Wide Passband Research Articles

A wideband reconfigurable filtering phase shifter based on Stub-loaded multimode resonators

Abstract In this paper, a type of reconfigurable filtering phase shifters (RFPSs) composed of stepped-impendence stub-loaded multimode resonators (SLMMR) is proposed. High frequency selectivity and wideband characteristics are realized in the presented work. Four transmission poles (TPs) are generated in the passband to exhibit a flat and wide passband. Meanwhile, the proposed SLMMR produces two controllable transmission zeros (TZs), which improves the frequency selectivity effectively. Meanwhile, radiofrequency switches are utilized to facilitate the transition between different phase shifts. Finally, the proposed RFPSs are designed and fabricated to verify the method. The measured results indicate that the designed RFPSs, which can be turned from 45° to 90° and from 135° to 180°, are capable of realizing more than 40 % FBW with a center frequency of 3.5 GHz.

A ridged waveguide filter design with ultra-wideband and harmonic suppression

In this paper, a new structure for wide-band rectangular waveguide bandpass filters with distinguished harmonic suppression is presented. The filter is realized by using ridged waveguides in both resonant cavities and coupling windows and a metal plate, which performs like a low-pass filter and makes it arduous to form parasitic passbands. According to the field analysis and out-of-band response, the ridge structure can expand pass bandwidth and obtain a wide stopband by harmonic suppression. The filter is designed to perform a passband of 67% fractional bandwidth at center frequency at 75 GHz. The harmonic suppression of the design is increased from 1.5 times to 3.6 times the center frequency of the filter with 20 dB suppression levels. Finally, the measurement results validate the proposed design.

Attenuation properties of a meta-pipe: Analytical, experimental, and numerical prediction

Flexural vibration characteristics of a meta-pipe are investigated in this paper. Initially, the metamaterial piping system consisting of a homogeneous pipe and periodic flexible supports is designed. Subsequently, the dispersion relationship which is a function of the wavenumber and the frequency is derived employing the transfer matrix method and Bloch’s theorem. The designed system reveals a zero-frequency stopband and a wide passband in the examined frequency range, which are verified by both experimental and numerical results. To enhance the performance of this system, it is essential to effectively control the obtained passband. For this, a single-degree-of-freedom localized resonator is designed, which is subsequently installed at the center of each unit-cell of the pipe. The dispersion properties of this system are first evaluated analytically and then validated using experimental and numerical methods. Finally, the effect of pipe system parameters and resonator properties on the stopband characteristics is studied in depth. It was observed that the stopband properties can be effectively tuned by appropriately designing the piping system and resonators. The results presented in this study offer valuable insights into the propagation characteristics of flexural waves and the strategies devised for controlling vibrations in pipes.

High-selectivity wideband bandpass filter based on quintuple-mode stub-loaded resonator and defected ground structures

Abstract A high-selectivity wideband bandpass filter (BPF) based on a quintuple-mode stub-loaded resonator and defected ground structures (DGSs) is presented. Thanks to the symmetrical topology, the even/odd theory is adopted for analyses. By properly adjusting the stub dimensions, the resonant frequencies of the transmission poles and zeros can be controlled to obtain wide passband and sharp out-of-band rejection performances. The bandwidth of the upper stopband is further extended by introducing a pair of DGSs under the interdigital coupled line feeding structures, and the spurious response rejection is improved by 18.9 dB. A BPF prototype that operates at 6 GHz with a fractional bandwidth (RBW) of 70 % is manufactured for validation. The measured insertion loss and return loss are 1.3 and 17 dB, respectively. The measured out-of-band rejection over DC-2 GHz and 8.8–21 GHz are better than −30 dB.

