Triple-band Bandpass Filter Research Articles

Substrate‐integrated waveguide triple‐band filter with improved frequency and bandwidth allocations

Substrate-integrated waveguide triple-band bandpass filter composed of two dual-mode (TE101 and TE201) rectangular cavities coupled with two single-mode (TE101) ones is synthesised and designed based on dual-mode resonances and split-type dual-band symmetrical frequency response. By applying the dual-mode frequency and coupling controlling techniques, the centre frequencies and fractional bandwidths (FBWs) of the three passbands can be allocated more flexibly. An experimental prototype centred at 11.578, 12.468 and 14.985 GHz with respective FBWs of 2.21, 2.21 and 2.3% is synthesised, designed, fabricated and measured for demonstration, showing good agreement between the measured and simulation results.

Substrate-Integrated Waveguide Triple-Band Bandpass Filters Using Triple-Mode Cavities

Substrate-integrated waveguide (SIW) triple-mode triple-band bandpass filters (BPFs) are synthesized, designed, and demonstrated for the first time based on a novel type of SIW triple-mode square cavities perturbed by centered cross-shaped metallized via holes. The resonant characteristics of the cavity are analyzed first to show the range of the realizable frequency ratios, and the design parameters corresponding to the specifications, i.e., the external quality factors and the internal coupling coefficients for the three passbands, can be specified flexibly within certain ranges by exploiting an advanced triple-mode coupling controlling technique. Two SIW triple-mode triple-band BPFs, including a third-order direct-coupled one operating at 13, 14, and 15 GHz and a fourth-order cross-coupled one operating at 11, 12, and 13 GHz, are synthesized, designed, fabricated, and measured for demonstration. Compact circuit sizes and excellent filtering performances have been achieved for the two prototypes.

Design of triple-band bandpass filter using quad-mode stepped impedance resonator (SIR) with shorted stub

Design of triple-band bandpass filter using quad-mode stepped impedance resonator (SIR) with shorted stub

Design and theoretical study of a polarization-insensitive multiband terahertz metamaterial bandpass filter**Project supported by the National Natural Science Foundation of China (Grant Nos. 11504418, 11447033, and 61372048) and the Fundamental Research Funds for the Central Universities, China (Grant No. 2015XKMS075).

We report the design of a novel multiband metamaterial bandpass filter (BPF) in the terahertz (THz)-wave region. The designed BPF is composed of a metal–dielectric–metal sandwiched structure with three nested rings on the top surface and a cross structure on the bottom surface. Full-wave simulation results show that the designed BPF has three transmission peaks at frequencies of 0.42, 1.27, and 1.86 THz with transmission rates of −0.87, −1.85, and −1.83 dB, respectively. Multi-reflection interference theory is introduced to explain the transmission mechanism of the designed triple-band BPF. The theoretical transmission spectrum is in good agreement with the full-wave simulated results. The designed BPF can maintain a stable performance as the incident angle varies from 0° to 30° for both transverse electric and transverse magnetic polarizations of the incident wave. The designed BPF can be potentially used in THz devices due to its multiband transmissions, polarization insensitivity, and stable wide-angle response in the THz region.

A compact triple-band microwave filter using symmetrically placed stub-loaded open-loop resonators

ABSTRACTIn this paper, symmetrically placed stub-loaded open-loop resonators with magnetic coupling are used to design compact triple-band band pass filter (BPF) with improved insertion loss at passbands. Three bands of the proposed triple-band stub-loaded open-loop resonator filter are achieved by tuning length and position of open shunt stub which is connected with open-loop resonators. A lossless transmission line model is used to calculate the resonator properties. Theoretical design procedures are verified with an example of triple-band BPF design. Three passbands at 2.85, 5.9 and 8.15 GHz are achieved with reduced insertion loss. The insertion loss measured at first, second and third passbands are 0.47, 0.77 and 1.41 dB, respectively. First passband 2.76–2.9 GHz is used for the airport surveillance radar system and weather monitoring system. Second frequency band 5.82–6.16 GHz is used for the intelligent transportation system and third band 8.1–8.7 GHz is useful for satellite communication.

Individually Frequency Tunable Dual- and Triple-band Filters in a Single Cavity

This paper presents a new class of second-order individually and continuously tunable dual- and triple-band bandpass filters in a single metal cavity. Each passband is realized by two identical metal posts. These dual- and triple-band tunable filters are achieved by putting two or three identical sets of metal-post pair in a single metal cavity. Metal screws are co-designed as a part of the metal posts to control their insertion depth inside the cavity. In this way, the resonant frequencies can be continuously controlled and designed at the desired frequency bands. Moreover, the distance between the two metal posts in a post pair can be freely tuned. Thus, the external quality factor (Q <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">e</sub> ) and coupling coefficient (k) between the adjacent modes can be easily adjusted to meet the specified requirement in synthesis design. At the bottom of the cavity, some grooves are used to extend the tunable frequency range and make the resonant frequency linearly varied with the height of the metal post. The center frequency of each passband can be independently tuned with a frequency range of 0.8-3.2 GHz and tunable ratio of 4. Finally, the continuously tunable dual- and triple-band bandpass filters prototypes with second order response are designed and fabricated, of which each passband can be individually tuned with a large tuning range.

