuned digital signal using a first image isolation filter to output a first isolation image that corresponds to the first desired frequency; isolating the one of the M images of the second complex tuned digital signal using a second image isolation filter to output a second isolated image that corresponds to the second desired frequency; combining the first isolated image of the first complex tuned digital signal and the second isolated image of the first complex tuned digital signal into a combined complex signal; performing quadrature modulation to convert the combined complex signal into a combined real signal; converting the combined real signal into an analog signal using a digital-to-analog converter, DAC,, wherein the DAC is driven by a local oscillator; and filtering the analog signal to select an analog signal located at the first desired frequency and an analog signal located at the second desired frequency, wherein the first phase parameter is selected to control a static phase offset between the analog signal located at the first desired frequency and the analog signal located at the second desired frequency. performing complex tuning on a first digital baseband signal to produce a first complex tuned digital signal translated in the frequency domain, wherein performing complex tuning on the first digital baseband signal comprises controlling a first phase parameter; performing complex tuning on a second digital baseband signal to produce a second complex tuned digital signal translated in the frequency domain; interpolating the first complex tuned digital signal by a first integer factor N to create N equally spaced images (105 a) in the frequency domain, one of the N images corresponding to a first desired frequency; interpolating the second complex tuned digital signal by a second integer factor M to create M equally spaced images in the frequency domain, one of the M images corresponding to a second desired frequency; isolating the one of the N images of the first complex tuned digital signal using a first image isolation filter to output a first isolation image that corresponds to the first desired frequency; isolating the one of the M images of the second complex tuned digital signal using a second image isolation filter to output a second isolated image that corresponds to the second desired frequency; combining the first isolated image of the first complex tuned digital signal and the second isolated image of the first complex tuned digital signal into a combined complex signal; performing quadrature modulation to convert the combined complex signal into a combined real signal; converting the combined real signal into an analog signal using a digital-to-analog converter, DAC,, wherein the DAC is driven by a local oscillator; and filtering the analog signal to select an analog signal located at the first desired frequency and an analog signal located at the second desired frequency, wherein the first phase parameter is selected to control a static phase offset between the analog signal located at the first desired frequency and the analog signal located at the second desired frequency. wherein the first phase parameter is selected to control a static phase offset between the analog signal located at the first desired frequency and the analog signal located at the second desired frequency.