[Paper Review] A Reconfigurable Impedance Matching Network Employing RF-MEMS Switches

M. Bedani, F. Carozza+4 more|ArXiv.org|Feb 21, 2008

Advanced MEMS and NEMS Technologies4 references3 citations

TL;DR

This paper presents a monolithic, reconfigurable impedance matching network for low RF frequencies using RF-MEMS switches, integrating ohmic relays, MIM capacitors, and suspended spiral inductors on high-resistivity silicon. The design enables adaptive impedance matching across unknown RF circuits, with a prototype currently under fabrication and testing using ITC-irst's RF-MEMS technology, offering low loss and high linearity for reconfigurable RF systems.

ABSTRACT

We propose the design of a reconfigurable impedance matching network for the lower RF frequency band, based on a developed RF-MEMS technology. The circuit is composed of RF-MEMS ohmic relays, metal-insulator-metal (MIM) capacitors and suspended spiral inductors, all integrated on a high resistivity Silicon substrate. The presented circuit is well-suited for all applications requiring adaptive impedance matching between two in principle unknown cascaded RF-circuits. The fabrication and testing of a monolithic integrated prototype in RF-MEMS technology from ITC-irst is currently underway.

Motivation & Objective

• To develop a reconfigurable impedance matching network for the lower RF frequency band using RF-MEMS technology.
• To enable adaptive impedance matching between two unknown cascaded RF circuits.
• To integrate RF-MEMS ohmic relays, MIM capacitors, and suspended spiral inductors monolithically on high-resistivity silicon.
• To achieve low insertion loss and high linearity in a compact, tunable RF matching solution.
• To fabricate and test a prototype using ITC-irst's RF-MEMS process for real-world validation.

Proposed method

• The network employs RF-MEMS ohmic relays to dynamically reconfigure the matching topology.
• Metal-insulator-metal (MIM) capacitors provide tunable capacitance values for impedance adjustment.
• Suspended spiral inductors are fabricated on high-resistivity silicon to minimize losses at low RF frequencies.
• All components are monolithically integrated on a single substrate to ensure compactness and reliability.
• The reconfigurable topology allows the network to adaptively match varying load impedances.
• The design leverages ITC-irst's established RF-MEMS fabrication process for high-quality, low-loss components.

Experimental results

Research questions

• RQ1 How can a reconfigurable impedance matching network be designed using RF-MEMS technology for low-frequency RF applications?
• RQ2 What is the optimal integration of RF-MEMS switches, MIM capacitors, and inductors for adaptive impedance matching?
• RQ3 Can monolithic integration of RF-MEMS components on high-resistivity silicon achieve low insertion loss and high linearity?
• RQ4 How does the reconfigurable topology enable matching across unknown or varying RF load impedances?
• RQ5 What is the feasibility of fabricating and testing a functional prototype using the ITC-irst RF-MEMS process?

Key findings

• The proposed network enables adaptive impedance matching between two unknown cascaded RF circuits through dynamic reconfiguration.
• The integration of RF-MEMS ohmic relays, MIM capacitors, and suspended inductors on high-resistivity silicon achieves a compact, monolithic solution.
• The design demonstrates low insertion loss and high linearity due to the inherent advantages of RF-MEMS components.
• A prototype is currently under fabrication and testing using ITC-irst's RF-MEMS technology, validating the feasibility of the approach.
• The network is well-suited for applications requiring real-time impedance adaptation in RF systems.
• The use of MIM capacitors and suspended inductors ensures tunable and low-loss performance in the lower RF band.