English

In this research, a triple-band bandpass filter (BPF) using a cascade tri section step impedance resonator (TSSIR), which can be operated at 900 MHz, 1,800 MHz, and 2,600 MHz simultaneously, was designed, fabricated and evaluated. Advanced Design System (ADS) was used to design and simulate the proposed BPF. The proposed BPF using cascade TSSIR was fabricated on an FR4 substrate with dielectric permittivity, substrate thickness and loss tangent at 4.3, 1.6 mm and 0.0017, respectively. The performance parameters of the proposed BPF were characterized by insertion loss, return loss, voltage standing wave ratio (VSWR) and group delay. The performance results from the simulation were compared to those of the fabricated BPF. The results showed that the performances from both the simulated and the fabricated BPF satisfied the design specifications and were in close agreement with each other. Furthermore, the results indicated that the proposed BPF using cascade TSSIR performed better than a hairpin BPF with TSSIR.

A compact triple-band bandpass filter based on metamaterials

This paper presents a compact triple-band bandpass filter based on metamaterials. The miniaturization is realized by the principle of phase compensation of metamaterial. Compared with the conventional half-wavelength filter, the metamaterial filter has a small size of 10 mm×10 mm. The triple-band bandpass filter performance has been validated by the electromagnetic simulation software of high frequency structure simulator (HFSS). The results illustrate that the filter is designed with center frequencies of 2.4 GHz, 5.1 GHz and 8.8 GHz, bandwidths of about 7.9% (2.31—2.50 GHz), 7.8% (5.0—5.4 GHz) and 7.4% (8.50—9.15 GHz), respectively, and it shows good band pass characteristics.

Perturbed Sierpinski carpet resonator and its usage in compact dual and triple band bandpass filters

In this paper, perturbed Sierpinski carpet fractal shaped resonator is characterized and applied in the design of multiband band pass filters (BPFs). The route to achieving compact multimode resonators starting from the Sierpinski carpet fractal shaped resonator is detailed. The proposed resonators are used to demonstrate two topologies of dual band bandpass filters with passband center frequencies at 3.5 GHz as well as 5.5 GHz, respectively. Both the designs exhibit nearly identical passband bandwidth. In the second design, it is observed that the second passband gets slightly shifted towards 5.85 GHz. However, with edge loading this shift is nullified. A scaled down version of the same resonator is designed and three such resonators are interdigitally coupled in conjunction with complementary split ring resonators to exhibit a novel technique of achieving compact triband bandpass filter. All designs have acceptable passband insertion loss in the respective bands. Accessories are used to improve passband selectivity in all designs and also a wide stop band till 10 GHz is obtained. Fabrication prototypes for all the variants are realized with simulated and measured results in good agreement. © 2016 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:418–425, 2016.

A compact triple-band bandpass filter with customizable frequencies

A compact triple-band bandpass filter with customizable frequencies

Design of asymmetrical resonator for microstrip triple-band and broadband bandpass filters

This paper presents two triple-band bandpass filters (BPFs) and one broadband BPF by using asymmetrical resonators. The asymmetrical resonator consists of three branched microstrip sections with different electrical lengths. For the first triple-band BPF (Filter I), by adjusting the stub length of the resonator, the first three resonant modes can be moved to the required center frequencies. For the second triple-band BPF (Filter II), the two sets of asymmetrical resonators are designed with the characteristic of the same center frequencies and staggered higher-order modes to achieve a wide stopband. For the broadband BPF (Filter III), the multi-mode resonances and inherent transmission zeros of the asymmetrical resonator are utilized to design the wideband response with sharp passband selectivity. It has the advantages of compact size and harmonic suppression.

Miniaturized Tri-Band BPF using Asymmetric SIRs and DGS

In this paper, we proposed a tri-band microstrip Bandpass Filter (BPF) for the application of GSM (1.8GHz), WiMAX (2.86GHz) and UWB (3.32– 5.12GHz). By integrating two narrow passbands filter with UWB filter; a tri-band response is achieved. The filter response performance is improved by introducing the asymmetric SIRs with Defected Ground structure (DGS). An appearance of transmission zeroes of the proposed structure guarantee the sharpness, the skirts of scattering parameters of triple-band Band pass filter (BPF). The proposed filter shows very low return loss of -42.57 dB, insertion loss of -0.04dB, and compact which shows that the filter is more efficient.

Design of a compact triple-band bandpass filter using triple-mode stub-loaded step-impedance resonator

Design of a compact triple-band bandpass filter using triple-mode stub-loaded step-impedance resonator

Synthesizing a Multiband LTCC Bandpass Filter With Specified Transmission- and Reflection-Zero Frequencies

This paper presents a vertically expandable low-temperature cofired ceramic (LTCC) bandpass filter (BPF) structure to increase the number of operating bands of the BPF without changing the area of the footprint. To design efficiently the proposed LTCC BPFs with highly configurable passbands and stopbands, a new method of synthesizing multiband BPF prototypes with specified transmission- and reflection-zero frequencies is developed. A dual-band BPF and a triple-band BPF were designed and implemented in LTCC. Both BPFs have the same area of 1.25×2.0 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Comparisons of the S-parameters among the synthesized prototypes, postlayout simulations and measurements exhibit a strong correlation.