A study on develop the High-Performance Wide - Band LNA for use with IEEE frequency

In this research, a low-noise amplifier (LNA) with uniform growth, silent operation, and absolutely brilliant uniformity is suggested to be utilized in bandwidth transmitters, with a comparative channel capacity (RBW) of 110%. To enhance extended the reach, researchers present a cascode with dual feedbacks and a wide bandpass (BPDWB) matching network formed from bias and parasitic characteristics. The techniques for constructing a corresponding networking are also shown, and measurements indicate that the channel's resonance frequency is a great pairing for the required resistance in the range from through 3.5 GHz. Resistance matched precision and efficiency in prediction are both boosted by the envisaged BPDWB networks. Paper presents a low amplifiers (LNA) in 0.25 m GaAs father made high mobility electrons semiconductor (GaAs pHEMT) developers and researchers NF0.55 at mhz. Additionally, for the range of frequency of 8.5-20 MHz, overall bit error rate (NF) is somewhere between 2.19 to 3.23 dB, while another NF maximum (vase: internet: mia2bf00852: mia2bf00852-math-0012) varied between 1.55 - 2.91 db. At top of just that, a two-tone test with a frequency separation of 50 MHz demonstrates that the suggested LNA may accomplish high IIP3 of 0.96 frequency range.

Multi-stopband filter based on frequency selective surface

This paper presents the design of a terahertz multi-stopband filter based on a metasurface structure which consisting of multiple metallic strips. By adjusting the dimensions and arrangement of these metallic strips placed on a dielectric substrate, the precise control of the filter performance is achieved. This structure exploits the electromagnetic resonances of metallic strips at terahertz frequencies to generate stopbands, thereby enabling selective filtering. Numerical studies demonstrates that these configurations can produce multiple stopbands within the 4.2 to 15.5 THz frequency range, with tunable center frequencies and bandwidths. Through the research of the transverse and longitudinal filter model structure, the band-stop filter with more stopbands can be realized, and the transmission valley value is kept within 5 %, which is crucial for enhancing filter performance. Moreover, the study reveals that tuning the dimensions of the metallic strips can modulate the resonances, resulting in a redshift of the filter's central frequency and an expansion of the passband width. These findings provide a new method for the performance improvement of terahertz filters, advanced filtering technology and electromagnetic wave control technology.

Modified Inverted CSRR and Stepped Impedance Stub based Bandstop Filter with wide passband

Modified Inverted CSRR and Stepped Impedance Stub based Bandstop Filter with wide passband

A high-selectivity filtering DDPA with raised DDPs and metal vias

ABSTRACT A high-selectivity filtering dense dielectric patch (DDP) antenna (DDPA) with raised DDPs and metal vias is proposed in this paper. The proposed filtering DDPA has three resonant modes, the first two modes are TE 11 mode and the third mode is TE 12 mode. The first TE 11 mode is generated because of the centrally raised small DDP. The second TE 11 mode and the TE 12 mode are the modes of DDP itself. The proposed filtering DDPA has two radiation nulls (RNs). The low-frequency radiation null (LFRN) is generated by loading equal length parallel slots on the ground. DDP itself has a non-radiative high-frequency radiation null (HFRN). By loading symmetrical same metal vias on the DDP, the radiative TE 12 mode and the non-radiative TE 12 mode move to the low-frequency at the same time. That results in a wider passband and excellent high-frequency response. The proposed filtering DDPA is manufactured and measured for verification. The impedance bandwidth is 8.2% from 3.75 GHz to 4.07 GHz. The average gain is 7.7 dBi, and the average roll-off rate is 177 dB/GHz. The measured results prove that the proposed filtering DDPA has good radiation performance and high-selectivity.

Compact wide single‐/dual‐band bandpass filter with equal inductance configuration in thin film IPD technology

AbstractHere, based on thin film integrated passive device (TF‐IPD) technology, compact ultra‐wideband (UWB) bandpass filter (BPF) and dual‐band bandpass filter (DBBPF) with equal inductance configuration are proposed. The configuration of equal inductance in a circuit contributes to reducing variables, simplifying the physical structure, and shortening the debugging time in the TF‐IPD design process. Despite all the inductors being equal in value, a wide passband can still be achieved. The measured results show that the centre frequency of UBW BPF is 11.43 GHz, and the 3‐dB fractional bandwidth (FBW) is 133% (3.87–18.99 GHz). And the 3‐dB FBWs of DBBPF centred at 6.5 GHz and 16.2 GHz are 92% (3.51–9.49 GHz) and 35% (13.33–18.98 GHz), respectively. The stopband of UBW BPF and DBBPF can be extended to 47.7 GHz and 44.8 GHz in sizes of 321 µm × 856 µm and 235 µm × 846 µm, respectively (excluding measuring pads).

