Filters

Filters are frequency-selective components that pass desired signals while attenuating unwanted frequencies — essential for EMI compliance, signal integrity, and RF selectivity. This category includes EMI/RFI filters (feedthrough capacitors, ferrite cores, common mode chokes), SAW (surface acoustic wave) filters, BAW (bulk acoustic wave) filters, ceramic filters, LC filters, and active filters. Key parameters for EMI filters: insertion loss vs frequency, rated current/voltage, DC resistance, and form factor (feedthrough, SMD chip, panel mount). For SAW/BAW filters: center frequency, bandwidth, insertion loss, and out-of-band rejection — critical for cellular (4G/5G), Wi-Fi, and GPS front-end modules. Popular manufacturers: Murata, TDK, Taiyo Yuden, Qualcomm (RF360), Qorvo, AVX/Kyocera, and Schaffner.