Patent ID: 7535394

Claim:
An apparatus for generating signals comprising; a digital signal processing element for processing a signal, the digital signal processing element comprising: a low-pass filter for extracting a low frequency portion of a waveform; a high-pass filter for extracting a high frequency portion of the waveform; and a mixing element for mixing a local oscillator with the high frequency portion of the waveform to generate a lower frequency version of the high frequency portion of the waveform; a plurality of digital-to-analog converters, each having a bandwidth and each producing a D/A output signal; at least one upconverter, the at least one upconverter receiving a D/A output signal and producing an upconverted signal; and a combining element that receives and combines at least one D/A output signal and at least one upconverted signal and produces a final output signal; whereby the final output signal includes spectral content occupying a substantially contiguous frequency band whose width is greater than the bandwidth of any one of the plurality of digital-to-analog converters.