Yagi-Uda Antenna Research Articles

Design of a High Gain Yagi-Uda Antenna Array for VHF-Band Radar Applications

Design of a High Gain Yagi-Uda Antenna Array for VHF-Band Radar Applications

CUSTR- A VHF phased array radar for observation of atmospheric dynamics and ionospheric plasma irregularities

A VHF phased array radar for atmospheric dynamics observation is installed at the University of Calcutta, Kolkata. The Calcutta University Stratosphere-Troposphere Radar (CUSTR) operates at 53 MHz with 475 three sub-element Yagi-Uda antenna array. The CUSTR system is a high-power fully active phased array system with a dedicated 2 kW solid-state Transmit-Receiver Module (TRM) attached to each antenna, providing a total peak power of 950 kW with 47.5 kW average power at 5% maximum duty ratio. The system provides electronic beam steering capability to steer the beam 360° in azimuth direction with a maximum off-zenith angle of 40°. The array is configured with 25 sub-arrays and operates either in a combined mode in Doppler Beam Swinging or in Spaced Antenna mode using a multi-channel digital receiver system. The TRM has been designed to provide a very short pulse of 0.5 µs and a long pulse of 128 µs. The system description along with the initial scientific observations such as atmospheric boundary layer, troposphere-lower stratosphere wind measurements along with preliminary wind validation, mesosphere echoes and ionosphere irregularities are presented.

Self-organizing surrogate-assisted non-dominated sorting differential evolution

Multi-objective optimization problems (MOPs) involve optimizing multiple conflicting objectives simultaneously, resulting in a set of Pareto optimal solutions. Due to the high computational or financial cost associated with evaluating fitness, expensive multi-objective optimization problems (EMOPs) further complicate the optimization process. Surrogate-assisted evolutionary algorithms (SAEAs) have emerged as a promising approach to address EMOPs by substituting costly evaluations with computationally efficient surrogate models. This paper introduces the self-organizing surrogate-assisted non-dominated sorting differential evolution (SSDE), which uses surrogate model based on a self-organizing map (SOM) to approximate the fitness function. SSDE offers advantages such as reduced computational cost, improved accuracy, and the speed of enhanced convergence. The SOM-based surrogate models effectively capture the underlying structure of the Pareto optimal set and Pareto optimal front, leading to superior approximations of the fitness function. Experimental results on benchmark functions and real-world problems, including Model-Free Adaptive Control (MFAC) and the Yagi-Uda Antenna design, demonstrate the competitiveness and efficiency of SSDE compared to other algorithms.

Retraction notice: High gain switched beam Yagi-Uda antenna for millimeter wave communications

Retraction notice: High gain switched beam Yagi-Uda antenna for millimeter wave communications

Microstrip Yagi–Uda Antenna with Hexagonal Magnetic Dipoles for Wi-Fi Applications

Microstrip Yagi–Uda Antenna with Hexagonal Magnetic Dipoles for Wi-Fi Applications

Tunable THz absorbers based on LC-tuned Yagi-Uda antennas

ABSTRACT This study examines the structural configuration of Yagi-Uda micro-antenna arrays, the resonant properties of which are tunable through nematic liquid crystals in the terahertz spectral region. Reorienting liquid crystals by varying the voltage applied to the liquid crystal cell allows for control of the reflectance and absorbance amplitudes within the 7–12 THz operational frequency range. The reflectance and absorbance control ranges are around 50–60% across most of the frequency range, notably reaching approximately 90% at 11.1 THz. The optimal operational voltage ranges for the presented structure were approximately 1.1–1.9 V at the lower frequencies and 1.4–2.5 V at higher frequencies. This research highlights the potential of such metamaterial designs for efficient and adaptable applications in the THz spectrum.

Nano antenna-assisted quantum dots emission into high-index planar waveguide

Integrated quantum photonic circuits require the efficient coupling of photon sources to photonic waveguides. Hybrid plasmonic/photonic platforms are a promising approach, taking advantage of both plasmon modal confinement for efficient coupling to a nearby emitter and photonic circuitry for optical data transfer and processing. In this work, we established directional quantum dot (QD) emission coupling to a planar TiO2 waveguide assisted by a Yagi-Uda antenna. Antenna on waveguide is first designed by scaling radio frequency dimensions to nano-optics, taking into account the hybrid plasmonic/photonic platform. Design is then optimized by full numerical simulations. We fabricate the antenna on a TiO2 planar waveguide and deposit a few QDs close to the Yagi-Uda antenna. The optical characterization shows clear directional coupling originating from antenna effect. We estimate the coupling efficiency and directivity of the light emitted into the waveguide.

