Title :
Wide piezoelectric tuning of LTCC bandpass filters
Author :
Al-Ahmad, Mahmoud ; Maenner, Ruth ; Matz, Richard ; Russer, Peter
Abstract :
The increasing number of frequency bands and services in wireless communications is causing a demand for analogue active and passive frontend components with wide bandwidth or tuning range, respectively. Similar to micro-electromechanical systems (MEMS), this work presents a parallel plate capacitor with multilayer dielectrics and piezoelectrically movable top electrode as an advantageous tunable element with no addition of any lossy material. When applied as a shunt capacitor in a coupled microstrip-line LTCC bandpass filter, the center frequency of the filter is tuned from 1.1 GHz to 2.6 GHz with 200 V control voltage and low insertion loss of 2 to 4 dB. The analysis of the device by full-wave simulation reveals a potential tuning range from 0.8 GHz to 2.8 GHz when the thin-film processability of the LTCC surface is properly controlled.
Keywords :
UHF filters; band-pass filters; capacitors; circuit tuning; coupled circuits; crystal filters; microstrip filters; 0.8 to 2.8 GHz; 1.1 to 2.6 GHz; 2 to 4 dB; 200 V; coupled microstrip-line LTCC bandpass filter; filter tuning; multilayer dielectrics; parallel plate capacitors; piezoelectric materials; piezoelectrical movable top electrode; shunt capacitors; thin film processing; tunable filters; wide piezoelectric tuning; Band pass filters; Bandwidth; Capacitors; Dielectric losses; Frequency; Microelectromechanical systems; Micromechanical devices; Nonhomogeneous media; Tuning; Wireless communication;
Conference_Titel :
Microwave Symposium Digest, 2005 IEEE MTT-S International
Print_ISBN :
0-7803-8845-3
DOI :
10.1109/MWSYM.2005.1516910
