Band Notch Research Articles

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.

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

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

A compact band-notched antenna with high isolation for UWB MIMO applications

AbstractA compact antenna module with a single band notch at wireless local area network (WLAN) (5.725–5.825 GHz) for ultra-wideband (UWB) multiple input multiple output (MIMO) applications is proposed. Proposed antenna which acquires size of 0.299 λ × 0.413 λ × 0.005 λ mm3 at 3.1 GHz consists of two symmetrical radiators placed side by side on global merchandise link (GML) 1000 substrate (εr = 3.2, tan δ = 0.004). Isolation between the antenna elements is >18 dB in the whole UWB band, which is achieved by introducing the vertical stub and H-slot between the monopole radiators in the ground plane. The simulated and measured results of the antenna system are in good agreement. The proposed antenna covers entire UWB with impedance bandwidth (|S11| < −15 dB) from 3.1 to 11 GHz except at WLAN notched band. The designed antenna module bears low envelope correlation coefficient and minimal multiplexing efficiency hence fulfilling criteria suitable for various wireless MIMO applications.

A compact printed ultra-wideband filtenna with low dispersion for WiMAX and WLAN interference cancellation

A printed monopole filtenna fed by a co-planar waveguide with U-shaped split slot on patch and circular split ring resonator pairs at the other side of feed is proposed in this letter. The compact filtenna of dimension 0.32λ × 0.215λ (λ denotes wavelength corresponding to 2.68 GHz) is capable of providing large bandwidth from 2.68 to 8.72 GHz with dual frequency notch bands over 3.28–3.84 and 4.95–6.02 GHz, primarily to eliminate the WiMAX and WLAN interferences. The dual notched antenna performances are evaluated by simulation and experimental measurement and compared to those of recently reported ultra-wideband (UWB) notched antennas. The proposed filtenna provides bidirectional E-plane and omni-directional H-plane radiation patterns with gain variation of 2–4.5 dBi and average radiation efficiency of 78% in its pass band. Also the filtenna offers minimal dispersion characteristic as stable group delay response, and linear variation of transfer function (S21) is achieved in its pass bandwidth.

CPW-Fed Wide Band Micro-machined Fractal Antenna with Band-notched Function

In this paper, a straightforward yet effective design methodology to design wideband antenna with band notched characteristics has been proposed. Sierpinski carpet fractal geometry has been used to realize the antenna structure. Co-planar waveguide feed is used with a novel structure to achieve larger impedance bandwidth and band notching characteristics. Proposed antenna is designed using High Frequency Structure Simulator (HFSS) on a low cost FR4 substrate (ɛr=4.4) which resonates at three frequencies 1.51 GHz (1.19-2.06GHz), 6.53 GHz and 8.99 GHz (4.44-9.54 GHz) while a band is notched at 10.46 GHz (9.32-11.92 GHz). The proposed antenna has an electrical dimension of 0.36 λm× 0.24 λm, here λm is the wavelength with respect to lowest resonating frequency of the antenna. The resonating and radiation characteristics of the antenna are verified experimentally. Further, investigations are made to achieve easy integration of the antenna to the monolithic microwave integrated circuits. For that the antenna has been designed on micro-machined high index Silicon substrate which improve matching and gain of the antenna. The results of the micro-machined Sierpinski carpet fractal antenna are highly convincing over the conventional FR4 based antenna.

A compact flexible fractal ultra‐wideband antenna with band notch characteristic

AbstractA compact flexible fractal ultra‐wideband antenna with band notch characteristic is presented. The antenna is printed on a 12.5 μm flexible polyimide substrate, and an impedance bandwidth of 15.48 GHz (3.6‐19.08 GHz) is achieved along with an overall antenna size of 20.5 × 13.9 mm2. The design of the hexagonal radiator in the fourth iteration effectively enhances the impedance bandwidth of the antenna. By arranging two symmetrical complementary split ring resonators on the ground plane, the band rejection of the X‐band uplink frequency from 7.9 to 8.41 GHz is achieved. The average gain of the antenna can reach 3 dBi in the pass band, while the gain in the notch band is greatly reduced to below 0 dBi. Compared with the existing structure, the antenna has a larger bandwidth and a smaller size. Furthermore, the antenna is tested under bending effects. Test results show that this antenna can be used for integration on flexible electronic devices.

