Quintuple-mode wideband bandpass filters with improved out-of-band rejection

2019 ◽  
Vol 12 (4) ◽  
pp. 276-281
Author(s):  
Musab Hameed ◽  
Gaobiao Xiao ◽  
Lina Qiu ◽  
Tayyab Hameed
Keyword(s):  
Rectangular Waveguide ◽  
Bandpass Filters ◽  
Transverse Magnetic ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Resonant Modes ◽  
Coaxial Lines ◽  
Good Agreement

AbstractThis paper presents design of quintuple-mode wideband bandpass filters, implemented with off-centered perturbed metallic cylinders in a rectangular waveguide cavity. Three perturbation cylinders are placed at the bottom of the rectangular waveguide cavity, along with a pair of perpendicularly fed coaxial lines; excite five quasi-transverse magnetic modes to realize the desired passband. The height of the waveguide cavity and the shape of the perturbation cylinders are exploited to shift the resonant modes far away from the passband and achieve a good out-of-band rejection and sharp skirt selectivity. The filter operates at the center frequency of 2.68 GHz with a wide fractional bandwidth of 43%. The proposed filter is fabricated with aluminum. The measured and simulated results are in good agreement with each other.

scholarly journals Quadruple-Mode Wideband Bandpass Filter with Improved Out-of-Band Rejection

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 300 ◽  
Author(s):  
Musab Hameed ◽  
Gaobiao Xiao ◽  
Ali Najam ◽  
Lina Qiu ◽  
Tayyab Hameed
Keyword(s):  
Rectangular Waveguide ◽  
Bandpass Filter ◽  
Transverse Magnetic ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Compact Size ◽  
Coaxial Lines ◽  
Good Agreement

This paper proposes a method for designing a quadruple-mode wideband bandpass filter using off-centered perturbed metallic cylinders in a rectangular waveguide cavity with compact size and improved out-of-band rejection. Two off-centered perturbation cylinders were placed at the bottom of the rectangular waveguide cavity along with a pair of perpendicularly-fed coaxial lines, which excited four quasi-transverse magnetic (TM) modes to realize the desired passband. The height of the waveguide cavity and the shape of the perturbation cylinders were exploited to achieve an all quasi-TM modes filter with good out-of-band rejection and sharp skirt selectivity. The proposed filter operates at 2.93 GHz center frequency with 38% wide fractional bandwidth (FBW). The proposed filter is fabricated using aluminum. The measured and simulated results are in good agreement with each other.

scholarly journals Novel Hexagonal Dual-Mode Substrate Integrated Waveguide Filter with Source-Load Coupling

2014 ◽  
Vol 2014 ◽  
pp. 1-5
Author(s):  
Ziqiang Xu ◽  
Gen Zhang ◽  
Hong Xia ◽  
Meijuan Xu
Keyword(s):  
Center Frequency ◽  
Substrate Integrated Waveguide ◽  
Fractional Bandwidth ◽  
Dual Mode ◽  
Transmission Zeros ◽  
Cavity Structure ◽  
Waveguide Filter ◽  
And Performance ◽  
Single Cavity ◽  
Good Agreement

Hexagonal dual-mode cavity and its application to substrate integrated waveguide (SIW) filter are presented. The hexagonal SIW resonator which can combine flexibility of rectangular cavity and performance of circular cavity is convenient for dual-mode bandpass filters design. By introducing coupling between source and load, the filter not only has good selectivity due to two controllable transmission zeros, but also has a small size by the virtue of its single-cavity structure. A demonstration filter with a center frequency of 10 GHz and a 3 dB fractional bandwidth of 4% is designed and fabricated to validate the proposed structure. Measured results are in good agreement with simulated ones.

scholarly journals A New Ultracompact Narrow Bandpass Microstrip Filter Using Double-Negative Quasiplanar Cells

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Mohammad Reza Khawary ◽  
Vahid Nayyeri ◽  
Seyed Mohammad Hashemi ◽  
Mohammad Soleimani
Keyword(s):  
Printed Circuit Board ◽  
High Selectivity ◽  
Bandpass Filter ◽  
Circuit Board ◽  
Center Frequency ◽  
Double Negative ◽  
Fractional Bandwidth ◽  
Printed Circuit ◽  
Full Wave ◽  
Good Agreement

