Shinnosuke Soda

Tunable MEMS hybrid coupler and L-band tunable filter

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.

An Rfmems Switched Capacitor Array for a Tunable Band Pass Filter

In this paper, we present an RFMEMS switched capacitor array, which is proposed as a RF component to achieve various kinds of tunable RF filters. Our RFMEMS switched capacitor array consists of RFMEMS direct contact switches and metal-insulator-metal capacitors. In order to obtain reliable capacitors, the metal sacrificial layer for the RFMEMS switch fabrication is also applied to the capacitor implementation. We have achieved a C- to Ku-band tunable band pass filter by using the RFMEMS switched capacitor array. The capacitance of capacitor is designed corresponding to each tuning state of the band pass filter, which is selected by the RFMEMS switch operation. The insertion losses of the band pass filter were 7.1dB, 4.9 dB and 6.2 dB at 8 GHz, 12 GHz and 16 GHz, respectively.

L-band reflection-type RF-MEMS tunable BPF

This paper proposes the reflection-type tunable band pass filter (BPF) for the L band. The filter is composed of two identical MEMS tunable BRFs, which are connected to a 90-degree hybrid circuit. The trial fabrication validates the configuration by showing the low loss in seven bands from 0.8 GHz to 2.4 GHz.