An Ultra-Wideband Low Noise Amplifier with Air-suspended RF MEMS Inductors

This paper presents the design and simulation of a CMOS Ultra-wideband differential Low Noise Amplifier with Air-suspended MEMS inductors substituting standard planar spiral inductors. Air-suspended MEMS inductors offer higher quality inductance and higher frequency of operation when compared to monolithic spiral planar inductors. This extends the capabilities of a mixed-signal CMOS process, allowing for a high gain, full spectrum, 3.1 - 10.6GHz UWB Low Noise Amplifier. The basic architecture of the LNA designed herein exhibits a differential amplifier core with active input and output impedance matching. Simulations reveal that the LNA maintains a gain of 13.0dB with a ±0.3dB ripple over the band of 3.1-10.6GHz. Despite the use of an active input matching stage, the LNA achieved a simulated noise figure ranging from 3.5-4.2dB over the band of operation. The input and output active matching stages maintain less than -10dB reflection coefficients with a 50Ω termination over the desired frequency range of operation.