Picosecond digital-to-impulse generator in Silicon

In this paper, a direct digital-to-impulse architecture is presented that generates impulses with a measured record pulse-width of shorter than 8psec and an output peak power of 6mW. It is shown that the timing of the generated impulses can be locked to the edge of an input trigger with a high timing accuracy. It is also shown that the peak amplitude of the impulses can be programmed. In addition to time-domain measurements, frequency-domain spectrum is measured from DC to 75GHz. At 75GHz, the generated impulses have a frequency stability of better than 4Hz at 20dB below peak. The impulse train also achieves a timing jitter of better than 240fsec. The chip is fabricated in a 130nm SiGe BiCMOS process.