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Article
Publication date: 21 September 2020

Sandhya Ramalingam, Umma Habiba Hyder Ali and Sharmeela Chenniappan

This paper aims to design a dual mode X-band substrate integrated waveguide (SIW) bandpass filter in the conventional SIW structure. A pair of back-to-back square and split ring…

Abstract

Purpose

This paper aims to design a dual mode X-band substrate integrated waveguide (SIW) bandpass filter in the conventional SIW structure. A pair of back-to-back square and split ring resonator is introduced in the single-layer SIW bandpass filter. The various coupling configurations of SIW bandpass filter using split square ring slot resonator is designed to obtain dual resonant mode in the passband. It is shown that the measured results agree with the simulated results to meet compact size, lower the transmission coefficient, better reflection coefficient, sharp sideband rejection and minimal group delay.

Design/methodology/approach

A spurious suppression of wideband response is suppressed using an open stub in the transmission line. The width and length of the stub are tuned to suppress the wideband spurs in the stopband. The measured 3 dB bandwidth is from 8.76 to 14.24 GHz with a fractional bandwidth of 48.04% at a center frequency of 11.63 GHz, 12.59 GHz. The structure is analyzed using the equivalent circuit model, and the simulated analysis is based on an advanced design system software.

Findings

This paper discusses the characteristics of resonator below the waveguide cut-off frequency with their working principles and applications. Considering the difficulties in combining the resonators with a metallic waveguide, a new guided wave structure – the SIW is designed, which is synthesized on a planar substrate with linear periodic arrays of metallized via based on the printed circuit board.

Originality/value

This study has investigated the wave propagation problem of the SIW loaded by square ring slot-loaded resonator. The electric dipole nature of the resonator has been used to achieve a forward passband in a waveguide environment. The proposed filters have numerous advantages such as high-quality factor, low insertion loss, easy to integrate with the other planar circuits and, most importantly, compact size.

Details

Circuit World, vol. 48 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 6 August 2019

Karthie S. and Salivahanan S.

This paper aims to present the design of a novel triangular-shaped wideband microstrip bandpass filter implemented on a low-cost substrate with a notched band for interference…

87

Abstract

Purpose

This paper aims to present the design of a novel triangular-shaped wideband microstrip bandpass filter implemented on a low-cost substrate with a notched band for interference rejection.

Design/methodology/approach

The conventional dual-stub filter is embedded with simple fractal-based triangular-circular geometries through various iterations to reject wireless local area network (WLAN) signals with a notched band at 5.8 GHz.

Findings

The filter covers a wide frequency band from 3.1 to 8.8 GHz and has a fractional bandwidth of 98 per cent with the lower passband of 57.5 per cent and upper passband of 31.6 per cent separated by a notched band at 5.8 GHz. The proposed wideband prototype bandpass filter is fabricated in FR-4 substrate using PCB technology and the simulation results are validated with measurement results which include insertion loss, return loss and group delay. The fabricated filter has a sharp rejection of 28.3 dB at 5.8 GHz. Measured results show good agreement with simulated responses. The performance of the fractal-based wideband filter is compared with other wideband bandpass filters.

Originality/value

In the proposed work, a fractal-based wideband bandpass filter with a notched band is reported. The conventional dual-stub filter is deployed with triangular-circular geometry to design a wideband filter with a notched band to suppress interference signals at WLAN frequency. The proposed wideband filter exhibits smaller size and better interference rejection compared to other wideband bandpass filter designs implemented on low-cost substrate reported in the literature. The aforementioned wideband filter finds application in wideband wireless communication systems.

Details

Circuit World, vol. 45 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 5 January 2024

Divya Shree M. and Srinivasa Rao Inabathini

This paper aims to present the simulation, fabrication and testing of a novel ultra-wide band (UWB) band-pass filters (BPFs) with better transmission and rejection characteristics…

Abstract

Purpose

This paper aims to present the simulation, fabrication and testing of a novel ultra-wide band (UWB) band-pass filters (BPFs) with better transmission and rejection characteristics on a low-loss Taconic substrate and analyze using the coupled theory of resonators for UWB range covering L, S, C and X bands for radars, global positioning system (GPS) and satellite communication applications.

Design/methodology/approach

The filter is designed with a bent coupled transmission line on the top copper layer. Defected ground structures (DGSs) like complementary split ring resonators (CSRRs), V-shaped resonators, rectangular slots and quad circle slots (positioned inwards and outwards) are etched in the ground layer of the filter. The circular orientation of V-shaped resonators adds compactness when linearly placed. By arranging the quad circle slots outwards and inwards at the corner and core of the ground plane, respectively, two filters (Filters I and II) are designed, fabricated and measured. These two filters feature a quasi-elliptic response with transmission zeros (TZs) on either side of the bandpass response, making it highly selective and reflection poles (RPs), resulting in a low-loss filter response. The transmission line model and coupled line theory are implemented to analyze the proposed filters.

