• 한국항해항만학회지
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• 제36권9호
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• pp.737-740
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• 2012

A miniaturized CMOS bandpass filter for a single RF transceiver system is presented, using diagonally end-shorted coupled lines and lumped capacitors. In contrast to conventional miniaturized coupled line filters, it is proven that the effective permittivity variation of the coupled transmission line has no effect on shifting the center frequency when the bandpass filter is highly miniaturized. A bandpass filter at a center frequency of 2 GHz was fabricated by $0.18{\mu}m$ CMOS technology. The insertion loss with the die area of $1500{\mu}m{\times}1000{\mu}m$ is -5.14 dB. Simulated results are well agreed with the easurements. It also verify the center frequency stability in the compact size bandpass filter.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.17-22
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• 2005

This paper presents a improvement equivalent circuit model for Miniaturized LTCC bandpass filter with two transmission zeros using feed-back capacitor. The bandpass filter equivalent circuit is evaluated by parallel network analysis. Besides, the filter is modeled by proposed passive element modeling algorithm in previous work. Compared to the equivalent circuit of established paper that is configured by excepted capacitance between ground plate and signal plate, this model can include that. The result, the LTCC bandpass filter reduce layers and the size is more smaller.

• 한국항해항만학회지
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• 제31권9호
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• pp.759-762
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• 2007

A novel miniaturized CMOS C-Band bandpass filter based on diagonally end-shorted coupled lines and interdigital capacitors is proposed. The utilized coupled lines structure reduced the configuration in size, as small as a few degrees. Moreover, the characteristic of interdigital capacitor, relatively high Q and good capacitance tolerance, accounts for the satisfied performance of this new filter. A two-stage bandpass filter was designed and fabricated with chip surface area only $1.02{\times}1.4\;mm^2$.

• 한국항해항만학회지
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• 제35권4호
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• pp.299-302
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• 2011

In this letter, the effect of quality factor on center frequency deviation in miniaturized coupled line bandpass filter (BPF) with diagonally end-shorted at their opposite sides and lumped capacitors is theoretically analyzed. The miniaturized BPF of a two-stage structure with two types of quality factors in standard CMOS process was designed and manufactured at 5.5 GHz. The die area of BPF was $1.44{\times}0.41\;mm^2$. The measured center frequency of BPF with a quality factor of 4.9 was deviated from 5.5 GHz to 4.7 GHz. The one with 14.8 was shifted to 5GHz. The theoretical and measured results validate that quality factor influences the center frequency shift of BPF.

• 한국전자파학회논문지
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• 제10권5호
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• pp.680-687
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• 1999

An extensive study on miniaturized bandpass filter(BPF) appropriate for mobile communication systems is presented in this paper. The miniaturization has been accomplished by incorporating low-loss high-index materials inside a resonating cavity fabricated in silicon substrate using micromachining etching techniques. By use of materials with dielectric constant $\varepsilon_r$=500, filters with volume less than 0.11 $mm^3$ have been designed at the center frequency of 5.8 GHz with 3.3% bandwidth. The electrical performances and design tolerances of these filters for a variety of materials and shapes are discussed and design guidelines are presented herein.

• Journal of Electrical Engineering and Technology
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• 제7권4호
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• pp.582-588
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• 2012

In this paper, a highly miniaturized and performed UWB bandpass filter has been newly designed and implemented by embedding all the passive elements into a multi-layered PCB substrate with high dielectric $SrTiO_3$ composite film for 3.1 - 4.75 GHz compact UWB system applications. The high dielectric composite film was utilized to increase the capacitance densities and quality factors of capacitors embedded into the PCB. In order to reduce the size of the filter and avoid parasitic EM coupling between the embedded filter circuit elements, it was designed by using a $3^{rd}$ order Chebyshev circuit topology and a capacitive coupled transformation technology. Independent transmission zeros were also applied for improving the attenuation of the filter at the desired stopbands. The measured insertion and return losses in the passband were better than 1.68 and 12 dB, with a minimum value of 0.78 dB. The transmission zeros of the measured response were occurred at 2.2 and 5.15 GHz resulting in excellent suppressions of 31 and 20 dB at WLAN bands of 2.4 and 5.15 GHz, respectively. The size of the fabricated bandpass filter was $2.9{\times}2.8{\times}0.55(H)mm^3$.

