Designed Antenna Structure Research Articles

CPW-Fed 8-Shaped Monopole Antenna for Ultra Wideband Applications

AbstractA CPW-fed 8-shaped monopole antenna for ultra wideband applications is presented. It consists of a 8-shaped monopole and two quarter elliptical coplanar waveguide ground planes. An impedance bandwidth from 5.4 GHz to 23.83 GHz is achieved. The radiation patterns are observed to be omnidirectional and bidirectional in E-and H-plane respectively at lower resonances. At higher frequencies, the radiation patterns are found to be nearly omnidirectional in both planes. The group delay variation is also observed to be constant in the operating frequency range. A good agreement is found between the simulation and experimental results. The designed antenna structure has miniaturized dimensions and wider bandwidth as compared to other already reported monopole structures.

CPW-fed third iterative square-shaped fractal antenna for UWB applications

A CPW-fed square shaped fractal antenna for ultrawideband applications is presented. The bandwidth is enhanced using three iterations of square radiating patch, modified feed line, and rectangular notch-loaded ground plane. The designed antenna structure has an impedance bandwidth of 3.4–15 GHz along with omnidirectional radiation patterns in the entire operating band with an average gain of 4 dB. A good agreement between the simulation and experimental results is observed. The designed antenna structure has advantages of miniaturized size and wider bandwidth in comparison to previously reported structures. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:92–99, 2016

Fractal dipole antenna for UWB applications

A double-printed elliptical slot inscribed, rectangular fractal dipole antenna for ultrawideband (UWB) applications is presented. The fractal geometry is applied to the dipole elements for size miniaturization and bandwidth enhancement. Further, bandwidth enhancement is achieved using linearly tapered microstrip feed line. The antenna has reflection coefficient less than −10 dB for the frequency range of 3.7–17 GHz. The designed antenna structure has omnidirectional radiation patterns in H-plane and directional in E-plane for UWB band with an average gain of 3 dB. A fidelity factor of 0.60 is achieved between the transmitted and received pulses. A good agreement between the simulated and experimental results is achieved. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:39–47, 2016

Modified theta‐shaped monopole antenna with defected ground structure for UWB applications

ABSTRACTA compact modified theta‐shaped monopole antenna for ultrawideband communication is presented. It consists of a modified theta‐shaped radiator fed with a modified microstrip feedline and rectangular notch‐loaded quarter elliptical coplanar waveguide ground plane. An impedance bandwidth of 4.35–20.75 GHz (131%) below −10 dB reflection coefficient line is achieved. The designed antenna structure has nearly omnidirectional radiation pattern in H‐plane and bidirectional pattern in E‐plane. The cross polarization level is also 20 dB lesser than copolarization level in every direction at lower frequencies. The performance of the designed antenna structure for three substrate materials, that is, FR‐4 epoxy, carbon nanotubes, and Ni0.2Co0.2Zn0.6Fe2O4, are also studied. The experimental and simulation results are found to be in good agreement. The designed antenna structure has advantage of wider bandwidth along with smaller dimensions as compared to previously reported monopole structures. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1625–1632, 2015

Beveled monopole antenna with slot loaded semicircular like ground plane for UWB applications

A beveled monopole antenna for UWB communication systems is presented. It is fed by a 50-Ω modified microstrip feedline. The impedance matching is improved using beveled patch, modified feedline, and semicircular like ground plane. The bandwidth is further enhanced by the excitation of an additional resonance at higher frequency due to the loading of ground plane with a pair of rectangular slots. The antenna is fabricated on a low cost FR-4 epoxy substrate having size of 40 mm (Lsub) × 30 mm (Wsub) × 1.6 mm (h). A VSWR ratio of 7.1:1 is achieved for an impedance bandwidth of 2.4–17.1 GHz (14.7 GHz i.e., 150.77%). The antenna structure has omnidirectional radiation pattern and an average peak realized gain of 3.5 dB. The experimental and simulated results are found to be in good agreement. The designed antenna structure has wide bandwidth with a size comparable to those of earlier reported ones. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1289–1296, 2015

Design of Widebeam Tapered Slot Antenna for Wideband Airborne Active Phased Array Radar

Background/Objectives: Vivaldi antenna is a prime candidate for wide band applications. This work involves a design of miniaturized tapered slot antenna operating with X-band frequency to achieve wide scan capability, wide beam, maximum gain and minimum return loss for active phased array antenna. Methods/Statistical Analysis: The design of Vivaldi Exponentially Tapered Slot Antenna (VETSA) and analysis of radiation patterns, return loss, beam width and scan angle are done through the use of electromagnetic simulation software HFSS. The analysis was carried out in 3D and 2D. Further, testing and measurement of fabricated Vivaldi antenna using Vector Network Analyzer and radiation patterns are observed in Anechoic Chamber. Design of linear array and planar array is also presented. Findings: VETSA satisfies the requirements on the maximum reflection coefficient < -10 dB for ±60o scan from broadside in E-and H-planes. The realized antenna showed a symmetric pattern, minimum return loss, better 3-dB beam width in principal planes with gain of 3-dB, and VSWR ≤ 2 in X-band frequency. The result of linear array with 9-elements demonstrates good radiation characteristics with gain of 13 dB with low SLL including coupling effects in the X-band operating frequency. The uniformly illuminated array beam pattern shows that the array can scan over the desired scan volume of ±60o in E-plane and ±55o in H-plane. VETSA is a promising candidate to operate in wideband frequency with wide scanning performance in airborne radar applications. Application/Improvements: The designed antenna structure and array are good candidates and is expected to find applications in integration with monolithic millimeter-wave integrated circuits on combat aircraft.