Findings

Two filters by placing the quad circle slots outwards (Filter I) and inwards (Filter II) were designed, fabricated and tested. The fabricated model (Filter I) provides transmission with a maximum insertion loss of 2.65 dB from 1.5 GHz to 9.2 GHz. Four TZs and five RPs are observed in the frequency response. The lower and upper stopband band width (BW) of the measured Filter I are 1.2 GHz and 5.5 GHz of upper stopband BW with rejection level greater than 10 dB, respectively. Filter II (inward quad circle slots) operates from 1.4 GHz to 9.05 GHz with 1.65 dB maximum insertion loss inside the passband with four TZs and four RPs, which, in turn, enhances the filter characteristics in terms of selectivity, flatness and stopband. Moreover, 1 GHz BW of lower and upper stopbands are observed. Thus, the fabricated filters (Filters I and II) are therefore evaluated, and the outcomes show good agreement with the electromagnetic simulation response.

Research limitations/implications

The limitation of this work is the back radiation caused by DGS, which can be eradicated by placing the filter in the cavity and retaining its performance.

Practical implications

The proposed UWB BPFs with novel resonators find their role in the UWB range covering L, S, C and X bands for radars, GPS and satellite communication applications.

Originality/value

To the best of the authors’ knowledge, for the first time, the authors develop a compact UWB BPFs (Filters I and II) with BW greater than 7.5 GHz by combining reformed coupled lines and DGS resonators (CSRRs, V-shaped resonators [modified hairpin resonators], rectangular slots and quad circle slots [inwards and outwards]) for radars, GPS and satellite communication applications.

Details

Microelectronics International, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 28 December 2021

Karthie S., Zuvairiya Parveen J., Yogeshwari D. and Venkadeshwari E.

The purpose of this paper is to present the design of a compact microstrip bandpass filter (BPF) in dual-mode configuration loaded with cross-loop and square ring slots on a…

96

Abstract

Purpose

The purpose of this paper is to present the design of a compact microstrip bandpass filter (BPF) in dual-mode configuration loaded with cross-loop and square ring slots on a square patch resonator for C-band applications.

Design/methodology/approach

In the proposed design, the dual-mode response for the filter is realized with two transmission zeros (TZs) by the insertion of a perturbation element at the diagonal corner of the square patch resonator with orthogonal feed lines. Such TZs at the edges of the passband result in better selectivity for the proposed BPF. Moreover, the cross-loop and square ring slots are etched on a square patch resonator to obtain a miniaturized BPF.

Findings

The proposed dual-mode microstrip filter fabricated in RT/duroid 6010 substrate using PCB technology has a measured minimum insertion loss of 1.8 dB and return loss better than 24.5 dB with a fractional bandwidth (FBW) of 6.9%. A compact size of 7.35 × 7.35 mm2 is achieved for the slotted patch resonator-based dual-mode BPF at the center frequency of 4.76 GHz. As compared with the conventional square patch resonator, a size reduction of 61% is achieved with the proposed slotted design. The feasibility of the filter design is confirmed by the good agreement between the measured and simulated responses. The performance of the proposed filter structure is compared with other dual-mode filter works.

Originality/value

In the proposed work, a compact dual-mode BPF is reported with slotted structures. The conventional square patch resonator is deployed with cross-loop and square ring slots to design a dual-mode filter with a square perturbation element at its diagonal corner. The proposed filter exhibits compact size and favorable performance compared to other dual-mode filter works reported in literature. The aforementioned design of the dual-mode BPF at 4.76 GHz is suitable for applications in the lower part of the C-band.

Details

Microelectronics International, vol. 39 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 10 May 2022

Ponnammal P. and Manjula J.

This paper is aimed to study the design of a miniaturized filter with tri-band characteristics. In this paper, perturbation is used to realize circuit miniaturization and…

Abstract

Purpose

This paper is aimed to study the design of a miniaturized filter with tri-band characteristics. In this paper, perturbation is used to realize circuit miniaturization and multi-band by exploiting the inductive property. During this process, vias are added for twofold benefit, namely, circuit miniaturization and enhanced frequency selectivity at high frequency. Thus, with the introduction of the shorting via, the single-band dual-mode bandpass filter is converted into a tri-band filter with a smaller electrical size.

Design/methodology/approach

This paper presents the design and characterization of a miniaturized two-port filter with tri-band operating characteristics. The proposed filter is constructed using a square patch resonator operating at 5.2 GHz with a capacitively coupled feed configuration. A square perturbation is added to the corner of the square patch to achieve diagonal symmetry and to excite dual mode. The perturbation offers a sharp transmission zero defining bandwidth of the proposed filter. In addition, a shorting post is introduced to achieve an 88% size reduction by lowering the operating frequency to 1.8 GHz.

