Microstrip Bandstop Filter Research Articles

English

A compact dual-band microstrip bandstop filter (BSF) is proposed. This filter combines a conventional two open stubs BSF and an optimum BSF. Simulations show this filter generates two stopbands around 2.52 GHz and 5.02 GHz without increasing the circuit size much, compared with the conventional BSF.

Average Power Handling Capability of Microstrip Passive Circuits Considering Metal Housing and Environment Conditions

In this paper, the average power handling capability (APHC) of microstrip passive circuits considering the metal housing and environment conditions is investigated in detail. A systematic method is proposed for the computation of the APHC of microstrip circuits in open and enclosed metal housing configurations, typically used in microwave components. The method also yields an estimate of the maximum temperature in a microstrip circuit for a given input power. Closed-form equations accounting for external conditions, such as convection or radiation heat transfer are given to evaluate the APHC. For validation, two microstrip bandstop filters centered at 10 GHz are analyzed following the proposed model, and the results are compared with those simulated showing a good agreement. In addition, both circuits are fabricated and characterized. Thermal profile measurements are provided, confirming the predicted results. The effect of the topology layout and the electromagnetic performance on the APHC are also discussed.

Design of ultra‐wideband bandstop filter using defected ground structure

A simple wideband bandstop filter which yields equal ripples in the stopband is described. The filter comprises only two resonators and a connecting transmission line. Ultra-wide stopband characteristic is achieved by realising three transmission zeros near the passband edges. Stopband rejection depth and bandwidth can be controlled by impedances of the configuration. The defected ground structure is chosen to realise the high impedance line. To validate the proposed topology, a compact microstrip bandstop filter centred at 1.5 GHz with a measured 20 dB rejection bandwidth of about 139% is fabricated.

Compact Bandstop Filter for UHF in Modified Meander Arrangement with Capacitors

ABSTRACTWe present a novel bandstop microstrip filter with coupling capacitors. The microstrip is arranged in a meander‐like pattern, with particular segments coupled by capacitors. This layout provides good results and reduced filter's size, with readily tunable transmittance that can be modified for notch‐like operation or wide stop band. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2110–2113, 2013

Design and implemention of very compact band‐stop filter with petal‐shaped stub for radar applications

AbstractIn this article, we introduce a compact microstrip band stop filter (BSF) at X‐band frequency range and this shall be used in local oscillator chain for X‐band transceiver. Presented microstrip filter consists of a transmission line with a petal‐shaped stub and a ground plane with a modified rectangular‐shaped defected ground structure (DGS). Operation frequencies of the filter can be easily controlled by changing four protruded T‐shaped strips in the petal‐shaped structure. The DGS slot evolved from photonic band gap (PBG) is embedded to achieve a good impedance matching and the required filter's characteristics. The proposed band‐stop filter has wide bandwidth from 8–12 GHz for X‐band Communications that can be used in Radar applications. Good agreement between simulated and measured results cause that excellent stop‐band performance could be obtained through the X‐band frequency range. The proposed microstrip filter fabricated on a Rogers RT/Duroid 5880 substrate with a relative dielectric constant of 2.2 and has a very small size of 10 × 15 mm2. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1130–1132, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27518

QUASI-ELLIPTIC MICROSTRIP BANDSTOP FILTER USING TAP COUPLED OPEN-LOOP RESONATORS

In this paper, we will present a quasi-elliptic bandstop filter using asynchronously tuned resonators. To demonstrate this technique, a novel broadband microstrip bandstop filter is also proposed using distributed resonators. To achieve wide bandwidth using distributed resonators, strong couplings are required. This is achieved using tap coupled to avoid very narrow gaps which are costly to manufacture. The filter exhibits a factional bandwidth of approximately 35%. A simple practical transformation technique for transforming Chebyshev bandstop filter to asynchronously tuned quasi-elliptic bandstop filter will be presented.

Very Compact Bandstop Filters Based on Miniaturized Complementary Metamaterial Resonators

In this paper, a design of very compact microstrip bandstop filters based on complementary split ring resonators (CSRRs) is proposed. Two techniques of metamaterial miniaturization are used to optimize the physical and electrical size of the CSRR. The bandstop filter is produced by an array of miniaturized loaded CSRRs etched on the center line of a microstrip. The size of the proposed filter, is as small as 0.58 cm2, and its electrical length is very small with only 0.08 λ0), compared to a conventional bandstop filter, a miniaturization of a factor 5 while the bandstop performance is maintained. A very good agreement obtained between the measurement and the simulation results.

