Title :
Reconfigurable multiband SAW filters for LTE applications
Author :
Xiaoming Lu ; Galipeau, J. ; Mouthaan, K. ; Briot, E.H. ; Abbott, B.
Author_Institution :
ECE Dept., Nat. Univ. of Singapore, Singapore, Singapore
Abstract :
Reconfigurable surface acoustic wave (SAW) filters are presented for the 700 MHz frequency band currently allocated to Long Term Evolution (LTE). Unlike traditional SAW filters with a fixed center frequency, the proposed filters have a reconfigurable center frequency. First, a novel modular ladder type topology is proposed incorporating SAW resonators and GaAs Single Pole Single Throw (SPST) switches within the basic reconfigurable filter. The measured center frequency in the low band state is 696 MHz and the BW is 3.4%. In the high band state the measured center frequency is 718 MHz and the BW is 2.6%. The center frequency shift is 3.2%. Spurious responses caused by switches are an important design consideration and the root causes of the spurious responses in high band and low band are identified. Then a novel filter topology using Single Pole Double Throw (SPDT) absorptive switches is proposed to remove the spurious responses in the high band state. Finally the root cause of the remaining spurious response is analyzed and a solution is proposed.
Keywords :
III-V semiconductors; Long Term Evolution; gallium arsenide; ladder filters; surface acoustic wave filters; GaAs; GaAs single pole single throw; LTE; Long Term Evolution; SAW resonator; SPDT absorptive switches; SPST switches; filter topology; frequency 696 MHz; frequency 700 MHz; frequency 718 MHz; modular ladder type topology; reconfigurable center frequency; reconfigurable multiband SAW filter; single pole double throw switches; spurious response; surface acoustic wave; Filter banks; Frequency measurement; Insertion loss; Loss measurement; Resonant frequency; Resonator filters; SAW filters; LTE; SAW filters; reconfigurable; switch;
Conference_Titel :
Power Amplifiers for Wireless and Radio Applications (PAWR), 2013 IEEE Topical Conference on
Conference_Location :
Santa Clara, CA
Print_ISBN :
978-1-4673-2915-6
Electronic_ISBN :
978-1-4673-2931-6
DOI :
10.1109/PAWR.2013.6490196