Wirelessly Pattern Reconfigurable Yagi Antenna Based on Radio Frequency Identification

This paper presents, for the first time, the implementation of a pattern reconfigurable Yagi-Uda antenna utilizing radio frequency identification (RFID) technology for remote pattern control. The proposed scheme emphasizes the use of wireless communication instead of long metal cables, resulting in improved stability of the antenna’s pattern and return loss. Two low-power consumption single-pole-double-throw (SPDT) switches are employed on a passive resonator, enabling it to function as a director or reflector under the long-range control (up to 25 m) of an RFID reader. Measurement results demonstrate a −10 dB impedance bandwidth of 4.2% and a gain of 7 dBi at 2.41 GHz. The entire system operates with an ultra-low power consumption of 12 μW.

Design of the Wearable Microstrip Yagi-Uda Antenna for IoT Applications

Design of the Wearable Microstrip Yagi-Uda Antenna for IoT Applications

Self-steering Yagi-Uda antenna positioning system for television

The aim of this study is to develop a prototype that automatically improves the position of a Yagi-Uda antenna using a microcontroller and to illustrate its radiation pattern through the use of MATLAB<sup>®</sup>. This study is intended for students and professors in the electronics engineering field. This served as their educational materials for teaching antenna system principles and theories. Developmental and experimental methods were used to achieve the objectives. The materials and components generally used in this study are a Yagi-Uda antenna, stepper motor, Arduino Uno, L293D motor shield, USB TV stick tuner, slotted optocoupler, ADS1115, coax cable splitter, speaker stand, and timing belt. The statistical tool used in this study was a Z-test to find out if the experiment results were significant. In testing the effectiveness of the automatic antenna system, the TV display in every increment of 1.8° was taken. It was the basis for the effectiveness of the study. At 5% α/2 level (1.96), the computed z value is 1.76, which is less than 1.96. Therefore, there is no significant difference between the picture quality of the TV display at every angle and the desired angle with maximum reception of the signal with the integration of MATLAB<sup>®</sup>.

High-Permittivity Dielectric Half-Loop Yagi-Uda Antenna With End-Fire Radiation

High-Permittivity Dielectric Half-Loop Yagi-Uda Antenna With End-Fire Radiation

Diplexer Antenna for 5G Full-duplex Application

This work proposes a spiral filter-based diplexer antenna for dual-band full-duplex 5G application in C-band. The shared radiator is formed by a cross-shape Yagi-Uda antenna. The dual-band full-duplex characteristic is obtained by applying a diplexer with two different band-stop filters (BSFs) based on a high-order rectangular spiral-shaped open-stub filter. The proposed diplexer antenna is suitable for modern 5G full-duplex communication system applications with a small frequency ratio and high isolation between two ports by applying a Wilkinson power divider. The diplexer antenna is designed, fabricated, and measured, showing good performance of channel isolations of 27 dB/23 dB and the antenna gain of 4.7 dBi/4.2 dBi at two operation bands from 3.56 GHz to 3.68 GHz and from 3.72 GHz to 3.83 GHz covering the required 100 MHz maximum bandwidth in C-band while its frequency ratio is only 1.04.

Optimization Assisted by Neural Network-Based Machine Learning in Electromagnetic Applications

We introduce an optimization assisted by a neural network (ONN) predictor to the electromagnetic community. ONN belongs to the class of the surrogate model-based optimization approaches, and approximates the objective function using a non-linear approximator – neural network. We provide a comprehensive description of the ONN algorithm and the details of its mathematical formulations. We apply ONN to optimize three popular benchmark functions and compare its performance with some commonly used optimization algorithms, namely particle swarm optimization, genetic algorithm, and Bayesian optimization. For the first time, we demonstrate ONN’s applicability and effectiveness in antenna design problems by optimizing a six-element Yagi-Uda antenna and by solving a challenging ten-dimensional dual-band slotted patch antenna constrained optimization problem. To achieve this, ONN is linked with a full-wave electromagnetic simulation solver through an application user interface. The optimized slotted patch is fabricated and measured to demonstrate how ONN can be part of the full antenna design process. Our empirical results indicate that ONN requires less objective function evaluations to reach the same qualitative point and reaches better optimal points for the same number of iterations for the studied benchmark functions and antenna optimization problems compared to the aforementioned baseline optimization algorithms.

