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Radiation Characteristics of a Quarter-Wave Monopole Antenna above Virtual Ground
Abstract and Figures
In recent years, monopole antennas have become one of the vital components of cellular mobile communications and internet networks across the globe. Their relatively easy and low fabrication cost and faster installation makes them an obvious choice for developing countries. The most common form is the quarter-wave monopole, in which the antenna is approximately 1/4 of a wavelength of the radio waves. In this paper, we present the analytical treatment of a quarter-wave monopole antenna above virtual ground. Virtual ground is realized by using bent radials around the vertical monopole element. Radiation resistance and gain of the quarter-wave monopole are mathematically derived and three-dimensional radiation patterns are simulated using sinusoidal current distribution. It is observed that for the case of the quarter-wave monopole, we achieve twice the gain of a dipole antenna of half-wavelength long. As the radiated power is limited to upper hemisphere of the ground plane, the total radiated power of the quarter-wave monopole is half of that of a dipole. Hence, the value of radiation resistance of the monopole is half of that of a dipole.
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... However, using such equation in different applications was found to be limited. Many researchers have used the quarter wave monopole antenna for their experimental and practical work [18][19][20][21]. Nevertheless, to the best of our knowledge, there is no power equation considering the antenna's length. ...
... , where n=0, 1, 2, 3, 4, 5, 6, K.). Figure 3 reveals that the quarter wave monopole antenna is highly efficient. The results are in a good agreement with some reported observations [18][19][20][21]. Here, the measured voltage of the output signal can provide a good indication of the harvested energy and will coincide with the pattern of simulated power as shown in figure 3. Figure 4 presents the electric circuits of a radio transmitter and a receiving wire antenna. ...
Antenna is an essential component of telecommunication devices. Recently, the antenna has been used as a receiver in the rectenna solar cells as well as a vital component of cellular mobile telecommunications. The power of the received signal may depend on the physical shape of the monopole receiving antenna. The optimization of antenna's geometry is essential to improve the antenna performance as a receiver. It is widely accepted that the physical length of the monopole antenna; with one fourth of the incident wavelength; possesses an optimal efficiency. In the current study, a power equation based on a recently modified electromagnetic (EM) wave theory has been derived. The proposed formula has been used to calculate the optimum length of the monopole antenna to optimize the received power by the antenna. The angle between the direction of the antenna's plane corresponding to the direction of the propagation of the EM wave has been considered. some experimental investigations have been considered to confirm our theoretical investigations. In our experiment, the output voltage has been considered as a good indication of the harvested energy of the monopole antenna.
... The commercial traditional receivers employ vertically polarized telescopic whip antennas, which receive signals from all directions with equal density since a monopole antenna provides an omnidirectional radiation pattern (Khan, Azim and Islam, 2014). As a result, a telescopic whip antenna cannot distinguish the desired signal from the interference, as both penetrate into the receiver despite arriving from different directions. ...
... The result showed that the larger the ground plane, the lower the direction of maximum radiation and as the ground plane approaches infinite size, the radiation pattern approaches maximum in the x-y plane. The authors in [8] analyzed the Radiation Characteristics of a Quarter-Wave Monopole Antenna above Virtual Ground. Analysis of the result shows that, for the case of the quarter-wave monopole antenna, twice the gain of a dipole antenna of half-wavelength long was achieved and the value of radiation resistance of the monopole is half of that of a dipole. ...
This paper presents the performance analysis of a Full-wave Loop Antenna and a Quarter Wave Monopole Antenna. The Radiation Patterns of the two antennas were generated using the Lab-Volt Antenna Measurement System with a view to evaluating the Half Power Beam width, Directivity and Directive Gains of the two antennas. The directivity of the quarter wave monopole antenna was found to be 4.6dB which is almost twice 2.43dB of the full-wave loop antenna. Also, the directive gain of the quarter wave monopole antenna was found to be 1.96 dB higher than that of the full-wave loop antenna which was found to be-0.22dBd.
... The result showed that the larger the ground plane, the lower the direction of maximum radiation and as the ground plane approaches infinite size, the radiation pattern approaches maximum in the x-y plane. The authors in [8] analyzed the Radiation Characteristics of a Quarter-Wave Monopole Antenna above Virtual Ground. Analysis of the result shows that, for the case of the quarter-wave monopole antenna, twice the gain of a dipole antenna of half-wavelength long was achieved and the value of radiation resistance of the monopole is half of that of a dipole. ...
This paper presents the performance analysis of a Full-wave Loop Antenna and a Quarter Wave Monopole Antenna. The Radiation Patterns of the two antennas were generated using the Lab-Volt Antenna Measurement System with a view to evaluating the Half Power Beam width, Directivity and Directive Gains of the two antennas. The directivity of the quarter wave monopole antenna was found to be 4.6dB which is almost twice 2.43dB of the full-wave loop antenna. Also, the directive gain of the quarter wave monopole antenna was found to be 1.96 dB higher than that of the full-wave loop antenna which was found to be-0.22dBd.
... The impedance bandwidth of a thin monopole can be increased by changing the wire element geometry, for example by thickening or meandering the wire element or adding some loading. The design of monopole antenna in the shape of top-hat, dielectric loaded, discone, caged and various loaded monopoles are discussed [1][2][3][4][5][6][7]. But these elements tend to be bulky and occupy a relatively large physical volume. ...
