Wideband Microstrip Bandpass Filter Based on EBG Concept

In this paper, a multiple-mode resonator (MMR) using localized substrate integrated artificial dielectric (L-SIAD) is proposed to construct a compact ultra-wideband (UWB) bandpass filter (BPF). Due to the electromagnetic bandgap (EBG) property of L-SIAD, this MMR provides a broad upper stopband for the BPF. Meanwhile, broadside coupled-lines are used to provide tight coupling and sharp skirt for the BPF by the coupling transmission zero. Finally, such a UWB BPF is designed and fabricated. The measured results demonstrated that this filter has broad upper stopband, sharp rejection skirt, and low insertion loss in passband with flat group delay.

A compact ultra-wideband (UWB) bandpass filter (BPF) with three transmission zeros in the notched-band is presented in this paper. A dual coupled microstrip/coplanar waveguide (CPW) structure with slotlines on the bottom are used. The notched-band is generated by a pair of small U-shaped slot-line on the bottom layer and a hollow microstrip resonator on the top layer, and three transmission zeros are achieved at frequency 5.85GHz, 5.9GHz, 5.95GHz without extra circuit size. The UWB bandpass filter (BPF) has been designed, fabricated and measured. The measured results agree with the simulated result closely.

A novel ultra-wideband (UWB) bandpass filter (BPF) with dual notched bands using the hybrid microstrip and coplanar waveguide (CPW) structure is proposed, to prevent interference problems between the UWB radio system and existing radio systems. A multiple-mode resonator on a CPW is formed to allocate its first three resonant modes around the lower-end, centre and upper-end of the 3.1 to 10.6 GHz UWB passband. Its two sides are fed by two microstrip-to-CPW transitions with enhanced frequency-dispersive coupling degree. The dual narrow notched bands are introduced by embedding a open stub in the CPW line and etching two U-shaped slots on the ground plane to form defected ground structures (DGSs) in each side of the microstrip structure. Then, dual-band rejected filtering properties in the C-band (3.7–4.2 GHz) and WLAN (5.15–5.825 GHz) are achieved. The UWB bandpass filter with notched bands has been carried out by designs and related simulations to demonstrate the notch-band-included and upper-stopband-improved performances.

A compact ultra-wideband (UWB) bandpass filter (BPF) is implemented with stepped impedance resonators (SIR) and T-shaped line. Fractional bandwidth (FBW) of the UWB BPF can be adjusted properly by changing the impedance ratio of the SIR. A transmission zero is created by the central open stub of the T-shaped line to suppress the second harmonic of the filter. In addition, the filter size is further reduced by introducing T-shaped transmission line. The resulting UWB filter indicates a FBW of 108% with three transmission zeros at 2.3, 11.1 and 13.4 GHz. Good agreement can be observed between simulated and measured responses.

An ultra-wideband (UWB) bandpass filter (BPF) with two cascaded cross-shaped resonators is proposed and implemented. As the starting work of this letter, a cross-shaped resonator with wide passband is introduced. With the use of even- and odd-mode approach, this initial resonator is characterized and designed to build up a UWB BPF. And then, a cascaded UWB BPF is fabricated to satisfy Federal Communications Commission indoor mask.

A compact ultra-wideband (UWB) band-pass filter (BPF) with band-notch function is presented in this paper. In the proposed structure defected ground structure (DGS) and four short-circuited bent stubs are used in order to improve the performance of the filter and reduce the size of the filter simultaneously. The upper stop-band with more than 15dB attenuation level extends to 20 GHz. Moreover, a meander-line embedded open-circuited (EOC) stub inside a slot on the main resonator is employed in order to create a narrow band-notch function at WLAN frequencies. The measurement results for the fabricated UWB BPF are in good agreement with simulation predictions and reveals that it satisfies well the demands of the Federal Communications Committee (FCC) with a band-notch function at 5.5 GHz.

In this paper, an ultra-wideband (UWB) band-pass filter (BPF) with a sharp notch band is presented. The UWB BPF consists of modified elliptical-ring and multi-mode stub-loaded resonator (MM-SLR). By adding the asymmetric tight coupled lines resonator via input/output (I/O) lines, it can be achieved UWB band-pass response. With adding two bends to the middle resonator, a notch band at 6.86 GHz is created, so that it can be controlled using the mathematical formulas (MF). In the meantime, the equivalent circuit of the middle resonator is obtained using L–C analysis. Measured results of fabricated filter have the advantage such as ultra-wide pass band (flandfHof the defined UWB pass band are 3.776 and 10.42 GHz, which satisfy the requirements of FCC-specified UWB limits), compact size, low insertion loss <0.65 dB and the stop band of the proposed filter is from 11.1 to 16.32 GHz with attenuation of −39.8 to −42.14 dB, respectively. The proposed UWB filter is realized using the substrate with dielectric constant of 2.2 and substrate height of 0.787 mm. Experimental verification is provided and good agreement has been found between simulation and measurement results.

