Omnidirectional Radiation Pattern Research Articles

A single-feed circularly polarized antenna with a low vertical profile and hemispherical axial-ratio beam coverage

ABSTRACT A novel wide axial-ratio beamwidth (ARBW) circularly polarized (CP) antenna with a single layer substrate fed by a single probe is proposed. It consists of an inner annular slotted radiator containing eight outer sector units with arc branches, a ground plane, and eight grounded vias. The antenna has an ARBW covering the upper hemisphere and has a low vertical profile. The ultra-hemispherical ARBW is formed by ingeniously merging the endfire omnidirectional CP radiation pattern with the boresight CP radiation pattern. The two radiation patterns can be excited by a central coaxial probe without an additional feeding network. An antenna prototype of dimensions 1.15 × 1.15 × 0.02 (λ 0 3) is fabricated and measured to validate the design concept. Measured results show that the impedance bandwidth of the proposed antenna is 2.0% (3.328–3.394 GHz) and the 3 dB axial ratio (AR) bandwidth is 1.3% (3.332–3.374 GHz). The 3 dB AR beamwidth can cover more than 217° and the maximum gain is 0.79 dBic at 3.35 GHz. A good agreement between the simulated and measured results is obtained.

A compact coupling-fed omnidirectional wideband filtering antenna with high selectivity

ABSTRACT This paper presents a compact coupling-fed omnidirectional wideband filtering antenna with high selectivity for modern wireless communication systems. The antenna integrates a coupling-fed driven patch with a symmetrical printed Г-shaped dipole, facilitating wideband performance and high selectivity through multiple coupling paths. Coupling-fed structure introduces radiation nulls (RNs), achieving an operating bandwidth of 54.5% for |S11| ≤ −10 dB and out-of-band suppression of −9 dB without requiring additional circuits. Simulations and experiments validate the antenna’s performance, demonstrating multiple resonant frequencies and consistent omnidirectional radiation patterns. Compared to traditional designs, it offers superior bandwidth and selectivity, making it suitable for integration into planar RF circuits in applications such as Wi-Fi 6, 5 G, and radar systems.

A Compact and Flexible Monopole Antenna with Controllable Bandwidth

In this paper, a compact antenna with flexible and controllable bandwidth characteristics is proposed. To ensure wide coverage along with an omnidirectional radiation pattern, a monopole structure was utilized as the primary radiating element of the proposed antenna. The monopole was fed using a coplanar waveguide technique to achieve a single-layer design. To alter the operating bandwidth, defined by a reflection coefficient of less than -10 dB, a single stub was directly connected to the feeding transmission line. By controlling the stub's length, matching performance in the high-frequency range was found to undergo significant degradation, indicating that the operating bandwidth could be controlled. Furthermore, for validation, two antenna prototypes were fabricated and measured under different circumstances. In the unbending mode, the design without the stub achieved a wideband of 51.6%, while the other design with the stub exhibited a narrower band of about 19.6%. Additionally, the antennas worked efficiently when operating in bending mode. It is also worth noting that the antenna gain and radiation pattern remained stable across the entire operating bandwidth.

A novel UWB in‐body printed microstrip feed monopole antenna with dual band‐stop capabilities

AbstractThis paper presents an innovative and condensed blueprint for an ultra‐wideband (UWB) printed monopole antenna, aiming to augment bandwidth and achieve dual band‐stop capabilities, all while accounting for the impact of the human body model on stop bands. The proposed design showcases a square radiating patch situated on the top layer of the substrate, complemented by a ground plane etched on the underside, integrating two sets of adapted U‐shaped slots. Such a configuration delivers a broad operational fractional bandwidth that surpasses 132%. Within our design, a modified C‐shaped slot in the radiation patch creates the first band‐stop property, while a pair of modified F‐shaped slots etched in the radiation patch generates the second stop‐band property. Measuring 12 mm × 18 mm × 0.8 mm, the antenna offers a compact form factor, broad bandwidth, cost‐effectiveness, omnidirectional radiation patterns within the H‐plane and acceptable behavior for using in In‐body microwave applications.

