Band Notch Research Articles

A novel UWB MIMO antenna array with band notch characteristics using parasitic decoupler

ABSTRACT This paper presents a 4 × 4 multiple-input–multiple-output (MIMO) antenna array for ultra-wide band (UWB) applications with 5.5 GHz wireless local area network (WLAN) band rejection characteristics. The single UWB antenna element consists of modified patch antenna with partial ground plane. WLAN band has been rejected by etching a U-shaped slot in the antenna element. The antenna elements have been arranged in a planar geometry where each element is orthogonal to its adjacent element. A fan-shaped parasitic decoupler, that consists of four strip lines connected with a central square-shaped conductor, is placed among the antenna elements. The dimensions of the antenna array are 67 × 67 × 1.6 mm3. Full wave simulations and experiments have been conducted where measured peak gain and average isolation were 8.1 and −20 dB, respectively. The calculated envelop correction coefficient was less than 0.01.

Design of ultra‐wideband antenna with high‐selectivity band notches using fragment‐type etch pattern

AbstractBy specifying objective functions defining the two bands to be notched with high roll‐off criteria (ROCs), optimization searching for the best fragment‐type etch pattern on ultra‐wideband (UWB) antenna is implemented by using multi‐objective optimization. The optimization with too many objective functions requires special treatment to improve the searching efficiency. In this design, two slits are preset on appropriate positions on different sides of the UWB radiator to constrain the decision space for etch pattern searching and yield two initial notched bands to speed up the optimization. For demonstration, a UWB patch antenna is designed with dual‐band notches of ROC = 0.63 at WiMAX band and ROC = 0.65 at WLAN band. Both the simulation and measurement results indicate that there is significant improvement of the selectivity of the dual‐band notches.

A CPW‐fed band notched wideband circularly polarized ZOR antenna based on CRLH‐TL approach

This article presents design and analysis of three wide band zeroth-order resonance antennas (antennas I, II, and III) using composite right and left-handed transmission line (CRLH-TL) approach. Coplanar waveguide technology, single layer via-less structures are used to have the design flexibility. The bandwidth characteristics are analyzed by using lumped parameters of CRLH-TL. By introducing a simple slot in the ground plane of antenna I both bandwidth enhancement and circularly polarization characteristics are achieved in antenna II. Another quarter wave L-shaped slot has been introduced in the ground plane of antenna II to introduce a notch band in the frequency response of antenna III. Achieved measured 10 dB return loss bandwidth of antenna I and antenna II are 960 (3.3-4.26 GHz) and 2890 MHz (2.77-5.66 GHz), respectively. Antenna III offers measured 10 dB return loss bandwidth of 3220 MHz (2.32-5.54 GHz) with a band notch from 2.39 to 2.99 GHz that isolates the 2.4 GHz WLAN and 3.5 GHz WiMAX band. Antenna II and antenna III have circular polarization property with measured axial ratio bandwidth of 440 MHz. The measured peak realized gain of antennas II and III is around 1.53-2.9 dBi.

Ultrawideband microstrip patch antenna with quadruple band notch characteristic using negative permittivity unit cells

AbstractThis article presents the design of an ultrawideband antenna with quadruple band notch characteristic using negative permittivity unit cells. Quad notched band characteristics are achieved at desired frequency bands by etching four complementary split ring resonators on the modified rectangular patch, which is then validated by experimental results. The antenna has impedance bandwidth for voltage standing wave ratio (VSWR) <2 from 2.85 to 11.52 GHz, with a notched band characteristic in the sub‐6 GHz 5G (3.39‐3.82 GHz), IEEE 802.11a WLAN at 5.2 GHz (5.13‐5.40 GHz), IEEE 802.11a WLAN at 5.8 GHz (5.71‐5.91 GHz), and ITU 8 GHz (7.5‐8.61 GHz) signal bands. Furthermore, the antenna has a compact overall size of 40 × 30 × 0.81 mm3 with a stable radiation patterns.

Integration of MIMO and Cognitive Radio for Sub-6 GHz 5G Applications

A multiple-input–multiple-output (MIMO) antenna system has been designed on a single substrate representing both types of cognitive radio (CR), i.e., interweave and underlay. The design consists of a four-port MIMO antenna for three selectable modes of the operation (modes). These modes are wideband antenna, frequency-tunable narrowband antenna, and wideband antenna with frequency-tunable band notch. The first, second, and third modes correspond to the sensing antenna, interweave CR communicating antenna, and underlay CR communicating antenna, respectively. These modes are achieved by incorporating multipurpose filters into the microstrip feedline part of the four antenna ports. The MIMO antenna system is designed for 5G applications in sub-6 GHz band (2.50–4.20 GHz). In wideband mode, the four-port MIMO antenna has a sensing frequency range of 2.00–5.70 GHz. While in the second mode of operation, it exhibits narrowband frequency tunability from 3.21 to 4.00 GHz. Finally, in the third mode of operation, the band-notch frequency of the antenna is tunable from 3.37 to 4.00 GHz. The complete structure was fabricated on Rogers RO4350 substrate, and the simulation results were verified by measurement.

