Microwave demonstration of Purcell effect enhanced radiation efficiency

We experimentally demonstrate a Purcell effect-based design technique for improved impedance matching, and thus enhanced the reflection coefficient 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 1.99 GHz and 2.84 GHz, yielding Purcell enhancement factors of 1762 and 411 times increase respectively, and near perfect radiation efficiency.

Automated summary

We experimentally demonstrate a Purcell effect-based design technique to improve the impedance matching and reflection coefficient of a small microwave emitter. By comparing the radiated field phase in air and in a dielectric environment, we optimize the structure of a dielectric hemisphere above a ground plane, resulting in a significant increase in radiation efficiency. The optimized system exhibits strong coupling with two omnidirectional radiation modes at 1.99 GHz and 2.84 GHz, achieving Purcell enhancement factors of 1762 and 411 times, respectively, and near perfect radiation efficiency.