Millimeter-Wave Dual-Mode RF Front-End  Circuits for All-Optical ADC  ​

Future generations of radar, remote sensing, wireless communications, and surveillance technologies are reliant upon high frequency broadband digital receiver chips capable of capturing millimeter wave signals and digitize at rates of 40GSPS with 10 effective bits that requires high dynamic range and low power consumption of under 1W. Our senior design team will collaborate with graduate students in Prof. Daryoush laboratory to design, model, and optimize heterogeneously integrated RF integrated circuits (RFIC) of SiGe HBT of Tower foundry as part of driver for implementing RF front-end electronics. Our group is expanding upon designs from previous year's senior design efforts on this multi-year project. The spiral antenna designed by the prior senior design group will be assembled and tested at the Lockheed Martin anechoic chamber. Our custom circuits are to interface high frequency spiral antenna (20-40GHz) with optical spatial modulator through realization of low noise amplifier (LNA) for broadband of 20-40GHz, followed with double balanced Gilbert cell mixer for down-conversion of 1-21GHz, a distributed amplifier (DA) of 1-21GHz, and limiter circuits for spatially separating optical quantizers. Prior single-ended amplifier designs will be converted to differential and frequency range will be expanded. System performances are calculated to meet the high dynamic range required for AOADC with total of 10ENOB. The concept of free-space optical quantizers using spatially integrated optical apertures are tested using cylindrical optical lens focused across Binary/Gray codes optical apertures mounted over CCD camera. Quantization performances of 2 spatially integrated 5 ENOB are compared to 3 optical masks of 4 ENOB.