Band Notch Research Articles

Design and Development of Adaptive filter for Real Time Signal Processing

In Communication the signal is distorted due to noise and the notch filters are used for eliminating unwanted frequencies For filtering the signal in a specific band Notch filter is used. Notch filter can pass the signal below and above notch frequency. In most of the signal processing applications frequency estimation of narrow band signals in noisy environment are required For frequency detection and tracking Adaptive IIR filter or Adaptive FIR filters can be used. Adaptive FIR Filter is more stable than Adaptive IIR filter. In most practical applications Adaptive IIR Notch Filter (AIIRNF)is used The advantage of Adaptive IIR notch filter over FIR Filter is less number of filter coefficients and less complexity in design In this paper Adaptive IIR Notch filter is designed for real time applications. The performance of designed adaptive IIR Notch filter is evaluated based on Magnitude and Frequency response.

Design and Analysis of Multi Band Notched MIMO Antenna for Portable UWB Applications

A MIMO antenna having circular patch with CPW feeding is proposed in this paper. Design, Simulation, Fabrication and testing of MIMO antenna with different band notching characteristics are proposed in this paper. The designed antennas are suitable for portable UWB applications. UWB is the most promising technology which provides high data rate with in short range. In 2002 Federal Communication Commission (FCC) has approved a frequency band of 3.1–10.6 GHz for unlicensed applications. Within the band of UWB some of the wireless Communication bands with different frequencies are also operating. So to avoid interference, band dispensation characteristics are proposed. In this paper single dual, triple and quad band notch MIMO antennas are designed, simulated and tested and their results are reported. Elimination of interference with existing wireless bands like WiMAX, WLAN, X—Band Satellite Communication System and ITU is the prime focus of the paper. Concentric rings with rectangular split bricks are placed on the patch to eliminate the interference with the existing bands. Different antennas are designed and simulated using CST microwave studio software and the antenna parameters like Return losses (S11), Gain, VSWR, Radiation patterns and Correlation Coefficient are measured. Quad band notch antenna is fabricated using RT/Duroid 5880 substrate material with height 1.57 mm. To get better Isolation the antennas are placed vertically and a stub is placed in between the antennas. The quad band antenna able to notch WiMAX, WLAN, X—band and ITU band and port Isolation (S12) is very good and envelope correlation is below 0.001 in UWB frequency spectrum.

Cordate-shaped UWB-MIMO antenna with notch band characteristic and high isolation

PurposeThis paper aims to design a most demanding low profile and compact ultra-wide band (UWB) antenna system for various wireless applications. The performance (in terms of data rate) of UWB system is improved by using multiple-input-multiple-output (MIMO) technology with it. Owing to the overlap of other existing licensed bands with that of UWB, electromagnetic signals can interfere. So, notched band UWB MIMO antenna system reported here which is highly compact, bandwidth efficient, superior data rate and high inter-element isolation comparatively to other reported designs.Design/methodology/approachA 49 × 49 × 1.6 mm3 quad-port UWB MIMO antenna with specific bandwidth elimination property is designed. The proposed planar MIMO configuration comprises unique four identical “Cordate-shaped” monopole radiators fed by 2.3-mm thick microstrip-lines. The radiators are located right-angled to each other to enhance inter-element isolation. Further, a different approach of slitted-substrate is applied to minimize the overall size and mutual coupling of the MIMO antenna, as a substitute of decoupling and matching structures. The defected ground structure is used to obtain −10 dB impedance bandwidth in entire UWB band, without compromising with the lower cut-off frequency response. Further, to eliminate the undesired resonant band (WLAN at 5.5 GHz) from UWB, a rounded split ring resonator is introduced in monopole patch.FindingsIn the entire operating band of 2.8 to 11 GHz, isolation among elements is more than 24 dB, envelope correlation coefficient less than 0.002, diversity gain greater than 9.99 dB and TARC less than −7 dB are obtained at all 4-ports.Research limitations/implicationsThe measured parameters of the fabricated prototype antenna on FR4 substrate are found in good agreement with the simulated results. The small variation in software results and hardware results are observed due to hardware design limitations.Practical implicationsThe proposed design may be used for any wireless application following in the range of UWB.Originality/valueIt can be shown from graphs of measured parameters of the fabricated prototype antenna. They found to be in good agreement with the simulated results.