Triangular fractal loaded reconfigurable antenna with notch band characteristics

AbstractThe article presents circular ring antenna loaded with triangular shaped fractals covers wide band communication systems. The proposed antenna consists of circular ring‐shaped antenna with three concentric ring‐shaped fractals are loaded inside the ring. It is designed and provides the fractional bandwidth of about 116%. The designed modal is equipped with a ground plane antenna is loaded with parasitic elements through which the reconfigurability is achieved. The reconfigurability and notching frequency bands of antenna is achieved by placing HPND‐4005 pin diodes in the Ground plane. The maximum shift in frequency is achieved for when Diode 1 is ON condition and Diode 2 is OFF condition. Similarly, antenna provides triple notching frequencies like WLAN, WiMAX and some of the x‐band applications. The antenna provides gain of 4.5 dB at different switching conditions and covers frequency applications like LTE 2300 (2.3‐2.4 GHz), WiBro (2.3‐2.39), RFID (2.44‐2.45 GHz), ISM (2.45‐2.48 GHz), WLAN (5.15‐5.35 GHz), Mobile and satellite applications (7.25‐7.37 GHz) and also mobile communication applications (8.02‐8.2 GHz) and some of the x‐band applications.

Compact, Isolation Enhanced, Band-Notched SWB–MIMO Antenna Suited for Wireless Personal Communications

Herein, a Conductor Backed Co-Planar Waveguide fed, compact, slotted Multiple–Input–Multiple–Output or MIMO antenna having Super Wideband (SWB) response and tunable band-notching feature is presented. In addition, an improved method for cut-off frequency prediction of the antenna is formulated. A super wide frequency response from 01.21 to 34.0 GHz and notches at Wireless Local Area Networks or WLAN bands (04.92–05.83 GHz) and Worldwide Inter-operability for Microwave Access or WiMAX bands (03.30 GHz–03.70 GHz) are obtained. By fine tuning the dimensions of the Split Ring Resonator Structure introduced in the radiating element, band-notched characteristics centered at 05.50 GHz WLAN band is obtained. A second band notch having centre frequency at 03.50 GHz for the WiMAX band is obtained by the introduction of a Spiral Microstrip Defected Structure in the feeding segment. The antenna is 20 × 36 × 1 mm3 in dimension. Acceptable gain all through the functional bandwidth, excepting the notched bands makes the MIMO antenna a novel contender for SWB operations particularly for Wireless Personal Communications.

Ultra-Wideband Planar Antenna with Notched-Band for WIMAX, WLAN and MSAT Applications

Ultra-wideband (UWB) with triple band notch characteristics was presented. WIMAX, WLAN and Meteorological Satellite (MSAT) frequency bandwidths were rejected in the UWB planar antenna composed from a single layer conductor element. Frequency bandwidths for WIMAX, WLAN and MSAT are allocated at 3.3~3.7, 5~6 and 7.4~8.4GHz, respectively. Conductor element etching method was used as the means to realize the band notch characteristics as it was considered convenient and simple. Two slits were etched on the ground plane while on the elliptical element, a single slit. The slits were designed for simplicity in the means of achieving the desired band notch characteristics. The proposed antenna design was compact and low profile. The antenna performances were compared with the reference antenna and the results were negligible.

