Band-notched Ultra-wideband Antenna Research Articles

A Compact Reconfigurable Dual Band-Notched Ultra-Wideband Antenna using Varactor Diodes

In this paper, a reconfigurable dual band-notched ultra-wideband (UWB) antenna is presented. The antenna design consists of a circular shape with two pairs of the L-resonator. To realize the notch characteristics in WLAN at 5.2 GHz and 5.8 GHz bands, the half wavelength of the L-resonator is introduced in the design. The T-shaped notch is etched in the ground to enhance the bandwidth which covers the UWB operating frequency range from 3.219 – 10.863 GHz. The proposed reconfigurable dual band-notched UWB antenna shows good impedance matching for the simulated in the physical layout. Furthermore, the proposed antenna has a compact size of 37.6 x 28 mm2. This proposed reconfigurable design can provide an alternative solution for the wireless system in the designing of a band-notched antenna with a good tuning capability.

Study on frequency and impulse response of novel triple band notched UWB antenna in indoor environments

In this paper, a novel fork shaped structure backed plane is added to a simple UWB (ultra wideband) slot antenna to enhance the impedance bandwidth as well as create triple band notched characteristics for Impulse Radio (IR) UWB applications. This fork-shaped structure is connected to a rectangular radiating patch at four different points through the cylindrical pins. The proposed antenna with this fork-shaped structure shows a very wide impedance bandwidth which spans from 2.5 up to more than 20 GHz and offers triple band-notched properties in WiMAX, WLAN and X-band downlink satellite communication spectrums. Moreover, the proposed antenna shows good radiation features such as gain, radiation efficiency and radiation patterns. A comprehensive investigation on the antenna time domain performance is also performed throughout the paper, and the effect of the proposed antenna on the two popular excitation pulses including modulated Gaussian (MG) and square root raised cosine (SRRC) pulses is fully investigated. A frequency-domain measurement setup is applied to measure time domain characteristics of the proposed antenna. Also, the realistic indoor multipath propagation channel characteristics when the proposed antennas are applied as the transmitter and receiver antennas are studied. Sub-band divided ray tracing method is used to simulate channel characteristics.

Time-domain analysis of compact dual band-notched slot antenna in indoor environments

AbstractFrequency- and time-domain characteristics as well as indoor propagation channel impulse response of a compact dual band-notched ultra-wideband (UWB) slot antenna are investigated in this paper. The antenna consists of a narrow rectangular radiation patch and a rectangular wide slot in the modified ground plane. A pair of L-shaped stubs are connected to the radiation patch to obtain band-notched property in WLAN band and a narrow straight stub is placed on the back side of the substrate to create band-notched characteristics in X-band downlink satellite communication system. Moreover, two small parasitic strips are added to the radiation patch to enhance the bandwidth (BW) of the antenna up to 14 GHz. A comprehensive study on time-domain and indoor propagation channel characteristics of the proposed antenna is also presented throughout the paper. A ray-tracing approach based on geometrical optics is applied to analyze the indoor channel characteristics. The designed antenna not only has a wide BW and compact size but also has appropriate radiation and time-domain characteristics over the antenna operating BW. The measured and simulated results are in good agreement. These advantages make the proposed antenna as a desirable option for UWB impulse radio applications.

Study on frequency and time domain properties of novel triple band notched UWB antenna in indoor propagation channel

Frequency and time domain characteristics of a novel and compact triple band notched ultra wideband (UWB) monopole antenna are investigated. To realize UWB characteristics, the lower edges of a simple rectangular radiating patch are truncated and a new structure including a semi-circle like ring stub is added to the rear side of the antenna. To avoid interferences with coexisting narrow band systems such as WiMAX, WLAN, and X band, two inverse L-shaped slots, a semi-circle like ring slot and two C-shaped resonators are incorporated in the antenna geometry, respectively. The effect of the proposed antenna on a modulated Gaussian pulse as an excitation signal in different scenarios is fully studied. Moreover, the channel impulse response of a simple indoor environment is investigated when a pair of the proposed antennas are applied as transmitting and receiving antennas. Sub-band divided ray tracing method based on the geometrical optics and uniform theory of diffraction is used to simulate the impulse response of the propagation channel. A frequency domain measurement campaign is also employed to measure the channel characteristics. The measured results are compared with those obtained from the simulations to validate the design procedure.