Design of SWB Antenna with Triple Band Notch Characteristics for Multipurpose Wireless Applications

A compact concentric structured monopole antenna for super wide band (SWB) applications with triple notch band characteristics is designed and experimentally validated. The antenna covers an immense impedance bandwidth (1.6–47.5 GHz) with sharp triple notch bands at 1.8–2.2 GHz, 4–7.2 GHz, and 9.8–10.4 GHz to eliminate interference from co-existing advanced wireless services (AWS), C bands, and X bands, respectively. By loading an E-shaped stub connected at the top of the patch and by etching a split elliptical slot at the lower end of the radiating patch, the band rejection characteristics from 1.8–2.2 GHz for the AWS and 4–7.2 GHz for the C band are achieved, respectively. Further, by making use of a C-shaped resonator near the feed line, band rejection from 9.8–10.4 GHz for the X band is obtained. By varying the parameters of the antenna, the notch bands are controlled independently over a wide range of frequencies. The antenna provides good radiation characteristics, constant group delay response, and better gain over the pass band. The experimental results indicate that the designed antenna offers a remarkable reduction in gain and high variation in group delay over the stop bands. To characterize the wideband property and linear phase response of the designed antenna, its time-domain performance is extensively described and evaluated, which assure pulse transmission with minimum distortion.

A Polarization-Insensitive Band-Notched Absorber for Radar Cross Section Reduction

A polarization-insensitive broadband absorber with a notch band characteristic has been presented for radar cross section (RCS) reduction applications. The proposed design is a three-layered structure, consisting of metal-printed substrate layers separated by air spacers. The top layer is a resistor-loaded convoluted cross-dipole geometry that results in a wideband absorption. The band-notch response is achieved by careful design of a square loop in the middle layer, and the bottom layer is a complete metal ground. The overall structure exhibits two discrete absorption bands (having absorptivity above 90%) over the frequency ranges of 2.12 to 4.15 GHz and 6.08 to 9.58 GHz, whereas a reflective behavior is obtained from 4.3 to 5.65 GHz. The proposed geometry has several novel features, such as compact topology (with unit cell size of 0.137 λL, λL being the lowest operating wavelength), low profile, polarization-insensitivity, and wide operating bandwidth of 127.52%, unlike the existing band-notched absorbers. By deriving an equivalent circuit model and several parametric variations, the performance of the proposed absorber has been qualitatively analyzed. A sample prototype has also been fabricated and reasonable agreement among the circuit analysis, simulation response, and measured result is obtained under normal incidence.

Miniaturised band notched printed LPDA design with meander fractal dipole for UWB communication

ABSTRACT In this paper, a miniaturised band-notched Printed Log Periodic Dipole Array (PLPDA) is designed with fractal dipole for UWB Communication. The miniaturisation is achieved using Meander fractal geometry applied to each dipole element of the PLPDA. The sub-sectional tapered concept is integrated to achieve notches in the WLAN band (5.15 GHz-5.825 GHz) and the WiMAX band (3.4 GHz-3.6 GHz). A broad bandwidth of 7.78 GHz is achieved here by using this fractal geometry-based band-notch concept. The structure of UWB-PLPDA is fabricated on a RO3003 substrate material. Initially, a surface area reduction of 79% in the case of PLPDA with sub-sectional tapered dipole and later, a surface area reduction of 82% with improved performances in case of PLPDA with meander line fractal, are achieved compared to the simple PLPDA design. The simulated design models are physically fabricated, and the measured results found in good agreement with the simulated results. The proposed miniaturised PLPDA is a suitable candidate for high-speed-short-range wireless communications.

