• 한국항행학회논문지
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• 제27권1호
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• pp.57-62
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• 2023

본 논문은 이중 모드 SIR(stepped-impedance resonator)과 평행 결합선로를 이용한 3중-대역 대역통과 필터를 제안한다. 제안된 필터는 단락 종단을 갖는 inter-digital 및 comb-line 형태의 평행 결합선로와 개방형 스터브를 갖는 U-자형 SIR로 구성되었다. 개방형 스터브가 있는 2개의 U-자형 SIR은 첫 번째와 세 번째 통과 대역을 만들고, 중앙의 평행 결합선로 공진기는 두 번째 통과 대역을 만든다. 5개의 공진기와 평행 결합선로 구조의 우/기모드 입력 임피던스를 해석하여 3중-대역 대역통과 필터의 산란 파라미터를 유도하였다. 유도된 산란 파라미터를 이용하여 새로운 3중-대역 대역통과 필터를 설계하고 제작하였다. 제작된 필터는 0.2×0.19 λ_g²의 작은 크기를 가지며, 측정 결과는 높은 대역 격리도를 보여 주고 있다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 통신소사이어티 추계학술대회논문집
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• pp.317-322
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• 2003

In this paper, we design a slow-wave bandpass filter that uses a microstrip line periodically loaded with microstrip ing resonators for WLAN(5 GHz). Unlike conventional slow-wave filters, this filter is designed to produce a narrow passband at the fundamental mode of the resonators and provide lower insertion loss than that of parallel- or cross-coupled ring bandpass filters. A PBG(Photonic Band Gap) structure patterned in the ground plane is used to suppress the spurious transmission and extend out-of-band rejections Experimental result shows that the first spurious response in the stopband of the slow-wave bandpass filter can be rejected using a PBG structure.

• 전기학회논문지
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• 제57권11호
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• pp.2127-2130
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• 2008

In this paper, a tunable bandpass filter with mutual inductive coupling circuits is newly designed and demonstrated for UHF TV tuner ranged from Ch.14(473MHz) to Ch.69(803MHz) applications. Conventional HF tuning circuit with an electromagnetic bandpass filter has several problems such as large size, high volume and high cost, since the electromagnetic filter is comprised of several passive components and air core inductors to be assembled and controlled manually. To address these obstacles, peaking chip inductor was newly applied for constructing the mutual inductive coupling circuit. The proposed circuit was newly and optimally designed, since the chip inductor showed lower components Q-value than the air core inductor. A varactor diode has been also used to fabricate the proposed tunable bandpass filter for RF tuning circuit. The fabricated tunable filter exhibited low insertion loss of approximately -3dB, high return loss of below -10dB, and large tuning bandwidth of 330MHz.

• 전자공학회논문지A
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• 제32A권9호
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• pp.1229-1235
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• 1995

In this paper an elliptic response dual-mode 4-pole bandpass filter was designed, manu-factured, and tested. A dual-mode filter having two stages cascaded double-tuned cavities which are resonant in two independent orthogonal TE113 circular-cavity modes and provide a bandpass response. A 4-pole dual-mode elliptic function bandpass filter has a center frequency of 14.022 GHz with a bandwidth of 36 MHz which is the first channel of the KOREASAT up-link frequency. The measured experimental results of a dual-mode filter are 1 dB insertion loss in the passband and 20 dB out-of-rejection.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.278-282
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• 2003

The rapid growth of wireless and mobile communications has stimulated the development of multilayer filter technology. In this paper, one type of aperture-coupled microstrip interdigital-loop resonators in a multilayer structure are proposed and investigated for the applications to the design of a new class of compact microstrip bandpass filter. The new filter configuration consists of two arrays of microstrip interdigital-loop resonators that can be coupled through the apertures on the common ground plane. Depending on the arrangement of the apertures, different filtering characteristics can easily be realized. The results of measurement are almost similar to those of simulation.

