Research on the Current Situation and Development Trend of Wireless Base Station Filters

The rapid development of wireless base stations drives the continuous evolution of base station filters. In the 4G system, high-power filters tend to be miniaturized, low-cost and high-power. Filters or duplexer are mainly metal coaxial cavities and will be replaced by dielectric waveguide duplexers step by step.. The 5G low-frequency filters also tend to be miniaturized and low-cost .They are mainly based on metal and ceramic solutions, and will gradually transition to RF front-end filters, including bulk acoustic wave (BAW) and low-temperature co-firing ceramic (LTCC). The antenna-in-package (AIP) form of filter and antenna integration is a mature millimeter-wave technology at present. The frequency selection surface or plasma form in the THz filter may be the key technology in the future. In addition, filtering antenna, Multi-bands, ultra-wideband, and tunable filters are also new technologies of base station filters in the future.