Complex Quadruplet Zero Locations from the Perturbed Values of Cross-Coupled Lumped Element

Kee-Hong Um 한국인터넷방송통신학회 2017 Journal of Advanced Smart Convergence Vol.6 No.4

In this paper, complex quadruplet zeros of microwave filter systems are investigated. For the cascaded systems the chain matrices are most conveniently used to derive the voltage transfer function of Laplace transform with cascaded two-port subsystems. The convenient relations of transfer function and chain matrix are used in order to find the transmission zeros. Starting from a ladder network, we introduced a crossed-coupled lumped element, in order to show the improved response of bandpass filter. By solving the transmission zero characteristic equation derived from the cascaded subsystems, we found the zeros of filter system with externally cross-coupled lumped elements. With the cross-coupled elements of capacitors, the numerator polynomial of system transfer function is used to locate the quadruplet zeros in complex plane. When the two pairs of double are on the zeros jw-axis, with the perturbed values of element, we learned that the transition band of lowpass filter is improved. By solving the characteristic equation of cascaded transfer function, we can obtain the zeros of the cross-coupled filter system, as a result of perturbed values on lumped element.

Complex Quadruplet Zero Locations from the Perturbed Values of Cross-Coupled Lumped Element

엄기홍 한국인터넷방송통신학회 2017 Journal of Advanced Smart Convergence Vol.6 No.4

In this paper, complex quadruplet zeros of microwave filter systems are investigated. For the cascaded systems the chain matrices are most conveniently used to derive the voltage transfer function of Laplace transform with cascaded two-port subsystems. The convenient relations of transfer function and chain matrix are used in order to find the transmission zeros. Starting from a ladder network, we introduced a crossed-coupled lumped element, in order to show the improved response of bandpass filter. By solving the transmission zero characteristic equation derived from the cascaded subsystems, we found the zeros of filter system with externally cross-coupled lumped elements. With the cross-coupled elements of capacitors, the numerator polynomial of system transfer function is used to locate the quadruplet zeros in complex plane. When the two pairs of double are on the zeros

Complex Quadruplet Zero Locations from the Perturbed Values of Cross-Coupled Lumped Element

Um, Kee-Hong The Institute of Internet 2017 International journal of advanced smart convergenc Vol.6 No.4

In this paper, complex quadruplet zeros of microwave filter systems are investigated. For the cascaded systems the chain matrices are most conveniently used to derive the voltage transfer function of Laplace transform with cascaded two-port subsystems. The convenient relations of transfer function and chain matrix are used in order to find the transmission zeros. Starting from a ladder network, we introduced a crossed-coupled lumped element, in order to show the improved response of bandpass filter. By solving the transmission zero characteristic equation derived from the cascaded subsystems, we found the zeros of filter system with externally cross-coupled lumped elements. With the cross-coupled elements of capacitors, the numerator polynomial of system transfer function is used to locate the quadruplet zeros in complex plane. When the two pairs of double are on the zeros -axis, with the perturbed values of element, we learned that the transition band of lowpass filter is improved. By solving the characteristic equation of cascaded transfer function, we can obtain the zeros of the cross-coupled filter system, as a result of perturbed values on lumped element.

A dual-mode waveguide pseudo-elliptic filter with zero-shifting properties

Lee, Juseop,Uhm, Man Seok,Yom, In-Bok,Kim, Jeong Phill Wiley Subscription Services, Inc., A Wiley Company 2005 MICROWAVE AND OPTICAL TECHNOLOGY LETTERS Vol.47 No.4

<P>This paper describes the design and realization of dual-mode waveguide filters with zero-shifting properties. The transmission zero can be shifted from one side of the passband to the other by simply changing the resonant frequencies of the resonators. Without changing the physical dimensions of the resonators and coupling irises, transmission zeros can be shifted by adjusting the tuning and coupling screws. The filters are realized and the measured results show good agreement with the simulated ones. © 2005 Wiley Periodicals, Inc. Microwave Opt Technol Lett 47: 357–359, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.21169</P>

Stopband-Extended and Size-Miniaturized Low-Pass Filter with Three Transmission Zeros

Lin Li,Jia Bao,Jing-jing Du,Yaming Wang 한국전자통신연구원 2014 ETRI Journal Vol.36 No.2

This paper presents a compact structure composed ofan upper high-impedance transmission line, a middleextended parallel coupled line, and a pair of inter-coupledsymmetrical stepped impedance stubs. Detailedinvestigation into this structure based on an equivalentcircuit analysis reveals that this proposed structureexhibits a quasi-elliptic low-pass filtering response withthree transmission zeros. Moreover, the positions of thethree transmission zeros can be tuned and reallocatedflexibly by choosing the proper circuit parameters. Finally,the design concept is validated through the design,fabrication, and measurement of two exemplary low-passfilters (LPFs) with one single unit and two cascadedasymmetric units. The measured results agree well withthe simulated results. In addition, in the range of 1.42 fc to7.03 fc, the fabricated quasi-elliptic LPFs experimentallydemonstrate a very wide upper-stopband of 20 dB using acompact size of only 0.0089λg2, where λg is the guidedwavelength of a 50 Ω transmission line at the centralfrequency.

A Method for Improving Stopband Characteristics of a Dual-Band Filter

Jahyeon Lee,Yeongseog Lim 한국전자파학회JEES 2011 Journal of Electromagnetic Engineering and Science Vol.11 No.3

This paper presents a simple and effective method for improving stopband rejection characteristics of previously studied dual-band filters. Small electric couplings were applied to the symmetrically positioned shunt resonators, which divided each transmission zero into two transmission zeros without any effect on passbands. We were able to achieve improved stopband rejection characteristics by these additional transmission zeros. For the filter application, we designed a dual-band filter with improved stopband characteristics using microstrip quasi-lumped elements. The electric couplings that control the location of transmission zeros are controlled by the distance between symmetric open stubs of the filter. The filter was fabricated with a relative dielectric constant of 3.5 and a thickness of 0.76 ㎜. The fabricated filter has a small size (14.6×13.2×0.76 ㎜) and a low insertion loss when compared with conventional filters.

