Ultra-wideband Bandpass Fllter Research Articles

A NEW COMPACT MICROSTRIP UWB BANDPASS FILTER WITH TRIPLE-NOTCHED BANDS

A new microstrip ultra-wideband (UWB) bandpass fllter (BPF) with triple-notched bands is presented in this paper. The circuit topology and its corresponding electrical parameters of the initial microstrip UWB BPF are desired by a variation of genetic algorithm (VGA). Then, triple-notched bands inside the UWB passband are implemented by coupling a square ring short stub loaded resonator (SRSSLR) to the main transmission line of the initial microstrip UWB BPF. The triple-notched bands can be easily generated and set at any desired frequencies by varying the designed parameters of SRSSLR. For veriflcation, a microstrip UWB BPF with triple-notched bands respectively centered at frequencies of 4.3GHz, 5.8GHz, and 8.1GHz is designed and fabricated. Simulated and experimental results are in good agreement.

NOVEL BAND-NOTCHED UWB BANDPASS FILTER USING MICROSTRIP/SLOTLINE RING RESONATORS

A novel ultra-wideband (UWB) bandpass fllter (BPF) with notched band based on microstrip/slotline ring resonators is presented in this paper. The UWB BPF is fabricated with two microstrip ring resonators on the top copper layer and a slotline ring resonator on the bottom ground layer. Thus, an ultra-wide passband can be achieved owing to the coupling efiects and microstrip/slotline transitions of these three ring resonators. Then, a notched band which is created at 8.0GHz for satellite communication system is designed based on loaded short-circuited stubs. Both the simulated and measured results show that this compact UWB BPF has good performances of wide passband and notched band.

COMPACT MICROSTRIP UWB BANDPASS FILTER WITH TWO BAND-NOTCHES FOR UWB APPLICATIONS

A new microstrip ultra-wideband (UWB) bandpass fllter (BPF) with dual sharply rejected notched bands based on E-shaped resonator is proposed in this paper. The basic UWB BPF is designed using two microstrip interdigital coupled lines and one rectangular patch multiple-mode resonator (MMR). Then, to achieve dual band-notched performance, the proposed dual-mode E-shaped resonator is investigated and coupled to the rectangular patch multiple-mode resonator of the basic UWB BPF. To validate the design theory, a microstrip UWB BPF with two notch-bands centered at the frequencies of 5.8GHz and 8.0GHz, respectively, is designed and fabricated. Both simulation and experimental results are provided with good agreement.

COMPACT MICROSTRIP UWB BANDPASS FILTER WITH TRIPLE-NOTCHED BANDS AND WIDE UPPER STOPBAND

A novel compact ultra-wideband (UWB) bandpass fllter (BPF) with triple sharply notched bands and wide upper stopband is proposed. The basic UWB BPF is composed of two microstrip interdigital coupled lines and one multiple-mode resonator (MMR). Then, to achieve triple band-notched performance, the proposed triple-mode stepped impedance resonator (TMSIR) is studied and coupled to the interdigital coupled lines of the basic UWB BPF. To validate the design theory, a microstrip UWB BPF with three notched bands respectively centered at 5.2GHz, 5.8GHz, and 6.8GHz is designed and fabricated. Both simulated and experimental results are provided with good agreement.

A NOVEL APPROACH TO DESIGN OF MICROSTRIP UWB BANDPASS FILTER USING MODIFIED GENETIC ALGORITHM

A novel approach to design microstrip ultra-wideband (UWB) bandpass fllter (BPF) using modifled genetic algorithm (MGA) is proposed in this paper. To achieve high e-ciency and accuracy, conventional GA is modifled. By improving the fltness evaluation, selection, crossover, and mutation, the two possible drawbacks of conventional GA, i.e., slow rate of convergence and local-best solution, are overcome. The modifled genetic algorithm is then applied to simultaneously search for the appropriate circuit topology and the corresponding electrical parameters with UWB characteristic. To demonstrate the efiectiveness of the novel approach, a new microstrip UWB BPF is designed and fabricated. Measurement results agree well with the design index and full-wave EM simulated results.