A Compact 8-States Frequency Reconfigurable UWB Antenna

To meet the anti-interference and multi-function requirements of the antenna, a compact 8-states frequency reconfigurable ultra-wideband (UWB) monopole antenna is proposed. The antenna consists of a coplanar waveguide structure (CPW), defected ground structure (DGS), rectangular radiation patch, and stepped feed line. Band rejections at the C band, WLAN, and X band are generated by two C-slots and inverted U-slot, respectively. Three PIN diodes are connected across the C-slots and inverted U-slot. By controlling the on/off state of PIN diodes to realize notch reconfiguration. The antenna size is only 22 mm $\times 13$ mm $\times0.8$ mm. The measured results show that the antenna can work in 8 states. The impedance bandwidth of UWB mode is 2.82-13.25 GHz, the relative bandwidth is 129.8%. The notch band is 3.19-4.58 GHz, 5.26-6.21 GHz, and 7.87-8.73 GHz, respectively. The antenna has stable gain, good omnidirectional radiation performance, and can switch freely between UWB mode and each notch band mode.

A Novel UWB Monopole Antenna with Reconfigurable Band Notch Characteristics Based on PIN Diodes

Our design for a novel UWB monopole antenna structure with reconfigurable band notch characteristics based on PIN diodes is presented in this paper. The proposed antenna is comprised of a modified circular patch and a partial ground plane. The band-notch characteristics are achieved by etching a slot on the partial ground plane and inserting three PIN diodes into the slots for adjusting the operating antenna bands. The reconfigurability is achieved by adding three PIN diodes to obtain eight states with UWB, dual and triple operating bands which can be obtained by changing the PIN state from ON to OFF, and vice versa. The proposed design shows a simple biasing process to switch the frequency bands with insignificant gain variation and low radiation efficiency reduction. The reconfigurability of the frequency is accomplished by adjusting the effective slot length through modifying the PIN diodes states at the desired operating bands. The desired operating frequency bands can be obtained by switching the diodes. A systematic parametric study based on a numerical analysis is invoked to verify and refine the proposed performance. The proposed antenna is fabricated on FR-4 substrate with dimensions of 50×60×1 mm3. The proposed antenna performance was tested experimentally and compared to the simulated results from CSTMW based on FIT. Experimental results were in concordance with simulated results. We found that the proposed antenna design had simple geometry and it was easy to control the frequency bands to suit the applications of WiMAX and WiFi systems.

Frequency-Agile WLAN Notch UWB Antenna for URLLC Applications

This paper introduces a compact dual notched UWB antenna with an independently controllable WLAN notched band integrated with fixed WiMAX band-notch. The proposed antenna utilizes a slot resonator placed in the main radiator of the antenna for fixed WiMAX band notch, while an inverted L-shaped resonator in the partial ground plane for achieving frequency agility within WLAN notched band. The inverted L-shaped resonator is also loaded with fixed and variable capacitors to control and adjust the WLAN notch. The WLAN notched band can be controlled independently with a wide range of tunability without disturbing the WiMAX band-notch performance. Step by step design approach of the proposed antenna is discussed and the corresponding mathematical analysis of the proposed resonators are provided in both cases. Simulation of the proposed antenna is performed utilizing commercially available 3D-EM simulator, Ansoft High Frequency Structure Simulator (HFSS). The proposed antenna has high selectivity with experimental validation in terms of reflection coefficient, radiation characteristics, antenna gain, and percentage radiation efficiency. The corresponding measured frequency response of the input port corresponds quite well with the calculations and simulations in both cases. The proposed antenna is advantageous and can adjust according to the device requirements and be one of the attractive candidates for overlay cognitive radio UWB applications and URLLC service in 5G tactile internet. The proposed multi-functional antenna can also be used for wireless vital signs monitoring, sensing applications, and microwave imaging techniques.

