2 research outputs found
Analysis and Design Considerations for Achieving the Fundamental Limits of Phase Noise in mmWave Oscillators with On-Chip MEMS Resonator
Very small electromechanical coupling coefficient in micro-electromechanical
systems (MEMS) or acoustic resonators is quite of a concern for oscillator
performance, specially at mmWave frequencies. This small coefficient is the
manifestation of the small ratio of motional capacitance to static capacitance
in the resonators. This work provides a general solution to overcome the
problem of relatively high static capacitance at mmWave frequencies and
presents analysis and design techniques for achieving extremely low phase noise
and a very high figure-of-merit (FoM) in an on-chip MEMS resonator based mmWave
oscillator. The proposed analysis and techniques are validated with design and
simulation of a 30 GHz oscillator with MEMS resonator having quality factor of
10,000 in 14 nm GF technology. Post layout simulation results show that it
achieves a phase noise of -132 dBc/Hz and FoM of 217 dBc/Hz at offset of 1 MHz.Comment: 5 page, 9 figures, 2 tables, transactio
A mmWave Oscillator Design Utilizing High-Q Active-Mode On-Chip MEMS Resonators for Improved Fundamental Limits of Phase Noise
(RFT) allows very high-Q active mode resonators, promising crystal-less
monolithic clock generation for mmWave systems. However, there is a strong need
for design of mmWave oscillators that utilize the high-Q of active-mode RFT
(AM-RFT) optimally, while handling unique challenges such as resonator's low
electromechanical transduction. In this brief, we develop a theory and through
design and post-layout simulations in 14 nm Global Foundry process, we show the
first active oscillator with AM-RFT at 30 GHz, which improves the fundamental
limits of phase noise and figure-of-merit as compared to the oscillators with
conventional LC resonators. For AM-RFT with Q factor of 10K, post layout
simulation results show that the proposed oscillator exhibits phase noise less
than -140 dBc per Hz and figure-of-merit greater than 228 dBc per Hz at 1 MHz
offset for 30 GHz center frequency, which are more than 25 dB better than the
existing monolithic LC oscillators