Compact UWB Bandpass Filter Research Articles

Design and Analysis of Compact Microstrip UWB Band pass Filter with a Notched Band Using Defected Microstrip Structure

Abstract This paper presents design of ring–shaped wide-band band pass filter with notched band. The ring –shaped UWB BPF using a simplified composite right/left handed (SCRLH) resonator. The narrow band notch responses produced by DMS (Defected trip Micros Structure) was introduced at a frequency of 5.2 GHz in order to reject any undesired signals which may interfere with the wideband communication systems. This band pass filter is designed to pass the UWB signals between 2.9 GHz to 10.2GHz and to eliminate WLAN signal (5.2 GHz). The resulting filter has been found to possess a compact size of 20mm×30mm. This design is simulated by CST microwave software based on the Finite Integration Technique (FIT).

Compact UWB bandpass filter with sharp roll‐off using APCL structure

In this letter, a quintuple-mode bandpass filter for a UWB system with improved performance is presented. The presented filter is implemented with asymmetric parallel-coupled lines loaded open stub and short stub connected at the symmetrical plane of the filter to increase its frequency selectivity. Five resonant frequencies within the UWB band and two transmission zeros at the lower and upper passband/stopband edges are observed. A filter prototype is fabricated for verification and the experimental data are corresponding well with the simulated results. The proposed filter achieves a bandwidth that can exactly cover the whole UWB frequency band. Moreover, this filter has a compact size (0.645 λ g × 0.318 λ g ) and low insertion loss.

Compact UWB bandpass filter with dual-notch bands using asymmetric tri-section stepped impedance resonator

In this study, a novel high selective UWB band pass filter (BPF) with dual notch band is presented. UWB BPF is realized using stub-loaded multiple-mode resonator (MMR). The MMR is constructed by loading a quintuple mode open stub at the centre in an asymmetric tri-section stepped impedance resonator (ATSSIR). Five modes, including two odd modes and three even modes, placed within UWB band. Two transmission zeros generated by the fractal stub improve the passband selectivity greatly. Two half wavelength long fractal Hilbert resonators are embedded near I/O line to achieve notch bands at 5.1 and 5.9 GHz. Aperture-backed interdigital coupled-lines are implemented to improve the coupling. The proposed prototype is fabricated and tested. The measured insertion loss is observed to be within 1.5 dB over the passband. By virtue of two transmission zeros (TZs), on either side of the passband, at 5.1 and 5.9 GHz, respectively, the passband selectivity is achieved with measured roll-off factor at around 34 dB/octave. The out-of-band rejection of the filter is greater than 22 dB up to 18 GHz. The simulated results are in good agreement with the measured responses.

Compact UWB bandpass filter based on grounded square patch resonator

A novel UWB bandpass filter based on a grounded square patch resonator with slots is proposed. Owing to this specific geometry, three fundamental resonances of the resonator can be independently controlled and by their even distribution within the UWB range, an UWB passband can be formed. An UWB filter with in-band insertion loss <0.9 dB, group delay variation of 0.25 ns, and very small size of only 0.26λ g × 0.26λ g has been designed and fabricated, and measurement results are in good agreement with simulations.

Design of a compact multi-mode UWB band pass filter with flexible notch band employing interdigital coupled lines

A novel ultra-wideband Microstrip bandpass filter using Radial Stub Loaded Resonator (RSLR) and interdigital coupled Lines is presented in this paper. The RSLR and decagonal patch form a resonator named M to create tuneable multiple notches in the passband for the suppression of Wireless Local Area Network systems’ interference. To realize sharp roll-off, two adjustable transmission nulls are located at the lower and upper frequencies out of the passband. Even and odd-mode analysis is presented to calculate modal resonance frequencies contributing to create the ultra-wide passband. Bessel function is employed to estimate the input impedance of the radial stub which is used in formulation of even and odd mode admittances. Simulated and measured results show a passband from 3.4 to 12 GHz (135% bandwidth around 6.39 GHz) with a rejection notch at 4.99 GHz is achieved with return losses better than 14 and 12 dB in the first and second passbands, respectively. The insertion loss is lower than 0.9 dB in the 90% of passband and rejection level is greater than 19 dB from 12.25 to 17.45 GHz.

COMPACT BALANCED UWB BPF BASED ON HMSIW AND D-DGS

A compact balanced UWB bandpass filter (BPF) is proposed in this paper, which is based on the half-mode substrate integrated waveguide (HMSIW) and the differential defected ground structure (D-DGS). Using the HMSIW, the filter can achieve compact size, wide passband and good compatibility. Two D-DGS cells are employed to provide good suppression for the common-mode (CM) noise, while they have small effect on the performance of differential-mode (DM) signals. To validate the design theory, a microstrip balanced UWB BPF is designed, fabricated and measured to meet compact size, low insertion loss, good return loss as well as proper bandwidth. The predicted results are compared with measured data and show reasonable agreement.

High-Selective Compact UWB Bandpass Filter With Dual Notch Bands

In this letter, a novel high selective UWB band pass filter (BPF) with dual notch bands is presented. UWB BPF is realized using open stub and short stub loaded resonator (SLR). The resonators are realized to incorporate four resonating modes in the UWB passband extending from 3.14 to 10.53 GHz. Two transmission zeroes at 3.01 and 10.68 GHz, near to the UWB passband, increases the selectivity of the filter. Half wavelength long spiral resonators as slots are implemented in ground plane to achieve notch band at 5.13 GHz and an inward folded resonator is placed near to the open SLR to achieve notch at 8.0 GHz. Measured passband insertion loss is within 1.5 dB. The prototype of the proposed UWB BPF is fabricated and measured. Simulated response of the designed BPF agrees well with the measured result.

