Abstract: Phase-change material (PCM)-based RF switches are promising candidates for reconfigurable wireless systems due to their low insertion loss, high isolation, non-volatile operation, and scalability towards millimetre-wave frequencies. Among PCM materials, germanium telluride (GeTe) offers a favourable combination of low crystalline-state resistance and large resistance contrast between its crystalline and amorphous phases. However, achieving broadband RF performance at high frequencies remains challenging due to electromagnetic effects and structural non-idealities.

This work presents the electromagnetic optimisation and electrothermal validation of a four-terminal single-pole single-throw (SPST) GeTe RF switch through full-wave electromagnetic and multiphysics simulations. A coplanar waveguide (CPW)-based methodology is developed to enhance field confinement, suppress radiation loss, control conductor and dielectric attenuation, and maintain impedance continuity. The resulting framework is applied to develop an optimised CPW architecture and a novel via-assisted grounded coplanar waveguide (GCPW) GeTe RF switch architecture. The final CPW and via-assisted GCPW designs demonstrate broadband operation up to 180 GHz and 145 GHz, respectively, while maintaining insertion loss below 1 dB and isolation above 25 dB across the operating bandwidth. Electrothermal simulations confirm successful phase-transition operation through Joule heating. Reliable SET and RESET switching are demonstrated using 7 V, 990 ns and 10.6 V, 190 ns voltage pulses, respectively. The combined electromagnetic and electrothermal design methodology establishes a practical framework for the development of broadband, low-loss, and highly reconfigurable GeTe RF switches for future mmWave communication systems.

Event Details
Title: Electromagnetic Layout Optimisation of a GeTe Phase Change RF Switch with Electrothermal Validation
Date: June 24, 2026 at 03:00 PM
Venue: Google Meet (https://meet.google.com/udr-ifwg-ffd)
Speaker: Mr. AASTIK (EE23S043)
Guide: Dr. Anbarasu Manivannan
Type: MS seminar

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