Triple Rectangular Notch UWB Antenna Using EBG and SRR

This paper investigates an ultra-wideband (UWB) antenna with a triple-rectangular notch band at 5G, WLAN, and Satellite downlink bands. The 5G and WLAN bands are notched by using a pair of electromagnetic bandgap (EBG) structures while the satellite downlink band is notched by using two split-ring resonators (SRRs). The EBG structure is a metallic conductor loaded on the backside of the radiator which is connected to the patch via a shorting pin. The SRRs consist of a pair of metallic rings etched on the backside of the feedline. The simulated and measured results show that the proposed antenna has an operational bandwidth from 3.1 - 11.8 GHz for |S11| <; -10 rejecting 5G sub-6 GHz (3.4 - 3.9 GHz), WLAN (5.15 - 5.825 GHz), and satellite downlink band (7.25 - 7.75 GHz) signals with high selectivity. The peak gain of the UWB antenna is 3.86 dBi but it sharply decreases up to -13 dBi at stop-bands. The antenna also has additional advantages of the overall compact size (20 x 26 x 1.52 mm3) with stable gain and radiation patterns at the pass-bands.

Synthesis design of wideband bandpass filter with narrow notch band

AbstractIn this article, a novel wideband bandpass filter (BPF) with narrow notch band is presented. It is composed of two sets of shunt microstrip‐to‐slotline vertical transitions, a coplanar waveguide (CPW) connecting line, and a meandering half‐wavelength slotline section. Utilizing the synthesis method based on the transmission line network, a four‐pole BPF with Chebyshev equal‐ripple frequency response is realized in the desired passband. The narrow notch band with 3‐dB fractional bandwidth (FBW) of 3% at the center frequency 2.75 GHz is introduced by an embedding meandering slotline stub. To verify the theoretical prediction, the proposed BPF is fabricated and measured. The circuit model and EM simulation are consistent with theoretical calculation and test results, which sufficiently confirm the correctness and feasibility of the design method.

Design of a Super Compact UWB Filter Based on Hybrid Technique with a Notch Band Using Open Circuited Stubs

This paper presents a new design of a super compact Ultra wideband (UWB) band-pass filter (BPF) with rejection of X-band satellite applications. For covering the UWB bandpass, the proposed filter is realized using hybrid technique which is achieved by using a Microstrip-Coplanar waveguide-Microstrip transition. The basic structure consists of a modified microstrip in the top layer and CPW in the bottom layer. Later, open-circuited stubs are embedded in the top to implement in-band transmission zeros (TZ) so as to circumvent interference. The simulated results show that the UWB bandpass filter has a high adaptation (S11 ≤ −18 dB) and insertion loss better than 0.4 dB at the passband. The impedance bandwidths are about 114% (3–11 GHz) with upper stopband extends to more than 14 GHz with a depth of greater than 38 dB. In addition, the UWB BPF shows a flat group delay performance with a variation of about 0.15 ns over the entire bandwidth. A prototype of the filter is fabricated and tested. Good agreement is achieved between measurement and simulation. The proposed UWB BPF is compact in size with overall dimensions of 14 by 9.2 mm2. Consequently, the obtained results prove that the presented filter is suitable for UWB wireless devices.

A compact UWB antenna with triple band notch reconfigurability

AbstractA compact ultrawideband (UWB) antenna with reconfigurable triple band notch characteristics is proposed in this paper. The antenna consists of a coplanar waveguide-fed top-cut circular-shaped radiator with two etched C-shaped slots, a pair of split-ring resonators (SRRs) on the backside and four p-type intrinsic n-type (PIN) diodes integrated in the slots and SRRs. By controlling the current distribution in the slots and SRRs, the antenna can realize eight band notch states with independent switch ability, which allows UWB to coexist with 5G (3.3–4.4 GHz)/WiMAX (3.3–3.6 GHz), WLAN (5.15–5.825 GHz), and X-band (7.9–8.4 GHz) bands without interference. By utilizing a nested structure of C-shaped slots and SRRs on the backside, a compact size of 18 × 19.5 mm2 is achieved along with multimode triple band notch reconfigurability. The antenna covers a bandwidth of 3.1–10.6 GHz. A prototype is fabricated and tested. The simulated and experimental results are in good agreement.