Compact balanced UWB bandpass filter with one narrow notched band

ABSTRACTA compact balanced ultra‐wideband bandpass filter (BPF) with one sharply notched band is presented in this article. The proposed BPF based on microstrip‐to‐slotline transition obtains favorable uniform differential‐mode response and good common‐mode suppression. Moreover, one narrow notched band with a 3 dB bandwidth of 6.8% is realized by introducing one coupled half‐wavelength resonator. The fabricated filter has a more than 25% size reduction compared to the designs reported in open literature. The predicted results are compared with measured ones and good agreement is achieved. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1626–1629, 2014

Compact UWB Bandpass Filter as Cascaded Center-Tapped CRLH Transmission-Line ZORs for Improved Stopband

The design of a new compact UWB bandpass filter is proposed which has cascaded center-tapped microstrip composite right/left-handed transmission-line zeroth-order resonators (CRLH-TL ZORs). In an attempt to reduce the size. instead of the convention half-wavelength resonators or periodic and multiple CRLH-TL cells, only one cell ZOR geometry is adopted as each resonator in the filter. Additionally, two center-tapped ZORs are coupled to increase the slope of the skirt. Besides, stepped impedance matching parts are placed in the paths to the input and output ports to enhance passband and stopband performances. The proposed filter is shown to have the overall size of 0.69 λ g × 0.70 λ g the insertion loss much less than 1 dB, and an acceptable return loss performance in the predicted and measured results.

Compact UWB bandpass filter using folded-T-shaped resonator with a notch-band

This paper presents a compact ultra-wideband bandpass filter based on a folded-T-shaped resonator with a notch-band. Characterized by theoretical analysis, the T-shaped resonator makes it easier to control resonant modes, and two transmission zeros appear in the lower and upper stopbands to improve skirt selectivity. A narrow slot is embedded within the resonator, in order to produce a bandstop characteristic. In this way, a notched band is introduced around 5.75 GHz, and the bandwidth and coupling strength of the notch-band could be tuned easily. Finally, a filter is fabricated and measured, and the measured results are in good agreement with simulation, demonstrating good insertion/return losses as well as a notch-band application.

A compact UWB bandpass filter with WLAN rejection using a slot ring resonator

AbstractThis article presents a novel ultra‐wideband bandpass filter with controllable notched bands, compact size, and relaxed fabrication requirements.Its implementation is based on a rectangular slot ring resonator with an embedded S‐shaped slotline. The behavior of the rectangular slot ring resonator is characterized and subsequently adopted to build the wide passband. The notched band necessary for rejecting wireless local‐area network (WLAN) signals is implemented by the S‐shaped slotline. A prototype filter is implemented based on the proposed structure and good agreement is found between simulations and measurements. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 1980–1984, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25381

SIR형 Transversal 구조를 이용한 새로운 소형 초광대역 대역 통과 여파기의 설계

본 논문에서는, 병렬 결합의 두 전송선으로 구성된 transversal 여파 특성 구조와 SIR 개념을 함께 이용하여, 급격한 차단 특성, 낮은 삽입 손실, 평탄한 군지연 특성을 가지는 새로운 소형 UWB 대역 통과 여파기가 개발된다. 요구되는 대역 특성을 얻기 위해, 매우 넓은 대역에서의 낮은 삽입 손실을 확보한 채, 다수의 차단용 극점들이 생성된다. 또한 상대적으로 작은 구조로써 높은 차수의 급격한 차단 특성을 구현하고, 동시에 UWB 응용에 적합하도록 완만한 군지연을 구현한 것이 장점이다. 제안한 기술의 타당성이 이론과 실험에 의해 증명된다. A new compact UWB bandpass filter with sharp-rejection, low insertion-loss and flat group-delay is developed In this paper, using the transversal filtering combined with SIR(stepped impedance resonator) concept. To form the required passband, multiple out-of-band transmission zeros are created around band-edges, securing very low insertion loss in the very wide frequency range. Also it is found to be beneficial to realize a sharp rejection of higher order with a relatively small overall size and simultaneously have very smoothly varying group-delay which is proper for the UWB applications. The validity of the proposed technique is proven theoretically and experimentally.

A compact UWB bandpass filter with a wide upper stopband using multiple transmission zeros

AbstractIn this article, a compact bandpass filter is proposed for lower band (3.1–4.9 GHz) of ultra‐wideband applications. The filter is mainly composed of a pseudo‐interdigital wideband bandpass filter (PI‐WBF) and a multiple transmission‐zeros structure (MTZS), being a bandstop filter. By using the MTZS, multiple transmission zeros can be located in the upper stopband of the PI‐WBF. The design procedure is discussed in detail. The designed filter was fabricated and measured. Measured results also have a good agreement with the simulated results. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 380–382, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23103

Planar microstrip UWB bandpass filter using U-shaped slot coupling structure

A compact planar microstrip UWB bandpass filter is proposed. It is realised by cascading a lowpass filter and a highpass filter. A transmission line with U-shaped slots coupled with two DGS units on the back of the circuit board has the characteristic of highpass, while a periodic uniform DGS array has the characteristic of lowpass. Combining these two structures, a new UWB bandpass filter (BPF) is fabricated and measured. Measured results show that the proposed BPF has wide bandwidth from 3.0 to 10.9 GHz, all the measured return loss less than 13 dB in the passband. The BPF achieves a wide stopband with 18 dB attenuation up to 18.0 GHz.