Design Simulation of TRI Band Microstrip Patch Antenna with Back To Back E Shape Slot

A conventional rectangular microstrip patch antenna is considered for this research and further cutting various notches in the conventional structure to make a back to back E-shape microstrip patch antenna structure. The designed antenna structure is further simulated and the simulation result in terms of bandwidth, gain, directivity and efficiency is observed. The observation includes the frequency bands in which the designed antenna can operate properly, the amount of gain in those frequency bands and their efficiency. The result shows that the designed antenna is suitable to work in three different frequency bands with a good amount of gain and efficiency. This whole task is performed over IE3D simulation software, a MoM based simulation software. The return losses obtained are -12.23dB at 3.95GHz, -22.90dB at 6.81GHz and -26.42dB at 7.87GHz of triple band back to back E-shape microstrip patch antenna.

Antenna without Phase Center for DOA Estimation in Compressive Array Processing

Recently, Compressive Sensing (CS) has been applied to array signal processing. In theory, Direction-of-Arrival (DOA) estimation based on CS recovery can work well in correlated environments. However, a large number of sensors (i.e., linear measurements) are still needed for CS recovery. To improve on this, we propose a new CS-based DOA estimation method with a recently designed antenna structure called the Asymmetric Antenna without Phase Center (Asym-AWPC). The best reconstruction is achieved by solving the l1-norm optimization problem, which is cast as an l1-regularized least-squares program. Simulated results indicate the effectiveness of the proposed CS-based Asym-AWPC DOA estimator in a multipath environment over a recent Asym-AWPC DOA estimator but using the Multiple Signal Classification (MUSIC) rather than CS. Further improvement on the resolution can be achieved by tuning the degree of asymmetry in designing the Asym-AWPC.

Higher order mode excitation for high gain microstrip patch antenna

Higher order mode excitation in the microstrip patch has been achieved to alleviate the low gain problem associated with this particular class of antennas. This higher order mode excitation is achieved by geometric modification of the radiating patch. The designed antenna structure is simple in nature, provides easy fabrication and manufacturing while exhibiting high gain characteristic. The proposed antenna has a measured gain of 10.21dBi at the operating frequency of 16GHz. The half power beam width is approximately 36° and 34° in the H- and E- planes respectively. The antenna can be used in the different applications related to the Ku band.

Metamaterial-based “sabre” antenna

The “sabre” antenna is an array of two monopole elements, vertically polarized with omnidirectional radiation patterns, and placed on either side of a composite material on the tail of an airplane. As an in-phase reflector plane, the antenna uses a compact dual-layer high-impedance surface (DL-HIS) with offset mushroom-like Sivenpiper square shape unit cells. This topology allows one to control both operational frequency and bandgap width, while reducing the total height of the antenna to under λ0/36. The designed antenna structure has a wide bandwidth higher than 24% around 1.4 GHz. The measurements and numerical simulations agree very well. L'antenne « sabre » est une antenne réseau formée de deux monopôles à polarisation verticale et rayonnement omnidirectionnel, placées de part et d'autre d'un matériau composite sur la dérive d'un avion. L'antenne utilise, comme plan réflecteur en phase, une surface haute impédance (SHI) formée d'une double-couche de cellules champignons de « type Sivenpiper » carrées décalées. La topologie choisie permet de contrôler simultanément la fréquence centrale et la largeur de bande utile pour une compacité optimum, avec une hauteur totale inférieure à λ0/36. La structure antennaire présente une bande passante supérieure à 24% autour de 1,4 GHz. Les mesures et les simulations numériques sont en bon accord.

Design of Beam Waveguide Antenna Structure for TT&amp;C Ship

According to the special working environment of TT&amp;C ships, S/X/Ka frequency TT&amp;C system needs to be developed by using beam waveguide antenna technology in order to ensure Goddess of the moon project. Antenna structure design is one of the key technologies in the TT&amp;C system. This paper designs the antenna structure detailedly, in which features and design parameters of antenna reflector, antenna seat, shaft angle detection and safety protection devices are given. The load of antenna structure is simulated and calculated based on ANSYS and results show that the designed antenna structure is reasonable, antenna parameters and components configuration are correct, all that fully meets the requirement.

Triple Band Planar Antenna for Wireless Communication

This paper presents a triple band planar antenna for wireless communication. The antenna is printed on FR4 substrate. The patch shape and the ground plane are studied to achieve the desired bandwidth. The reconfiguration of antenna is studied to improve the performance of antenna in terms of the return loss behavior. The designed antenna structure is simulated using CST Microwave studio. The simulation results in terms of return loss are studied. The antenna satisfies triple band operation with good radiation characteristics.