There are various patch antennas used for Wi-Fi and Wi-MAX applications But, the problems with them are low gain, low power handling capacity and hence, conventional yagi-uda antennas are used Conventional yagi-uda antennas are used in applications where high gain and directionality are required Generally, numbers of directors are added to increase gain of these antennas But, here we present modified yagi-uda antennas, in which the gain and bandwidth can be enhanced by not adding additional directors

In this paper, we initially discuss the designs of various yagi-uda antennas with uniform, non-uniform spacings between directors and then we discuss their gain and bandwidth enhancement by various approaches Simulation results show that, the proposed techniques can enhance gain as well as bandwidth when compared with the traditional yagi-uda antennas

Design of a Yagi-Uda Antenna With Gain and Bandwidth Enhancement for Wi-Fi and Wi-Max Applications

UWB dual-port self-decoupled o-shaped monopole MIMO antenna with small-size easily extendable design and high diversity performance for millimeter-wave 5G applications

This paper is aimed to evaluate the performance of the Yagi-Uda Antenna with squared shaped Antenna element and compare its performance from conventional spherical shaped Yagi Antenna. For this job, two Yagi-Uda Antennas has been designed at 2GHz frequency with two different shape of Antenna element. The Antenna’s potential characteristics such as return loss, radiation pattern, have been measured for the analysis of proposed Antenna. The related designing parameters were also discussed in this paper.

http://www.ijoar.org/journals/IJOARCE/papers/Performance_Investigation_of_Yagi_Uda_Antenna_Using_Different_Shapes_of_Antenna_Element.pdf

Performance Investigation Of Yagi-Uda Antenna Using Different Shapes Of Antenna Element At 2GHz

In this study, a novel Vivaldi antenna with dimensions of 100 mm × 85 mm × 1.6 mm, designed for a moisture measurement system, is built to enhance the gain of conventional Vivaldi antennas in the low-frequency band to suit the needs of moisture detection. The fence structure and choke slot are modified to enhance the antenna’s radiation properties in the low-frequency band, and simulation is performed to determine how different structural parameters affect the antenna’s performance. The results show that in the frequency band of 5-6 GHz, the voltage standing-wave ratio (VSWR) of the antenna is less than 2, and the gain at 5.8 GHz reaches 16.2 dBi after installing the lens. Compared with conventional unmodified Vivaldi antennas, the gain at 5.8 GHz increases by approximately 6.11 dBi. The antenna is then processed and measured, and the measured results are in good agreement with the simulated results; hence, the antenna can be widely used in the field of moisture detection.

/pdf/low-cost-lens-antenna-design-for-microwave-moisture-1ta5erfw.pdf

Low-Cost Lens Antenna Design for Microwave Moisture Detection

In this paper, a circularly polarised dielectric resonator-based MIMO filtering antenna is designed and analyzed. The unique feature of the proposed antenna is the combination of circular polarisation characteristics with filtering response at mm-wave. Cylindrical ceramic excited by asymmetrical plus-shaped slot provides two important characteristics: (a) generate dual orthogonal degenerated mode with 900 phase shifts in between 27.0 GHz and 27.33 GHz; and (b) produce the radiation nulls at 25.5 and 27.75 GHz respectively. Two identical ports are placed orthogonally to provide the lesser mutual coupling i.e. approx. −30 dB. Experimental outcomes confirm the operating band of the proposed antenna from 25.5 GHz to 27.79 GHz. In between the operating frequency range, the proposed radiator provides broadside radiation characteristics due to the creation of mode. The peak gain of the proposed antenna is about 5.0 dBi. Diversity parameters (such as ECC, DG, and TARC) are within satisfactory limits. All these properties of the proposed radiator make it fit for a 5G communication system.

Circularly Polarised Dielectric Resonator based Two Port Filtenna for Millimeter-Wave 5G Communication System

A novel multiple‐input multiple‐output double asymmetrical cylindrical dielectric resonator antenna (MIMO‐DCDRA) with modified stub line feed is discussed and proposed in this work. Two unequal CDRA are placed diagonally to each other and are electromagnetically coupled with feeding arrangement via two asymmetrical circular apertures. By performing the optimization of the dimensional parameters, a significant impedance bandwidth of 70.84% ranging from 2.87 to 5.76 GHz and axial ratio bandwidth (ARBW) of 34.89% is obtained. Antenna gain is about 5.0 dBi within the operating frequency. The proposed MIMO‐DCDRA exhibits a low mutual coupling of (|S21| & |S12| < −20 dB) with the incorporation of a neutralization line. There are various diversity parameters that are also discussed in terms of mutual coupling, envelop correlation coefficient (ECC < 0.002), diversity gain (DG > 9.995), and channel capacity loss (CCL < 0.3 bits/s/Hz) over the entire impedance bandwidth.

Two asymmetric cylindrical dielectric resonator loaded dual port multiple‐input multiple‐output antenna for wide band application with circular polarization attributes

In this paper, a Vivaldi antenna with a grooved, tapered slot loaded with an artificial material lens (AML) is designed and analyzed. The unique feature of the proposed antenna is to provide excellent gain (more than 5.0 dBi) over the entire ultra‐wide bandwidth within the compact area, i.e., 40 × 45 mm2. For improving the gain, symmetrical slot matrices were etched at the flare and AML unit cells were imprinted at the extended dielectric portion. Measured results confirm its operating frequency range from 4.65 to 12.65 GHz, having a peak gain of 9.2 dBi to a minimum of 5 dBi. As compared to conventional antenna, the proposed Vivaldi antenna shows an increase in gain of 2.2 dBi. Furthermore, time‐domain analysis suggests very good isolation (∼35 dB), linear phase response, and negligible group delay (∼1 ns). The compact size, wide bandwidth, good gain, stable radiation, and transient features make it a suitable choice for imaging, and communication applications.

A high gain and wide bandwidth Grooved AML loaded Vivaldi Antenna design for imaging and communication applications

A yagi-uda antenna for L-band (1- 2GHz) frequency range is presented. The designing formulas and related antenna characteristics such as return loss, radiation pattern and gain were also discussed in this paper.

http://www.researchgate.net/profile/Gulshan_Sharma5/publication/265802301_Yagi-Uda_Antenna_For_L-Band_Frequency_Range/links/5509b0ce0cf20f127f902339.pdf

Yagi-Uda Antenna For L-Band Frequency Range

In this article, various machine learning (ML) algorithms such as Artificial neural network (ANN), Random Forest, XG boost, K nearest neighbor (KNN), and Knowledge-based neural network (KBNN) are used for efficient optimization of dielectric resonator antenna (DRA). ML models are used to predict the |S11| for a particular set of frequency, resonator height, aperture radius, and resonator radius. Finally, a comparative performance analysis of different ML algorithms has been done with the outcomes of the HFSS EM simulator. Error percentage is in between 1.0% and 7.0% with different ML algorithms. Antenna design is also fabricated and tested. The performance of the fabricated prototype is very close to different ML algorithms and HFSS obtained outcomes. 

Anand N. Sharma

Papers

Circularly Polarised Dielectric Resonator based Two Port Filtenna for Millimeter-Wave 5G Communication System

Two asymmetric cylindrical dielectric resonator loaded dual port multiple‐input multiple‐output antenna for wide band application with circular polarization attributes

A high gain and wide bandwidth Grooved AML loaded Vivaldi Antenna design for imaging and communication applications

Yagi-Uda Antenna For L-Band Frequency Range

Aperture Coupled Dielectric Resonator Antenna Optimisation using Machine Learning Techniques