• 한국전자파학회논문지
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• 제14권12호
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• pp.1264-1268
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• 2003

본 논문에서는 밀리미터파 대역에서 NRD guide를 이용한 듀플렉서를 설계하였다. 설계된 듀플렉서는 두개의 stepped-impedance 필터와 한 개의 T-Junction으로 구성되어 있다. 차단영역 도파관 등가회로를 이용하여 stepped-impedance 필터를 설계하였고, T-Junction은 반사손실을 -20 dB 이하로 최적화하였다. 듀플렉서를 제작하여 측정한 결과 응답특성이 시뮬레이션 결과와 일치함을 확인하였다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.169-172
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• 2002

In this paper, the design formulas for bandpass filters using parallel coupled stepped impedance resonators(SIR) are derived. General content about basic feature of stepped impedance resonators(SIR) is represented. The filters and duplexer using stepped impedance resonators(SIR) have been designed and realized with the presented design method at IMT-2000 frequency band Simulations have used serenade circuit simulation and HFSS EM-simulation. We were showed excellent agreements between SIR design theory and simulation results on the multi-layer filter/duplexer.

• Journal of electromagnetic engineering and science
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• 제11권2호
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• pp.91-96
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• 2011

In this paper, we propose a microstrip bandpass filter using stepped-impedance coupled-line hairpin resonators. The stepped-impedance coupled-line hairpin resonator has extended harmonic suppression in comparison with a conventional hairpin resonator due to transmission zero and the movement of harmonic frequencies resulting from the stepped-impedance characteristic. A high-pass type impedance/admittance inverter is employed in order to improve the lower frequency skirt characteristics of the passband. A 4-pole bandpass filter is designed and fabricated at 1.8 GHz. The measured results show the excellent attenuation performance at the stopband which is greater than 30 dB up to 10 GHz.

• 대한전자공학회논문지SD
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• 제44권12호
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• pp.7-11
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• 2007

본 논문에서는 MMIC 응용을 위한 dielectric-supported air-gapped microstrip line (DAML) 구조를 이용하여 dual-mode stepped impedance 링 공진기를 설계 제작하였다. 링 공진기는 표면 마이크로머시닝 기술을 이용하여 만들어졌다. DAML ring resonator는 다층구조로써 공기중에 위치한 신호선과 MMIC 응용에 적합하도록 CPW가 한 평면에 구성되 있으며 DAML-CPW 트랜지션이 자유로운게 특징이다. DAML 링 공진기는 $10{\mu}m$ 높이로 GaAs 기판 으로부터 띄어져 있다. 대역통과 여파기는 dual-mode 공진을 하며 stepped impedance 이용한 구조이다. 측정결과로 중심주파수 97 GHz에선 감쇠특성은 15 dB, 삽입손실은 2.65 dB를 보였으며, 상대 대역폭은 12 %를 나타냈다. 이같은 구조의 대역통과 여파기는 MMIC 와의 직접화에 유리하다.

• Journal of electromagnetic engineering and science
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• 제10권1호
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• pp.1-5
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• 2010

A spurious suppressed bandpass filter is proposed and discussed using the stepped impedance resonator(SIR) on a substrate-integrated waveguide(SIW) structure with a double-layer substrate. The second resonance of the fundamental $TE_{10}$ mode can be controlled by adjusting the electrical length and impedance ratio of each SIR. The spurious suppressed SIW bandpass filter shows the measurement results of the insertion loss of 3.98 dB and return loss of less than 11.58 dB at the center frequency of 12 GHz. Also, the second spurious frequency is improved to about $1.5f_0$ compared with $1.33f_0$.

• ETRI Journal
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• 제32권1호
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• pp.148-150
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• 2010

This letter presents the design of a compact bandstop filter (BSF) operating at two frequencies. The proposed BSF consists of open-ended stepped impedance resonators (OSIR) and an end-shorted parallel-coupled microstrip line (E-PCML). The OSIRs are used to achieve the impedance-controlled stopband positions. The wide BSF bandwidths are achieved through enhanced coupling of the E-PCML. Explicit design guidelines are derived using a lossless transmission line model. To validate theoretical predictions, a prototype dual-band BSF operating at 900 MHz and 2,100 MHz with fractional bandwidths of 72% and 36%, respectively, is implemented in microstrip.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.625-628
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• 1998

This paper presents the design method of a temperature stable stepped-impedance resonator using composite material. In this method temperature coefficient of dielectric constant $(\tau\varepsilon)$ and thermal expansion coefficient $(\alpha1)$ of dielectric material were considered. Ba(Zn1/3Nb2/3)O3 and CaZrO3 as composite material having opposite signs of temperature coefficient of dielectric constant were selected. The length of this resonator for the temperature stability of resonance frequency was calculated at 900MHz, 1.4㎓ and 1.9㎓. It was found that the ratio of the length of positive $\tau\varepsilon$ materal to the length of negative $\tau\varepsilon$ material is constant at various resonance frequencies.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.150-154
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• 2003

In this letter, a novel compact duplexer which consists of Tx and Rx Filter using microstrip line ${\lambda}/4$ resonators with a pair of tap-connected open-ended stepped impedance stubs is designed. The tapped open stubs not only work as K-inverters but also introduce attenuation poles, attenuation poles are located at upper and lower side of the passband by adjusting the open stub length and width. The result of measurement duplexer has been yielded better isolation and sharper skirt behavior than that with a conventional bandpass filter and similar to those of simulation results.

• Journal of electromagnetic engineering and science
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• 제7권4호
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• pp.190-194
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• 2007

In this paper, a cross-coupled microstrip combline bandpass filter using stepped-impedance resonators(SIRs) is proposed. In order to improve the selectivity as well as the insertion loss, the SIR configuration is used. The cross coupling is also introduced to enhance the selectivity. The improvement of the insertion loss is demonstrated not only by deriving the quality factor of the SIR but through the measured performances. Both the proposed and the conventional combline bandpass filter with 5 % of fractional bandwidth at 2 GHz were fabricated and tested. Compared to the conventional combline bandpass filter, the proposed one exhibits the improved selectivity as well as the lower insertion loss characteristics.

• 한국전자파학회논문지
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• 제13권10호
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• pp.1078-1082
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• 2002

두 스텁이 커플된 마이크로스트립 계단 임피던스 저역통과 필터의 전송선로의 폭과 edge 캐패시턴스의 변화에 따른 삽입손실 특성을 연구하였다. 이 구조에서 커플링효과는 전송선로의 폭과 스텁의 갭 간격에 의존하며 적절한 조건에서 3개의 감쇄폴이 생겨 넓은 저지대역을 가진다. 또한, 두 스텁 사이에 존재하는 edge 캐패시턴스는 3개의 감쇄폴을 가지기 위해서 중요한 역할을 한다. 이것을 [S] 파라피터를 구하여 확인했다.