Reconfigurable band notch butterfly-wing shaped ultra-wide band antenna using varactor diodes

In this paper, a CPW fed UWB planar monopole Butterfly’s-wing shaped antenna with reconfigurable band notch characteristics is presented, tested and fabricated in the beginning three eelliptical patches are used to construct the antenna, then three elliptical slots have been created to improve the performance of the antenna. By using suitable varactor diodes in suitable positions in the slots a notch frequency can be obtained. The notch frequency of the antenna can be controlled by varying the varactor diodes’ capacitance that varied from 0.2 to 1.4 pf and frequency tunability can be achieved without modifying the basic antenna geometry. The proposed antenna is suitable for downlink band notching applications in C-band satellite (3.6–4.2 GHz). Finite element method FEM is used to simulate the proposed structures using HFSS. A prototype of the proposed antenna using three capacitor elements is fabricated and S11 is measured. Three 0.5 pf single capacitor element are used instead of the varactor diodes which are not available in the laboratory and the measured S11 is compared with the simulated results. Very good agreement has been obtained between them. The proposed antenna without and with capacitors yield directive patterns in the E-plane and omnidirectional patterns in H-plane. Also the gain is suppressed in the notch frequency.

Simulation and practical study of L and inverted L slot heptaband rectangular microstrip antenna-notch band characteristics

The experimental and simulation study of microstrip antenna with rectangular patch etched with L and inverted L slot is presented with band-notch nature for wireless frequency band operation. Designed antenna is housed in volume of 5 cm × 5 cm × 0.16 cm and operates between 4 and 18 GHz. The incorporating of L and inverted L slots results in split of resonating modes to exhibit the notch band property. The antenna shows the broadside nature of radiation characteristics with 3.76 dB gain at its operating frequency. The various antenna design parameters with specifications of the antennas are given and simulation, practical results are discussed in detail. The simulated, experimental results nearly match each other. Such a designed antenna may be used in SAR, X-band wireless systems applications.

Compact tri‐notched wideband bandpass filter based on multiple resonances with wide upper stopband

AbstractIn this letter, a compact tri‐notched wideband bandpass filter based on stub‐loaded ring resonator (SLRR) and shorted stub‐loaded stepped impedance resonators (SSLSIR) with wide upper stopband is presented. The wideband characteristic is excited by coupling SLRR and SSLSIR with the arrangement of defected ground structures on the back of the substrate. By placing two sets of SSLSIRs inside and outside of the SLRR, three reflection poles can be formed in passband to introduce three notch bands with adjustable center frequencies. The quarter‐wavelength inter digital coupled lines are used to generate multiple transmission zeros to suppress high‐order harmonics to achieve a wide upper stopband characteristic. For validation, a wideband bandpass filter with a passband from 2.2 to 7.5 GHz and notch bands at 2.87, 5.69, and 6.5 GHz is fabricated. Measured results show that the 20 dB attenuation upper stopband can extend to 29 GHz.

Design and Experimental Analysis of Miniaturized Octa-Port UWB/SWB-MIMO Antenna With Triple-Band Rejection Characteristics

This paper introduces the design and experimental analysis of an eight-port Ultra Wide Band (UWB)/Super Wide Band MIMO antenna with the with triple-band rejection characteristics. The proposed UWB design includes a square-shaped radiator and a shared partial ground with novel hexagonal-ring type fencing decoupling structure to achieve UWB and a high degree of isolation between radiating elements. The partial ground with hexagonal-ring type fencing is employed to achieve a broad impedance matching of 7.4 GHz (3.1–12 GHz), while the notch bands are realized at 5 GHz (4.6 to 5.9 GHz), 8 GHz (7.70–8.43 GHz), and 10.5 GHz (10.3–10.98 GHz) by using Substrate Integrated Waveguide(SIW) based metallic via integration of hexagonal and semi-hexagonal parasitic slot stub with radiator. The band notch band characteristics obtained autonomously without modifying antenna performance. The fabricated antenna is having a very compact size of mm. The important antenna characteristics of proposed antenna, such as bandwidth (7.4 GHz), isolation (>20 dB), gain(0-7.5), efficiency(80%), radiation pattern, Envelop Correlation Coefficient(ECC)(0.015), Total Active Reflection Coefficient (TARC) and Channel Capacity Loss (CCL) are examined.