Compact Size Triple Notched-bands UWB Antenna with Sharp Band-Rejection Characteristics at WiMAX and WLAN Bands

In this paper, a compact triple band-notched Ultra Wideband (UWB) antenna with sharp band-elimination features and controlled notched bandwidths is proposed and discussed. The design is made up of a rectangular-shaped patch UWB planar monopole antenna with double collections of band-notched configurations. The band-notched configurations are involved to produce the desired lower and upper stop bands with good frequency selectivity and suitable stop bandwidths. The first notch is realized by using a C-shaped slot etched in the radiating patch in order to eliminate the interference at the WiMAX (3.4 - 3.8 GHz) applications. The second and the third notches are realized together by using a pair of U-shaped resonators that are located beside the feed line in both sides to eliminate the interference with the lower WLAN (5.15–5.35 GHz) and the higher WLAN (5.725–5.825GHz) bands. Additionally, the bandwidths of the lower and upper stop bands can be control separately by changing the parameters of the band-notched configurations. Furthermore, the suggested triple notched bands UWB antenna is optimized, fabricated, and measured for verification purposes. The measured results are close to the simulated ones.

Analysis and Design of a Dual Band-Notched UWB Antenna Using Complementary Split Ring Resonator

In this paper, the complementary split ring resonator (CSRR) is studied and applied to design a printed ultra wideband (UWB) antenna with dual band-notched characteristics. Dual band-notched function is obtained by incorporating the CSRR in the radiating element and the ground plane of the proposed UWB antenna. The designed antenna has a small size and operates over the frequency band from 3.2 GHz to 13.5 GHz, with dual-band rejection at 3.5 GHz (WiMAX band) and the other at 5-6 GHz (WLAN band). The antenna electromagnetic characteristics such as the S (11) parameter, the radiation pattern and the gain are simulated using HFSS and CST. The obtained results are in good agreement and show that the proposed antenna can be used for UWB applications.

A compact dual band-notched UWB circular monopole antenna with parasitic resonators

A compact dual band-notched Ultra-wideband (UWB) circular monopole antenna that has two parasitic resonators in the ground plane is presented in this paper. The Inverted–U and Iron shaped parasitic resonators are located on the back side of the radiating patch to achieve the band rejection characteristics from 5 to 5.4 GHz for WLAN and 7.8 to 8.4 GHz for ITU band respectively. By cutting a rectangular slot on the ground plane, additional resonance is excited at the higher frequency band, and hence much wider impedance bandwidth can be attained. Applications of the proposed dual band-notched ultra-wideband (UWB) antenna structure with 5.2 GHz and 8.2 GHz center frequencies are demonstrated experimentally. Measured and simulated results of the magnitude of S11, radiation patterns and realized gains show good agreement.

Design of a Circularly Polarised Dual Band Notched Ultra Wideband Antenna with Fractal DGS for S-Band and C-Band Applications

Design of a Circularly Polarised Dual Band Notched Ultra Wideband Antenna with Fractal DGS for S-Band and C-Band Applications

A low-profile dual port UWB-MIMO/diversity antenna with band rejection ability

A band notched ultra-wideband (UWB) antenna is presented in this article as a good prospect for multiple-input multiple-output (MIMO)/diversity application. The proposed MIMO antenna is constituted of two modified rectangle-shaped patch antenna elements. A stepped stub is extended from the modified ground plane as a decoupling element between the radiators to realize a good isolation level between them. A band rejection response is obtained by connecting an open resonant stub to each of the radiators. The simulated prototype is fabricated and tested for verification. Results reveal that the proposed prototype provides a 10 dB return loss bandwidth from 3.08 to 10.98 GHz with band notch characteristics from 4.98 to 5.96 GHz, and a good port isolation level (S21 ≤ 20). Diversity performances are ensured in terms of total active reflection coefficient, envelope correlation coefficient (<0.013 except notch band), diversity gain (≈9.51 dB), mean effective gain ratio (≈1), and channel capacity loss (≤0.35 bps/HZ except notch band). It evidences that the presented band notched UWB antenna can be a good prospective for MIMO/diversity applications.