A highly miniaturized LTCC dual-band UWB filter using independent transmission zeros and lowpass filters

Cheon, S.J.,Park, J.Y. Mackintosh Publications] 2014 Microelectronics Journal Vol.45 No.7

In this paper, a compact dual-band ultra-wideband (UWB) filter has been newly designed and fabricated for 3.1-4.75GHz and 6.0-8.5GHz UWB system applications by embedding all passive lumped elements into low temperature co-fired ceramic (LTCC) substrate. In order to reduce its size/volume and prevent parasitic electromagnetic (EM) coupling between the embedded passive elements, it was newly designed by using a modified 3rd order Chebyshev filter topology and J-inverter transformation technology. Moreover, in order to completely reject the wireless local area network (WLAN) bands of 2.4GHz and 5.15GHz, an independent transmission zeros technology was applied. For forming the higher passband, lowpass filters were also applied with two LC resonant circuits by using roll-off characteristics by independent transmission zeros. The measured insertion losses in the lower and upper passbands were better than 2.5 and 2.3dB, respectively. Return loss and group delay were better than 8dB and 0.61ns, respectively in all the passbands. Independent transmission zeros that occurred at 5.17 and 5.42GHz provided suppression of 22dB at the WLAN band. The size/volume of the fabricated LTCC dual-band UWB filter was 3.65x2.35x0.65 (H)mm<SUP>3</SUP>.

Pursuit of optimal synthetic conditions for obtaining colloidal zero-valent iron nanoparticles by scanning pulsed laser ablation in liquids

Ruth Lahoz,Eva Natividad,Álvaro Mayoral,Christian Rentenberger,Daniel Díaz-Fernández,Eduardo J. Félix,Leonardo Soriano,Wolfgang Kautek,Oscar Bomati-Miguel 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.81 No.-

Liquid-Assisted Pulsed Laser Ablation (LA-PLA) is a promising top-down method to directly synthesizecolloidal dispersions of nanoparticles in a eco-friendly manner. However, the role of LA-PLA synthesisparameters is not yet fully agreed. This work seeks to optimize the production of nanoscale zero-valentiron (nZVI) particles suitable for biomedical or environmental applications using nanosecond LA-PLA oniron targets with different ablation media, laser and target scanning parameters. The use of alcohols assolvents produces iron-iron oxide core-shell nanoparticles with amorphous cores, except for a smallcrystalline fraction corresponding to the biggest core sizes. Decreasing carbon chain length andcomplexity leads to a thinning of the carbonaceous material coatings and an increase of the colloidalstability and the nanoparticle productivity. Moreover, a decrease of solvent density and surface tensionallows obtaining reduced sizes and polydispersity values. Among, laser and scanning parameters, thepulse accumulation per spot displayed a clear effect in boosting size and productivity. As main outcome,aqueous dispersions with suitable colloidal properties are obtained, either by transferring to water ofoptimized nZVI particles produced in ethanol, or by direct formation of nZVI particles and in situ coatingwith hydrophilic molecules in aqueous solutions of these molecules.

0도 CRLH 전송선로를 이용한 전력 분배기

김승환 ( Seung Hwan Kim ),김영 ( Young Kim ),윤영철 ( Young Chul Yoon ) 韓國航行學會 2009 韓國航行學會論文誌 Vol.13 No.5

SSLNR 기반의 ZF-THP를 위한 새로운 빔형성 기법

조용석(Yong-soeck Cho),변윤식(Youn-shik Byun) 한국통신학회 2013 韓國通信學會論文誌 Vol.38 No.4C

본 논문에서는 협력 빔형성(Coordinated Multi-Point Coordinated Beamforming : CoMP CB) 시나리오에서 인접한 사용자들 때문에 발생되는 간섭(Inter User Interference : IUI)을 제거하기 위해 사용된 Block Diagonal Geometric Mean Decomposition(BD-GMD)기반의 IUI 제거 알고리즘을 Successive Signal to Leakage plus Noise Ratio(SSLNR) 환경에서의 ZF(Zero-Forcing)에 적용하여 누출 전력을 제거한다. 또 IUI 제거 알고리즘을 사용했을 시 문제가 되는 원하는 신호 전력(Desired signal power)의 크기를 크게 보장할 수 없다는 점을 보완하기 위해 적절한 채널 열 순열(Channel ordering)을 수행하여 원하는 신호의 전력을 높인다. IUI 제거 알고리즘 사용과 적절한 채널 열 순열을 통해 기존의 SSLNR-Zero-Forcing Tomlinson Harashima precoding(ZF-THP) 기법보다 더 나은 비트오류확률(Bit Error Rate : BER)성능을 낼 수 있다. In this paper, Inter user interference elimination algorithm based on Block Diagonal Geometric Mean Decomposition(BD-GMD) for eliminating inter user interference apply to Zero-Forcing in the Successive Signal to Leakage plus Noise Ratio(SSLNR) in Coordinated Multi-Point Coordinated Beamforming system(CoMP CB). As a result, the leakage power is eliminated. The inter user interference elimination algorithm, however, cannot guarantee the enough desired signal power therefore we perform the channel ordering to overcome this disadvantage and increase the desired signal power. The simulation results show that the proposed scheme provides the improved Bit Error Rate(BER) performance compared with existing SSLNR-Zero-Forcing-Tomlinson Harashima precoding(SSLNR-ZF-THP).