A line of cavity bandpass filters from Anatech Microwave Co. has been developed for outdoor use in 2.4-GHz WiFi systems. The compact filters measure just 108 x 56 x 21 mm and are supplied with female Type N connectors. The typical insertion loss is less than 3 dB across a 22-MHz passband, with better than 15-dB return loss. The filters provide more than 60-dB out-of-band rejection and feature amplitude ripple of less than 0.25 dB across the passband. Harmonic rejection is more than 90 dB. The miniature WiFi filters can handle power levels to 50 W. They are rated for operating temperatures from -40 to +85 deg. C.