Compact UWB-MIMO Triple Notched Antenna for Isolation Reduction

In this article compact multiple input multiple output (MIMO) antenna with triple notch at the ultra-wideband application having two identical monopole antennas is proposed. The two inverted ‘U’ shaped slots are etched on the antenna geometry. The proposed antenna gets notch obtain notch characteristics at three frequencies i.e. 3.51–4.3 (WiMAX), 5.5–5.6 (WLAN) and 8.4–8.8 (X-band applications in UWB spectrum the proposed antenna is designed on FR4 substrate with a compact size of 20 × 34 × 1.6 mm3. The proposed antenna was designed and analysed HFSS 13. An excellent triple notch characteristic is obtained after insertion of Inverted ‘U-shaped compact slot on the radiators. At the centre of the triple notch bands a significant drop in the gain, efficiency of the antenna is seen this indicates a good suppression in the interference of two elements. The simulated and measured results show that the proposed is used for UWB MIMO diversity systems. Thus the proposed antenna two elements are used reduce isolation between channels for ultra wideband MIMO diversity systems.

Dynamically Reconfigurable UWB Antenna Using an FET Switch Powered by Wireless RF Harvested Energy

In this article, a dynamically reconfigurable dual-layer ultra-wideband (UWB) antenna integrated with an energy harvesting (EH) system for powering a GaAs FET switch is presented. The UWB antenna dynamically creates a notch band in the presence of an interfering signal at 5.6 GHz and it goes back to normal UWB operation when the interferer is removed. For the switching operation, the FET switch is powered using only harvested energy carried by the interfering signals. The UWB antenna on the front layer is a microstrip-fed monopole with an embedded elliptical slot. A quarter wavelength linear stub acts as a resonator inside the slot, which is connected and disconnected using the low-power FET switch. The UWB antenna shares the RF ground with a very compact EH system that consists of a planar inverted-F antenna, a very compact voltage-doubler rectifier, and a passive direct-current (dc)-to-dc boost converter. The boost converter elevates the rectified voltage to above the 3.3 V threshold, which is the minimum voltage needed for the actuation of the FET switch. The dynamic notch-band reconfiguration of the UWB antenna without the need for an external dc power source is made possible when the collected power at the input of the rectifier is higher than -12 dBm.

Band Rejections for WLAN and WIMAX Utilizing UWB Planar Antenna by Slits in the Conductor Elements

Band rejections for WLAN and WIMAX frequency bandwidths are realized in a UWB planar antenna utilizing a single slit in an elliptical element. WLAN and WIMAX communication system frequency bandwidths have been known to coexist with the UWB frequency bandwidth. Coexistence of multiple frequency bandwidths are susceptible to disadvantage and could cause interferences to other communication system. The disadvantages could be in form of signal disruption, data loss and equipment malfunctions [1–3]. Thus, it is essential to eliminate WLAN frequency bandwidth from the UWB communication system. Slits are employed to influence the exterior current distribution on the radiator and therefore, has generated mismatched of the input impedance. The phenomenon has caused the band notch characteristic and thus, rejected the frequency bandwidths for 5 to 6 and 3.3 to 3.7GHz, respectively. The structures of the slits are simple in a compact design of the UWB planar antenna. The UWB planar antennas with band rejections are compared with the reference antenna. The reflection coefficients S11 for the designed UWB planar antennas have rejected the frequency bandwidths for 5 to 6 and 3.3 to 3.7GHz, consecutively. The peak of the notched-band reflection coefficient S11 for the frequency bandwidths 5 to 6 and 3.3 to 3.7GHz are about -3 and -4dB, respectively. Surface currents are distributed in the slit areas. The radiation patterns are illustrated for the frequency 3.5, 7.5 and 9.5GHz for the single notched-band, while 4.5, 7.5 and 9.5GHz for the dual notched-band characteristics. Radiation patterns for the single and dual notched-band in the H- and E-planes for the designed antennas are in omni- and bi-directional, respectively. Maximum gains G are in the —z and -x direction in the H- and E- plane, for the UWB planar antenna with single and dual notched-band characteristics.