Dual Polarized Reconfigurable MIMO Antenna for Multi-Band Functioning

This work presents the development, fabrication, and measurements of a new Ultra-wideband sensing multi-band frequency reconfigurable MIMO Active Integrated Antenna (AIA). The proposed antenna has two frequency reconfigured (switching element PIN diodes) planar inverted F-shape antennas (PIFA) using meandered line (ML) structures and a Mirror-shape UWB sensing antenna. The Mirror-shape UWB sensing antenna is integrated with 2x2 MIMO Meandered line PIFA elements for spectrum sensing. PIN diodes (BAR 6402V) are used to provide all digital switching on/off combination modes to attain frequency reconfigurability. Varactor diodes are used for tuning over the wide band. The proposed antenna senses a wide frequency band from 0.5GHz-3GHz and provides frequency reconfigurability over the five bands based on BARP6402V switching modes (0.78GHz-1.01GHz, 1.34GHz-1.62GHz, 1.85GHz-2.18GHz, 2.44GHz-2.67GHz, and 2.76GHz-2.80GHz). All the measured resultant performance parameters are compared with simulation software results. The antenna system is fabricated on an FR4 substrate of size 120mmX65mmX1.6mm. The proposed method used to achieve frequency reconfigurable ultra-wideband MIMO provides a high gain 6.15dBi at a frequency of 1.75GHz. The research also analyzed and investigated all 2x2 MIMO resultant parameters like Total Active Reflection Coefficient (TARC), Isolation coefficient, Envelope correlation Coefficients (ECC), Diversity Gain (DG), Multiplexing efficiency, etc. The proposed antenna is applicable for sensing, communication, & UWB sensing, and cognitive radio (CR) applications since it exhibits stable excellent gain and Omni-directional radiation pattern over the desired bands. Because of its reconfigurable nature, the same antenna also supports use in multiple general-purpose applications like GPS tracing, LTE, UMTS, GSM1800, rescue operation, Wi-Fi/Bluetooth/ISM/WLAN, CDMA, etc applications.

Development and investigation of a compact band-notched MIMO antenna attaining wideband isolation for UWB applications

The sequential layout of a portable ultra-wideband (UWB) monopole antenna, transforming into a compact band-notch (3.15–4.3 GHz rejecting the Wi-Max and the C-Band) multiple-input multiple-output (MIMO) antenna is described in this paper. The diversity layout is designed within a compact size of 39 (l) × 18 (W) mm2. Due to the opposite orientation of the two radiators in the diversity configuration and the use of a rectangular parasitic strip near the feed lines, high and wideband isolation (of >20 dB) is attained over the entire UWB spectrum. The proposed layout depicts a stable omnidirectional radiation pattern and a maximal gain of 1.82 dB. The envelope correlation coefficient (ECC) is found to be below 0.18 for the entire UWB spectrum. Empirical verifications in terms of vital diversity parameters and analogy with competing layouts strengthen the candidature of the intended MIMO layout for UWB wireless portable applications.

A Novel Dual-Band Omnidirectional Horizontally Polarised Antenna Using Slotted Ground for Wi-Fi Applications

This letter explores an innovative approach to designing a compact, dual-band, omnidirectional, horizontally polarised (OHP) patch antenna with a low profile. The antenna’s ground plane is meticulously etched with radial and arch slots to create open-circuited stubs. This design generates two circulating current loops: one beneath the circular patch and the other on the outer side of the circular patch, comprised of four circular stubs. These current loops operate in unison to produce dual-band resonance and in-phase circulating current on the ground at both resonance frequencies. The antenna’s configuration includes four circular stubs formed by printing sequential radial and bent slots beneath the patch. This arrangement generates an omnidirectional radiation pattern in the azimuth plane at the upper resonance frequency. In addition, four open circular stubs outside the patch are integrated into the ground plane cascaded to the inner four stubs to achieve resonance at the lower frequency. The complete dimensions of the proposed antenna configuration are 0.29λ0 × 0.29λ0 × 0.025λ0, with bandwidths of 2.84% and 2.77% corresponding to measured resonance frequencies of 2.457 and 5.27 GHz, respectively. The measured gains are 1.2 dBi at the lower resonance frequency and 0.8 dBi at the upper resonance frequency. Furthermore, the measured roundness of the radiation pattern remains within 1 dB at the lower frequency band and within 2.8 dB at the upper-frequency band.

