New type of band-pass filters for mobile radio communication equipment

This paper describes compact band-pass filters for duplexer of 900 MHz high capacity mobile radio communication equipment. Band-pass filters developed here are constructed with a newly developed resonator of which Q-factor is higher than conventional capacitor-loaded resonators especially in the range of the small size resonator. Another type of filter with this resonator is fabricated using high dielectric material which was developed for the purpose of resonators at microwave frequency.