The recent trends in airborne communication system has result in requirement for design and development of broadband antenna with features like compact size, aerodynamically suitable and light weight. A slanted monopole radiator is used which is enclosed in a radome. The proposed antenna has design at S-band and can be scaled to any other band. The simulated and measured reflection characteristics of the antenna along with the radiation patterns and gain are presented and discussed. Moreover, the ability of the antenna to withstand sturdy conditions and to avoid the light striking by blocking the DC current is also discussed and finally the conclusion is drawn accordingly.
The book contains the papers of the participants of XIII. Croatian Symposium on Physics Teaching with the thematic title Modern Curriculum and Physics Teaching, held in Hotel Donat in Zadar from 19 to 21 April 2017, organized by the Croatian Physical Society and the Education and Teacher Training Agency. This symposium is dedicated to the importance and desirable structure and content of the modern physics curriculum in the context of expressed societal needs and efforts to improve and modernize physics education. (https://hpd.hr/eskola-fizika/sns2017/ )
This study reports a novel technique utilising a standing-wave node as a virtual ground to implement an impedance matching network and power level tuning in a ground eliminated (GE) open-ended resonant coil structure. This technique with GE open-ended coils can potentially be used in wireless power transmission (WPT) systems, where an unknown metallic, ungrounded, arbitrary environment is used as a signal propagation medium to deliver electric power to several distributed nodes. To satisfy WPT standards the proposed resonant WPT system with the matching network is implemented and tested at 13.56 MHz. A comprehensive study of the GE open-ended resonant coil structure demonstrates ground-plane effects and the necessity of an impedance matching network in no-ground signal situations. The experimental results confirm the theoretical analysis presenting 9% improvements in mismatch efficiency, and 13.1 times in power transmission efficiency at 13.56 MHz when the matching network is deployed.
Introduction to Antenna Placement and Installation introduces the characteristics of antennas and their integration on aircraft. The book covers antenna siting and placement, computational antenna modelling on structures, measurement on sub-scale models of the airframe, full-scale ground measurements and in-flight measurements. The author addresses the different stages in the process of developing an entire antenna layout, as well as covering individual retrofits on existing platforms. She explains the physics of antenna placement qualitatively, thus obviating the requirement to understand complex mathematical equations. Provides a reference book & guide written primarily for Antenna and Integration Engineers but which will also be of interest to Systems Engineers and Project Managers. Includes chapters on aircraft systems using antennas, restrictions & trade-offs, frequency & spatial coverage considerations, effect of other antennas & obstacles, RF interoperability issues associated with radiated emissions, computer modelling software, scaled model & full-scale measurements, comparison between measurements & modelling, as well as ground tests and in-flight measurements. Describes techniques that can be applied equally to antennas on other structures such as land or sea vehicles and spacecraft. Illustrated throughout with figures & diagrams as well as a full colour plates.
Previously, we proposed a small high-active-gain antenna called the double-folded monopole antenna using the coaxial cable [5]. This antenna has a relatively high resistance near 50 Ω even though antenna size is small with 0.15 wave length. The present paper is the first report of the coaxial cable loaded monopole antenna with reduced size. Using this antenna, we developed a different type of the double-folded monopole antenna with coaxial cable by a simple modification. Finally, we discuss about difference of new double-folded monopole antenna with coaxial cable from previously developed double-folded monopole antenna using coaxial cable.
Based on that triangle monopole antenna has wide frequency band, this paper proposes a novel composite triangle monopole antenna, which is composed of three similar triangle metal plates. Through the electromagnetic simulation software CST Microwave Studioreg, we obtain its characteristics under the condition that its ground-plate is infinite perfect conductor. The simulation results show that the composite triangle monopole antenna not only has wide impedance frequency band, but also takes up smaller space comparing with triangle rnonopole antenna. On the above foundation, we construct composite triangle dipole antenna with two symmetrical composite triangle monopoles without ground-plate and simulate its impedance characteristic, the simulation results further prove that the composite triangle dipoles antenna has stable input impedance between 0.15 GHz and 2.0 GHz (resistance = 150 Omega, reactance = 0 Omega) and has wide frequency band.
He received his M Germany and B.S. in Electrical and Electronic Engineering (2009) from BUET, Dhaka, Bangladesh. He worked as a research assistant in the Institute of Electron Devices and Circuits of Ulm University from Currently, he is working as a lecturer in the Electrical and
- Niazul Islam Khan Was Born In
- Jhalakati
Niazul Islam Khan was born in Jhalakati, Bangladesh
in 1987. He received his M.S. in Microelectronics
(2012) from Ulm University, Ulm, Germany and B.S.
in Electrical and Electronic Engineering (2009) from
BUET, Dhaka, Bangladesh. He worked as a research
assistant in the Institute of Electron Devices and
Circuits of Ulm University from May 2010 to March
2012. Currently, he is working as a lecturer in the
Electrical and Electronic Engineering Department of
East West University, Dhaka, Bangladesh. His research interest includes
photonics, optoelectronics and fields and waves. He is a recipient of
Deutschland stipend in 2011.
Restricted space antennas
- W Fair
W. Fair Jr., Restricted space antennas. [Online]. Available:
http://www.comportco.com/~w5alt/antennas/notes/antnotes.php?pg=
21
Practical Antenna Design: 140-150 MHz VHF Transceivers
- E C Latorilla
E. C. Latorilla, Practical Antenna Design: 140-150 MHz VHF
Transceivers, 3 rd ed., Intellin Organization, LLC., 2006.