Electromagnetic band gap coupled tri-notched miniaturized ultra-wideband antenna loaded with slot and parasitic strip

An electromagnetic band gap (EBG) coupled miniaturized tri-notched printed ultra-wideband (UWB) monopole microstrip antenna having dimensions of 22 mm × 26 mm × 1.6 mm loaded with a slot in radiating patch and a parasitic strip in the ground plane has been presented. The proposed structure incorporates a square-shaped metallic radiating patch with a square EBG structure adjacent to the microstrip feed line, a U-shaped meandered slot over the radiating element, and a U-shaped parasitic resonator at the ground plane beneath the radiating element, to reject the C-band satellite downlink (3.7 to 4.2 GHz), WLAN frequency band (5.15 to 5.85 GHz), and X-band satellite downlink (7.25 to 7.75 GHz) frequency bands, respectively. The designed antenna operates in the frequency range from 3 to 11.1 GHz, with an impedance bandwidth of 8.1 GHz and a percentage bandwidth of 114%. Modification steps incorporating into the reference antenna to achieve the desired design objectives have been discussed, along with parametric studies. The proposed design has been simulated using Ansys HFSS, and measurement has been taken using standard measurement technique and compared with the simulated results.     

Frequency Reconfigurable Antennas Design for Cognitive Radio Applications with Different Number of Sub-bands Based on Genetic Algorithm

This paper proposes frequency reconfigurable antennas using genetic algorithm, suitable for cognitive radio applications. The optimization is applied to find the slot shape and the switches locations in the ground plane of monopole antennas for adjustment of the bandwidth. We introduce a new cost function appropriate for designing antennas for cognitive radio applications. In the first design, the presented antenna can operate in the band of 1.9–3.8 GHz and two sub-bands 1.8–2.78 and 2.78–3.8 GHz using the possible minimum number of switches. In the second design, the proposed antenna works in a wide operating band of 1.85–4 GHz and three different sub-bands 1.72–2.27, 2.27–2.9 and 2.9–3.75 GHz. The proposed antenna with three modes of operation is fabricated and the comparison of the simulated and measured results shows a good agreement.

     

Design of UWB monopole antenna with dual notched band characteristics by using π-shaped slot and EBG resonator

In this paper, we propose the design of coplanar waveguide (CPW) ultra-wideband (UWB) dual notched band monopole antenna with a π-shaped slot and EBG is proposed. The designed antenna produces an impedance bandwidth of 2.7–11.7 GHz (VSWR < 2), except with 3.4 GHz (3.3–3.7 GHz) for S-band WiMAX application and 6.9 GHz (6.5–7.2 GHz) for C-band IEEE INSAT applications. Here, the lower and upper notches are realized by proposing a π-shaped slot on the radiating element and an electromagnetic bandgap structure as a resonator integrated on either side of the ground plane. Meanwhile, the impedance over a frequency range and current distribution are also plotted for the proposed design. The antenna prototype is fabricated and characterized experimentally for validation purpose. Fair matching is observed among the simulated and measured results.     

Miniaturized wideband dual linearly and circularly polarized printed square slot antenna for multiradio wireless systems

A dual symmetrical coplanar waveguide (CPW)-fed small size wideband printed square slot antenna (SSA) with dual linearly and circularly polarized radiation capability is presented. The antenna is composed using a square slot, two symmetrical orthogonal CPW feed lines connected to horizontal and vertical arm of L-shaped radiator, an embedded parasitic inverted-L strip at the lower left corner of the square ground slot and engraving slots in the ground plane. Circular polarization (CP) is achieved due to two orthogonal CPW feed lines and a common L-shaped radiator. Isolation between ports is improved by engraving slots at the lower left corner of ground plane and embedded parasitic inverted-L strip. The sense of dual-polarization can be changed in pass-band by changing the port excitation. Measured antenna reveals that an 84.4% (4.6 GHz, 3.15–7.75 GHz) −10 dB impedance bandwidth (IBW) and about 33% (2.03 GHz, 5.12–7.15 GHz) 3-dB axial ratio bandwidth (ARBW). Isolation between ports <−16 dB is achieved over usable CP band.     

