Elliptical Monopole Antenna Research Articles

PD Flexible Built-In High-Sensitivity Elliptical Monopole Antenna Sensor.

In view of the insufficient signal detection sensitivity of Gas Insulated Switchgear (GIS), partial discharge (PD), ultra-high frequency (UHF), and failure to conform with GIS surface structure when the existing rigid stereo structure UHF sensor is built in, this paper, using rectangular patch antenna equivalent technique, trapezoidal ground plane technique, and coplanar waveguide (CPW) feed line index asymptotic linearization technique, conducts research on a flexible built-in high-sensitivity elliptic monopole antenna. The flexible antenna, with a thickness of only 0.28 mm, can be kept at a voltage standing wave ratio (VSWR) of less than three in the 300 MHz to 3 GHz band under the curvature radius of 0, 100, 300, and 500 mm, and at less than two in the 650 MHz to 3 GHz band. Through the true 220 kV-GIS partial discharge experimental platform built to analyze the high frequency electromagnetic wave detection performance of the built-in flexible antenna, it is shown that the flexible built-in high-sensitivity elliptical monopole antenna designed in this paper can effectively detect the characteristic signals of high-frequency electromagnetic waves emitted by partial discharges with an average discharge amount below 10 pC.

On Design of a Triple Elliptical Super Wideband Antenna for 5G Applications

A novel compact triple elliptical monopole antenna has been designed, analyzed and fabricated for super wideband applications. To enhance the impedance bandwidth, the author proposed a monopole antenna with a triple elliptical patch excited by a 50Ω triangular tapered microstrip feedline. Further improvement is achieved by optimally modifying the Defected Ground Structure (DGS) of the antenna. The proposed patch structure is mounted on a Roger’s RT-Duroid 5880 substrate (ϵ_r= 2.2, tan δ = 0.0009) and has compact physical dimensions of 27 mm × 29.5 mm. The fabricated antenna covers the frequency band from 1.91 GHz to 43.5 GHz for S₁₁ ≤ -10 dB with a fractional bandwidth of >183.17% and has a ratio bandwidth of 22.77:1. This extended bandwidth coverage permits the antenna to operate for wide range of application including 5G and Internet of Things (IoT). The proposed antenna has a very Bandwidth Dimension Ratio (BDR) of 5761.87 which makes it the best candidate for superwideband antenna. Far field measurements disclose an omnidirectional radiation pattern across the frequency of operation. Further, the farfield Radar Cross Section (RCS) is analyzed through simulation and it is to be noted that relatively low values are obtained through out the frequency of operation. In addition, the compactness of the proposed antenna is theoretically verified with the aid of fundamental dimension limit theorem.

Compact UWB‐to‐C band reconfigurable filtenna based on elliptical monopole antenna integrated with bandpass filter for cognitive radio systems

In this study, a compact configuration of frequency reconfigurable filtenna, designed by integrating a bandpass filter and with a monopole radiator, is demonstrated for achieving high-frequency selectivity along with compact size. The proposed filtenna can be efficiently tuned between ultra-wideband (UWB) and C-band states of operation. A bandpass filter, based on rectangular stepped impedance stub loaded multiple-mode resonator (MMR), is embedded to an elliptical monopole radiator to construct the filtenna circuit. The filtenna design approach leaves out the necessity of cascading an additional 50 Ω microstrip feed line in between the antenna and filter elements which makes the system more compact. The designed filtenna occupies 3.6–10.6 GHz band in its UWB state of operation and 3.63–4.70 GHz band in its C-band state of operation, respectively. The UWB operating state is intended for spectrum sensing application whereas the C-band operating state can be implemented for communication in a cognitive radio environment. The shifting between two operating states is controlled by appropriately switching the PIN diodes. An average peak gain of 2 dBi is observed within the passband. The overall size of the filtenna is optimised to 1.35 λ 0 × 0.96 λ 0 × 0.04 λ 0 ( λ 0 is calculated at 6.85 GHz). For validation purpose, the filtenna prototype is fabricated and characterised. A very close agreement is achieved with the suggested configuration.