A design of ultra wide-band microstrip bandpass filter with tunable notch response of wireless communication system is presented in this paper. The five order bandpass filter is designed using optimum distributed highpass integrated with Defected Microstrip Structure (DMS). The bandpass filter was designed at wideband frequency from 3.1GHz to 10.6GHz. The insertion loss and return loss of this project is set to better than 0.5dB and 20dB respectively. The DMS is implemented in this design in order to remove undesired frequency in wireless communication system. The pin diode is added to act as a switch to tuning the notch response. When the pin diode off, the notch response produce a sharp response at 5.906GHz (WLAN). When the pin diode on, the notch response is removed from the passband and provide full UWB passband. This design is simulated by ADS software and using Roger Duroid 4350B with a dielectric constant of 3.48, substrate thickness 0.508mm and loss tangent 0.0019.

A novel ultra-wideband (UWB) bandpass filter is proposed on an aperture-backed microstrip line. With an aperture on the ground, a non-uniform resonator is constructed with the first three resonant modes occurring within the UWB band while the parallel coupling between resonator and feeders is largely enhanced. The designed filter exhibits good UWB passband behaviour with insertion loss <1.0 dB and group delay variation <0.25 ns.

In this research paper, design & simulation of a super wide band microstrip patch antenna, a ultrawideband (UWB) microstrip filter and a UWB microstrip filtenna using HFSS vs 15 software have been proposed. Firstly, a rectangular shape monopole patch antenna and a parallel coupled microstrip UWB bandpass filter (BPF) are separately designed. The proposed antenna is designed on a low cost FR4 substrate with height of 1.6 mm and loss tangent of 0.02. The antenna is then integrated with UWB bandpass filter. The integrated antenna filter system is called UWB filtering antenna or filtenna. Simulated results in the terms of peak gain and bandwidth for the proposed antenna are obtained 5.9 dBi and 16.9 GHz in the frequency range 3.1 to 20 GHz, respectively. It is seen that the BPF shows the simulated transmission characteristics in the entire UWB band in better extend. The simulated result of the proposed filtenna exhibits better frequency response in UWB range as well as better out of band rejection capability. Compact size and bandwidth of the proposed UWB microstrip filtenna which exhibits better UWB band characteristics are obtained as 15 × 27 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> and 7.46 GHz in the frequency range 3.1 to 10.6 GHz, respectively.

This paper presents a ultra-wideband (UWB) bandpass filter (BPF) with one controllable notch band. The proposed BPF covers a bandpass frequency area from 3.1 to 10.6 GHz. Which is consists of a main transmission line with characteristic impedance 50 Ohms, and five loaded short-/open-circuit microstrip lines. Hereinto, one shorted-circuit stub is used to achieve low frequency stopband and cut-off frequency stopband, and other four open-circuit stubs are utilized to realize the target notch band and to optimize high frequency stopband performance. To obtain a certain notch-band bandwidth, two stubs working for notch band are designed with adjusted gap distance to couple with each other. Based on theoretical analysis, simulation by HFSS tool and optimization, an UWB BPF with one notch band bandwidth from about 4.94 to 6.38 GHz with -10 dB is established to cover bandpass domain from 3.1 to 10.6 GHz. Analysis and simulation data are in good agreement, the design method is verified well..

A novel design method of ultra wide filter based on the composite right/left-handed transmission line (CRLH-TL) theory is presented in paper. The composite right/left-handed TL with the high-pass characters of left-handed transmission line (LH-TL) and the low-pass characters of right-handed transmission line (RH-TL) are used to construct the ultra wideband (UWB) bandpass filter. Defected ground structure (DGS) and microstrip interdigital capacitors are introduced to satisfy the necessity of the UWB filter. The many cells composite right/left-handed UWB filters are fabricated and measured. Agreement between simulated and measured responses of these filters is demonstrated.

In this paper, a novel synthesis theory is proposed to design ultra-wideband (UWB) bandpass filters using 3λ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> /4 (λ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> is the wavelength at central frequency of the filter) parallel-coupled line resonators. By using the first two resonant modes of the 3λ <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> /4 parallel-coupled line resonators, this kind of UWB BPF can achieve a wide bandwidth larger than 100%. In order to alleviate the requirement on fabrication precision, aperture-enhanced coupled lines are introduced in the filter. A three-degree UWB filter with a midband frequency of 6.85GHz is synthesized, simulated and fabricated. Measured results indicate that the filter is low loss in the passband, and the attenuations in the lower and upper stopbands satisfy the indoor limit issued by the Federal Communications Commission (FCC).

An ultra-wideband (UWB) bandpass filter based on transversal signal-interaction concepts is proposed. By cascading a planar Marchand balun and two transmission lines with different electrical lengths, a new UWB bandpass filter (fractional bandwidth 86-111.5%) with two transmission zeros close to the passband is realised. Good agreement is observed between the simulated and measured results.

This paper presents a novel ultra wideband (UWB) bandpass filter (BPF) with a notch-band at specified frequency. Moreover, its equivalent circuit model (ECM) is also investigated. The proposed filter consists of a stepped impedance resonator (SIR), a parallel coupled feed line on the top and a rectangular shaped defected ground structure (DGS) on the bottom of the structure. The notch band can be shifted to any other desired frequency by tuning the length of the parallel coupled feed line. Good performances in terms of wide stop-band rejection, low insertion loss, high return loss and more compact size (7.99 × 6 mm2) than those reported in literature are achieved. In addition, simulation results accomplished by ECM are in good agreement with the full-wave EM.