• 한국전자파학회논문지
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• 제10권2호
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• pp.237-246
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• 1999

본 논문에서는 corrugated 구조 도파관의 저역통과 특성과 이중 계단형 불연속 구조 도파관의 고역통과 특성 을 결합하여 기존의 반파장 공진기를 이용한 여파기보다 크기가 상당히 작고 SpUriOUS 특성이 우수한 소형 도파관 대역통과 여파기를 설계하였다. 불연속면에서 발생하는 고차 모드에 의한 영향을 고려하기 위하여 최저차 모드만으로 설계한 여파기의 특성을 길이 보상을 통해 수정하였고, 모드 정합법을 이용한 특성 해석 프로그램과 상용 소프트웨어 $OSA90^{TM}$을 통해 최적화 하였다. 중심주파수 10 GHz, 대역폭 800 MHz의 7단 대역통과 여파기 를 대칭 구조로 설계, 제작하였다. 측정 결과에서 중심주파수 9.97 GHz, 대역폭 840 MHz, 삽입손실 0.97 dB의 특성을 얻었고, 그 길이는 64.38 mm이다. 첫 번째 spunous 응답은 26.1 GHz에서 나타났다.

• Journal of electromagnetic engineering and science
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• 제8권1호
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• pp.12-16
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• 2008

In this paper, we introduce a coupling, which is achieved through the aperture instead of the conventional edge coupling, so that the bandpass filter is reduced less than half in size compared to conventional planar type. The resulting filter configuration has a near two-fold symmetry, where the aperture coupling is used in the middle of the coupling stages. We designed a bandpass filter using two tapped hairpin resonators, of which the order becomes four. The designed bandpass filter has the size of $8.9{\times}18.3\;mm$. It has the return loss better than 17dB and the insertion loss of less than 5 dB in overall passband. The measured results show good agreements with simulated ones.

• 대한전자공학회논문지TC
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• 제38권2호
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• pp.13-18
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• 2001

본 논문에서는 소형화된 구형 SIR(Stepped Impedance Resonators)을 이용하여 IMT-2000에 적용할 수 있는 중심주파수 1.95GHz에서 60MHz의 대역폭을 갖는 4-극 준-타원 함수 대역통과필터를 설계 및 제작하였다. 시뮬레이션은 NUFDTD(Nonuniform Finite Difference Time Domain)을 사용하여 3가지 기본 결합구조에 대한 결합계수를 구하였다. 소형화된 구형 SIR은 기존의 마이크로스트립 구형 개방 루프 공진기 필터 보다 50% 이상의 크기를 감소됨을 알 수 있었다. SIR을 대역통과필터에 적용시 제 3고조파 내에서의 스퓨리어스 응답 특성은 최대 19dB의 우수한 특성을 보였으며, 실험한 결과와 시뮬레이션 결과가 잘 일치하였다.

• 전자공학회논문지D
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• 제34D권9호
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• pp.15-20
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• 1997

Waveguide bandpass filters using E-plane or H-plane discontinuities have been used in many satellite communication systems. Since the transmitter and receiver of such systems tend to be getting smaller, components such as bandpass filters must also be reduced in size. In this paper, in order to reduce the waveguide, itself, of which bandpass filters consist, double plane step waveguide discontinuities are considered. They are analyzed using the mode matching method and the genralized scattering parameter of the cascaded structure is calculated. The characteristics of the bandpass filter which is designed using the reduced size waveguide is optimized by OSA90$^{TM}$. The bandpass filter has a good characteristics and smaller size than those made of the E-plane or H-plane step discontinuities.s.