Highly-Linear Magnet-Free Microelectromechanical Circulators

TL;DR

This paper introduces a magnet-free MEMS-based circulator with high linearity, broad bandwidth, and low power consumption, achieved through innovative resonator commutation and high-Q design, addressing key limitations of previous circulators.

Contribution

It presents the first demonstration of a high-performance, magnet-free MEMS circulator with a novel circuit design using high-Q resonators and RF switches, enabling smaller size and lower power.

Findings

Broad bandwidth of 34.7 MHz at 2.5 GHz

Low insertion loss of 4 dB

High linearity with P1dB=28 dBm and IIP3=40 dBm

Abstract

This paper reports the first demonstration of a magnet-free, high performance microelectromechanical system (MEMS) based circulator. An innovative circuit based on the commutation of MEMS resonators with high quality (Q) factor using RF switches is designed and implemented. Thanks to the high Q factor, a much smaller modulation frequency can be achieved compared to the previous demonstrations, reducing the power consumption and enabling the use of high power-handling switches. Furthermore, the MEMS resonators greatly reduce the required inductance value, guaranteeing much smaller form factor compared to the previous LC demonstrations. The demonstrated circulator shows broad BW (15 dB-IX BW=34.7 MHz for an operational frequency around 2.5 GHz), low IL (4 dB), high IX (30 dB), high linearity (P1dB=28 dBm; IIP3=40 dBm) and at the same time low power consumption, addressing several of the current limitations hindering the full development of magnet-free circulators.