Findings

The prototype filter has insertion less than 1.2 dB and return loss better than 12 dB throughout all the realized frequency bands. The prototype filter is fabricated and the simulation results are validated using experimental measurements. The realized fractional bandwidths of the proposed bandpass filter are 11/5.6/1 at 1.8/4.6/5.85 GHz, respectively. The quality factor of the proposed antenna is greater than 80 and a peak Q-factor of 387 is realized at 5.85 GHz. The high Q-factor indicates low loss and improved selectivity. The rejection levels in the stopband are greater than 20 dB.

Originality/value

The results indicate that the proposed filter is a suitable choice for low-power small-scale wireless systems operating in the microwave bands. The realized filter has the smallest footprint of 0.36λeff  × 0.19λeff where λeff is the effective wavelength calculated at the lowest frequency of operation.

Details

Microelectronics International, vol. 39 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 December 1999

Barbara Dziurdzia, Stanislaw Nowak, Michal Ciez, Wojciech Gregorczyk, Heiko Thust and Erich Polzer

The paper presents the application of two advanced thick‐film techniques: etching of fired thick‐films and photoimaging of photosensitive thick‐films for fabrication bandpass…

Abstract

The paper presents the application of two advanced thick‐film techniques: etching of fired thick‐films and photoimaging of photosensitive thick‐films for fabrication bandpass microwave filters operating in the frequency range from 6 to 14 GHz. Modified screen printing through ultra‐thin calendered screens is used for comparative goals. Advanced techniques are combined with novel thick‐film conductors including photosensitive pastes and etchable pastes.

Details

Microelectronics International, vol. 16 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 9 March 2010

Jeffrey S. Fu, Dong‐Hua Yang, Chin‐I Yeh, Hsien‐Chin Chiu, Kuo‐Sheng Chin, Hsuan‐Ling Kao and Jui‐Ching Cheng

The purpose of this paper is to introduce a non‐uniform Chebyshev distributed low‐pass filter (LPF) with dumbbell‐shaped photonic bandgap structure (PBGs), implemented in the 50 …

Abstract

Purpose

The purpose of this paper is to introduce a non‐uniform Chebyshev distributed low‐pass filter (LPF) with dumbbell‐shaped photonic bandgap structure (PBGs), implemented in the 50 Ω microstrip line, with improved defected ground structure.

Design/methodology/approach

The non‐uniform distribution of PBGs and dumbbell‐shaped DGS of PBGs have been discussed in open literatures. In this study, the influence of FF of PBGs in dumbbell‐shaped PBG is represented.

Findings

By varying filling factor (FF) of the periodic structure from 0.25 to 0.8 of the dumbbell squares can generate better rejection band than uniform dumbbell LPF. Different FF of each square can produce different band rejection range and then yields the LPF with different cutoff. By using chirp adjustment of distance between PBGs, the band rejection performance can be optimized.

Originality/value

It can be seen that the chirped and non‐uniform dumbbell‐shaped PBGs generate excellent bandgap performances in linearly varying period (chirped devices) than those of structures with constant period (non‐chirped or uniform devices).

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 June 2022

Ponnammal P. and Manjula J.

Modern wireless communications need novel microwave components that can be effectively used for high data rate and low-power applications. The operating environment decides the…

Abstract

Purpose

Modern wireless communications need novel microwave components that can be effectively used for high data rate and low-power applications. The operating environment decides the severity of the noise coupled to the transceiver system from the ambient environment. In a deep fading environment, narrowband systems fail where the wideband systems come for rescue. Thus, the microwave components are ought to switch between the narrowband and wideband states. This paper aims to study the design of a bandpass filter to meet the requirements by appropriately switching between the dual narrowband frequencies and single ultra-wideband frequency band.

Design/methodology/approach

The design and implementation of a compact microwave filter with reconfigurable bandwidth characteristics are presented in this paper. The proposed filter is constructed using a hexagonal ring with shorted perturbation along one corner. The filter is capacitively coupled to the external excitation source. External stubs are connected to the corners of the hexagonal resonator to obtain dual passband characteristics centred at 2.1 and 4.5 GHz. The external stubs are configured to achieve bandwidth reconfigurable characteristics. PIN diodes are used with a suitable biasing network to obtain reconfiguration. In the reconfigured state, the proposed two-port filter offers a continuous bandwidth from 2.1 to 5.9 GHz. The roll-off rate along the band edges is improved by increasing the order of the filter.