Broadband Dual-Polarized Cup Dielectric Resonator Antenna With Stable Omnidirectional Radiation Patterns

Broadband Dual-Polarized Cup Dielectric Resonator Antenna With Stable Omnidirectional Radiation Patterns

A 4-port flexible MIMO antenna with isolation enhancement for wireless IoT applications

This paper presents a conformal, miniaturized, and geometrically simple monopole antenna designed for Vehicle–to–Everything (V2X) communications. The antenna consists of a flexible substrate, radiating patch, ground, and metallic stubs. Meandered lines are added to the U-shaped radiator to achieve the required bandwidth of the antenna. The antenna has |S11|< −10 dB magnitude from 5.06 to 7.24 GHz, attaining a peak low magnitude of–68 dB. The antenna is configured into a 4-port Multiple–Input–Multiple–Output (MIMO) setup to minimize the mutual coupling between its elements. The proposed flexible MIMO antenna offers bandwidth from 5.37 to 7.34 GHz and a peak moderate gain of 4.63 dBi with omnidirectional stable radiation patterns. To improve the mutual coupling, two hollow concentric circular structures, in combination with a pair of stub networks are integrated between the elements of the MIMO system. The transmission coefficient and surface current analysis confirm the effectiveness of the decoupling structure. The presented MIMO antenna is characterized by high isolation, a low envelope correlation coefficient (ECC), and high diversity gain, suitable for V2X MIMO communication scenarios.

Development and comprehensive evaluation of a dual-port textile UWB MIMO antenna for biomedical use

In this paper, a textile two-port multi-input multi-output (MIMO) half-circle antenna with corrugated borders is designed and fully analyzed for nearfield ultra-wideband biomedical diagnostic applications. The orthogonal polarization technique is introduced for mutual coupling reduction, signal quality, and imaging accuracy improvement. A low pass filter with significant out-of-band rejection is inserted between the two MIMO structural elements to improve the isolation from element to element. For simple system integration, A 50 ohms feed coplanar waveguide is suggested for each element. The entire antenna is constructed using textile materials, with the radiating element composed of conductor fabric. The substrate, on the other hand, is crafted from cotton material which possesses a relative permittivity of and a tan δ value of 0.025. The size of each antenna element has low-profile dimensions of 40 × 40 × 0.3 mm3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${mm}^{3}$$\\end{document}. The measured results obtained demonstrate an extremely broad bandwidth extends from 2.5 GHz to 12 GHz. Omnidirectional radiation pattern is obtained, with 6 dBi maximum gain and 96% efficiency. In order to ensure flexibility, a range of bending conditions were analyzed, and the durability was assessed through wash ability testing. Safety was confirmed by measuring the specific absorption rate. Furthermore, time domain and MIMO performance assessments were performed to ensure its suitability for imaging systems.

UN AMPLIO ESPECTRO DE SUSTRATO HEXAGONAL DE OCTAVO MODO PARA APLICACIONES EN BANDA C, S, X

The following article explains how to make a basic ultra-wide bandwidth (UBW) wearable fractal antenna. The antenna is printed on denim fabric with a dielectric constant of 1.7 and a loss tangent of 0.02. The suggested antenna is 45 x 44.92 x 0.5 mm3. The antenna is fed by an inserted microstrip line with a decreased ground structure. It operates at ultrawide band frequencies of 4.36 GHz to 11.12 GHz. The antenna offers an omnidirectional radiation pattern with a gain of more than 2.4 dBi across the entire working band... It achieves a bandwidth of 6767 MHz. The proposed antenna possesses key characteristics such as a simple structure, ease of fabrication, stable omnidirectional radiation pattern, reasonable gain, and directivity, which make it suitable for applications in the C, S, and X bands. Keywords: Textile antenna, UWB, denim fabric, flexible antenna, denim substrate

Design of a Compact and Wideband Printed Monopole Antenna With Stable Omnidirectional Radiation Patterns

Design of a Compact and Wideband Printed Monopole Antenna With Stable Omnidirectional Radiation Patterns

Design of a planar microstrip antenna with wide bandwidth and omnidirectional radiation patterns using tightly coupled structures

AbstractA wideband planar microstrip antenna with good horizontally polarized omnidirectional radiation performance is presented. Using tightly coupled structures, six planar dipole elements are deployed in a circular pattern, and radiation is synthesized into a horizontal omnidirectional radiation pattern by superposing the far‐field pattern of the six dipoles. Owing to the tight coupling between radiating elements, the proposed antenna has a wide operating band. The radiating elements are printed on a printed circuit board and excited by a balun with uniform magnitude and synchronized current. A prototype is manufactured and measured. The measurement results show that the impedance bandwidth of the proposed antenna is 102. The gain variation of the horizontal omnidirectional pattern is less than 1.2 dB in the 1.27–3.89 GHz band. Within the operating frequency band, the total efficiency and radiation efficiency are greater than 82% and 88%, respectively. The diameter of the antenna is 0.48, where is the wavelength corresponding to the lowest frequency in the operating band.