COMPACT ULTRA-WIDEBAND BANDPASS FILTER WITH SHARP ATTENUATION USING MODIFIED COMPOSITE RIGHT/LEFT-HANDED TRANSMISSION LINES

In this paper, the characteristics of novel modifled composite right/left-handed (CRLH) transmission lines are discussed, and an ultra-wideband (UWB) bandpass fllter (BPF) using the modifled CRLH transmission lines is presented. Design formulas of a novel modifled CRLH unit cell are theoretically derived. Based on the design formulas, the UWB bandpass fllter with three unit cells is designed, fabricated, and measured. The measurement results show that the UWB bandpass fllter has an insertion loss of less than 1dB, bandwidths of 2:9 » 49GHz, and a rejection of greater than 50dB at 5.8GHz.

COMPACT MICROSTRIP UWB BANDPASS FILTER WITH TRIPLE-NOTCHED BANDS

A new microstrip ultra-wideband (UWB) bandpass fllter (BPF) with triple-notched bands is presented in this paper. The circuit topology and its corresponding electrical parameters of the initial microstrip UWB BPF are desired by a variation of genetic algorithm (VGA). Then, triple-notched bands inside the UWB passband are implemented by coupling a square ring short stub loaded resonator (SRSSLR) to the main transmission line of the initial microstrip UWB BPF. The triple-notched bands can be easily generated and set at any desired frequencies by varying the designed parameters of SRSSLR. For veriflcation, a microstrip UWB BPF with triple-notched bands respectively centered at frequencies of 4.3GHz, 5.8GHz, and 8.1GHz is designed and fabricated. Simulated and experimental results are in good agreement.

MINIATURIZED UWB BANDPASS FILTER WITH DUAL NOTCH BANDS AND WIDE UPPER STOPBAND

In this paper, a miniature ultrawideband (UWB) bandpass fllter with dual notch bands and wide upper stopband is presented. The ultrawide passband characteristic is achieved using a microstrip to slot line transition, and a wide upper stop band is realized using an elliptical lowpass fllter. The dual band notches at 5.46GHz and 8.04GHz are obtained by incorporating defected microstrip structure in the input and output sections. A prototype of the proposed UWB bandpass fllter is fabricated and measured. The equivalent circuit of the proposed fllter is also presented. A good agreement between the measured, EM simulated and circuit simulated responses is obtained.

COMPACT NOTCHED ULTRA-WIDEBAND BANDPASS FILTER WITH IMPROVED OUT-OF-BAND PERFORMANCE USING QUASI ELECTROMAGNETIC BANDGAP STRUCTURE

In this paper, a compact notched ultra-wideband (UWB) bandpass fllter with improved out-of-band performance using quasi electromagnetic bandgap (EBG) structure is proposed. Firstly, a UWB bandpass fllter based on a stepped-impedance stub-loaded resonator (SISLR) is combined with quasi-EBG structures, which suppress the undesired spurious bands to improve the out-of-band performance. In order to eliminate the interference caused by WLAN, a notched band is introduced at 5.2GHz, which is implemented by adding a folded stepped-impedance resonator (SIR) near the stub of the SISLR. At last, the proposed fllter is fabricated and measured. Good performances of the UWB fllter have been demonstrated both in the simulated and measured results.

A NOVEL COMPACT ULTRA-WIDEBAND BANDPASS FILTER WITH SIMULTANEOUS NARROW NOTCHED BAND AND OUT-OF-BAND PERFORMANCE IMPROVEMENT

A compact ultra-wideband (UWB) bandpass fllter (BPF) with simultaneous narrow notched band and out-of-band performance improvement is presented. The UWB BPF is built up using the hybrid microstrip and coplanar waveguide (CPW) structure. By employing the split-ring resonator (SRR) which is defected on the lower plane, the narrow notched band was introduced. The center and bandwidth of the notched band can be controlled by adjusting the length and width of the SRRs. A novel cross-shape patch is constructed to implement transmission stopband in the upper out-of-band so as to suppress the spurious passband. The novel UWB BPF is designed and fabricated. The measured insertion loss is less than 1.6dB, the return loss is more than 13dB and the variation of group delay is less than 0.12ns. The width of narrow notched band is about 0.15GHz and the attenuation is 18dB at the center frequency of 5.76GHz. The upper stopband is up to 15.2GHz with rejection greater than 20dB.

A COMPACT UWB BANDPASS FILTER WITH IMPROVED OUT-OF-BAND PERFORMANCE USING MODIFIED COUPLING STRUCTURE

A compact ultra-wideband (UWB) bandpass fllter (BPF) with improved harmonic suppression using a modifled coupling structure is presented in this paper. The modifled coupling structure is constructed by taper-connecting two folded open stubs to the traditional parallel-coupled lines, which shows an improved characteristic in harmonic suppression. By integrating the proposed coupling and the stepped-impedance stub loaded resonator (SISLR), a UWB BPF is flnally built and tested. The simulated and measured results are in good agreement with each other, exhibiting good wideband flltering characteristic and improved out-of-band performance.

