RF-CMOS-MEMS based frequency-reconfigurable amplifiers

Abstract

Chips from a foundry RF process are post-processed to release MEMS passive devices and enable single-chip reconfigurable circuits. A MEMS variable capacitor, capable of 7:1 tuning ratio, reconfigures a narrow-band low-noise amplifier and a power amplifier over a 1 GHz frequency range. A suspended MEMS inductor, with > 50% improvement in Q, lowers amplifier power consumption.

A low-noise amplifier with continuously-tuned input matching frequency and output resonance frequency

“…Furthermore, high gain, low power, moderate linearity and good matching between input matching frequency and output resonance frequency are also required. Among different LNA structures, wideband [1,2], concurrent [3,4] and reconfigurable [5][6][7][8][9][10][11][12][13][14] LNAs have attracted extensive attention. A wideband LNA has flat gain and low return loss over a wide frequency range.…”

“…However, for a larger number of frequency bands, discrete tuning is not suitable, as it is harder to design for good input matching and it necessitates additional passive components, which increases the overall area of the LNA. On the other hand, the continuously-tuned LNA can be used to improve the yield of the design, because it is less sensitive to process variations, and any frequency shift caused by bond wires, parasitics and device corners can be adjusted electronically [8][9][10][11][12][13][14]. It is important that both the load resonance frequency and input matching frequency are aligned and tuned simultaneously.…”

“…It is important that both the load resonance frequency and input matching frequency are aligned and tuned simultaneously. To do so, both electrical [8][9][10][11][12] and mechanical [13,14] tuning can be used. Although MEMS techniques can be used for mechanical tuning, the NF of the designed LNA based on this technique still needs to be further improved [14].…”

A K-Band RF-MEMS-Enabled Reconfigurable and Multifunctional Low-Noise Amplifier Hybrid Circuit

“…RF-MEMS together with active circuitry (such as lownoise/power amplifiers) have with a few notable exceptions mainly been realised up to 5-10 GHz (see, e.g., [4][5][6][7][8][9][10][11][12][13][14]) which still leaves room for significant improvements to be made with respect to RF performance, frequency range, and functionality as well as to achieve reduced complexity and lower costs. Measured s-parameter data of a 26-30 GHz MEMS-switched transmit/receive circuit was reported in [5].…”