Enhanced Circularly Polarized Antenna for Body Centric Communication

Abstract: This study introduces a miniaturized circularly polarized ultra-wideband (UWB) antenna designed specifically for body-centric communication applications, with a focus on its performance across different frequencies. Fabricated on jean fabric, the antenna offers exceptional flexibility and seamless integration into clothing, making it ideal for wearable devices. The design achieves circular polarization through the utilization of an asymmetric stepped L-shaped ground plane and a crossshaped stub integrated into the radiator structure.Operating across the UWB frequency spectrum ranging from 3 GHz to 9.5 GHz, the antenna exhibits consistent and reliable performance in terms of gain, radiation pattern, and current distribution. ensuring effective signal transmission and reception. Importantly, the antenna complies with FCC specific absorption rate (SAR) limits, ensuring safety in wearable applications.Throughout the frequency range, the antenna maintains an omnidirectional radiation pattern, facilitating reliable on-body communication regardless of orientation. This characteristic is crucial for maintaining connectivity and signal quality in body-centric communication systems.Analysis of the current distribution confirms the antenna's effectiveness across different frequency bands, further validating its performance and suitability for body-centric communication applications.

Design and analysis of a small size triple band printed antenna for 3G/4G/5G/future 5.8G IoT applications

SummaryThis paper presents a compact (20 × 20 × 1.59 mm3), (0.34λg × 0.34λg × 0.01λg at 2.4 GHz) triple band monopole antenna for Internet of Things (IoT) applications. The geometry of the antenna consists of (i) U‐shape monopole with feed line, (ii) stubs, and (iii) modified ground to achieve three independent operating bands ranging from (i) 2.4–2.48 GHz for industrial, scientific, and medical (ISM)/3G; (ii) 3.4–3.6 GHz for 4G/5G; and (iii) 5.725–5.825 GHz for 5.8G Wi‐Fi/extended 5G. Various parameters, input impedance, and current distribution of the proposed structure are carried out to investigate the effects of stub, ground plane and analyze the radiation. The measured result covers the three individual bands in range of 2.38–2.48 GHz, 3.41–3.61 GHz, and 5.76–6.04 GHz, respectively, and exhibits stable omnidirectional radiation patterns, acceptable antenna gain, and efficiency in the operating bands. The experimental result of the fabricated antenna closely matches with the simulated result. Therefore, satisfactory result ensures its ability to work for 3G/4G/5G/extended 5G IoT portable applications.

Comprehensive Analysis of Xiaomi Mi 8 GNSS Antenna Performance.

The interest in precise point positioning techniques using smartphones increased with the launch of the world's first dual-frequency L1/L5 GNSS smartphone, Xiaomi Mi 8. The smartphone GNSS antenna is low-cost, sensitive to multipath, and limited by physical space and design. The main purpose of this work is to determine the mechanical location and antenna performance in terms of radiation pattern in an anechoic chamber using a Vector Network Analyzer (VNA) and robotic positioning platform by varying the elevation and azimuth angles between the transmitter and smartphone GNSS antennas; the power received and satellite visibility are developed in an outdoor scenario. The results show a Planar Inverted-F Antenna with an omnidirectional radiation pattern without gain. The L1/E1/B1 and L5/E5a/B2a GNSS antennas are physically located at the top face of the screen, with dimensions of 48 × 17 mm and 60 × 13 mm, respectively. With the screen with line-of-sight toward the sky, L5 satellites have a better signal-noise ratio (SNR), unlike the back side, which loses 99% of the data in the PPP solution. Under multipath scenarios, the L1 GNSS smartphone antenna works with 25% less power than the GPS user segment recommendation, showing high sensitivity to track weak signals.

