TY - GEN
T1 - Tunable MEMS hybrid coupler and L-band tunable filter
AU - Nishino, Tamotsu
AU - Kitsukawa, Yusuke
AU - Hangai, Masatake
AU - Lee, Sang Seok
AU - Soda, Shin Nosuke
AU - Miyazaki, Moriyasu
AU - Naitoh, Izuru
AU - Konishi, Yoshihiko
PY - 2009
Y1 - 2009
N2 - Simultaneous control of frequency and coupling coefficient of a directional coupler provides a wide band tunable hybrid coupler. This hybrid coupler is combined with identical two tunable band rejection filters (BRF), to achieve a small-size wide-band tunable band pass filter (BPF). The BPF is called a reflection-type BPF and has a feature of converting rejection frequency bands of the BRF to pass frequency bands. In this paper, we derive the minimum insertion/reflection loss of the lumped element BPF and BRF, considering only the equivalent series resistance (ESR) of tuning devices. The results showed their minimum insertion loss was -5.2dB and reflection loss was -0.35dB if the ESR is 1Ω. Considering the results, we prioritize a reflection-type filter as a prospective low insertion loss tunable BPF. Even though the BRF could be miniaturized and be adapted to wide frequency region by adopting lumped elements, the hybrid coupler might restrict the wide tuning range. Then we propose new tunable hybrid coupler, which alters its coupling coefficient as well as its center frequency, to provide equal transmission and coupling coefficients in wide frequency range. Validation has been done by fabricating tunable BPF composed of 1.2/2GHz selectable MEMS hybrid coupler and 800MHz-2.4GHz seven-band MEMS tunable BRF. The total loss was around -5dB and filter size was as small as 5.2 x 12.3mm2.
AB - Simultaneous control of frequency and coupling coefficient of a directional coupler provides a wide band tunable hybrid coupler. This hybrid coupler is combined with identical two tunable band rejection filters (BRF), to achieve a small-size wide-band tunable band pass filter (BPF). The BPF is called a reflection-type BPF and has a feature of converting rejection frequency bands of the BRF to pass frequency bands. In this paper, we derive the minimum insertion/reflection loss of the lumped element BPF and BRF, considering only the equivalent series resistance (ESR) of tuning devices. The results showed their minimum insertion loss was -5.2dB and reflection loss was -0.35dB if the ESR is 1Ω. Considering the results, we prioritize a reflection-type filter as a prospective low insertion loss tunable BPF. Even though the BRF could be miniaturized and be adapted to wide frequency region by adopting lumped elements, the hybrid coupler might restrict the wide tuning range. Then we propose new tunable hybrid coupler, which alters its coupling coefficient as well as its center frequency, to provide equal transmission and coupling coefficients in wide frequency range. Validation has been done by fabricating tunable BPF composed of 1.2/2GHz selectable MEMS hybrid coupler and 800MHz-2.4GHz seven-band MEMS tunable BRF. The total loss was around -5dB and filter size was as small as 5.2 x 12.3mm2.
KW - Lumped-element filters
KW - Reflection-type filters
KW - RF-MEMS
KW - Tunable couplers
KW - Tunable filters
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U2 - 10.1109/MWSYM.2009.5165879
DO - 10.1109/MWSYM.2009.5165879
M3 - Conference contribution
AN - SCOPUS:77949998084
SN - 9781424428045
T3 - IEEE MTT-S International Microwave Symposium Digest
SP - 1045
EP - 1048
BT - IMS 2009 - 2009 IEEE MTT-S International Microwave Symposium Digest
T2 - 2009 IEEE MTT-S International Microwave Symposium, IMS 2009
Y2 - 7 June 2009 through 12 June 2009
ER -