A New Generation of 5G Filter Technology

5G implementation is accelerating worldwide, creating new challenges for wireless technology in mobile devices. The drive to deliver higher data rates with 5G has resulted in an enormous increase in RF complexity: the use of new higher-frequency bands, increasing complexity of modulation schemes, increasing number of antennas, carrier aggregation (CA) and E-UTRA New Radio Dual Connecticity (EN-DC) are all being used extensively to increase  bandwidth. These trends increase the probability of interference in mobile devices and to mitigate this, advances in RF filtering technology are required. Space available for the RF front end (RFFE) is shrinking, which means filters must also become smaller and more highly integrated. If that wasn’t enough, filters also need to handle higher power to maintain adequate design margins and maximize handset operating range.

Bulk acoustic wave (BAW) filters are evolving to address these challenges, along with other approaches such as antenna routing and antenna tuning. BAW technology is advancing toward handling higher frequencies up to 7 GHz – the upper limit of 5G frequency range 1 (FR1). BAW filters provide low insertion loss that helps maintain RF output power and steep skirts to avoid interference, which makes them extremely efficient at dissipating heat at high power levels. A new generation of BAW technology, called micro-BAW (µBAW), saves board space by making filters smaller and easier to integrate into RFFE modules that support 5G requirements.