This paper presents a novel ultracompact narrow bandpass filter with high selectivity. The proposed filter is composed of cascading two basic cells. Each cell is basically a microstrip line loaded with a quasiplanar resonator and series gaps which can be fabricated using a standard multilayer printed circuit board technology. The structure is analyzed through an equivalent circuit and full-wave simulations. The simulation results are compared with experimental measurements demonstrating a good agreement between them. The measurement indicates that the realized bandpass filter at the center frequency of 1 GHz has a fractional bandwidth of 2.2%. Most importantly, in comparison with other similar recent works, it is shown that the proposed filter has the smallest size.

scholarly journals High Selectivity Dual-Band Bandpass Filter with Tunable Lower Passband

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Wei-Qiang Pan ◽  
Xiao-Lan Zhao ◽  
Yao Zhang ◽  
Jin-Xu Xu
Keyword(s):  
High Selectivity ◽  
Bandpass Filter ◽  
Bandpass Filters ◽  
Dual Band ◽  
Transmission Zeros ◽  
Resonant Modes ◽  
Novel Method ◽  
Good Agreement ◽  
Tunable Bandpass Filter

This paper presents a novel method to design dual-band bandpass filters with tunable lower passband and fixed upper passband. It utilizes a trimode resonator with three controllable resonant modes. Discriminating coupling is used to suppress the unwanted mode to avoid the interference. Varactors are utilized to realize tunable responses. The bandwidth of the two bands can be controlled individually. Transmission zeros are generated near the passband edges, resulting in high selectivity. For demonstration, a tunable bandpass filter is implemented. Good agreement between the prediction and measurement validates the proposed method.

scholarly journals Bandwidth Enhancement on Half-Mode Substrate Integrated Waveguide Antenna Using Cavity-Backed Triangular Slot

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Dian Widi Astuti ◽  
Muhamad Asvial ◽  
Fitri Yuli Zulkifli ◽  
Eko Tjipto Rahardjo
Keyword(s):  
Waveguide Structure ◽  
Slot Antenna ◽  
Center Frequency ◽  
Substrate Integrated Waveguide ◽  
Fractional Bandwidth ◽  
Radiation Characteristics ◽  
Bandwidth Enhancement ◽  
Rectangular Slot ◽  
Design Evolution ◽  
Good Agreement

This paper proposes bandwidth enhancement of a cavity-backed slot antenna using a triangular slot on a half-mode substrate integrated waveguide structure antenna. The bandwidth enhancement was achieved by combining the fixed TE101 and the downward shifting TE102 modes, resulting in hybrid modes. The design evolution of the slot antenna from a half nonresonating rectangular slot to a triangular slot antenna increased the fractional bandwidth. The simulation result showed that fractional bandwidth increased from 6.27% to 9.1%. It was confirmed by measurement that the fractional bandwidth of 9.87% was achieved which reflects a 350 MHz bandwidth with center frequency at 3.84 GHz. The measured gain at center frequency was 4.2 dBi. It is shown that the radiation characteristics obtained from both measurement and simulation results are in very good agreement.

scholarly journals Multiple-Mode Wideband Bandpass Filter Using Split Ring Resonators in a Rectangular Waveguide Cavity

Electronics ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 356 ◽  
Author(s):  
Musab Hameed ◽  
Gaobiao Xiao ◽  
Lina Qiu ◽  
Can Xiong ◽  
Tayyab Hameed
Keyword(s):  
Rectangular Waveguide ◽  
Bandpass Filter ◽  
Split Ring Resonator ◽  
Ring Resonators ◽  
Center Frequency ◽  
Split Ring ◽  
Cavity Resonators ◽  
Resonant Modes ◽  
Coaxial Probes ◽  
Multi Mode

This paper presents a simple split ring resonator excitation to realize a multi-mode wideband bandpass filter in a rectangular waveguide cavity. The proposed resonator employs two rectangular split rings attached with two coaxial probes extended into the cavity to excite two resonant modes, unlike the conventional cavity resonators which employ conductive cylinders in the cavities to achieve the same results. A hybrid magnetic (HM) mode and a hybrid electric (HE) mode are the two hybrid modes excited to realize the wideband bandpass filter. The filter operates at 2.5 GHz center frequency with 53% fractional bandwidth. Finally, the prototypes of a second and a fourth order filter are fabricated for results validation. Measured results are in good agreement with the simulated ones.