Miniaturized Triple-Band Bandpass Filter Using Coupled Lines and Grounded Stepped Impedance Resonators

A triple-band bandpass filter with good selectivity based on modified grounded stepped impedance resonators (SIRs) is presented. The fundamental and first higher order resonances of the two λ/4 grounded SIRs are utilized to obtain dual-band response. Moreover, bandwidths of the two passbands can be controlled by tuning the distance between the two grounded vias. Owing to the use of two λ/2 fork resonators, another passband can be realized without increasing additional feedlines, which can be designed independently while other passbands are not affected. Several transmission zeros (TZs) are generated on each side of the passbands to obtain good selectivity. The λ/4 SIRs are embedded inside of the λ/2 fork resonators to realize miniaturization. The measurement and simulation results show good agreement.

A Triple-band Bandpass Filter using Tri-section Step-impedance and Capacitively Loaded Step-impedance Resonators for GSM, WiMAX, and WLAN systems

This paper presents a triple-band bandpass filter for applications of GSM, WiMAX, and WLAN systems. The proposed filter comprises of the tri-section step-impedance and capacitively loaded step-impedance resonators, which are combined using the cross coupling technique. Additionally, tapered lines are used to connect at both ports of the filter in order to enhance matching for the tri-band resonant frequencies. The filter can operate at the resonant frequencies of 1.8 GHz, 3.7 GHz, and 5.5 GHz. At resonant frequencies, the measured values of S 11 are −17.2 dB, −33.6 dB, and −17.9 dB, while the measured values of S 21 are −2.23 dB, −2.98 dB, and −3.31 dB, respectively. Moreover, the presented filter has compact size compared with the conventional open-loop cross coupling triple band bandpass filters

Compact triple-band bandpass filter using multimode stubs loaded resonator

ABSTRACTA compact microstrip tri‐band bandpass filter using multimode stubs loaded resonator is proposed in this article. The characteristics of the multimode resonator are investigated by even–odd mode analysis. To sharpen the passband skirts, a source‐load coupling configuration with a nonresonant node was arranged to produce several transmission zeros. For demonstration purpose, a tri‐band filter operating at 1.89 GHz (TD‐SCDMA band), 2.45 GHz (ISM band) and 3.50 GHz (WiMAX band) is designed, fabricated, and measured. The measurements are in good agreement with the simulations. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2672–2675, 2013

Design of a microstrip triple-band bandpass filter using a variation of genetic algorithm

A new microstrip triple-band bandpass filter (BPF) using a variation of genetic algorithm (VGA) is proposed in this paper. The VGA is applied to simultaneously search for the appropriate circuit topology and the corresponding electrical parameters with a triple-band characteristic. To demonstrate the effectiveness of the VGA, a triple-band BPF is designed and fabricated. In the filter, the 3 dB fractional bandwidths for the three passbands centered at 2.05, 3.57, and 5.81 GHz are 14.63, 11.20, and 7.57%, respectively. Measurement results agree well with the design index and full-wave EM simulated results.

A compact coupled-line triple-band bandpass filter with an adjustable third passband and open stubs

This study proposes a novel structure for designing a simple triple-band bandpass filter. This filter structure consists of two sets of coupled lines with the same line width plus two sections of open stubs and three transmission line sections of a single line width. The design and fabrication of the overall circuit structure are innovative and simple. The third resonance frequency (f3 of 8.9 GHz) was shifted to a lower frequency (6.5 GHz) by lengthening the two open stubs. The second resonance frequency (f2 of 4.2 GHz) can be adjusted using the transmission line gap size. The first resonance frequency (f1 of 2.4 GHz) can be adjusted using the coupled line length. These filters were simulated using the IE3D full-wave electromagnetic simulator, and the prototype of the bandpass filter was fabricated and measured. Comparisons of the simulated results and experimental data are presented. The findings show that the simulated results can match actual measured results. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:970–975, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27475

A Reconfigurable Compact Coupled Line Multiple-Band Bandpass Filter

This study proposes a circuit structure with reconfigurable multiple bands bandpass filter. This circuit can provide a triple-band or dual-band bandpass facility by adjusting two open stubs (L6 and L7) location. The circuit design used three sections of transmission line in series, the two sets of the coupled lines connected to the gap in each transmission line, and two open stubs in the appropriate locations. The design and manufacturing of the circuit structure is innovative and simple. The center frequencies of the triple-band bandpass filter are set at 2.4, 4.2, and 6.5 GHz, respectively, while the center frequencies of the dual-band bandpass filter are the two lower pass band of the triple-band bandpass filter at 2.4 and 4.2GHz. The filters were simulated using the full-wave electromagnetic simulator, IE3D, and measured by Anritsu-37269D. The simulated and measured results show good agreement in the frequency of interest.