A Design of a Terahertz Microstrip Bandstop Filter with Defected Ground Structure

A planar microstrip terahertz (THz) bandstop filter has been proposed with defected ground structure with high insertion loss (S21) in a stopband of −25.8 dB at 1.436 THz. The parameters of the circuit model have been extracted from the EM simulation results. A dielectric substrate of Benzocyclobutene (BCB) is used to realize a compact bandstop filter using modified hexagonal dumbbell-shape defected ground structure (DB-DGS). In this paper, a defected ground structure topology is used in aλ/4, 50 Ω microstrip line at THz frequency range for compactness. No article has been reported on the microstrip line at terahertz frequency regime using DGS topology. The proposed filter can be used for sensing and detection in biomedical instruments in DNA testing. All the simulations/cosimulations are carried out using a full-wave EM simulator CST V.9 Microwave Studio, HFSS V.10, and Agilent Design Suite (ADS).

A Pressure Responsive Fluidic Microstrip Open Stub Resonator Using a Liquid Metal Alloy

This letter describes a fluidic microstrip bandstop filter with transmission properties that change in discrete states. The filter consists of a liquid metal alloy - eutectic gallium indium (EGaIn) - as the conductive component in microfluidic channels. The fluidity of EGaIn allows the open stub resonator of the filter to change its length by flowing in response to an applied pressure. A series of posts in the channel defines the length of the stub filled by the metal and dictates the pressure needed for the liquid metal to flow and thereby extend the stub length. The frequency response of the filter changes in response to the changes in the length of the resonator stub. This approach is a simple method for creating tunable filters and impedance matching sections using soft materials that change dimensions in response to pressure.

A compact dual-band band-stop filter with high performance and controllable response

A fourth-order dual-band microstrip band-stop filter is proposed in this paper. Folded stepped impedance resonators are implemented as well as capacitive gap and inductive grounded via, thus the dual-band performance can be obtained in merely one resonator. Besides its compact size, simplicity, and good spurious band suppression, the filter also features its excellent mid-band rejection and skirt characteristic which is achieved by four reflection zeros adjacent to the dual resonating frequencies. Controllable response of filter is realized by tuning of gap capacity and via inductance, and the theory is verified by both simulation and experimental results that agree well with each other.

A Novel Microstrip Bandstop Filter and its Application to Reconfigurable Filter

In this paper, a novel bandstop filter based on microstrip LC resonators and 1-bit frequency reconfigurable bandstop filter are presented. The configuration of the proposed LC resonators has open structure and is suitable to load with reconfigurable capacitors. Lumped elements models have been developed, and the frequency tuning capability of the bandstop filter is studied, and it is shown that the filter stopband can be reconfigured by the loading capacitance. A 1-bit reconfigurable bandstop filter is designed based on the proposed novel bandstop filter loaded with two switchable 3.5mm × 6.5mm × 0.508mm Rogers 5880 single metal plane PCB capacitors. The prototype with compact overall size of 22mm × 39mm was designed and fabricated to validate the new structure. The measured stop-band central frequency is 3.04GHz and 2.513 GHz in cutoff state and connected state, respectively. 500 MHz central frequency reconfigurable capability is obtained.

HTS Bandstop Filter for Radio Astronomy

A novel miniaturized six-pole high temperature superconducting microstrip bandstop filter operating at S band is presented in this letter. A pseudo elliptical behavior in the frequency characteristic is introduced by designing the resonators to resonate at asynchronous frequencies and by varying the inter resonator phase difference. These filters have been installed in a cryogenic radio astronomy receiver with excellent results. Because of their sharp cut-off characteristics, the filters reduce satellite downlink interference signals by more than 40 dB while minimizing lost observing bandwidth.

Design and Implementation of a Microstrip Band-Stop Filter for Microwave Applications

Performance of Microwave system may be degraded since the interference may be exist due to the presence of signals from other existing wireless communication systems. Currently, the major interference are in-band signal from 802.lla WLAN system which occupies the 5-6GHz spectrum and signals from 802.11b WLAN system covering 2.4-2.48 frequency band. This paper presents the design of a modified L-shaped resonator bandstop filter for Microwave applications. The applicability of the proposed design method is demonstrated by a conventional 2.45GHz L-shaped bandstop filter with -60dB attenuation, which was extended to include a modified L-shaped resonator's design and result discussion. Methods of increasing bandwidth such as changing L-resonator width and cascading of filters are presented. The filters have been simulated using ADS design software and implemented on FR4 substrate.

