A 76dBΩ 1.7GHz 0.18µm CMOS tunable transimpedance amplifier using broadband current pre-amplifier for high frequency lateral micromechanical oscillators

The frequency reference oscillator is a pivotal block in modern radio transceivers. Currently, modern transceivers rely on off-chip low frequency (<100MHz) quartz crystal reference oscillators [1]. Silicon micromechanical oscillators are suitable alternative to quartz crystal oscillators due to their small form-factor, higher frequency, and integration potential with ICs [2]-[4]. In multi-gigahertz applications, large up-conversion ratio of synthesizers limits the performance of RF front-end. In addition, OFDM-based 3G/4G standards with stringent error vector magnitude (EVM) specification [5] demand a low phasenoise floor that for low frequency resonating tanks is only possible by reducing the 3-dB bandwidth (BW) of the low pass filter in the PLL. The small BW increases the size of filter and hence, complicates the integration of the synthesizer in a single chip. However, recent advances in micromachining technology have made the realization of post-CMOS-compatible UHF micromechanical oscillators possible [3], [4].