Novel Internet of Things (IoT) and 5G applications are driving the demand for faster wireless data exchange in a wide frequency range. Acoustic ultra-high-frequency (UHF) filters implementing piezoelectric resonators are among the most promising solutions to enable radio frequency (RF) front-end modules with large bandwidth and low insertions losses at the frequencies targeted by these new technologies. This thesis focuses on the design and optimization of one and two ports Aluminum Nitride based Two-Dimensional-Mode Resonators (2DMRs) for wide band applications. In the first part, a detailed analysis of the 2DMR state-of-the-art is reported and compared to other classes of acoustic resonators in terms of performance and scalability limitations.