A slot resonators based quintuple band-notched Y-shaped planar monopole ultra-wideband antenna

A Y-shaped ultra-wideband (UWB) monopole antenna containing modified ground plane with five stop bands is presented. An inverted U-shaped slot and a C-shaped slot are placed on Y-shaped radiating patch to achieve two notched bands while three pairs of C-shaped slots are placed at different positions on modified ground plane to achieve three more notched bands. The proposed antenna is designed, fabricated and experimentally tested. The designed Y-shaped antenna has overall dimensions of 36 × 38 × 1.6 mm³ (0.34λ_l × 0.36 λ_l × 0.016 λ_l) and has impedance bandwidth 2.86–13.3 GHz at |S₁₁| < −10 dB level. Measured band notches are achieved at 3.75/5.43/7.87/8.62/9.87 GHz centre notched frequencies to eliminate worldwide interoperability for microwave access (WiMAX) band (3.45–4.0 GHz), wireless local area network (WLAN) band (5.15–5.90 GHz), X-band for satellite communication (6.77–8.00 GHz), ITU-8 band (8.3–9.1 GHz), and radio navigation (RN) band (9.3–10.6 GHz), respectively. Variation of slot parameter on individual band notch is also investigated. Omnidirectional radiation pattern for XZ-plane and dipole-like radiation pattern for YZ-plane are observed. Stable gain, variation of phase response in linear fashion and group delay <1.3 ns for whole ultra-wideband except at band notches is achieved.     

Differential Dual‐Frequency Antenna for Wireless Communication

A novel differential dual‐frequency antenna using proximity coupling is proposed. Dual bands are realized by a slot in the ground plane. The lower resonant frequency is controlled by the slot in the ground plane, and the upper resonant frequency is mainly determined by the dimensions of the radiating patch. Measured results show that the proposed antenna can operate at 2.51 GHz and 5.38 GHz.     

Elliptical slot loaded partially segmented circular monopole antenna for super wideband application

This article inspects partially segmented circular monopole with elliptical slot for super wideband applications. Two significant characteristics of proposed antenna design are: (i) partially segmented circular monopole, notch loaded elliptical ground plane along with tapered microstrip line provides super wide bandwidth; (ii) elliptical slot in between the partially segmented circular monopole reduces the lower operating frequency (1.07 GHz–0.96 GHz), which in turn enhance the bandwidth dimension ratio (BDR). For verifying the simulated outcomes, antenna prototype is practically constructed and measured. The proposed antenna design attains frequency range from 0.96 GHz to 10.9 GHz (VSWR < 2) with bandwidth ratio of 11.35:1 and percentage bandwidth of 167.22%. Bandwidth dimension ratio of proposed radiator is 6975.22. Frequency as well as time domain analysis of proposed radiator approves its applicability for super wideband wireless applications.     

A Quad Band Metamaterial Miniaturized Antenna for Wireless Applications with Gain Enhancement

This paper presents a designing of dual-coated miniaturized metamaterial inspired quad band antenna for wireless standards with gain enhancement. Proposed design has compactness in size with electrical dimension of 0.239?×?0.351?×?0.0127 λ (30?×?44?×?1.6 mm³), at lower frequency of 2.39 GHz. The antenna consist a double printed slotted hexagonal shape radiating section with implementation of metamaterial rectangular split ring resonator. Antenna achieve quad bands for wireless standards WLAN (2.4/5.8 GHz), WiMAX (3.5 GHz), IEEE 802.11P (WAVE-5.9 GHz), ITU assigned X bands (7.25–7.75, 7.9–8.4 GHz) and satellite communication systems operating bands (C-band: 7.4–8.9 GHz and X-band: 8–10 GHz for satellite TV). An acceptable gain, stable radiation characteristics and good impedance matching are observed at all the resonant frequencies of the proposed structure. By application of proposed frequency selective surface an average enhancement of gain is about 4–5 dB over the operating band. Antenna fabricated and tested represent good agreement between the simulated and measured results.

     

Dual-band monopole antenna with shorted parasitic element

A printed dual-band C-shaped monopole antenna with a shorted parasitic element is proposed. The proposed antenna can provide two separate impedance bandwidths of 156 MHz (about 6.4% centred at 2.45 GHz) and 2048 MHz (about 37% centred at 5.5 GHz), making it easily cover the required bandwidths for wireless local area network (WLAN) operation in the 2.4 GHz band (about 3.4% bandwidth required) and 5.2/5.8 GHz bands (about 13% bandwidth required). Furthermore, the proposed antenna shows a low-profile of 635 mm above the ground plane. Details of the proposed antenna design and experimental results are presented and discussed.     