Miniaturized lowpass and bandstop filters using controlled coupling of open‐loop‐ring defected ground structure

AbstractIn this article, we present a compact microstrip bandstop filter using an open‐loop‐ring defected ground structure slot, etched in the ground plane and a simple Hi‐Lo line on the top layer. With the proposed coupling technique, a simple transformation from BSF to a corresponding LPF has been realized. The design procedure is validated using the commercial full‐wave simulator Microwave Office. The proposed BSF provides sharp transition characteristics, a wide upper stop band and improved passband response symmetry. Finally, the proposed filter structure has been fabricated and measured. The measurements are in a good agreement with the simulated results. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:2575–2578, 2010; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25527

Compact Wideband Bandstop Filter With Four Transmission Zeros

This work presents a new type of compact wideband bandstop filter (BSF) with four transmission zeros in the stopband. The proposed filter topology consists of a coupled line directional coupler connected in parallel to an interference transmission line. The filter characteristics can be easily controlled by the coupling factor of the coupled line coupler and the characteristic admittances of both the coupler and the transmission line. Design equations and curves are provided for the filter design. To validate the proposed topology, a compact microstrip BSF centered at 2.0 GHz with a measured 20 dB rejection bandwidth of 100% and sharp rejection characteristics is designed and built.

증가된 대역폭을 갖는 SRR 기반 대역 저지 여파기

In this paper, a new method to enhance the stop bandwidth of the compact microstrip bandstop filter based on split ring resonator(SRR) was proposed. To achieve wide stop bandwidth, we incorporated the SRR within the circular etched pattern of the defected ground structure(DGS). By incorporating the SRR within the circular etched pattern, a high magnetic coupling between SRR and signal line can be achieved. The high magnetic coupling enables the proposed structure to achieve a wide stop bandwidth. To verify the feasibility of the proposed structure, the proposed bandstop filter was compared with conventional bandstop filter employing SRRs which have been etched at both sides of the signal line. Simulation and experimental results show that the proposed structure provides an enhanced stop bandwidth compared with the conventional structure.

A miniature 5.2‐GHz bandstop microstrip filter using multilayer‐technique and coupled octagonal defected ground structure

AbstractIn this article, we propose a new compact defected ground structure (DGS) bandstop filter with broad pass‐band, low insertion loss in the stop‐band, and sharp transition from pass‐ to stop‐band. The bandstop filter structure is simple as it is composed of a pair of octagonal DGS slots and open stubs as a compensated microstrip capacitance. The filter is realized as a multiplayer structure with wide lossless stop‐band. The behavior of the filter has been investigated using EM as well as lumped‐element equivalent circuit model simulations. The design equations are derived using an equivalent circuit model of a parallel L–C resonator. The proposed filter has been optimized, fabricated, and measured. The agreement between the simulated and measured results confirms the effectiveness of the proposed concept. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2810–2813, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24770

Microstrip bandstop filter using a dual‐mode square loop resonator

AbstractDual‐mode microstrip bandstop filter, which has an inductive or capacitive perturbation element located at one of its corners, with a 90°‐bended λ/4 microstrip feeding line is proposed. The degenerate mode splitting of a conventional dual‐mode square loop resonator and the coupling coefficient between these modes are investigated. The filter characteristic is changed by the perturbation size. Finally, a novel dual‐mode microstrip bandstop filter is designed and realized using degenerate modes of dual‐mode microstrip square loop resonator. Two filters are designed, fabricated, and measured to demonstrate the validity of the proposed bandstop characteristic. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 147–150, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23967

Design of a compact and wideband microstrip bandstop filter

AbstractA novel bandstop filter (BSF), with a stop band covering GSM‐900, GSM1800, Bluetooth, and future 5 GHz applications which possesses the characteristics of compact size and wide bandwidth is proposed and fabricated. Parameters are optimized via numerical simulations. The simulations are performed via an in‐house‐prepared three dimensional (3D) finite‐difference time‐domain (FDTD) package. Measurements are carried out using an HP‐8510C network analyzer. The simulated and measured results show that the filter has wide stopband of 126% (1.7–7.8 GHz) for 3‐dB bandwidth. There is a good agreement between the simulated and experimental results. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2612–2614, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23742

Miniaturized Bandstop Filter Using Meander Spurline and Capacitively Loaded Stubs

A miniaturized bandstop filter (BSF) is introduced in this paper. The filter consists of one meander spurline and a pair of capacitively loaded stubs. The meander spurline with low resonant frequency and improved slow-wave factor exhibits excellent resonant bandgap characteristics which can be modeled by a longitudinally coupled resonator. The design of the proposed microstrip BSF is presented, and its performance is measured. Measurements show that there is a stopband from 2.3 to 5.6 GHz with S21 less than –20 dB. The total length of this BSF equals 23 mm.