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In this paper, design, fabrication and measurement of a novel microstrip dual-band bandpass filter (BPF) structure with a compact size using FR-4 glass epoxy material is presented. The filter structure is composed of folded non-uniform meander resonators. The proposed filter with a total size of 0.24λg × 0.16λg is designed to exhibit two passbands...
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In this article, a balanced microstrip dual‐band bandpass filter (BPF) is designed. The proposed filter is achieved by employing a microstrip U‐shape half‐wavelength resonator, a folded stub‐loaded resonator and balanced microstrip/slotline transition structures. The center frequencies and the fractional bandwidths of the two differential‐mode (DM)...
Citations
... Using metamaterials to design BPFs has been considered as an effective method to miniaturize the circuit. The BPFs using metamaterials, such as spoof plasmon polariton(SSPP) [8] and FR-4 glass epoxy material [9] have been reported in recent years. The split ring resonators(SRRs) [10,11], double split open-loop resonators (OLRs) [12], and shunted-line stepped-impedance resonators (SLSIRs) [13] are also adapted in the multiband BPF design. ...
In this paper, a compact balanced diplexer using a novel hairpin split ring resonator (H-SRR) is presented and demonstrated. Firstly, the working principle of the proposed H-SRR is described, which shows a negative permittivity or a negative permeability in the stopband. It can be used to construct compact passive components and improve the stopband rejection performance. Then, the differential-mode (DM) excitation and common-mode (CM) excitation are investigated, respectively. Under DM operation, the H-SRR can provide one DM resonant mode. Under CM operation, the H-SRR can excite two CM resonant modes far from the DM resonant mode, thus producing a desired CM rejection performance. Moreover, by introducing a mixed electromagnetic (EM) coupling, transmission zeros (TZs) are produced, significantly improving the DM isolation between the two channels. Finally, a balanced diplexer is designed and fabricated. The lower and higher channels of the diplexer are centered at 3.36 and 4.00 GHz. The DM channel isolation is better than 40/41 dB in the two passbands when the frequency ratio is less than 1.2, which is in satisfactory agreement with simulated results.
... Designing of filters with multiple bands is becoming increasingly important with the rapid expansion of wireless communication schemes. WLAN that operates at 2.45, 5.2, with 5.8 GHz, and WiMAX that operates at 3.5 with 5.2 GHz are application examples that should operate instantaneously without interference [10][11][12]. RF transceivers use multiband BPFs because of their unique properties of broad rejection band, deep transmission zeros, great selectivity, skirt frequency responses, and tunable behavior. Several strategies have been used to develop BPFs, like the stepped impe-dance resonator (SIR) [13][14][15], balanced BPFs [16][17][18], and so on. ...
In this paper, a new multiband bandpass filter using Kappa substrate has been designed to be operated under resonant frequencies of 3.02 and 3.56 GHz for the first band, 6.2 GHz for the second band, and 7.1 GHz for the third band with excellent scattering parameters. The projected filter employs dual micro-strip elements of non-symmetric step impedance resonators and uniform impedance resonator and microstrip feeder based on symmetric step impedance resonator. The filter has been in agreement simulated S11 and S21 scattering parameters using AWR and Sonnet electromagnetic solvers.
... With the repaid developments of the wireless communication systems, designing filters with multi bands is preferable. More studies have been conducted to achieve the dual-band response of the band pass filter since there are a lot of applications that should be operated simultaneously without any interference such as WLAN, which runs at 2.45, 5.2, and 5.8 GHz and WiMAX, which also runs at 3.5 and 5.2 GHz [10][11][12]. Due to the distinct properties of multiband BPFs, such as wide rejection band, deep transmission zeros, high selectivity, sharp roll-off rate, and tunable behavior, they have a specific place in the RF receivers. Various techniques were carried out in designing BPF such as stepped impedance resonator (SIR) [13][14][15], balanced BPFs [16][17][18], multilayer structures [19,20], substrate integrated waveguide (SIW) [21][22][23], dual-mode patch resonator [24], and meandered loop resonator [25]. ...
