Traveling wave based THz signal generation system and method thereof
TeraHertz signal generation system based on traveling-wave oscillators providing extraction of orders of magnitude higher oscillation frequencies resulting in frequency multipliers and THz transceivers that can generate, transmit and sense THz frequency signals for sensing/imaging.
1. A Traveling-Wave Frequency Multiplier [TWFM] comprising
a distributed wave oscillator providing accurate multiple phases of an oscillation;
said oscillator further comprising two or more independent electrical conductors forming transmission line loops of a differential medium for traveling wave oscillations;
a plurality of cross-coupled inverting amplifiers distributed along said transmission line loops;
a plurality of shorted transmission line stubs to provide biasing said cross-coupled amplifiers;
a plurality of resistors in series with said transmission line stubs to eliminate low-frequency mode of oscillation;
a plurality of varactors to provide tuning for high frequency, high-bandwidth oscillations in the range of at least from about sub-GHz to about THz;
a plurality of symmetric tapping points to tap a plurality of corresponding symmetric phases to affect higher order harmonic frequency extraction;
a plurality of summing points of said symmetric phases; and
a plurality of matching networks for combining said symmetric phases to affect further frequency multiplication.
2. The TWFM according to claim 1 , wherein each said independent conductor in said transmission line loops is structured to use the other as a differential sustainer.
3. The TWFM according to claim 1 , wherein said transmission line stubs comprise quarter wave (λ/4) lengths.
4. The TWFM according to claim 1 , wherein said shorted transmission line stubs are distributed symmetrically along said independent electrical conductors.
5. The TWFM according to claim 1 , wherein said matching network comprises λ/4 transmission-line harmonic matching and combining network.
6. The TWFM according to claim 1 , wherein said Traveling Wave Frequency Multiplier further comprises switching devices which turn on and off said oscillator using a modulating signal to form a Switching Traveling-Wave Frequency Multiplier [STWFM].