Three-Pole Tunable Bandpass Filters With Constant Fractional Bandwidth Using Mixed Comb-line Resonators

Frequenz ◽  
2014 ◽  
Vol 68 (9-10) ◽  
Author(s):  
Zhiyuan Zhao ◽  
Jiang Chen ◽  
Lin Yang ◽  
Kunhe Chen
Keyword(s):  
Frequency Band ◽  
Bandpass Filter ◽  
Bandpass Filters ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Tunable Bandpass Filter

AbstractA novel three-pole tunable bandpass filter using mixed combline resonators with a center frequency band of 0.9–1.8 GHz is proposed in this paper. The varactor-tuned filter is designed on a Rogers substrate with

scholarly journals Designing of Hairpin-Line Band Pass filters for DCS, UMTS and LTE-Systems

2017 ◽  
Vol 6 (3) ◽  
pp. 239 ◽  
Author(s):  
Muhammad Sayidi ◽  
Mudrik Alaydrus
Keyword(s):  
Communication Systems ◽  
Wireless Systems ◽  
Bandpass Filters ◽  
Coupling Factor ◽  
Center Frequency ◽  
Fractional Bandwidth ◽  
Microstrip Technology ◽  
Essential Components ◽  
Band Pass ◽  
Form Hairpin Structure

Bandpass filters are essential components in any wireless systems. They are designed for selecting desired signal from other signals. Especially in crowded frequency spectrums, accurate filter characteristics are required to guarantee the performance of the overall systems. DCS, UMTS and LTE systems are the actual communication systems used by hundred million users. Bandpass filters designed here is based on hairpin line structures and implemented in microstrip technology. The filters are five order Chebychev’s bandpass filters. The center frequency of each system determines the total length of the U-form hairpin structure. The design starts with exploiting the coupling between the resonators. The coupling between two adjacent resonators is determined by the fractional bandwidth of the system and the element value derived from the Chebychev’s approximation. The value of the coupling factor leads to the distance between two adjacent resonators. The simulation results conform to the specifications given in the standards. In general, the measurements verify the simulation. We see worse reflection factors and more insertion loss eventually due to bad soldering of the connectors to the filters. The shifting and width of the pass regions are also observed, which are probably due to the finite accuracy in prototyping the filters.

scholarly journals Evolution of Whispering Gallery Modes in Li-Doped ZnO Hexagonal Micro- and Nanostructures

2020 ◽  
Vol 10 (23) ◽  
pp. 8602
Author(s):  
Rocío Ariza ◽  
Belén Sotillo ◽  
Fernando Pavón ◽  
Ana Urbieta ◽  
Paloma Fernández
Keyword(s):  
Transverse Magnetic ◽  
Whispering Gallery Modes ◽  
Optical Cavities ◽  
Whispering Gallery ◽  
Resonant Modes ◽  
Fabry Perot ◽  
Doped Zno ◽  
Quality Factor Q ◽  
Good Agreement

The formation of optical cavities in Li-doped ZnO nanostructures was investigated. By means of the vapor–solid method, long micro- and nanostructures with a hexagonal cross-section were grown. These morphologies were favorable for Fabry-Pérot and whispering gallery modes to appear. A variety of structures with different sections was studied using µ-photoluminescence in both the transverse electric (TE) and transverse magnetic (TM) polarizations, showing well-pronounced optical resonant modes. The results showed a dominance of whispering gallery modes that were in good agreement with the calculated refractive index. The quality factor (Q) and finesse (F) were estimated, which demonstrated the quality of Li:ZnO structures as optical cavities.

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