• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.7 no.6
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• pp.31-37
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• 2008

In order to organize the Intelligent Transport System(ITS) as a communication equipment, the satellite and wireless system demand broadband characteristics for collecting information from the wide road. Band-pass filters (BPF) or broad BPFs used in such communication system are required for broadband characteristics. This paper presents a design of such broad BPF which can be used in the system. Designed BPF which was difficult to get broadband characteristics after realization, become possible to realize filter with broad bandwidth and compact structure using parallel coupled line. The designed filter achieved the insertion losses improved by 0.4 dB and the return losses improved by 17.4 dB respectively with 60% of bandwidth at the 5.8 GHz of the center frequency, respectively.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.3
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• pp.9-16
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• 1997

A 23GHz 1-stage LNA was designed by using new topology of coupled line type with EEsof softwares and modified by using MPIE numerical analysis. The parallel coupled filter-type matching sections give impedance matching and DC blocking simultaneously, and have small discontinuities. This matching scheme has simple structure in the design process and give small error. The EFT chip was directly attached to the ground metal. The designed LAN gives 6.2dB gain and 2.5dB noise figure without considering the loss of connectors. Through these results, it was verified that our design process, matching schemes and fabrication technologies was valied for developing 20GHz-band LNA.

• Journal of the Microelectronics and Packaging Society
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• v.11 no.4 s.33
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• pp.7-11
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• 2004

In this paper, a $\lambda$/4 hairpin resonator is applied to reduce the size of planar resonators for a 2.4 GHz Band LTCC MLC bandpass filter. The $\lambda$/4 hairpin resonator operates as stepped impedance resonator (SIR) without changing the width of the planar resonator. It is composed of two sections those are parallel coupled line and transmission line. The characteristic impedance of two sections is different each other. The design formulas of the bandpass filter using the coupling element at the arbitrary position are derived from even and odd-mode analysis. The formulas can take account of the arbitrary coupling of lumped and/or distributed resonators. The advantage of this filter is its abilities to change freely the coupling structure between two resonators. Experimental bandpass filters for 2.4 GHz Band are implemented and their performances are shown.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10A
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• pp.1031-1036
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• 2006

This paper proposes a novel BPF structure with less insertion loss and small size instead of the existing coupled line BPF for the output of the tripler using APDP (Anti-Parallel Diode Pair). This proposed BPF consists of the interdigital capacitor and spiral open stub. The proposed BPF has the insertion loss of less than 0.7dB within the band $(16.41{\sim}19.23GHz)$. The conversion loss of the tripler is about $16.6{\sim}18.5dB$ $(flatness<{\pm}1dB)$ at $5.72{\sim}6.28GHz$ of fundamental frequency. Its fundamental frequency and the fifth harmonic suppression characteristic at 6GHz are -32.16dBc and -44.6dBc, respectively And its phase noise attenuation characteristic is about 9.5dB at 100kHz.

• Progress in Superconductivity
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• v.4 no.2
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• pp.121-126
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• 2003

The single layer direct-coupled YBCO SQUID magnetometers have been fabricated and characterized for the purpose of the measurement of weak magnetic signals in unshielded environment. Two types of magnetometers have been designed and fabricated using 10 mm$\times$ 10 mm substrates. We could operate the conventional 3-mm-wide solid pickup loop magnetometers more stably than the 12-parallel-line pickup loop magnetometers in laboratory environment. We developed a first-order electronic gradiometer system using the SQUID sensors with axial displacement of 80 mm without any mechanical alignment of magnetometers. The system with a software filter using calculation of discrete Fourier transform could record clearly weak pulse signal of 100 pT in a magnetically disturbed environment.

• Proceedings of the KAIS Fall Conference
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• 2006.05a
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• pp.381-383
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• 2006

본 논문에서는 5.8Ghz ISM대역 평행 결합선로 대역통과 여파기를 설계 제작하였다. 긴본적인 설계는 저역통과 여파기에서 대역통과 여파기로 변환한 후, 직 병렬 공진기를 이용한 설계와 J-인버터를 이용해 평행 결합선로 대역통과 여파기를 구현하였다. 2개의 공진 주파수를 실제로 구현하기 어렵기 때문에 하나의 공진기만을 사용하기 위해 인버터를 사용하였다. 또한 실제적인 마이크로스트립 라인의 layout크기를 결정하기 위해 우수 기수 모드 임피던스를 해석하고 근사식을 통해 스트립라인의 치수를 결정하였다. 이런 과정을 토대로 5.8GHz ISM밴드용 평행 결합선로 대역통과 여파기를 설계, 제작하였다.

• 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.681-689
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• 2005

This paper presents an ultra wide band(UWB) mixer using anti-parallel diode pair(APDP) with simulation and measurement results. The proposed mixer adopts the even-harmonic direct conversion mixing, which consists of a couple of filter, in-phase wilkinson power divider, wideband $45^{\circ}$ power divider, and APDP. The m mixer is operating over 3.1 to 4.8 GHz and producing quadrature(I/Q) outputs with a conversion loss of 18 dB and input third order intercept point($IIP_3$) of 15 dBm. I/Q outputs also have difference of about 0.5 dB and phase difference of ${\times}3^{\circ}$ and $P_{1dB}$ of 2 dBm.