A Simple WiMAX and RFID Band-Notched UWB Bandpass Filter and Its Susceptibility Study

An ultra-wideband (UWB) bandpass filter (BPF) with a fractional bandwidth (FBW) of about 110%, transmission zero at the high-frequency edge, and band notches at the worldwide interoperability for microwave access (WiMAX) and radio frequency identification (RFID) band is presented in this paper. The filter is based on single short-circuited stub, U-shaped defected ground structure (DGS) array, two U-shaped resonators and two stepped impedance resonators (SIRs). The filter is compact and exhibits a selective filtering characteristic equivalent to a three-pole Chebyshev filter. The design procedure has been described and verified by full-wave electromagnetic (EM) simulation and measurement. The proposed filter has low insertion loss, sharp rejection, and excellent in and out band performance. Due to its applications in WiMAX and RFID systems, the filter may be subjected to high EM radiation from the antenna and nearby sources. Therefore, susceptibility study of such a filter is very important. Hence, the susceptibility study of the band-notched UWB BPF has been carried out by subjecting the structure to an interference source.

Stub loaded UWB Antenna for Dual Notch Bands

A Dual Notch ultra wideband antenna (UWB) is presented in this communication. The dual notch bands covers the WLAN and WiMAX frequencies. The Ultra wideband is achieved by introducing multiple techniques into a basic antenna. The basic radiating element is a rectangular patch with a pentagonal slot at the center for which the bottom two edges of the patch are truncated in steps. A ground with a rectangular slot at the middle is considered. The cumulative effect of edge truncated slotted patch and partial defective ground plane will generate ultra wideband. To generate notch bands two stubs are loaded into the pentagonal slot there by enabling isolation in the WLAN and WiMAX frequencies. Proposed antenna is having a bandwidth of 10.37GHz ranging from 3.08GHz to 13.45GHz with isolation ranging from 3.66GHz to 3.86GHz and 4.9GHz to 5.6GHz.

Compact Self Complementary UWB Antenna with Triple Band Notch Characteristics for Wireless Communications

the objective of this paper is to design and analysis of the Ultra wide Band Micro strip Patch Antenna which covers the Ultra Wide Band 2.9 to 21.5 GHz. To get an optimum results and performance of the projected self complementary UWB antenna depends on the study of dissimilar methods for optimizing the different parameters of the radiating patch along with notch dimensions. The proposed self complementary UWB antenna with overlapped rectangular shape patch and Defected DGS is designed with C-Slot in the radiating patch element and ground with L shaped slot which covers the whole UWB frequency band apart from band notches WLAN (5.125-5.825 GHz) ,Satellite Communications (7.9-8.5 GHz) and Ku band 13.4-14.5GHz.The UWB antenna performance is improved in terms of the Bandwidth by including Rectangular shaped slit between feeding element and the radiating patch. Now a days it is important to avoid existing wireless communication networks from the design of UWB antenna. The self complementary UWB antenna impedance bandwidth from 2.9 GHz to 21.5 GHz with a maximum of return loss S11 -43 dB at operating frequency10.5 GHz and with a Gain of 5.64dB.

Bandwidth Enhancement of a Wide Slot Antenna Using Fractal Geometry for UWB Application with Multiple Notched Bands

In this paper a combination of rectangular and elliptical fractal geometry is applied on a regular hexagonal wide slot antenna fabricated using a FR4 substrate to obtain ultra wide band (UWB) operation. The bandwidth enhancement of the wide slot antenna due to this fractal curve is studied in a step by step manner and the corresponding mathematical analysis is also presented. The comparison of the proposed fractal geometry with the existing fractal geometries is also exhibited. Multiple input multiple output performance of the proposed UWB antenna is also analysed. Two pairs of L-shaped slots are etched on the ground plane and a metallic ring is inserted inside the slot to produce triple band notch characteristics at 3.98 GHz, 5.56 GHz and 7.94 GHz. These three notch bands can avoid interference with existing WIMAX, downlink of C-band satellite communication, WLAN and uplink of X band satellite communication. The proposed band notched UWB antenna exhibits acceptable radiation characteristics with satisfactory gain, high radiation efficiency and constant group delay in the operation band.

