UCLA

In-band jammer/interference that cannot be isolated by a filter in today’s RF system could easily desensitize and saturate RF front-end. Performing signal processing directly at the RF front-end could reduce the in-band jammer/interference prior to the receiver to prevent the jamming, which enables the RF system has the ability to operate in the unpredicted and high interference environments. However, implementation of the signal processing block at the RF domain is usually challenging due to the insertion loss and noise introduced through the RF signal processing device could significantly degrade sensitivity and dynamic range of the receiver. Time-varying transmission line (TVTL), a novel RF circuit, which is time-varying capacitance periodically loaded on a transmission line, provides unique properties of low noise, low loss frequency conversion, broadband, and high power handling capability, provides a new solution enabling the RF signal processing at the RF front end. Meanwhile, the TVTL circuit can be integrated into the modern Monolithic Microwave Integrated Circuit (MMIC) technology, which offers small physical dimensions and has the compatibility with other circuit blocks.

In this thesis, TVTL’s theory and implementation are first introduced and studied. M-derived TVTL is designed and fabricated on MMIC and two types of correlators, open loop correlator, and closed loop correlator, based on the TVTL are studied, implemented and verified. Both frequency domain correlation tests and time domain decoder tests are carried out to validate the designed correlators. At the last, two advanced TVTL structures are proposed for the purpose of improving the power efficiency and conversion gain.