Rapid multi-band space-based optical timing: revolutionizing accretion physics

Optical timing with rapid, seconds-to-minutes cadences with high photometric precision and gap-free long baselines is necessary for an unambiguous physical picture of accretion phenomena, and is only possible from space. Exoplanet-hunting missions like Kepler and TESS have offered an outstanding new window into detailed jet and accretion physics, but have been severely hampered by incomplete calibration and systematics treatments and, most especially, a monochromatic single wide bandpass. Advances made using Kepler and TESS survey data, when considered alongside detailed, expensive multi-color experiments done from the ground, reveal the enormous potential of a space-based multi-color optical timing mission with a high energy focus.

A Wide Bandpass Elliptical Filtering Response Frequency-Selective Slab Based on Slotline- Backed Split-Ring Resonators

A Wide Bandpass Elliptical Filtering Response Frequency-Selective Slab Based on Slotline- Backed Split-Ring Resonators

A compact, low‐loss, and wide passband ratio substrate integrated waveguide triplexer based on complementary split ring resonators for multiband applications

SummaryIn this paper, a design of a substrate‐integrated waveguide (SIW) triplexer with improved low‐loss performance, passband ratio, and compactness based on the complementary split ring resonator (CSRR) structure is presented. The proposed triplexer operates at three passbands of 6, 8, and 10 GHz that correspond to the passband ratios of 1.33 and 1.67. By appropriately designing square CSRRs on the surface of the SIW structure, the low‐loss and compact resonator filters below the cut‐off frequency of the SIW at each operation frequency can be realized. The wide passband ratio is obtainable by adjusting the dimensions of the T‐junction. The measured results show the minimum insertion losses of 1.5, 1.4, and 1.9 dB at 6, 8, and 10 GHz, respectively. In addition, the minimum measured return losses are −9.33, −11.3, and −12.4 dB at the corresponding three passbands. The measured isolation between output ports is better than −17 dB in the frequency range from 5 to 11 GHz. The measured results agree well with simulations which are conducted by the CST Microwave Studio simulator. The proposed triplexer is designed on a cost‐effective RO4003C substrate with a compact size of 35 25 mm2

Active frequency-selective rasorber with wide range passband continuous tunability

In this paper, an active frequency-selective rasorber (AFSR) with a wide tunable range of passband windows is proposed. The proposed AFSR includes an absorption layer, a frequency selective layer, and an air spacer between them. The absorption layer is embedded with resistors to aid in the absorption of out-of-band unprofitable signals, and the frequency selective layer is designed to provide tunable transmission passbands through in-band beneficial signals. A design method for the AFSR embedded with varactors based on equivalent circuit model is proposed. Driven by an applied voltage, the transmission passband of the proposed AFSR can be shifted from 3.4 to 6.9 GHz. The absorption bandwidth covers from 6.4 to 14.1 GHz. In addition, the proposed AFSR exhibits stable performances up to 45° angle of incidence wave. The measurement results of the fabricated prototype are in good agreement with the simulation results. This work provides a feasible solution for flexible simultaneous regulation of radiation and scattering.

Design and Fabrication of 3.5 GHz Band-Pass Film Bulk Acoustic Resonator Filter.

