Microwave Demonstration of Purcell Effect Enhanced Radiation Efficiency

TL;DR

This paper experimentally demonstrates a microwave design technique based on the Purcell effect to significantly enhance radiation efficiency of small emitters through dielectric environment optimization.

Contribution

It introduces an iterative dielectric optimization method leveraging the Purcell effect to improve microwave emitter radiation efficiency.

Findings

Achieved Purcell enhancement factors of 8360 and 430 at specific frequencies.

Demonstrated near-perfect radiation efficiency in the optimized system.

Established a practical approach for impedance matching and efficiency improvement.

Abstract

We experimentally demonstrate a Purcell effect-based design technique for improved impedance matching, and thus enhanced radiation efficiency from a small microwave emitter. Using an iterative process centred on comparing the phase of the radiated field of the emitter in air with that of the emitter in a dielectric environment, we optimise the structure of a dielectric hemisphere above a ground plane surrounding a small monopolar microwave emitter in order to maximise its radiation efficiency. The optimised system shows very strong coupling between the emitter and two omnidirectional radiation modes at 2.00 GHz and 2.84 GHz, yielding Purcell enhancement factors of 8360 and 430 times increase respectively, and near perfect radiation efficiency.