Quasi-elliptic evanescent-mode filters using non-resonating mode waveguide cavities

2015 ◽  
Vol 7 (3-4) ◽  
pp. 211-218 ◽  
Author(s):  
Simone Bastioli ◽  
Richard V. Snyder
Keyword(s):  
Insertion Loss ◽  
Bandpass Filters ◽  
Experimental Results ◽  
The Other ◽  
Q Factor ◽  
Evanescent Mode ◽  
High Q ◽  
Transmission Zeros ◽  
Waveguide Cavities ◽  
A New Technique

A new technique to realize quasi-elliptic bandpass filters with extreme close-in rejection is presented in this paper. The basic idea consists of embedding non-resonating mode waveguide cavities within the structure of an evanescent-mode filter. Such a combination of cavities and resonators allows the generation of very close transmission zeros while realizing at the same time relatively wide passbands and stopbands. Both H-plane TE201 mode and E-plane TM110 mode configurations are used as non-resonating mode waveguide cavities. In contrast with the other elliptic evanescent-mode filters using conventional approaches, the insertion loss degradation at the filter cut-off frequencies is minimized thanks to the high-Q factor of the waveguide cavities, whose corresponding poles are located right at the edges of the passband. The experimental results of an evanescent-mode filter having 9.950–11.000 GHz passband and providing more than 45 dB rejection between 11.040 and 11.050 GHz validate the proposed solution.

Miniaturized Dual-Band Bandpass Filter Using Embedded Dual-Mode Resonator with Controllable Bandwidths

Frequenz ◽  
2016 ◽  
Vol 70 (9-10) ◽  
Author(s):  
Chuanming Zhu ◽  
Jin Xu ◽  
Wei Kang ◽  
Zhenxin Hu ◽  
Wen Wu
Keyword(s):  
Insertion Loss ◽  
Degrees Of Freedom ◽  
Bandpass Filter ◽  
The Other ◽  
Dual Band ◽  
Dual Mode ◽  
Transmission Zeros ◽  
Low Insertion Loss ◽  
Multiple Transmission ◽  
Mode Resonator

AbstractIn this paper, a miniaturized dual-band bandpass filter (DB-BPF) using embedded dual-mode resonator (DMR) with controllable bandwidths is proposed. Two passbands are generated by two sets of resonators operating at two different frequencies. One set of resonators is utilized not only as the resonant elements that yield the lower passband, but also as the feeding structures with source-load coupling to excite the other to produce the upper passband. Sufficient degrees of freedom are achieved to control the center frequencies and bandwidths of two passbands. Moreover, multiple transmission zeros (TZs) are created to improve the passband selectivity of the filter. The design of the filter has been demonstrated by the measurement. The filter features not only miniaturized circuit sizes, low insertion loss, independently controllable central frequencies, but also controllable bandwidths and TZs.

scholarly journals A Novel Symmetrical Split Ring Resonator Based on Microstrip for Microwave Sensors

2016 ◽  
Vol 16 (1) ◽  
pp. 21-27 ◽  
Author(s):  
Rammah A. Alahnomi ◽  
Z. Zakaria ◽  
E. Ruslan ◽  
Amyrul Azuan Mohd Bahar
Keyword(s):  
Insertion Loss ◽  
Ring Resonator ◽  
Performance Enhancement ◽  
Split Ring Resonator ◽  
Q Factor ◽  
Loose Coupling ◽  
Split Ring ◽  
Linear Coupling ◽  
High Q ◽  
Microwave Sensors

Abstract In this paper, novel symmetrical split ring resonator (SSRR) is proposed as a suitable component for performance enhancement of microwave sensors. SSRR has been employed for enhancing the insertion loss of the microwave sensors. Using the same device area, we can achieve a high Q-factor of 141.54 from the periphery enhancement using Quasi-linear coupling SSRR, whereas loose coupling SSRR can achieve a Q-factor of 33.98 only. Using Quasi-linear coupling SSRR, the Q-factor is enhanced 4.16 times the loose coupling SSRR using the same device area. After the optimization was made, the SSRR sensor with loose coupling scheme has achieved a very high Qfactor value around 407.34 while quasi-linear scheme has achieved high Q-factor value of 278.78 at the same operating frequency with smaller insertion loss. Spurious passbands at 1st, 2nd, 3rd, and 4th harmonics have been completely suppressed well above -20 dB rejection level without visible changes in the passband filter characteristics. The most significant of using SSRR is to be used for various industrial applications such as food industry, quality control, bio-sensing medicine and pharmacy. The simulation result that Quasi-linear coupling SSRR is a viable candidate for the performance enhancement of microwave sensors has been verified.