With the development of wireless communication, increasing signal processing presents higher requirements for radio frequency (RF) systems. Piezoelectric acoustic filters, as important elements of an RF front-end, have been widely used in 5G-generation systems. In this work, we propose a Sc0.2Al0.8N-based film bulk acoustic wave resonator (FBAR) for use in the design of radio frequency filters for the 5G mid-band spectrum with a passband from 3.4 to 3.6 GHz. With the excellent piezoelectric properties of Sc0.2Al0.8N, FBAR shows a large Keff2 of 13.1%, which can meet the requirement of passband width. Based on the resonant characteristics of Sc0.2Al0.8N FBAR devices, we demonstrate and fabricate different ladder-type FBAR filters with second, third and fourth orders. The test results show that the out-of-band rejection improves and the insertion loss decreases slightly as the filter order increases, although the frequency of the passband is lower than the predicted ones due to fabrication deviation. The passband from 3.27 to 3.47 GHz is achieved with a 200 MHz bandwidth and insertion loss lower than 2 dB. This work provides a potential approach using ScAlN-based FBAR technology to meet the band-pass filter requirements of 5G mid-band frequencies.

A high resolution miniature electron energy spectrometer

In this work we describe how a novel mass spectrometer design we recently reported on can be utilized as an electron spectrometer having excellent resolution and passband width. This new electron spectrometer is referred to as a segmented electrode electron spectrometer (SEES). We discuss the determination of the operating parameters for the instrument and provide a detailed assessment of the energy resolution and passband width. We compare the new instrument to hemispherical deflection analyzers (HDAs), a popular electron spectrometer topology. The instrument presented has a resolution ∼9.1x greater than an idealized HDA and an energy passband ∼2.1x wider. In addition, the instrument has a volume far below an HDA of identical outer radius, enabling simpler integration with other existing instrumentation like x-ray, electron, and/or ion sources and microscopes. The evolution of this instrument demonstrates a new framework for the development of electron spectrometers with improved performance characteristics.

Design of miniaturized wide band-pass plasmonic filters in MIM waveguides with tailored spectral filtering

This paper reports the design and numerical results of three new extremely compact and efficient flat-top band-pass plasmonic filters operating in the near-infrared region. The proposed structures are realized in metal–insulator-metal plasmonic waveguides based on stub, tilted T-junction and right-angle trapezoid configurations. A built-in parameterized genetic algorithm is applied to maximize the transmission efficiency, while at the same time contributing to shrinking down the size of the device structures. It is shown that the tunability of the optical filters can be realized by modulating their structural parameters to gain control over the band-pass filtering wavelengths. Numerical calculations are conducted based on the finite element method of CST Microwave Studio and demonstrate that the suggested ultra-compact plasmonic waveguide filters offer wide bandwidths of more than 270 nm, 424 nm, and 289 nm, with transmission efficiencies of higher than 80%, 74.2%, and 74.3%, respectively. The sizes of the proposed wavelength filters are 490 nm × 575 nm, 350 nm × 180 nm, and 420 nm × 150 nm, respectively, which make them attractive candidates for applications in high density photonic integrated circuits (PICs). As a result, because of the promising characteristics of the proposed topologies such as their high efficiency, compact size, tunability, and simple structure they may find applications in on-chip integration, laser technology, and multi-photon fluorescence.

A Multifunctionality Reconfigurable HMSIW Filter by Using EBG Structure and Diodes for C/X-Band Application

This letter presents a multifunctionality reconfigurable substrate-integrated waveguide (SIW) filter embedded in a microstrip line. The proposed filter used an electromagnetic bandgap structure (EBG) to compact the size and improve the electromagnetic features. The SIW filter consists of a three-cell EBG with metallic circular-shaped connected to the ground through cylindrical vias. Firstly, the base SIW structure offers a wide passband filtering response, and then, to obtain selective passband, wide band rejection, and controllable resonance frequencies, a three-cell EBG along with four diodes has been attached. The filter is designed and printed on a Rogers 4003 substrate with a thickness of 1 mm and is experimentally validated for functionalities operated at three modes with an average 3 dB bandwidth of 115 MHz in each frequency. In addition to that, two transmission zeros (TZ) have been produced in the upper band frequency. The filter’s response is also tunable by turning the diode off or on and changing the main parameters of EBG, the gab, and the position between cells. The study explores resonance frequency alterations in a three-state system of on/off. By eliminating or diminishing specific modes, and incorporating diodes, distinct resonance behaviors are observed. Moreover, shifting frequency resonance in a multiparameter system has been investigated. Increasing B1 induces a significant shift to lower values, while an increase in D1 leads to a decrease in the first and second resonance frequencies and an upward shift in the third. The designed filter has been fabricated and tested to compare and confirm simulated responses. Simulation and measurement results are in good agreement. The S-parameters of measured results gained a good response (>15 dB) within the passbands and stopbands and an insertion loss of 1.5 dB suitable for 5G and Wi-Fi systems.