Development of wideband CPW-fed hexagon-shaped circularly polarized slot antenna for wireless-communications

A hexagonal shaped circularly polarized (CP) wideband slot antenna using multiple stubs has been proposed and investigated. A hexagonal slot is created in the ground plane with tapered sections improving the impedance matching. Two radiators are incorporated in the structure, which is responsible for generating orthogonal degenerate modes; hence, CP radiation is achieved for the proposed antenna. For enhancing the gain of antenna, one radiator is directly connected to feed line and another one embedded in the ground plane. An inverted L-shaped arm is inserted in the slot to enhance and tune the circular polarized behavior. The presented radiator have input reflection coefficient ranges from 5.67 to 8.50 GHz (39.97%) and axial ratio bandwidth (ARBW) of 5.60–8.50 GHz (41.13%). The proposed antenna provides overlapping bandwidths of 5.67–8.50 GHz (39.97%) having average gains of 5.25 dBi within the entire frequency bands. The presented antenna is exceptionally good for the application of mobile and satellite communications.     

Switched WLAN-wideband tapered slot antenna

A switched band antenna that has a capability to operate in dual-band WLAN mode (2.4-2.485 GHz and 5.725-5.875 GHz), a single band WLAN mode of 2.4-2.485 GHz and a wideband mode (2.2-7.2 GHz) is presented. The antenna is based on a tapered slot antenna, which has a defected ground structure containing two switchable ring and two rectangular slots to provide a switched band property. Measurement results on a prototype antenna, with an ideal switch, fully demonstrate the performances of the proposed designs. The proposed antenna is suitable for use in a base station or an access point for WLAN and wideband applications and may be also useful in future multimode radio systems.     

Band-notched inverted-cone monopole antenna for compact UWB systems

A microstrip-fed planar ultra-wideband monopole antenna with bandnotch characteristics is proposed. The antenna size is compact (18 x 30 mm) and operates over an extremely wide band of 3-16 GHz. The proposed design consists of an inverted cone as the radiating patch and a tapered ground plane. Wideband matching is obtained by properly shaping the ground. A pair of symmetrically placed quarter wave slot resonators is embedded in the ground plane for rejecting the 5-6 GHz WLAN band. Results indicate a stable and omnidirectional radiation pattern with an average gain of 3 dBi and a sharp reduction in gain at notched frequencies. Moreover, measured group delay and transmission characteristics show excellent transient response.     

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.     

Broadband CPW-fed folded-slot monopole antenna for 5.8 GHz RFID application

A folded slot is introduced to expand the impedance bandwidth and miniaturise the size of a coplanar waveguide (CPW)-fed patch monopole antenna for radio frequency identification (RFID) applications. The designed antenna, which, including ground plane, is only 13 mm in height and 11 mm in width, can operate at the 5.8 GHz band with measured impedance bandwidth and average antenna gain of 30% and /spl ges/5 dBi, respectively, and also conical radiation patterns. These properties make the antenna suitable for RFID tags.     

Isolation enhancement for dual‐band MIMO antenna system using multiple slots loading technique

In this paper, a novel multiple slot loading technique is studied in detail for the isolation enhancement of the dual‐band MIMO antenna system. The proposed MIMO antenna design consists of the microstrip patch loaded with T‐shaped slots parallel to the non‐radiating edge of the patch. The frequency tuning could be achieved by varying the length of the T‐shape slot arm. The proposed MIMO antenna system is optimised for operation in WLAN and WiMAX applications. The isolation enhancement is achieved by providing simple multiple slots loaded in the ground plane between radiating elements. The length of the slots is λ/4 . The system is fabricated and tested using a vector network analyser and anechoic chamber. The reduction in mutual coupling up to ?29.16 dB and ?24.09 dB for the 2.4 GHz and 3.4 GHz, respectively, is achieved. The bandwidths are 62.3 MHz (3.33–3.39 GHz) and 55.5 MHz (2.37–2.42 GHz), respectively. The total gain obtained in this case is 1.8 dBi at 2.4 GHz and 1.2 dBi at 3.4 GHz, respectively. The dimensions of the proposed designed antenna are 70 mm × 60 mm × 1.6 mm. The results were also verified through mutual coupling parameters like envelope correlation coefficient (ECC) and channel capacity loss (CCL) at the desired frequencies.     

Metamaterial-based antenna with triangular slotted ground for efficiency improvement

A metamaterial-based antenna is presented that consists of periodic electromagnetic bandgap (EBG) cells on the top plane and triangular slots on the bottom ground plane. This proposed microstrip patch antenna can yield left-handed, zeroth-order and right-handed metamaterial resonances owing to the asymmetrical periodic structure of honeycomb- like EBG. Experimentally, the efficiency of this antenna is improved by about 14.7% at the zeroth-order resonant mode as the triangular slot length on the ground plane is increased from 0 to 5.5 mm.     

