High efficiency NLTL comb generator using time domain waveform synthesis technique

A waveform synthesizer for synthesizing a waveform having a first pulse segment, a second pulse segment and a third pulse segment, the wave form generating a flat output spectrum in a selected frequency band, the waveform synthesizer comprising:

• a first unit having a first time delay element and a first pulse generator generating the first pulse segment, a second unit having a second time delay element and a second pulse generator generating the second pulse segment, and a third unit having a third time delay element and a third pulse generator generating the third pulse segment, the first unit, the second unit and the third unit connected in parallel;
• and
• an input divider coupled to respective inputs of the first unit, the second unit, and the third unit the input divider dividing an input signal into a first signal instance, a second signal instance and a third signal instance that propagate through the first unit the second unit and the third unit to form the first pulse segment, the second pulse segment and the third pulse segment respectively, and an output combiner coupled to respective outputs of the first unit, the second unit, and the third unit combining the first pulse segment, the second pulse segment and the third pulse segment to form the waveform,
• wherein:
• each of the first pulse generator, the second pulse generator, and the third pulse generator include a sharpening circuit for sharpening a rising edge and a falling edge of the first pulse segment, the second pulse segment and the third pulse segment, the sharpening circuit comprising:
• a tunable delay element coupled to a first non-linear transmission line (NLTL);
• and
• a second NLTL coupled in parallel with the tunable delay element and the first NLTL.

An integrated circuit for synthesizing a waveform generating a flat output spectrum in a selected frequency band, the integrated circuit comprising:

• a substrate:
• and
• a pulse shaping circuit having:
• an pulse shaping circuit input divider dividing an input signal into a first pulse shaping circuit signal instance and a second pulse shaping circuit signal instance;
• a pulse sharpening unit including:
• a first sharpening unit coupled to the pulse shaping circuit input divider, the pulse shaping circuit input divider inputting the first pulse shaping circuit signal instance to the first sharpening unit, the first sharpening unit having a tunable delay element coupled to a first non-linear transmission line (NLTL), the first sharpening unit outputting a first pulse;
• and
• a second sharpening unit coupled to the pulse shaping circuit input divider, the pulse shaping circuit input divider inputting the second pulse shaping circuit signal instance to the second sharpening unit, the second sharpening unit having a second NLTL, the second sharpening unit coupled in parallel with the first sharpening unit, the second sharpening unit outputting a second pulse;
• and
• a pulse shaping circuit output combiner combining the first pulse and the second pulse to produce an output pulse segment,
• wherein the pulse sharpening unit is configured to sharpen a rising edge of the first pulse and a falling edge of the second pulse such that the output pulse segment includes a sharpened rising edge and a sharpened falling edge.