Compact triple-band bandpass filter using multi-mode HMSIW cavity and half-mode DGS

AbstractIn this paper, a triple-band bandpass filter using a multi-mode half-mode substrate integrated waveguide (HMSIW) cavity is presented. In this design, back-to-back connected half-mode defected ground structure (DGS) is loaded into the HMSIW cavity, which generates the first passband. The first four modes of HMSIW cavity are TM110, TM120, TM310, and TM320. They have been used to generate second and third passbands. The slot line perturbation is used to shift the modes close to each other. Here, TM110 and TM120 constitute second passband, and TM310 and TM320 give third passband. Moreover, the notch band is designed using embedded open-circuited stub to improve the attenuation between the second and third passbands. The proposed filter is designed and fabricated on RT/Duroid 5880 substrate with a thickness of 0.508 mm. The measured results are in line with simulated ones for each of the passbands, and the center frequencies are 6.28, 13, and 19.12 GHz.

Electromagnetic bandgap structure and split ring slot‐based monopole antenna for ultra‐wideband applications with dual band notch characteristics

AbstractReduced lightweight microstrip patch antennas have attracted considerable attention in ultra‐wideband (UWB) applications. In this article, a novel modified circular ultra‐wideband monopole antenna with dual‐band notch characteristics is proposed. A circular split‐ring slot and a mushroom‐electromagnetic bandgap‐type structure are employed to realize the dual‐band notch characteristics. The proposed antenna exhibits the bandwidth of 2.0‐12 GHz with a Voltage Standing Wave Ratio <2 except at the WiMAX band of 3.2‐3.7 GHz and wireless local area network band of 5.1‐5.8 GHz. The simulated and measured results of the proposed antenna, along with the design parameters, are reported and discussed in detail. The results show that the antenna is suitable for UWB applications.

DESIGN AND ANALYSIS OF T-STUB U-SLOT NOTCH BAND FREQUENCY RECONFIGURABLE ANTENNA USING PARAMETRIC ANALYSIS FOR WIRELESS COMMUNICATION APPLICATIONS

The design and analysis of a T-Stub U-Slot Frequency Reconfigurable Notch band antenna is considered in the present work using Coplanar Waveguide feed network for an efficient power transfer to improve the bandwidth characteristics of the antenna. The designed antenna has a dimension of 24X21X1.6 mm with FR4 substrate having a permittivity of 4.4. The proposed antenna consists of a T-Stub and U-Slots which are used to enhance the performance characteristics of the antenna. The reconfigurability is achieved by placing PIN diodes at T-Stub and U-Slots of the antenna design. The designed antenna is more suitable for WLAN, Wi-Fi, LTE and Bluetooth applications. Simulation results are obtained using CST tool and the same are presented at the end.

Design of high gain dual T-shaped stub antenna for satellite communication

The ultra wide band (UWB) antennas play a vital role in supporting different wireless standards and are suitable for wide variety of applications. This paper is aimed to present a novel UWB dual notch microstrip antenna with modified ground plane. The antenna is designed to operate in UWB ranging from 2 GHz to 12 GHz with multi band operation. This will help in operating the antenna for different operations independently. The proposed structure will operate in two notch bands 3.3-4 GHz (Wi-MAX), 5.05-5.9 GHz (WLAN) and the structure is suitable for long distance communications because of its increased directivity. The structure can also be used for X-Band applications for various applications of traffic control, weather forecasting and vehicle speed detection systems. It is observed that, the proposed structure is offering a gain of 5.2 dBi with improved directivity with a beam width of 42.230. This makes the antenna structure suitable for long distance satellite communications. The antenna is supporting the circular polarization at higher the frequencies and can be useful for the upcoming 5G mobile applications. Moreover, the proposed structure offers the less interference at the receiver. The structure is found to be smaller in dimensions, easily fabricated at low costs and can be integrated into any compact wireless devices. The structure is simulated using a commercially available software Ansys-HFSS and is analyzed.