Wideband Solar-Cell Integrated Yagi-Uda Antenna

Wideband Solar-Cell Integrated Yagi-Uda Antenna

Identification of Control Parameters Using Taguchi Method for Hybrid Real-Binary Differential Evolution Algorithm and Its Applications in Electromagnetic Optimization

The hybrid real-binary differential evolution (HDE) algorithm has been proficient in addressing electromagnetic optimization problems (EOPs) involving both real and binary variables. However, its optimization performance on different control parameter (CP) settings is not further studied, and the method to determine the values of CPs is more likely to use the trial-and-error method, which lacks universality on both unimodal and multimodal benchmarks. To completely account for the effect of CPs in HDE, the Taguchi method is utilized to identify the values of each CP. The orthogonal experiment result is the average rank of the mean values of 23 benchmark functions obtained by HDE and other classic optimization algorithms. Based on the analysis of variance results, three CPs that have a major effect on the performance of HDE are selected, and each of them is changed from level 1 to level 5 to further obtain the best combination of CPs, which is indicated as HDEN1. To further enhance the local search ability of HDEN1 for the global best, a modified algorithm (HDEN2) is proposed based on a novel mutation strategy selection method, and the simulation results demonstrate that the minimum values obtained by HDEN2 are smaller than those obtained by HDEN1. Two EOPs, including planar microwave absorber and Yagi-Uda antenna designs, are solved to validate the performance of HDEN1 and HDEN2. The results reveal that the HDEN1 and HDEN2 outperform HDE, demonstrating the efficacy of the proposed method for identifying the CPs of HDE. In the end, a low profile and wideband RCS reduction pixelated checkboard metasurface is optimized utilizing the HDEN2, proving that the proposed algorithm can be a good candidate for hybrid real-binary electromagnetic problems.

Effects of different manufacturing techniques on the performance of planar antennas

This study investigates antenna performance based on its manufacturing process. Two types of planar antennas are manufactured on FR-4 dielectric using three different techniques: traditional lithography, laser ablation, and the novel SSAIL (selective surface activation by laser) technique. Various characteristics, such as reflection coefficient, gain, half-power beamwidth, and surface conductivity, are measured to compare the results. These findings offer invaluable insights for choosing the most suitable antenna manufacturing technique, particularly since the SSAIL technique has not been previously compared to alternative methods in the context of antenna production. In both types of antennas, the highest gain is achieved using laser ablation, with the slot-loaded patch antenna reaching 8.5 dBi and the Yagi-Uda antenna reaching 9.76 dBi. Antennas manufactured using SSAIL technology are notable for their excellent resolution and usefulness in constructing structures on non-metallized dielectrics.

A Review on the Effects of Thermal Inversions and Electromagnetic Fields on Cell Cultures and Wireless Communications

Thermal inversions, typical in the winter season, consist of cold air at the Earth’s surface being trapped under a layer of warmer air. Such an effect keeps normal convective overturning of the atmosphere from penetrating through. This phenomenon highly increases the toxicity of the atmosphere, while modifying its dielectric constant, resulting in major implications in terms of public health and wireless communications. Indeed, air pollution in large cities (related, in most cases, to particulate matter that consists of different chemical components, which can have warming or cooling effects) is primarily caused by chemical and photochemical reactions in the atmosphere. Appropriate usage of array antennas allows the effective tracking of changes in humidity (e.g., coated Yagi-Uda antennas, which do not interfere with 5G) and in the dielectric constant (e.g., optimized quasi-Yagi-Uda antennas, yielding to accurate measurements of sulfides and black carbon concentration). Remarkably, important health effects come from the combined action of electromagnetic fields with fine and coarse black carbon particles. The appearance of ducts, which are caused by thermal inversions, provokes the creation of super-refractive regions in the troposphere as well, which result in the anomalous propagation of wireless communications.

The directional antenna tracker for enhancing range communication between UAVs and Ground Control Station

This paper discusses the development of an antenna tracker project focused on evaluating a 2.4 GHz Yagi Uda directional antenna connected to an NRF24L01 transceiver. It employs a gear reduction system for precise yaw and pitch control using two servo motors. The tracker calculates rotation angles using the Haversine formula for coordinates and inverse tangent trigonometry for elevation. Experiments took place in an open area with a stationary Ground Control Station (GCS) and a moving Unmanned Aerial Vehicle (UAV) to assess performance. The experiments comprised three tests: first, GCS without the Yagi Uda antenna or tracker; second, GCS with the Yagi Uda antenna but without the tracker, positioned along a 30-degree angle away from the transmitter; and third, GCS with both the Yagi Uda antenna and the tracker. The UAV gradually moved away from the tracker in 5-meter intervals until data loss occurred. The test results are based on received coordinates, distance, temperature, humidity, and data loss. Among the three tests, Test 3 demonstrates the best outcome, where the Yagi Uda antenna successfully receives data up to 180 meters before experiencing data loss.

Design of Singly Fed Dual-Band Antenna With a Large Frequency Ratio by Introducing a Monopole Mode to Yagi–Uda Antenna

Design of Singly Fed Dual-Band Antenna With a Large Frequency Ratio by Introducing a Monopole Mode to Yagi–Uda Antenna

Theoretical Analysis and Applications for the Element-Rotation-Based Circularly Polarized Yagi–Uda Antenna

Theoretical Analysis and Applications for the Element-Rotation-Based Circularly Polarized Yagi–Uda Antenna