With the arrival of 5G communication era, the resonator with high-frequency and ultra wide-bandwith has become an urgent demand of the communication industry. In this paper, a laterally excited bulk acoustic wave resonator (XBAR) with high frequency and ultra wide-bandwidth is designed and fabricated. The resonance frequency of the A1 mode resonator is 5.81 GHz, electromechanical coupling coefficient is up to 39.6% and a Q-3 dB value is 248, and the A3 mode shows a resonance frequency of 17.04 GHz and electromechanical coupling coefficient of 7.0%.The measured temperature coefficient of frequency (TCF) of the A1 and A3 modes of the resonator are -72.6×10-6/℃ and -38.5×10-6/℃, respectively. In addition, a new interdigital electrode (IDT) structure is proposed in this paper, which can suppress the spurious mode and greatly improve the performance of the resonator.