Compact Dual Band-Notched Monopole Antenna with Modified Radiating Patch for UWB Wireless Applications

Ultra-wideband (UWB) planar antennas with single or multiple notched frequency bands properties have recently been considered for various communications between wireless devices. In this study, a low profile microstrip monopole antenna with double band-filtering function is designed and investigated. FR-4 dielectric with properties of e = 4.4 and δ = 0.02 has been employed as the antenna substrate. The configuration of the proposed design is composed of a modified fork-shaped radiating patch with inverted Ω-shaped slot and a pair of coupled Γ-shaped parasitic structures, a feed-line and a ground plane. The proposed dual band-notched UWB antenna provides good impedance bandwidth characteristic from 2.89 to 12.43 GHz for VSWR <2 with two notched bands which cover all the 5.2/5.8 GHz of WLAN, 3.5/5.5 GHz of WiMAX and 4-GHz of C bands ranges. The antenna provides good radiation behavior with sufficient gain levels over its operation frequency band.

Compact Dual Band-Notched Characteristics UWB Antenna Using Nested G-Shaped Slots

This paper presents a dual band-notched characteristics ultra-wideband (UWB) printed monopole antenna with a compact size for wideband wireless communication applications. The proposed antenna has a leaf shape patch with nested G-shaped slots and a partially grounded plane fed with 50 Ω microstrip feed line. The designed antenna has a wide bandwidth of more than 9.86 GHz (2.3 GHz – 12.16 GHz). The return loss of the antenna is less than -10 dB except at the frequencies from 3.18 to 3.7 GHz for rejecting WiMAX and from 5.5 to 5.95 GHz for rejecting WLAN signals. The rejected frequency bands have been created using simple G-shaped slots etched within the patch. Multi notched bands are employed by nesting multi G-shaped slots without enlarging the antenna whole size. The central frequency of the notched bands is fully controlled by the G-slots dimensions. The proposed antenna has a compact size of 21×27 mm2. Extensive simulations are carried out using 3D full-wave FEM-based EM simulator. Parametric analyses to optimize the antenna parameters are performed. The proposed antenna exhibits nearly Omni-directional radiation pattern over the whole desired frequency bands. The measurements and EM simulations are in good agreement.

Design and analysis of triple band-notched micro-strip UWB antenna

Abstract In this paper, a compact ultra-wideband (UWB) antenna with triple notch bands is proposed. By etching out two ESRR of different dimensions in the radiating patch, two band-notched properties in the Wi-MAX (3–3.7 GHz), WLAN (5.125–5.825 GHz) are obtained. Furthermore, by placing SIR near the feed line–patch junction of the antenna, band notch property for the 7.9–8.4 GHz (X-band) frequencies is achieved. Design guidelines for implementing the notch-bands at the desired frequency regions are provided. The notched frequencies can be adjusted according to specification by altering the parameters of the ESRR and SIR. The effects of the key design parameters on band notch characteristics are also investigated. The realized antenna achieved an operating bandwidth (VSWR < 2) ranges from 2.94 to more than 11.3 GHz with triple notched bands of 3.0–3.7, 5.2–6.1, and 7.9–8.7 GHz. The proposed antenna is well designed and extensively investigated. The experimental results are given to verify that the proposed antenna with a wide bandwidth, three designated band-notched function which is suitable for modern high data rate UWB communication applications. The maximum simulated gain of the antenna is around 10.02 dBi with an average efficiency above 82.2% throughout the bandwidth.

