| 摘要 |
A digital waveform synthesizer (10) comprises a direct digital synthesizer (12) for providing a digitally synthesized input frequency signal. Further provided is a reference frequency generator (25) for providing clock and predetermined frequency reference signals. An upconverter and divider circuit (18, 18a) is coupled to the direct digital synthesizer (12) for upconverting and dividing the synthesized input frequency signal to provide a divided synthesized frequency signal. Said upconverter and divider circuit (18, 18a) comprises a mixer (14) having an input coupled to the direct digital synthesizer (12) for receiving the synthesized input frequency signal, and having a second input coupled to the reference signal generator (25) for receiving a first predetermined reference frequency signal; a bandpass filter (15) coupled to the mixer (14), a divide by N divider circuit (16), where N is the divide number, coupled to the bandpass filter (15); and a low pass filter (17) coupled to the divide by N divider circuit (16). An output upconverter circuit (21) is coupled to the upconverter and divider circuit (18, 18a) and to the reference frequency generator (25) for upconverting the divided synthesized frequency signal to provide a desired upconverter synthesized output frequency signal. <IMAGE> |