A Novel Diplexer Integrated With a Shielding Case Using High $Q$ -Factor Hybrid Resonator Bandpass Filters

2018 ◽  
Vol 28 (3) ◽  
pp. 215-217 ◽  
Author(s):  
Trong-Hieu Le ◽  
Xiao-Wei Zhu ◽  
Chuan Ge ◽  
Tuan-Viet Duong
Keyword(s):  
Bandpass Filters ◽  
Q Factor ◽  
High Q

Quasi-elliptic dual-band bandpass filters based on series-cascaded multi-resonant cells

2020 ◽  
Vol 12 (7) ◽  
pp. 609-614
Author(s):  
Andrea Ashley ◽  
Dakotah J. Simpson ◽  
Dimitra Psychogiou
Keyword(s):  
Radio Frequency ◽  
Insertion Loss ◽  
Transfer Functions ◽  
Bandpass Filters ◽  
Dual Band ◽  
Proof Of Concept ◽  
Lumped Element ◽  
Transmission Zeros ◽  
Design Competition ◽  
Implementation Scheme

AbstractThis paper reports on quasi-elliptic dual-band bandpass filters (BPFs) that were designed for the Filter Student Design Competition of the 2019 European Microwave Week. The proposed lumped-element (LE) BPF concept is based on two dual-band transversal cells and one multi-resonant cell that allow the realization of symmetric and asymmetric dual-band transfer functions shaped by six poles and five transmission zeros. A compact implementation scheme based on LE series resonators is proposed for size compactness and wide spurious free out-of-band response. For proof-of-concept demonstration purposes, a dual-band LE prototype with two passbands centered 1 and 1.5 GHz was designed, manufactured, and measured. It exhibited the following radio frequency measured performance characteristics. Passbands centered at 1.02 and 1.45 GHz, minimum insertion loss levels of 2.0 and 2.7 dB, and bandwidth of 146 and 105 MHz, respectively, for the first and the second passband, and out-of-band rejection >30 dB between 0 and 894 MHz, 1.17–1.34 GHz, and 1.72–6.9 GHz.

Tunable Voltage-Mode Bandpass Biquad Synthesis Using NAM Expansion Method

2016 ◽  
Vol 25 (05) ◽  
pp. 1650048 ◽  
Author(s):  
Huu-Duy Tran ◽  
Hung-Yu Wang ◽  
Chin-Shiuh Shieh ◽  
Min-Chuan Lin ◽  
Sin-Hong Lin
Keyword(s):  
Natural Frequency ◽  
Expansion Method ◽  
Bandpass Filters ◽  
High Order ◽  
Q Factor ◽  
High Q ◽  
Voltage Mode ◽  
Admittance Matrix ◽  
Mode Parameter ◽  
Synthesis Procedure

The synthesis of voltage-mode parameter tunable biquadratic bandpass filters using grounded capacitors is presented. To easily construct high-order filters, the synthesis of voltage-mode cascadable tunable biquadratic bandpass filters is also indicated. The synthesis procedure is based on the nodal admittance matrix (NAM) expansion method using nullor–mirror pathological elements. The synthesis of filters using grounded capacitors is considered since it is helpful for easing the elimination/accommodation of various parasitic effects for monolithic integration. The Q factor of the derived filters can be adjusted without changing the natural frequency, so the high-Q bandpass filters are attainable. The workability of some synthesized circuits is verified by HSPICE simulations.

Bandpass filters with N + 1 transmission zeros using λ/4 resonator and λ/2 resonator

2018 ◽  
Vol 10 (4) ◽  
pp. 401-404
Author(s):  
Di Lu ◽  
Xiao-Hong Tang ◽  
N. Scott Barker
Keyword(s):  
Bandpass Filter ◽  
Bandpass Filters ◽  
Experimental Results ◽  
Size Increase ◽  
Order Filter ◽  
Transmission Zeros ◽  
Filter Structure ◽  
Node Distribution ◽  
Filter Size ◽  
Novel Method

AbstractThe present paper presents a novel method to cope with the difficulty that an N-order filter can introduce a maximum number of transmission zeros (TZs) – no more than N. The method is described by a coupling topology and realized by a regular fully canonical filter structure to increase one more TZ for an N-order filter without any filter size increase. Besides, the TZ shift property, as another advantage of the proposed topology, is investigated. The coupling topology consists of a group of fully canonical coupling nodes with the harmonic node (non-resonating node (NRN)) excited by a λ/4 resonator. Owing to the unique coupling topology and coupling node distribution as well as the inclusion of an NRN, N + 1 TZs are generated by an N-order bandpass filter, while all the TZs are close to the passband and far away from the harmonic passband resulting the highly selective passbands. For demonstration, two-, three-, and four-order filters are designed and measured with the experimental results that confirm the proposed technique.

The Influence of Water Regime on the Performance of Aquatic Plants

1994 ◽  
Vol 29 (4) ◽  
pp. 127-132 ◽  
Author(s):  
Naomi Rea ◽  
George G. Ganf
Keyword(s):  
Deep Water ◽  
Aquatic Plants ◽  
Water Regime ◽  
Optimal Performance ◽  
Experimental Results ◽  
The Other ◽  
Full Potential ◽  
Influence Of Water ◽  
Emergent Species

Experimental results demonstrate bow small differences in depth and water regime have a significant affect on the accumulation and allocation of nutrients and biomass. Because the performance of aquatic plants depends on these factors, an understanding of their influence is essential to ensure that systems function at their full potential. The responses differed for two emergent species, indicating that within this morphological category, optimal performance will fall at different locations across a depth or water regime gradient. The performance of one species was unaffected by growth in mixture, whereas the other performed better in deep water and worse in shallow.

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