A 800 MHz band highly miniaturized radio frequency filter

An extermely small and low loss 800 MHz band filter has been developped to be used for a personal radio telephone equipment. The filter utilizes dielectric-loaded resonators and inter-resonator coupling through the small air spacing between the resonators. The experimental five stages Tschebyshev respone filter having 20 MHz band width and 1.4 dB insertion loss has the reduced volume of 10cm³and weight of 60 gramms.