A miniaturized multiband reconfigurable fractal slot antenna for GPS/GNSS/Bluetooth/WiMAX/X-band applications

A novel miniaturized multiband reconfigurable fractal slot antenna for switchable GPS/GNSS/Bluetooth/WiMax/X-band is reported. By utilizing a Koch fractal in the radiating part miniaturization of about 78.8% and 86% are achieved in volume and active patch area respectively. Multiband operations at 1.47–1.65 GHz (BW = 11.5%) GPS, 2.2–2.43 GHz (BW = 9.9%) Bluetooth, 3.4–3.89 GHz (BW = 13.4%) middle WiMAX, 5.61–5.84 GHz (BW = 4%) upper WiMAX and 9.8–10.73 GHz (BW = 9.05%) X-band, are achieved by slotted ground approach in conjunction with Complementary Split Ring Resonator (CSRR). Frequency reconfiguration characteristics in the antenna is accomplished by placing a PIN diode in the ground plane; thus making the antenna to exhibit switchable radiations at 1.91–2.34 GHz (BW = 20.73%) Bluetooth, 3.72–3.89 GHz (BW = 4.46%) middle WiMAX, 4.92–5.33 GHz (BW = 8.0%) upper WiMAX and 10.16–10.70 GHz (BW = 5.1%) X-band, under “ON” condition. During “OFF” condition, antenna exhibits switchable performances at 1.59–1.84 GHz (BW = 14.57%) GPS/GNSS, 3.77–4.12 GHz (BW = 8.87%) middle WiMAX, 5.1–5.35 GHz (BW = 4.78%) upper WiMAX and 10.27–10.62 GHz (BW = 3.35%) X-band. The antenna has a compact area of 35 × 30 mm², and exhibits acceptable gain, stable radiation patterns and good impedance matching at the targeted frequencies.     

Metamaterial inspired quad band circularly polarized antenna for WLAN/ISM/Bluetooth/WiMAX and satellite communication applications

A CPW fed metamaterial inspired Quadband circularly polarized antenna is presented in this article. The proposed antenna consists of defected ground structure with a radiating stub, which is at opposite side of the feedline. A waveguide mode of analysis is carried out for split ring resonator (SRR) and complimentary split ring resonator (CSRR) to enhance the properties of metamaterials. The proposed antenna analysis is taken iteration wise and used FR-4 Material as the substrate material with Ɛ_r = 4.4 and analysed using ANSYS electromagnetic desktop. The designed antenna projecting the peak gain of 4.8 dB and it is working in the application bands of WLAN/ISM/Bluetooth at 2.4 GHz, 5.8 GHz and 3.35 WiMAX band, X-band downlink satellite communication system (7.25–7.75 GHz) and ITU band (8–8.5 GHz) with fractional bandwidth of about 70%. Proposed antenna exhibits circular polarization at 2.39–2.55 GHz, 3.05–3.1 GHz, 4–5 GHz and 6.3–6.64 GHz respectively. To know the signal integrity of the antenna, time domain analysis is carried out for identical antennas in two conditions (face to face and side by side) with the help of CST microwave studio. The designed antenna showing excellent correlation in measurements with respect to simulation results.     

Design of band-notched antenna with DG-CEBG

Ultra-wideband (UWB) disc monopole antenna with crescent shaped slot for double band-notched features is presented. Planned antenna discards worldwide interoperability for microwave access (WiMAX) band (3.3–3.6 GHz) and wireless local area network (WLAN) band (5–6 GHz). Defected ground compact electromagnetic band gap (DG-CEBG) designs are used to accomplish band notches in WiMAX and WLAN bands. Defected ground planes are utilised to achieve compactness in electromagnetic band gap (EBG) structures. The proposed WiMAX and WLAN DG-CEBG designs show a compactness of around 46% and 50%, respectively, over mushroom EBG structures. Parametric analyses of DG-CEBG design factors are carried out to control the notched frequencies. Stepwise notch transition from upper to lower frequencies is presented with incremental inductance augmentation. The proposed antenna is made-up on low-cost FR-4 substrate of complete extents as (42 × 50 × 1.6) mm³.Fabricated sample antenna shows excellent consistency in simulated and measured outcomes.     

一种应用于WLAN/WiMAX的新颖的三分枝单极天线

提出了一种应用于WLAN/WiMAX的新颖的多分枝单极天线,天线有三个分枝,结构紧凑,其大小为26mm×24mm×1.6mm,加工出了天线并进行测试,测试结果表明天线具有良好的双波段工作特性,｜S11｜≤-10dB时对应中心频率2.47GHz和4.825GHz处带宽分别达4%和62.4%,覆盖WLAN的2.4/5.2/5.8GHz频段及WiMAX的3.5/5.5GHz频段,同时采用了接地板开槽技术以调整带宽,天线在上述频段有近似于全向辐射方向图。