A miniaturized printed UWB antenna with dual notching for X-b and and aeronautical radio navigation applications

A low cost miniaturized UWB microstrip antenna with dual notched band for X band and aeronautical radio navigation (ARN) is presented in this article. The antenna (19 16×"&gt; 25 mm 2 ) is composed of a half-circular ring as a radiation patch with an incomplete ground plane. The measured results indicate a fractional bandwidth of 112% for 16S11≤-"&gt; 10 dB between 3 to 10.6 GHz. The dual notched band has been achieved by incorporating window shaped microstrip closed ring resonators at the rear surface of the designed structure. The first notch band is centered at 7.5 GHz (7 8.1 GHz) to reject interference with X-band downlink (7.25 to 7.74 GHz) and second band centered at 9.1 GHz (8.6 9.4 GHz) to reject interference with aeronautical radio navigation (ARN) (8.7 to 9.2 GHz). The simulated and measured return loss, radiation pattern, and gain shows good agreement which confirms the applicability of the designed antenna for the intended UWB applications.

Design and Analysis of Integrated Wilkinson Power Divider-Fed Conformal High-Gain UWB Array Antenna with Band Rejection Characteristics for WLAN Applications

Flexible ultra-wideband (UWB) antenna arrays with band notching characteristics are proposed in this work. A new wideband and high-isolation Wilkinson power divider (WPD) is designed to construct the feed systems of the UWB antenna arrays. The proposed WPD is achieved by introducing a significant modification to the conventional WPD and the new one is composed of four isolation stages. Multiple stages helped to achieve wideband from 2[Formula: see text]GHz to more than 12[Formula: see text]GHz with high isolation characteristics of more than 20[Formula: see text]dB and insertion losses around 3.3[Formula: see text]dB. The designed WPD is then applied to feed two UWB monopole antenna arrays which offer a notched band centered at 5.5[Formula: see text]GHz to reject interference from wireless local area network (WLAN) system and can be integrated with curved surfaces. To verify the performance of the proposed structure, two array configurations are practically fabricated and measured. The results show that both the arrays have UWB operational bandwidth (3.5–11.8[Formula: see text]GHz for [Formula: see text] array and 3.6–12[Formula: see text]GHz for [Formula: see text] array) that includes the UWB spectrum. Attractive agreement between simulation and measurement results is obtained. Furthermore, the bending test is carried out on the [Formula: see text] array showing the good performance of the proposed system when installed on curved surfaces for different bent angles.

Ultrawideband Frequency-Selective Absorber Designed With an Adjustable and Highly Selective Notch

In this article, the working mechanism of a wideband absorber designed with an adjustable and highly selective notch band is studied, in which the narrow notch band is independently controlled by the lower lossless layer of the absorber, whereas the upper lossy layer loaded with lumped resistors realizes absorption. We present two instances with geometrically controlled and electrically controlled notch bands, respectively. Without decreasing absorption performance, the notch position can be flexibly adjusted throughout the entire frequency band by simply modifying the dimension of the lossless frequency-selective surface (FSS) or changing the capacitance of the varactor, i.e., using geometric control or electrical control. The narrow notch band allows two wide absorption bands to be retained on both sides; therefore, good stealth performance is still guaranteed. Equivalent circuit models (ECMs) are proposed to further explain the principle. The frequency-domain simulation, ECM, time-domain simulation, and experimental results are in good agreement and validate the adjustability and high selectivity of the notched absorbers. At the end of this article, an FSA-backed monopole antenna is simulated and measured, which clearly illustrates that these FSAs can serve as the ground plane for antennas and realize out-of-band RCS reduction.