Two dual-band second-order highly selective band pass filters operated at 3.5/5.5 GHz and 3.5/6 GHz for wireless local area network /worldwide interoperability for microwave access WLAN/WiMAX applications are introduced in this paper. The designed filters are inspired of utilizing two coupled open-loop resonators loaded with stub, spiral resonators and lumped capacitors. The filters are designed based on calculating the desired coupling matrix and the external quality factor. The first and the second filters are designed at the fundamental mode of 3.5 GHz then the first filter is loaded with two spiral resonators in the microstrip line to produce the desired band stop behaviour, which in turn achieves the second pass-band. However, the second band of the second filter is achieved by loading the stub with the lumped capacitors, which controls the second mode. The centre frequency of the second band is adjusted by varying the lumped capacitors values. The two designed filters have insertion loss less than 0.7 dB in the pass-band region, high selectivity with more than 4 transmission zeros and more than 20 dB attenuation level in the stop band region. The suggested filter has compact size and high selectivity with tunability behavior. The two filters are fabricated and measured to validate the simulated results.
... Nevertheless, researchers focused on multi-band filters due to its good performance in passing/rejecting applications which occupy narrow bandwidth. Many multi-band filters have been designed at the expense of either structure compactness or simplicity since multiple resonators have been used to achieve multi-band behaviour [19][20][21][22]. Researchers have solved some of the aforementioned problems by designing tunable metamaterial based planar filters with single band- pass/band-stop as reported in [23,24] but the reported models need further improvements to minimize the size although they have their own merits. ...
This paper presents the design of a novel epsilon-shaped metamaterial unit cell structure that is applicable for single-band and multi-band applications. A closed-form formulas to control the resonance frequencies of the proposed design are included. The proposed unit cell, which exhibits negative permeability at its frequency bands, is etched from the ground plane to form a band-stop filter. The filter design is constructed to validate the band-notched characteristics of the proposed unit cell. A lumped capacitor is inserted for size reduction purpose in addition to multi-resonance generation. The fundamental resonance frequency is translated from 3.62 GHz to 2.45 GHz, which means that the filter size will be more compact (more than 32% size reduction). The overall size of the proposed filter is 13 × 6 × 1.524 mm³, where the electrical size is 0.221λg× 0.102λg× 0.026λg at the lower frequency band (2.45 GHz). Two other resonance frequencies are generated at 5.3 GHz and 9.2 GHz, which confirm the multi-band behavior of the proposed filter. Good agreement between simulated and measured characteristics of the fabricated filter prototype is achieved.
In this paper, a miniaturized dual-band bandpass filter (DB-BPF) based on a dual-path stub-loaded resonator is presented. A transversal filtering design is introduced in the proposed DB-BPF, which provides two signal propagation paths from input to output. In total, six transmission poles and four transmission zeros are obtained, which improves overall filter selectivity. The fractional bandwidth (FBW) of dual bands with center frequencies of 2.24 and 7.35 GHz is 36.4% and 31.2%, respectively. The physical size of a fabricated filter is (0.43 ×0.17)λg , where λg is the guided wavelength at 2.24 GHz. The DB-BPF prototype is fabricated using a Roger Duroid RT/5880 substrate to further validate the result. The full-wave EM simulation and measured results show good agreement. The proposed dual-band bandpass is applicable to a wide range of modern communication technologies, including Wi-Fi, satellite, cellular, radar, and broadcast communication.
This chapter deals with the fundamentals of gas-cleaning technology. There are several new equipments introduced by the working principles and general recommendations to remove particles, such as cyclones, wet electrostatic precipitators, fabric lifters, and scrubbers. Some newer fiber materials like high silia, polyphenylene sulfide, meta-aramid fabric, polyamide fiber, ceramic, and metal have been found to have better physical characteristics. Pressure loss is the new factor that comes into consideration. The up-to-date abatement methods include membranes, photocatalysis, low-temperature plasma method, electron beam irradiation, and gas discharge. In addition, advanced fume control technology updated basic principles, and emission source characterization and common smoke trapping methods are also discussed. Different gases such as carbon monoxide, hydrocarbons, sulfur oxides, and nitrogen oxides have their specific sensors and analyzers. Technology and equipment have been improved to measure gaseous emissions, such as tunable diode laser absorption spectroscopy, interferometric amplification reflection method, photoionization detection method, potentiostatic electrolysis, differential lidar, differential optical absorption spectroscopy, and photoacoustic spectroscopy.
In this article, a compact dual band bandpass filter using V‐ and W‐shaped microstrip open lines is developed and analyzed. An equivalent lumped elements circuit, derived from the designed structure is presented and its elements are calculated based on its transfer function. The obtained equivalent circuit is interpreted with the geometric tuning results in particular the transmission zero relocations. The measurement results of the fabricated prototype agree with the simulations and confirm the design theory. The design can suit WLAN application.
