• Journal of electromagnetic engineering and science
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• v.2 no.2
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• pp.59-64
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• 2002

In this paper, 10$\mu$ m-elevated MEMS CPWs on various substrates are presented. Effective dielectric constants of elevated CPW(ECPW) on polyimide-loaded silicon or alumina substrate are examined and characteristic impedances are also computed versus elevation height. Dispersive property of ECPW and its electromagnetic field distributions are studied through 3-D FDTD algorithm for optimum design. Attenuation of ECPW is measured with TRL calibration procedure and revealed about 3.2 43 lower than that of conventional CPW on the same low-resistivity silicon at 40 CHz. ECPW on polyimide-loaded silicon with overlapped configuration reveals 0.2 dB/mm. Especially, alumina substrate imposes better attenuation than silicon.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.623-626
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• 2005

In this paper, we proposed a new type SIR bandpass filter using DAML. This filter is consisted of 2 layers with MEMS resonator layer and CPW feed line. DAML ring resonator is elevated with $10\;{\mu}m$ height from GaAs substrate. Using MEMS processing, we are able to realize SIR bandpass filter easily. Furthermore it is useful to integrate on conventional MMICs because it has CPW interfaces and ring resonator is isolated from substrate by air-gap. We optimized and measured the results that $S_{21}$ attenuation at rejected band is over 15 dB, insertion loss is inside the limit of 3 dB, and relative bandwidth is about 10 % at 60 GHz

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.7-11
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• 2007

In this paper, we proposed the dual-mode stepped impedance ring resonator bandpass filter for MMIC (Microwave Monolithic Integrated Circuit) applications using the dielectric-supported air-gapped microstrip line (DAML). The ring resonator fabricated by surface micromachining technology. This filter consists of a DAML resonator layer and a CPW feed line. The DAML ring resonator is elevated with $10{\mu}m$ height from GaAs substrate surface. This bandpass filter is $1-{\lambda}g$ type stepped impedance ring resonator including dual-mode resonance. From the measurements, we obtained attenuation of over 15 dB and insertion loss of 2.65 dB at the center frequency of 97 GHz. Relative bandwidth is about 12 % at 97 GHz. Furthermore, the proposed bandpass filter is useful to integrate with conventional MMICs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.7 s.98
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• pp.760-767
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• 2005

In this paper, we proposed a new type SIR bandpass filter using DAMLs. This filter is consisted of 2 layers with MEMS resonator layer and CPW feed line. DAMLs ring resonator is elevated with $10{\mu}m$ height from GaAs substrate. Using MEMS processing, we are able to realize SIR bandpass filter easily. Furthermore it is useful to integrate on conventional MMICs because it has CPW interfaces and ring resonator is isolated from substrate by air-gap. We optimized and measured the results that $S_{21}$ attenuation at rejected band is over 15 dB, insertion loss is inside the limit of 3 dB, and relative bandwidth is about $10\%$ at 60 GHz.

• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.335-338
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• 2004

We suggest Q-band MEMS MIMIC (Millimeter wave Monolithic Integrated Circuit) HEMT Oscillator using DAML (Dielectric-supported Airgapped Mcrostrip Line) structure. We elevated the signal lines from the substrate using dielectric post, in order to reduce the substrate dielectric loss and obtain low losses at millimeter-wave frequency. These DAML are composed with heist of $10\;{\mu}m$ and post size with $20\;{\mu}m\;{\times}\;20\;{\mu}m$. The MEMS oscillator was successfully integrated by the process of $0.1\;{\mu}m$ GaAs PHEMTs, CPW transmission line and DAML. The phase noise characteristic of the MEMS oscillator was improved more than 7.5 dBc/Hz at a 1 MHz offset frequency than that of the CPW oscillator And the high output power of 7.5 dBm was measured at 34.4 GHz.