Gain Augmentation of a Triple Notched Ultra-wideband Antenna using Compact Uniplanar Frequency Selective Surface for Ground Penetrating Radar

A simple structured, compact ultra-wideband (UWB) circular disk monopole antenna of dimension 35 × 30 × 0.8 mm3 that offers wide bandwidth from 2.64 to 9.36 GHz with sharp triple notch bands at 3.28–3.84, 5.08–5.44, and 5.62–6.06 GHz is integrated to the single-layer UWB frequency selective surface (FSS) that has unit cell dimension of 0.1136λL × 0.1136λL only where λL signifies the lower band-edge of UWB. Sharp triple notches are employed by embedding split-ring slot on circular patch and implanting dual circular split-ring resonator pairs at the backside of feed. Addition of FSS layer does not affect the antenna impedance band and offers significant antenna gain improvement by 2–4 dBi in the pass bandwidth with maximum gain of 8 dBi at 8.5 GHz. The antenna also provides high average radiation efficiency of 80%, improved radiation in the broadside direction and consistent group delay response in its pass band when integrated to the FSS layer. Working capability of proposed antenna-FSS structure is evaluated in proximity of soil test bed by keeping thin aluminum sheet at different buried levels. Adequate VSWR profile, linear transfer function response, and consistent group delay response in pass band ensure the eligibility of proposed antenna to work for ground penetrating radar.

Dual-Band Dual-Polarized Base Station Antenna With a Notch Band for 2/3/4/5G Communication Systems

This letter proposes a new design of a dual-band dual-polarized base station antenna with a notch band for second-generation (2G), 3G, 4G, and the sub-6 GHz 5G systems. The antenna is composed of a four-leaf loop radiator, two-layer parasitic annular disk and a pair of crossed Y-shaped baluns. By introducing mouse-ear shaped arm to the edge of each radiator, a dual-band operating characteristic and a notch band from 2.9–3.2 GHz are realized. The annular disks and gradient strips are beneficial for bandwidth enhancement. The measured results show that the proposed antenna offers two broad bands with the fractional bandwidth of 55.8% (1.55–2.75 GHz), and 14% (3.3–3.8 GHz) for voltage standing -wave ratio (VSWR) 30 dB. This design achieves stable gain of 7.1 ± 0.5 dB and half power beam width of 68 ± 5° during the working bands. These attractive features make the antenna an ideal candidate for 2G, 3G, 4G, and the sub-6 GHz 5G base station applications.

Design of UWB Band Notch Textile Antenna for Body-Centric Wireless Network with the Comparison of Five Different Textile Substrates

Designing an effective antenna on textile substrate is quite a challenging issue which needs close monitoring of antenna return loss performance, gain, radiation pattern, efficiency etc. This paper presents the basic design of Ultra Wideband (UWB) band notch textile antenna for body-centric wireless network. Moreover, Wireless Communication is a notable communication practice and the UWB body-centric wireless communication is one of the foremost attractive ones. Hence, to design the UWB textile antenna, five different substrates have been used and analyzed for better performance evaluation. Textile substrates make the antenna wearable, and therefore can be used in sport monitoring, and in different medical applications as well. Comparing the designed antenna with five different substrates, finally the antenna is proposed with 100% Polyester substrate because among the other four textile substrates, it shows better and also has the intended antenna performance.

Dual Band Notch, Compact, Low profile Hybrid Ultra Wideband RDRA

This paper presents a novel, compact Ultra Wide Band , Asymmetric Ring Rectangular Dielectric Resonator Antenna (ARRDRA), which is a unique combination of Thin Dielectric Resonator (DR), Fork shape patch and defective ground structure. The base of the proposed antenna is its Hybrid structure, which generates fundamental TM, TE and higher order modes that yields an impedance bandwidth of 119%. Proposed antenna provides a frequency range from 4.2 to 16.6 GHz with a stable radiation pattern and low cross polarization levels. Peak gain of 5.5 dB and average efficiency of 90% is obtained by the design. Antenna is elongated on a FR4 substrate of dimension 20 x 24x 2.168 mm3 and is particularly suitable for C band INSAT, Radio Altimeter, WLAN, Wi-Fi for high frequencies. Ease in fabrication due to simplicity, compactness, stable radiation pattern throughout the entire bandwidth are the key features of the presented design. Inclusion of Defective ground structure and asymmetric ring not only increases the bandwidth but also stabilize the gain and efficiency due to less surface current. Presented design launch an Ultra Wide Band antenna with sufficient band rejection at 4.48-5.34 and 5.64-8.33 GHz with stable radiation pattern and high gain.