Findings

The proposed filter operates in two states. In state 1, the filter operates with dual frequencies centred around 2 and 4.5 GHz with insertion loss less than <1 dB and return loss greater than 13 dB with a peak return loss of 21 and 31 dB at 2.1 and 2.15 GHz, respectively. In state 2, the filter operates from 2.1 to 5.9 GHz with insertion loss less than 1 dB and return loss greater than 12 dB. The filter exhibits four-pole characteristics with a peak return loss greater than 22 dB. Thus, the fractional bandwidth of the proposed filter is 17% and 16% in state 1, whereas the fractional bandwidth is 95% in state 2.

Originality/value

The proposed filter is the first of its kind to simultaneously offer miniaturization and bandwidth reconfiguration. The proposed second-order filter has two-pole characteristics in the narrowband state, whereas four-pole characteristics are realized in the wideband state. The growing interest in 4G and 5G wireless communications makes the proposed filter a suitable candidate for operation in the rich scattering environment.

Details

Microelectronics International, vol. 39 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 2 May 2023

Jasmine Vijithra A. and Gulam Nabi Alsath Mohammed

This study aims to design a compact filtering monopole antenna for 5G communication. The design is most suited for various applications within the frequency range of 2.2–3.8 GHz…

Abstract

Purpose

This study aims to design a compact filtering monopole antenna for 5G communication. The design is most suited for various applications within the frequency range of 2.2–3.8 GHz. It offers enhanced bandwidth and reasonable gain with wide-stopband performance.

Design/methodology/approach

A low-pass filter (LPF) of complementary split ring resonator (CSRR) with short-circuited stub lines is integrated with a compact defected coplanar waveguide fed truncated circular monopole ultrawideband (UWB) antenna. The reference UWB antenna etched on an FR4 substrate was coupled to the designed LPF to transform the UWB antenna into a wideband antenna. The effect of coupling is analyzed based on the real and imaginary responses of the terminal impedance (ZT) curve. Three short-circuited stub lines of asymmetric lengths are added to the CSRR LPF to suppress harmonics, thereby enhancing the stopband performance and impedance matching between the elements. The proposed filtering antenna is fabricated using a photolithography process, and the corresponding results are measured using a network analyzer (N9951A). The radiation parameters of the proposed filtering monopole antenna are tested in the anechoic chamber. The simulated/measured results are compared and are found in agreement with each other.

Findings

The proposed design suppresses 6.5f0 harmonics, resulting in wide stopband performance and increased gain selectivity at the transition edge. A peak suppression of −41 dB and an average suppression of −18 dB were attained throughout the stopband. An operating fractional bandwidth of 54.5%/143% with a peak gain of 3 dBi/5 dBi was obtained. The proposed filtering antenna supports 5G applications such as WiMAX, WLAN, n7, n38 IMT-E, n30 WCS, n40 TDD, n41 TDD, n48 TDD, n78 TDD and n90 TDD.

Originality/value

The proposed design is novel and compact and has a wide application in 5G communication. With the filter, the antenna operates in wideband, and without the filter, it operates in UWB. Besides, it offers enhanced stopband performance with high gain selectivity at the transition edge. Comparatively, a 50% improvement in bandwidth, 52% improvement in size reduction and 33% improvement in harmonic suppression are attained.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 42 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 6 February 2009

Xia Zhang, Johan Liu, Camilla Kärnfelt, Shiwei Ma, Xu Wang, Linqin Meng and Herbert Zirath

Liquid Crystal Polymer (LCP) materials are considered to be promising substrates for wireless applications because of their excellent properties. The purpose of this paper is to…

Abstract

Purpose

Liquid Crystal Polymer (LCP) materials are considered to be promising substrates for wireless applications because of their excellent properties. The purpose of this paper is to describe now a novel and compact microstrip ultra‐wideband bandpass filter (UWB BPF) with ultra‐fine conductor traces working over 22 to 29 GHz is fabricated on LCP substrates.

Design/methodology/approach

Using standard processing technology, such as photolithography, plasma pretreatment, sputter deposition and wet etching, a microstrip UWB BPF is fabricated on LCP substrates. In order to obtain better adhesion between LCP substrate and copper, the oxygen plasma pretreatment of the LCP substrate surface and a thin titanium adhesion layer are introduced before a copper layer is sputter‐deposited onto the substrate.

Findings

The measured and the simulated results agree well. The measured insertion loss is about 8 dB in the passband of the bandpass filter, which is a little high compared to the simulated result (∼5 dB). The out of band performance at both the high frequency and low frequency is very good, almost higher than 35 dB.

Originality/value

This paper presents the realization of (UWB BPF) working over 22 to 29 GHz based on an LCP substrate, which demonstrates the feasibility of the application of the LCP substrate in RF wireless systems and also gives some useful information for later research.

Details

Circuit World, vol. 35 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

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