Design of highly selective balanced bandpass filter with wide differential-mode stopband and high common-mode suppression

A highly selective and wide stopband bandpass filter (BPF) with multiple transmission poles (TPs) and transmission zeros (TZs) has been proposed. The BPF employs a box-like coupling structure consisting of two half-wavelength resonators and a dual-mode open stub loaded resonator, enabling the generation of two TZs and four TPs. Three controllable TZs are obtained by adding an annular spiral open stub to the terminal of the input and output coupling lines, which significantly improves the selectivity of the BPF. To achieve a wide stopband characteristic, a wide stopband unit with three additional TZs is cascaded within the structure. A balanced BPF is realized by introducing a microstrip-slotline-microstrip balun structure to the input and output ports of the proposed BPF. Experimental results validate the feasibility of the proposed BPF and balanced BPF applied in 2.45 GHz ISM band. The introduction of eight TZs gives the BPF a 20 dB rectangular coefficient of 1.3 with an upper stopband exceeding than 12 GHz. The balanced BPF can achieve 40 dB of high common-mode(CM) suppression in the passband, while differential-mode (DM) transmission is close to the performance of the proposed BPF. The minimum insertion loss for BPF and balanced BPF is 0.8 dB and 1.3 dB, respectively.

Analysis and design of a wide stop‐band and high out‐of‐band suppression BPF

AbstractThis paper proposes a wide bandpass filter (BPF) with high out‐of‐band suppression and wide stop‐band characteristics. An interdigital coupled line structure loaded by a rectangular resonator ring is employed to generate three transmission poles in the pass‐band and an additional transmission zero (TZ) in the stop‐band, thereby achieving a wider pass‐band while enhancing stop‐band suppression. Compared to traditional coupled‐line structures, the structure mentioned in this paper offers significant advantages in designing filters with wide stop‐bands and high out‐of‐band suppression. Furthermore, open‐circuit T‐stub, and a pair of open‐circuit stub are used to generate multiple parasitic TZs at high frequencies, which is adopted to further expand the stop‐band range. Measurement results shows that the insertion loss of the BPF is of −2.86 dB within the range of 7.05–12.20 GHz. The stop‐band ranges from 13 to 48 GHz with an out‐of‐band suppression of −27 dB, especially when the out‐of‐band suppression is −40 dB, the stop‐band frequency range is 16.40–31.35 GHz.

Novel Polyimide-Based Conformal Bandpass FSS for X-band RADAR Communications

A linearly polarized wide bandpass frequency selective surface (FSS) for RADAR communication application has been presented. The proposed FSS is constructed in a single layer with a size of 0.25 λ0. This FSS utilizes a rhombus slot comprised of a head slot and a meander line to provide a single-wideband resonance. The proposed FSS operates in the X-band communication frequency range from 7.98 to 12.1 GHz (4.12 GHz) and achieves a minimum insertion loss of 0.1 dB, respectively. The designed FSS is developed on a flexible substrate with a low profile of 0.05 mm. The FSS exhibits stable angular performance in the scope of incidence angle of 60º for both TE and TM modes. An equivalent circuit model is designed to depict the desired frequency response. Furthermore, a bending analysis has been carried out to verify the conformal nature of the proposed unit cell. The prototype is fabricated and the performances are validated with experimental results.