Hybrid Filter for 5G and 6G Applications

This paper gives a brief introduction on the radio frequency (RF) filter technologies that have been used for wireless communications. A hybrid filter design methodology is proposed to address the emerging challenges in the 5G and 6G wireless communication systems. The hybrid filter approach utilizes the co-design of integrated passive device (IPD) inductors (capacitors) and acoustic resonators to realize wide bandwidth (> 500 MHz) and high rejection (transition < 200 MHz) simultaneously. In this way, hybrid filters can achieve almost arbitrary wide bandwidth, which far exceeds the limitation posed by the electromechanical coupling coefficient of acoustic resonators in traditional ladder-type of filter design.