Triple band-notched UWB antenna using novel asymmetrical resonators

In this paper, a new Ultra-wideband (UWB) antenna with triple band-notched characteristics is presented. The antenna is composed of a semicircular radiator ended with trapezoidal structure, a rectangular ground plane, and occupies a compact structure of size 30×30mm2. By employing a parasitic strip in the backside of the radiator, etching a pair of inverted-L slots on the ground plane and introducing novel asymmetrical resonators alongside the feed line, three rejected bands are obtained. The proposed antenna provides an extremely wideband width ranging from 3.0GHz to 12GHz (|S11|<−10dB), except the tri-rejection bands of 3.39–3.88GHz, 5.11–5.97GHz, and 8.0–8.71GHz. Furthermore, the antenna achieves a square shape in the second notched band. In addition, cross polarization, radiation patterns and moderate gains are also investigated. Good agreement is obtained between the measurement and simulation, indicating the antenna is promising for UWB applications.

Compact printed high rejection triple band-notch UWB antenna with multiple wireless applications

In this paper, small printed urn-shape triple notch ultra-wideband (UWB) monopole antenna with diverse wireless applications is presented. Notch bands include WiMAX (IEEE802.16 3.30–3.80GHz), WLAN IEEE802.11a/h/j/n (5.15–5.35GHz, 5.25–5.35GHz, 5.47–5.725GHz, 5.725–5.825GHz), and X-band downlink satellite system (7.25–7.75GHz) and other multiple wireless services as close range radar (8–12GHz) in X-band & satellite communication (12–18GHz) in Ku-band. By including T-shape stub and etching two C-shaped slots on the radiating patch, triple band-notch function is obtained with measured high band rejection (VSWR=16.54 at 3.60GHz, VSWR=22.35 at 5.64GHz and VSWR=6.38 at 7.64GHz) and covers a wide useable fractional bandwidth of 154.56% (2.49–19.41GHz). In short the antenna offers triple band-notch UWB systems as a compact multifunctional antenna to reduce the number of antennas installed in wireless devices for accessing multiple wireless networks with wide radiation pattern.

Compact band-notched UWB antenna for MIMO applications in portable wireless devices

A compact 5.5 GHz band-notched ultra-wideband (UWB) 2-element antenna with high isolation for multiple-input multiple-output (MIMO) portable wireless devices in wireless personal area network (WPAN) application is proposed. The MIMO antenna is designed for 3.1–10.6 GHz range on Neltec substrate with compact dimension of 43 × 20 mm2 and is tested experimentally. For the rejection band at 5.5 GHz, a slot of length 1.0 λ is etched into the radiator. Simple structure, i.e., receded steps at ground are used to improve isolation by 3 dB between two UWB antennas. The simulated and measured results show |S11| ≤ −10 dB and |S21| ≤ −20 dB in most of the frequency range excluding the reject band at 5.5 GHz in UWB range. The measured, simulated and calculated results show that the proposed UWB MIMO antenna is a good candidate for UWB MIMO systems. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1390–1394, 2016

Multiobjective optimization of complex antenna structures using response surface models

A very efficient multiobjective (MO) design technique for complex antenna structures involving a large number of design parameters is presented. This design technique, multiobjective-fractional factorial design (MO-FFD), is very different from conventional Pareto-based MO algorithms, which take a great deal of effort to balance the trade-off between all the design specifications. By performing one single combination of simulations, all the response surface models of design goals are simultaneously built, and Derringer's desirability functions are readily applied to these models so that the optimum structure is obtained. Compared to classical MO algorithms such as Strength Pareto Evolutionary Algorithm 2, nondominated sorting particle swarm optimizer, and cultural MO particle swarm optimization, MO-FFD yields more desirable performances yet the required number of simulations is reduced by 97%. This article thoroughly illustrates the mathematical development of MO-FFD, deriving a novel application of ultrawideband (UWB) antennas because of its MO optimization capability. More explicitly, MO-FFD overcomes all the design challenges of dual band-notched UWB antennas including desired impedance characteristics, enhanced fidelity factors, and uniform peak gains over the passband, which are what conventional Pareto-based algorithms cannot attain. The measured results show that all the performance criteria are met; especially, the time-domain signal distortion is minimized. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:62–71, 2016.

