Micromachining Mo/AlN/Mo piezoelectric ring resonators

In this work we introduce a new transmitter/receiver sensor antenna for THz applications, by exploiting piezoelectric Mo/AlN/Mo rings realised through micromachining techniques. This kind of sensor antenna takes advantages of the piezoelectric effect which allows to tune the ring diameter thus enabling the modulation of a THz signal. The theoretical and numerical modelling analyzes a single transmitter/receiver THz sensor system. The numerical finite element method (FEM) modelling provides the radiation pattern of the receiver ring at 1 THz, and the theoretical modelling analyses the modulation principle of the transmitter antenna. We prove the presence of piezoelectric resonances in a frequency range from 30 KHz to 1 GHz by measuring the scattering parameters of four rings arranged on the same chip.