Design Research of Wearable Textile Antena

In this paper comprehensive analysis and design of textile antenna is presented. Low dielectric constant of textile material makes them suitable to be used as substrate. The proposed antenna is fabricated on jeans substrate having dielectric constant of 1.6. The proposed textile antenna has hexagonal shape with microstrip line feed .U shape slot on the patch and defected ground structure is incorporated in the design to obtain desired passband and stopband. The dimension of proposed hexagonal patch is 6.44 mm and its area is 108mm2 which is very compact as compared to previous works .This antenna can be used in two frequency bands one is centered at 3.9 GHz with bandwidth of 2.5 GHz and another is centered at 8.6 GHz with bandwidth of 2.4GHz.Along with these passband there is one stop band in the frequency range 5.1GHz to 8.1 GHz. Due to wide bandwidth this antenna can also be called as an ultra wideband antenna with notch band to avoid electromagnetic interference with WLAN (5.1 -5.8 GHz) and satellite application.

A Modified Compact Bi-Directional UWB Taperd Slot Antenna with Double Band-Notch Characteristics

This research puts forward a design regarding a novel compact bi-directional UWB (1.9–10.6 GHz) tapered slot patch antenna that has dual band-notches characteristics within 3.4–3.9 GHz applicable for WiMax application and 5-6 GHz applicable for WLAN (IEEE 802.11a and HIPERLAN/2 systems). A parasitic quasi-trapezoidal shape single split ring resonator SRR is positioned to secure the first WiMax band-notch to minimize the electromagnetic interference occurring in WiMax band. A single circular complementary split-ring resonator (CSRR) is etched to secure the second band-notch. Simulated and measured results showed a good match, thereby signifying that the proposed antenna is an optimum candidate for UWB communication applications along with the guide lines design to employ the notch bands in the preferred frequency regions.

Design and Implementation of Dual Notch Band Characteristics in UWB Antenna for Wireless Personal Communications

Design and Implementation of Dual Notch Band Characteristics in UWB Antenna for Wireless Personal Communications

A Novel UWB Antenna with Reconfigurable Notch Bands

A UWB antenna with reconfigurable notch band characteristics is proposed in this paper. The tunable notches are created using modified E shaped resonators that can be reconfigured to modified C shape; etched on either side of the microstrip feed line of a circular patch UWB antenna. The single and dual band rejection characteristics are created by using C and E shaped structure respectively. Reconfigurability is achieved by using two RF switches. By varying the ON and OFF states of the RF switches, two different notch bands are created; single notch band from 4 to 6.2 GHz and an additional notch band from 7.6 to 10 GHz are achieved. These wide bandwidth rejection performance leads to notching of WLAN, WiMAX, C-band frequencies and X band Satellite communication systems.

Reconfigurable dual notch band antenna on Si-substrate integrated with RF MEMS SP4T switch for GPS, 3G, 4G, bluetooth, UWB and close range radar applications

In this paper, a reconfigurable co-planner waveguide (CPW) fed circular shaped monopole ultra wide band (UWB) antenna with dual band notch characteristics based on silicon substrate is presented. The dual notch band characteristics are realized by inserting two slots, namely, U- and I-shaped, in the circular radiating patch to switch-off the WiMAX IEEE 802.16 (3.30–3.80 GHz) and WLAN IEEE 802.11a/h/j/n (5.15–5.35 GHz, 5.25–5.35 GHz, 5.47–5.725 GHz, 5.725–5.825 GHz) respectively. The reconfigurability from antenna is achieved by integrating the radio frequency micro-electro mechanical system based single pole four through (RF MEMS SP4T) switch in the U- and I-shaped slots of radiating patch. The measured results demonstrate the bandwidth of 0.68–16.23 GHz resulting in fractional bandwidth of 183.91%, and are well in accordance with the simulation results. The gain of proposed antenna varies from 2.58 to 5.05 dBi with radiation efficiency of 83–95% and exhibits the omnidirectional like pattern in H-plane and nearly dipole like pattern in the E-plane. Further, the performance of proposed antenna is analyzed by implementing an equivalent RLC resonant circuit model in both the frequency and time domain.

Compact Band Notched Slot Antenna for Ultra-Wideband (UWB) Applications Based on Strong Couplings Slots

A planar slot antenna operating at 2.75–9.75 GHz is studied for ultra-wideband (UWB) applications, where three controllable notched bands centered at 4, 5.9 and 8.45 GHz are further introduced to avoid some potential interferences. The elliptical slots and coplanar waveguide feeding lines are incorporated to achieve desired UWB operation. By introducing a V-shaped and two U-shaped slots on the CPW signal line, three notched bands are implemented, and each notch band can be adjusted independently. Measurements on the developed demonstrator match with the numerical simulations.