Compact tri-band T-shaped frequency reconfigurable antenna for cognitive radio applications

This paper presents, new compact tri-band and broadband frequency reconfigurable antenna for cognitive radio applications. The proposed antenna consists of an Ultrawideband sensing antenna and reconfigurable communicating antenna at the same substrate. The sensing antenna is a UWB printed elliptical monopole antenna operates at frequency band from 2.72 to 23.8 GHz which can cover the entire UWB frequency band from 3.1 to 10.6 GHz and cover the broadband up to 20 GHz. The communicating antenna is a T-shaped frequency reconfigurable antenna operates on three bands of 7.925 GHz, 13.16 GHz, and 14.48 GHz under (S11≤-10 dB) with a fractional bandwidth of 14.55%, 6.2%, and 3.3% respectively. The proposed antenna used to operate in two modes one for cognitive radio applications to cover WiMAX, land, Fixed and Mobile satellite, Radar, and broadband applications. The frequency reconfigurability is obtained by using only one RF switch (PIN diode) for changing the operating frequency. The antenna overall dimensions are 42x30x1.6 mm3 printed on an FR-4 epoxy substrate with relative dielectric constant εr=4.3, loss tangent tan (δ)=0.002 and 50Ω microstrip line feed. The maximum obtained simulated gain is 8.5 dB at 13.16 GHz. The S11 is under -20 dB and coupling between the two antennas is less than -15 dB at the resonant frequencies.

Wide to multiband elliptical monopole reconfigurable antenna for multimode systems applications

Wideband-multiband reconfigurable elliptical monopole antenna is investigated in this paper. By having conventional elliptical monopole antenna, wideband operating frequency is obtained. With the combination of dual pairs of slotted arms and a band-pass filter on the ground plane of the elliptical monopole, multiband is achieved. Dual-band operating frequencies at 1.6 GHz and 2.6 GHz while wideband operates from 3.35 GHz to 9 GHz. Therefore, wide range of wireless communication systems is obtained from the proposed antenna to support the multiband mode (i.e. GPS and LTE) and UWB systems. Frequency reconfigurable is achieved by controlling the switches integrated on the antenna structure. Simulated results of reflection coefficient, radiation patterns and gain performance are presented. The proposed antenna design is suitable candidate for different wireless communication applications.

Computer simulation and physical phantom models for estimating the dielectric properties of rhinoceros tissue.

In vivo and ex vivo sensors have the potential to aid tracking and anti-poaching endeavours and provide new insights into rhinoceros physiology and environment. However, the propagation of electromagnetic signals in rhinoceros tissue is currently not known. We present simulation and agar models of the rhinoceros that allow the investigation of electromagnetic propagation by in vivo and ex vivo devices without the need for surgery. Since the dielectric properties of rhinoceros tissue have not been documented, the conductivity and permittivity of the skin, fat, muscle, blood and other organs are first approximated by means of a meta-analysis that includes animals with similar physical properties. Subsequently, we develop anatomical models that include dermal layers, internal organs and a skeleton. We also develop a flank model that serves as an approximation of the anatomical model in certain situations. These models are used to determine the viability of communication between an in vivo device and an ex vivo device attached to the hind leg of the animal. Two types of antenna (microstrip-fed planar elliptical monopole antenna and printed inverted-F antenna) and three feasible implant locations (back, neck and chest) are considered. In addition to the computer models, phantom recipes using salt, sugar and agar are developed to match the dielectric properties of each tissue type at the industrial, scientific and medical (ISM) frequencies of 403MHz, 910MHz and 2.4GHz. The average error between the measured and theoretically predicted dielectric values was 6.22% over all recipes and 4.49% for the 2.4 GHz recipe specifically. When considering the predicted efficiency of the transmitting and receiving antennas, an agreement of 67.38% was demonstrated between the computer simulations and laboratory measurements using the agar rhinoceros flank models. Computer simulations using the anatomical model of the rhinoceros indicate that the chest is the optimal implant location and that best signal propagation is achieved using the planar inverted-F antenna (PIFA). Using this configuration, the simulations indicate that communication between the implant and an ex vivo device attached to the hind leg is challenging but possible. Furthermore, we find that the inclusion of factors such as the density and temperature of the phantom materials were found to be critical to the achievement of good agreement between practice and simulation.