Dual-band GPS/LoRa antenna for internet of thing applications

This paper presents the design and characterization of a compact dual-band microstrip antenna for GPS and long range (LoRa) internet of thing (IoT) applications. The antenna operates at 868 MHz and 1.57 GHz and has a gain of 3.35 dBi and 5.08 dBi, respectively. The antenna design is optimized using CST microwave studio software (MWS®), and both simulation and measurement results are in close agreement. The antenna features a directional E-plane and omnidirectional H-plane radiation pattern in each band of operation. The proposed antenna’s compact size and dual-band capability make it suitable for IoT applications that require GPS and LoRa communication in a small form factor. The results presented in this paper demonstrate the feasibility and effectiveness of the proposed antenna design.

Bandwidth‐enhanced horizontally polarized omnidirectional slot antenna based on single‐ridge trapezoidal waveguide

AbstractThis letter presents a Ku‐band horizontally polarized (HP) omnidirectional antenna based on single‐ridge trapezoidal waveguide (STW). Four groups of longitudinal slots are etched on a pair of back‐to‐back arranged STWs to achieve the HP omnidirectional radiation performance. The number and distribution of each radiation slot group are optimized to reduce the gain variation. An out‐of‐phase stripline power divider cascaded with two probe‐based vertical power dividers is used to excite all radiating slots in a series‐parallel hybrid structure, which helps to enhance the boresight radiation bandwidth. For demonstration, a prototype covering 14.5 to 15.5 GHz is designed, fabricated, and measured. Experimental results show that the good impedance matching (|S11|←14 dB) and the measured out‐of‐roundness for the omnidirectional radiation pattern are less than 4.4 dB within the desired frequency band. High gain and wideband omnidirectional radiation characteristics can provide a wide range of coverage and good signal transmission performance for outdoor wireless communication systems.

Design of a Dual-Band Printed Antenna for Modern Wireless Communications and Internet of Things Applications

Wireless technology is increasingly influenced by the advanced technological development of antennas. With the rapid expansion of Internet of Things ( IoT) application in the contemporary communication networks, the demand for small printed antennas is increasing, due to their small size and ease of design and manufacture to suit their various application. In this paper, the antenna is designed which is operating at two different frequency bands 2.40GHz and 5.78GHz. The design parameters of the antenna have been calculated using the transmission line model, and an antenna design program has been used for the simulation process is HFSS ( High frequency simulator structure ) tool, which is based on Finite Element Method (FEM). In this work, the proposed slot dual band patch antenna is implemented using FR4 substrate material with a thickness 1.6mm and relative permittivity 4.4. The size of the proposed antenna is just (28 × 27.7mm). The proposed antenna has Omni-directional radiation patterns on most of the operating band. The dual band antenna is designed by adding a slot to the top of the radiated patch. Therefore, the proposed dual- band antenna shows good performance, which is suitable for modern wireless communications and Internet of Things (IoT) applications. The measurements are found to be in good accordance with the simulated results.

DESIGN ANTENNA MIMO 2X2 PATCH RECTANGULAR FOR WIFI 6 APPLICATIONON 5GHZ BAND

The development of wireless network technology, particularly WiFi 6 at 5GHz, offers greater reliability and data transfer capacity. Antenna design is a crucial aspect in optimizing WiFi 6 networks in complex wireless environments. The study examined a rectangular patch 2x2 MIMO Antenna for WiFi 6 at 5GHz with a focus on improving network parameters such as return loss, bandwidth, VSWR, and gain. The use of various methods and references from Balanis (2005) and Webster (2021) supports the development of antenna technology, while previous research by Ni Putu Kartika Dewi (2019) strengthens the understanding of microstrip antennas for LTE applications. The main objectives of the study were to design and simulate a rectangular patch 2x2 MIMO Antenna for WiFi 6, as well as analyze simulation data using CST Studio Suite 2019 software. This research uses hardware in the form of Acer Aspire laptops and CST Studio Suite 2019 as simulation software and antenna design. The simulation results show that this antenna is able to work in the frequency range of 4.5-5.2 GHz with a bandwidth of 55.4 MHz and return loss of -20.677981 dB, VSWR 1.2038357, and gain 3.429 dBi with omnidirectional radiation patterns. However, the addition of antenna patches has an impact on decreasing gain. This study provides an in-depth understanding of MIMO antenna design to support WiFi 6 performance in complex wireless environments.