Design of Microstrip Lossy Filter Using an Extended Doublet Topology

Ni, Jia; Tang, Wenxing; Geschke, Riana

doi:10.1109/lmwc.2014.2309089

Cited by 19 publications

(11 citation statements)

References 7 publications

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“…Although the center frequency shifts to the lower side at about 4 MHz, it is found that the measured S-parameters are in good agreement with those from EM simulation. It is found that the advantages of the proposed BPF are flexibly controllable unloaded quality factor and good flatness in the passband compared with other references [14,15,16,21,26,27,28,29,30,31,32].…”

Section: Design Of Fourth-order Bpf With Flat Passbandmentioning

confidence: 89%

Bandpass filter with flat passband and transmission zeros using parallel-connected resistor loaded hairpin-shaped resonators

Tsukushi

Ono

Wada

2020

IEICE Electron. Express

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A fourth-order flat passband bandpass filter (BPF) is realized using proposed resonators and half-wave open-looped resonators. The fourth-order flat passband BPF is necessary to prepare at least two kinds of resonators that have high and low unloaded quality factors. The proposed resonator is configured based on a half-wave hairpin-shaped resonator with a parallel-connected resistor. It is assigned as a resonator with a low unloaded quality factor. The advantage of the proposed resonator is flexible adjustment of the unloaded quality factor by changing the value and setting position of the resistor. Using equations and electromagnetic simulation, we show that the unloaded quality factor can be controlled by setting the position of the resistor. A half-wave open-looped resonator is assigned as a resonator with a high unloaded quality factor. Furthermore, a fourth-order flat passband BPF with transmission zeros and a flat passband is constructed on a printed circuit board by using the proposed resonators and half-wave open-looped resonators. Flat passband characteristics of a fourthorder BPF is satisfied with the design specifications.

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Section: Design Of Fourth-order Bpf With Flat Passbandmentioning

confidence: 89%

Bandpass filter with flat passband and transmission zeros using parallel-connected resistor loaded hairpin-shaped resonators

Tsukushi

Ono

Wada

2020

IEICE Electron. Express

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“…Traditional filter synthesis assumes lossless resonators of an infinite quality factor (Q-factor). When applied to practical resonators of relatively low Q-factor, the frequency responses suffer from a degradation of performance in terms of insertion loss and selectivity especially at the bend edges, which affects the flatness of the insertion loss over the passband [1][2][3][4][5][6][7][8][9][10][11]. This particularly concerns narrowband filters where the variation of the insertion loss over the passband increases and puts extra burden on power equalization from the system design point of view.…”

Section: Introductionmentioning

confidence: 99%

A Microstrip Lossy Diplexer With Flat Channel Passbands

Zhang¹,

Wu²,

Sun³

et al. 2020

PIER M

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Passband flatness and band-edge selectivity in microwave filters with finite quality-factor resonators can be improved by the synthesis of lossy filters. This paper demonstrates the extension of this technique to a lossy diplexer by means of resistive coupling. A dual-mode stub-loaded resonator (SLR) junction and a fork-like feedline are used in the diplexer to address the challenge of independently controlling the external coupling from the common port to the two channel filters and therefore enable flexible realization of the channel bandwidth. The coupling matrices with resistive couplings for the lossy diplexer are generated. For verification, a microstrip lossy diplexer operating at 1.91 and 2.6 GHz was designed and tested. The flatness of the passband has been significantly improved, with a reduction of the passband insertion loss variation from 1.4/1.2 dB to 0.66/0.63 dB for the low/high band. The measured results are in good agreement with the simulations as well as the theoretical responses from the coupling matrix. This was also experimentally compared with a reference diplexer without resistive couplings.

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“…The principle of microwave lossy synthesis consists of adding and distributing losses into the coupled resonators network based on a lossless‐like transfer function. There are 2 ways to realize microwave lossy filter: one is using resistive cross couplings (RCCs) to introduce losses and the other is using nonuniform Q resonators …”

Section: Introductionmentioning

confidence: 99%

“…There are 2 ways to realize microwave lossy filter: one is using resistive cross couplings (RCCs) to introduce losses and the other is using nonuniform Q resonators. [7][8][9] The extracted pole synthesis was developed firstly in 10 and then full procedure was described in. 11,12 When compared with cross couplings, 13 extracted pole filters have a flexible structure to introduce the transmission zeros (TZs), which can also be controlled independently.…”

Section: Introductionmentioning

confidence: 99%

Computer-aided design of microstrip extracted-pole lossy filter

Zhou

Hong

2018

Int J RF Microw Comput Aided Eng

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In this article, computer‐aided design of a new type of microstrip lossy filter is described. The new type of lossy filter is realized by introducing resistive cross couplings into a microstrip extracted‐pole filter to achieve a flat passband. The high selectivity is achieved by introducing 2 transmission zeros using 2 extracted poles, which can be adjusted. An equivalent circuit model is established and its circuit parameters, which are useful for physical implementation of the filter, are determined in light of computer modeling. For demonstration, two 6‐pole filters centered at 2 GHz with fractional bandwidth (FBW) 6% and 20% are implemented. Experimental results, together with a theoretical comparison between different FBWs, and full‐wave electromagnetic simulation results are also presented.

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Design of Microstrip Lossy Filter Using an Extended Doublet Topology

Cited by 19 publications

References 7 publications

Bandpass filter with flat passband and transmission zeros using parallel-connected resistor loaded hairpin-shaped resonators

Bandpass filter with flat passband and transmission zeros using parallel-connected resistor loaded hairpin-shaped resonators

A Microstrip Lossy Diplexer With Flat Channel Passbands

Computer-aided design of microstrip extracted-pole lossy filter

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