Title :
Modified ladder-type 2.4GHz SAW filter with transmission zero
Author :
Novgorodov, V. ; Freisleben, S. ; Heide, P. ; Vossiek, M.
Abstract :
This paper describes the design of 2.4-2.5GHz bandpass ladder-type SAW filter and methods to improve its characteristics. The structure of the filter is based on modified π-type topology with external matching inductors. The piezoelectric crystal (LiTaO3) is placed on the low temperature co-fired ceramic (LTCC) substrate while all external elements are completely integrated into LTCC. Input sections of the filter with their characteristics were considered in detail what allowed to reduce the degradation of the filter characteristics due to increasing of its bandwidth. An effective way to create a transmission zero by introduction of magnetic coupling between input and output matching coils is presented in the paper.
Keywords :
UHF filters; band-pass filters; ceramics; ladder filters; lithium compounds; network topology; piezoelectric materials; surface acoustic wave filters; LiTaO3; bandpass ladder-type SAW filter; filter characteristics; frequency 2.4 GHz to 2.5 GHz; low temperature cofired ceramic substrate; magnetic coupling; matching coil; matching inductor; modified π-type topology; piezoelectric crystal; transmission zero; Band pass filters; Bandwidth; Capacitance; Coils; Inductance; Resonant frequency; Resonator filters;
Conference_Titel :
Ultrasonics Symposium (IUS), 2010 IEEE
Conference_Location :
San Diego, CA
Print_ISBN :
978-1-4577-0382-9
DOI :
10.1109/ULTSYM.2010.5935844