• Journal of electromagnetic engineering and science
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• 제13권4호
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• pp.263-266
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• 2013

A novel compact and low-loss VHF bandpass filter is presented with enhanced stopband performance using metamaterial zeroth order resonator (ZOR) characteristics. An in-line ZOR filter is initially suggested and changed to have transmission zeros (TZs) due to source-load coupling for effective improvement of the isolation from UHF wireless channels. The proposed filter is smaller than 1/10 of the conventional filters in terms of size and has relatively very low insertion loss (< 1 dB for the electromagnetic (EM) simulation and < 3 dB for the measurement) and return loss (<-20 dB) in the passband due to the approximately 80% size reduction and the higher isolation in the stopband due to the TZs. The circuit and EM simulation are in good agreement with the measurements.

• Journal of Electrical Engineering and Technology
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• 제8권2호
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• pp.371-375
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• 2013

The design of a new compact UWB bandpass filter is proposed, which has cascaded center-tapped microstrip composite right/left-handed transmission-line zeroth-order resonators (CRLH-TL ZORs). In an attempt to reduce the size, instead of the conventional half-wavelength resonators or periodic and multiple CRLH-TL cells, only one cell ZOR geometry is adopted as each resonator in the filter. Additionally, two center-tapped ZORs are coupled to increase the slope of the skirt. Besides, stepped impedance matching parts are placed in the paths to the input and output ports to enhance passband and stopband performances. The proposed filter is shown to have the overall size of $0.69{\lambda}_g{\times}0.70{\lambda}_g$, the insertion loss much less than 1 dB, and an acceptable return loss performance in the predicted and measured results.

• ETRI Journal
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• 제33권6호
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• pp.953-956
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• 2011

A novel dual-mode bandpass filter (BPF) using a dual spiral-shaped defected ground waveguide (DGW) resonator is proposed in this letter. The dual-mode characteristic of this filter is achieved by loading a defected T-shaped stub at the midline of the spiral-shaped DGW resonator. Also, non-orthogonal input and output feed-lines are adopted in the filter. Based on the compact DGW structure, a dual-mode BPF with central frequency of 1.5 GHz for the global positioning system is designed, fabricated, and measured. Measured results agree well with the predicted response and verify the proposed methodology.

• 한국전자파학회논문지
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• 제22권1호
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• pp.9-15
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• 2011

E 모양의 이중 모드 공진기를 변형하여 상.하측 대역의 대역폭 조절이 가능한 이중 대역 통과 필터를 설계 제작하였다. 변형된 E 모양의 이중 모드 공진기를 이용하여 even 모드 간의 결합이 odd 모드 공진점에 영향을 미치지 않게 만들었고, 이를 통하여 상측 대역의 대역폭을 효과적으로 조절할 수 있다. 그리고 급전 선로간의 결합을 통하여 차단 대역에 전송 영점을 발생시켜 차단 특성을 높였다. 대역폭 조절이 가능함을 보이기 위해 중심 주파수 2 GHz와 3 GHz에서 140 MHz의 동일한 대역폭을 갖는 필터를 설계하였다.

• 한국전자파학회논문지
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• 제15권2호
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• pp.159-164
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• 2004

본 논문에서는 SIR CPW 대역통과 여파기의 고조파 억압을 위한 접힌 피드 구조를 제안하였고 이를 이용해 SIR CPW 대역통과 여파기를 설계하였다. 제안된 접힌 피드 구조는 넓은 저지대역을 갖는 저역통과 여파기의 특성을 보이며, CPW 대역통과 여파기에서 고조파 억압에 매우 유용하게 이용될 수 있다. 시뮬레이션 및 측정결과 접힌 피드 구조를 갖는 SIR CPW 대역통과 여파기는 5.8 f$_{0}$까지 -20 dB 이 하로 고조파를 억압하는 우수한 특성을 보임을 알 수 있었다.다.