A Switchable Band-Notched UWB Antenna for Cognitive Radio Applications

ABSTRACTThis paper presents an ultrawideband (UWB) antenna with switchable band-notch for cognitive radio applications. The proposed antenna has a simple structure and compact size of 18 × 18 mm2. The designed antenna consists of a rectangular radiation patch with a rectangular-shaped element (p) etched on it. Also two rectangular-shaped parasitic elements (g1, g2) are embedded on the ground plane that is very critical to achieve the band-notch in wireless local-area network (WLAN) band. One ideal switch (SW) is inserted between the two rectangular parasitic elements on the ground plane. The function of the antenna can be changed by tuning status of the SW that make the notch band in the WLAN band (5.15–5.825 GHz). The UWB antenna is used for spectrum sensing in cognitive radio and the switchable band-notched antenna with filtering characteristic for reconfigurable operation. Also, a good agreement is found between the simulated and the measured reconfigurable antenna properties.

A dual band-notched ultra-wideband monopole antenna with spiral-slots and folded SIR-DGS as notch band structures

In this paper, an ultra-wideband (UWB) planar monopole antenna with impedance bandwidth from 2.83 to 11.56 GHz and dual band-notched characteristics is presented. The antenna consists of a small rectangular ground plane, a bat-shaped radiating patch, anda 50-Ω microstrip line. The notched bands are realized by introducing two different types of structures. The half-wavelength spiral-slots are etched on the radiating patch to obtain a notched band in 5.15 5.925 GHz for WLAN, HIPERLAN, and DSRC systems. Based on the single band-notched UWB antenna, the second notched band is realized by etching a folded stepped impedance resonator as defected ground structure on the ground plane for WiMAX and C-band communication systems. The notched frequencies can be adjusted by altering the length of resonant cells. Surface current distributions and equivalent circuit are used to illustrate the notched mechanism. The performance of this antenna both by simulation and by experiment indicates that the proposed antenna is suitable and a good candidate for UWB applications.

Controllable triple band‐notched monopole antenna for ultra‐wideband applications

This study presents a new design of a triple band-notched ultra-wideband antenna. The designed structure of the antenna is based on two radiating strips, and a microstrip feed-line on the front, an inverted T-shaped element and a partial ground on the back. By etching a slot off the ground plane, another resonance is excited resulting in the extended bandwidth. The antenna with new structure occupies a small size of 20 × 14 mm 2 . The measured results show that the antenna has a wide bandwidth from 2.8 to 12.5 GHz for voltage standing wave ratio less than 2 apart from the rejected bands from 3.0 to 3.8 GHz, 5.1 to 6.1 GHz and 7.8 to 8.9 GHz. Meanwhile, radiation patterns and gain at various frequencies have been given.

Design of a Stub-Loaded Ring-Resonator Slot for Antenna Applications

A T-shaped stub-loaded ring-resonator (SLRR) slot etched on the ground plane or on the radiating patch has been designed and analyzed for antenna applications. Compared with the conventional ring slot, the two resonant frequencies of the proposed SLRR-slot can be lowered, and can also be tunable by varying the parameters of the four T-shaped stubs. To validate the design concept, a tri-band printed antenna and a dual band-notched ultra-wideband (UWB) antenna using the SLRR-slot on the ground plane and radiating patch, respectively, are presented. For the tri-band antenna, a simple U-shaped slot etched on the microstrip feeding line is used to excite a third upper-frequency band independently without increasing the overall size of the antenna and without affecting the lower two bands. The proposed tri-band antenna has three frequency bands of 2.4, 3.5, and 5.8 GHz, and the dual band-notched UWB antenna can guarantee a very wide bandwidth from 3.0 to 12.0 GHz with dual undesired bands successfully. The experimental results including radiation patterns, peak gains and efficiencies of both antennas are presented.