Tunable Band-Notched High Selective UWB Filtering Monopole Antenna

This communication presents the design, fabrication, and testing of a tunable band-notched UWB filtering antenna. The proposed filtering antenna comprises a semiellipsoid radiator and a microstrip transmission line to cover the UWB communication bandwidth from 3.1 to 10.6 GHz. It also comprises two J-shaped open-ended stubs and an asymmetric T-shaped open-ended stub to create notch bands at 3.5 GHz (WiMAX), 5.2 GHz, and 5.8 GHz (WLAN) in the UWB spectrum. The center frequencies of the notch band are tuned continuously using varactors with percentage tuning of 7.5%, 5.38%, and 3.54%. The prototype is fabricated and experimentally validated.

A Reflectarray Antenna Designed With Gain Filtering and Low-RCS Properties

This paper presents a reflectarray (RA) antenna operating at X-band with gain filtering and low radar cross section (RCS) properties. The unit cell (UC) for the proposed RA antenna design combines a band-notched absorber unit and a dielectric lens unit together, where the dielectric lens unit serving as a phase shift is coated on the absorber unit to achieve codesign. Importantly, it is required that the UCs should still maintain the high notch-band-edge selectivity property that the band-notched absorber originally has when the profile of the dielectric lens unit is varied to cover a full phase cycle ( $2\pi$ ) for the proposed RA antenna design. For demonstration, an absorber is presented with a high notch-band-edge selectivity and a wide absorption bandwidth performance in vertical polarization and horizontal polarization, respectively; a dielectric lens based on square posts is rigorously designed to be coated on the absorber seamlessly to construct the desired UC. The simulation results show that the proposed RA antenna has a bandpass-like gain filtering performance and pencil-beam radiation patterns within the notch band, which is experimentally verified by the measured results. In addition, the measured results also reveal that the RCSs of the proposed RA antenna are significantly reduced compared to counterparts of the conventional RA antenna in horizontal polarization and out of the notch band in vertical polarization.

Irregular Hexagonal shaped antenna for UWB Applications

This paper presents the design of a microstrip line fed irregular hexagonal shaped monopole antenna. The antenna consists of a sliced semi-circular ground plane with a square slit below the feed line which exhibits an Ultra Wide Band (UWB) of 7.5GHz. A frequency notch band (5.1GHz – 5.57GHz) is obtained by introducing ‘U’ shaped slot on to the proposed antenna. The proposed monopole is fabricated, measured for reflection coefficient, radiation pattern and peak gain to validate the performance of the antenna.

Compact UWB monopole antenna with quadruple band notched characteristics

ABSTRACTA compact planar Ultrawideband (UWB) monopole antenna with quadruple band notch characteristics is proposed. The proposed antenna consists of a notched rectangular radiating patch with a 50 Ω microstrip feed line, and a defected ground plane. The quadruple band notched functions are achieved by utilising two inverted U-shaped slots, a symmetrical split ring resonator pair (SSRRP) and a via hole. The fabricated antenna has a compact size of 24 mm × 30 mm × 1.6 mm with an impedance bandwidth ranging from 2.86 to 12.2 GHz for magnitude of S11 < −10 dB. The four band notched characteristics of proposed antenna are in the WiMAX (worldwide interoperability for microwave access) band (3.25–3.55 GHz), C band (3.7–4.2 GHz), WLAN (wireless local area network) band (5.2–5.9 GHz) and the downlink frequency band of X band (7–7.8 GHz) for satellite communication are obtained. The measured and simulation results of proposed antenna are in good agreement to achieve impedance matching, stable radiation patterns, constant gain and group delay over the operating bandwidth.

UWB antenna with dynamically reconfigurable notch band using rectenna and active booster

In this study, an ultra-wideband (UWB) monopole antenna with a dynamically reconfigurable notch band, along with the associated RF-triggered power management unit (PMU) that enables the dynamic reconfigurability, are presented. The UWB monopole antenna has a rectangular slot which hosts a J-shaped stub, electrically connected with the radiator using one PIN diode switch. When the diode is OFF, the monopole antenna has a UWB characteristic, while when it is turned ON a frequency notch is created at 5.6 GHz. The diode is fed from a PMU that consists of a rectenna and a DC-to-DC active booster. When the rectenna that consists of a patch antenna and a rectifier receives a -11 dBm or higher 5.6 GHz signal, it rectifies the RF signal into a sufficiently high DC voltage. The rectified DC voltage is applied to the cascaded DC-to-DC booster as enabling signal, and the booster provides at its output terminal sufficient DC power to actuate the PIN diode and thus dynamically reconfigure the UWB antenna. The dynamically reconfigurable notch band is created immediately in response to the reception of an external, -11 dBm RF signal at 5.6 GHz, and it disappears in real time immediately after the external RF signal is removed.