COMPACT UWB BAND-PASS FILTER UTILIZING MODIFIED COMPOSITE RIGHT/LEFT-HANDED STRUCTURE WITH CROSS COUPLING

An ultra wide band (UWB) band-pass fllter (BPF) utilizing one modifled composite-right/left-handed (CRLH) unit cell is proposed. By introducing the capacitive cross coupling to the traditional CRLH structure, the phase shift in the right-handed pass- band can be controlled, meanwhile, the cross coupling has negligible efiect on the left-handed pass-band. The appropriate cross coupling can create three controllable transmission zeros. Thus, an UWB BPF with high selectivity is developed using only one unit cell, which leads to low insertion loss (less than 1.35dB) and compact size (0:47‚0£0:28‚0). The fabricated fllter exhibits a rejection level higher than 20dB at the stop-band from 11.95{16GHz and ∞at group delay across the pass-band.

COMPACT UWB FILTER BASED ON SURFACE-COUPLED STRUCTURE WITH DUAL NOTCHED BANDS

A novel compact ultra-wideband (UWB) band-pass fllter (BPF) based on surface-coupled structure is proposed. The surface- coupled structures and Y-shaped shorted stub resonator are adopted as quasi-lumped circuit elements to achieve UWB pass-band. To avoid the interference of the wireless local area network (WLAN) at 5.25 and 5.775GHz, two difierent quarter-wavelength lines are arranged on the ground of UWB BPF to generate dual narrow stop bands. Being developed from the quasi-lumped elements, the proposed UWB BPFs have very compact size. The fabricated UWB BPFs have the advantages of low insertion loss, good selectivity and ∞at group delay. Good agreement between equivalent circuit modeled, simulated and measured responses of these fllters is demonstrated.

COMPACT TRI-LAYER ULTRA-WIDEBAND BANDPASS FILTER WITH DUAL NOTCH BANDS

A compact ultra-wideband (UWB) bandpass fllter (BPF) with dual notch bands is presented using a tri-layer structure. In the design of UWB BPFs, it is desired to have a uniform 3.1GHz to 10.6GHz full-band transmission response. Dual notch bands are generated for flltering out the interferences caused by strong signals transmitted from WLAN and/or WiMAX systems at 5.8GHz and 3.5GHz, respectively. The sharp rejection of WiMAX signals is achieved by adding meander open-loop resonators on the middle layer. Another rejection of WLAN signals is introduced by adding a C- shaped resonator on the bottom layer. The proposed fllter is not only realized theoretically but also verifled by a full-wave electromagnetic simulation. The designed tri-layer UWB BPF with dual notch bands was fabricated by two FR4 printed circuit boards with the permittivity of 4.4 and the thickness of 0.8mm. The total area is 11mm£10:5mm.

AN ULTRA-WIDEBAND BANDPASS FILTER WITH A NOTCH-BAND AND WIDE STOPBAND USING DUMBBELL STUBS

In this paper, an ultra-wideband (UWB) bandpass fllter (BPF) with a notch-band at 5.8GHz is presented. The proposed fllter is constructed with multiple-mode resonator (MMR) using novel dumbbell stubs and one-arm-folded interdigital coupled lines in the input and output sides. The MMR consists of three pairs of shunt dumbbell stubs and a high impedance microstrip line. By adjusting the dimensions of the dumbbell stubs, the resonant modes of MMR are allocated in the UWB band. The arm-folded interdigital coupled lines are used to obtain a notch-band at 5.8GHz. Finally, the proposed UWB BPF is fabricated. The simulated and measured results are in good agreement with each other.

A MINIATURIZED UWB BPF BASED ON NOVEL SCRLH TRANSMISSION LINE STRUCTURE

A miniaturized ultra-wideband (UWB) bandpass fllter (BPF) with U-slot etched around the metallic via in the ground is proposed based on a simplifled composite right/left-handed transmission line (SCRLH TL) structure. The U-slot etched in the ground makes it feasible to reduce the overall size. A demonstration of FCC standard UWB bandpass fllter (BPF) is designed, fabricated and measured. Very good agreement is shown between measurement and simulation.