Shared‐aperture dual‐band orthogonally polarised antenna array for L‐band and S‐band applications

In this work, a novel dual-band orthogonally polarised, the shared-aperture array is proposed for the L-band and S-band frequencies. An elliptical monopole antenna is used as a radiating element in the proposed array. In this design, the common inter-element spacing is used for both the bands. Owing to this, L- and S-band arrays have the same number of elements. The L-band radiators are closely placed and designed taking the mutual coupling into account. The S-band antenna follows the traditional array design process. The inter-band coupling is reduced by using a metallic ridge in the reflector of the array. This array can be used in the dual-band radar applications. The proposed methodology offers the modular, low-profile and low-cost solution for a large array. To verify the proposed concept, a prototype array of 4 × 4 elements for each band has been fabricated and tested.

A compact cognitive radio UWB/reconfigurable antenna system with controllable communicating antenna bandwidth

ABSTRACTA low profile and compact size cognitive radio (CR) sensing/communicating antenna system is presented in this paper. A slotted elliptical monopole antenna is proposed as an ultra-wideband sensing antenna for the CR system, while the CR communication relies on a triangular reconfigurable monopole antenna. Two PIN diodes are attached to the reconfigurable antenna to provide four different wideband CR communications with variable bandwidths. The simulation and measured results are in good agreement, and they demonstrate that both antennas have an omnidirectional radiation pattern with acceptable gain values compatible with the portable CR devices. In addition, the results show low mutual coupling between the sensing antenna and the communicating antenna that reaches to values less than −16 dB for all operational modes of the PIN diodes.

A Compact Dual Band Gap Electromagnetic Band Gap Structure

In this communication, compact dual-bandgap two via double-slot-type electromagnetic bandgap (TVDS-EBG) structure is presented. The analysis of the TVDS-EBG structure is done by using the $LC$ model. Two resonance parallel $LC$ circuits per unit cell result dual-bandgap in the $x$ - and $y$ -directions. Compactness is achieved because of two via per unit cell, square slot, and inverse C-type slot on an EBG patch. The simulation of the unit cell TVDS-EBG is carried out using an eigenmode solution of Ansys high-frequency structure simulator. Simulated results are validated by experimental results. Simulated and experimental results prove that compared with a two-layer edge located via interdigital-EBG, edge located via-EBG, and Minkowski EBG, TVDS-EBG gives size reduction of 20.48%, 29.03%, and 31.25%, respectively, with a simple structure. The application of the proposed dual-bandgap TVDS-EBG for ultrawideband monopole antenna is also demonstrated. Simulated and measured results show that dual-band-notched can be obtained by using a unit cell of TVDS-EBG at fed line of an elliptical monopole antenna.

A frequency-reconfigurable elliptical monopole antenna for cognitive radio networks

In this paper, an elliptical disk monopole antenna with seven switchable states, including an ultrawideband (UWB) state and six narrowband states, is presented. It consists of an elliptical disk radiator to operate in the UWB mode for cognitive radio (CR) sensing. To operate in the narrowband mode, the antenna is fed through a defected ground structure (DGS) integrated microstrip line. Frequency reconfigurability is achieved by changing the DGS slot length using six electronic switches. The simple proposed design can cover a wide range of frequency bands from 0.75 to 12 GHz, has an omnidirectional radiation pattern with high gain, and is especially suitable as a CR front-end. The fabricated prototype shows good impedance matching in the specified frequency range.

A Wideband Printed Elliptical Monopole Antenna for Circular Polarization

A Wideband Printed Elliptical Monopole Antenna for Circular Polarization

Dual-Band Elliptical Planar Conductive Polymer Antenna Printed on a Flexible Substrate

In this communication, a fully organic dual-band antenna is presented. It consists of a coplanar waveguide coupled to an elliptical monopole antenna designed on a kapton substrate. This antenna is fabricated from a process, based on the use of a conductive polymer (Polyaniline) doped with multiwall carbon nanotubes, that has been optimized for this application. The flexibility of both kapton substrate and doped conductive polymer gives the antenna the ability to be freely crumpled paving the way to body-worn high data rate communications at microwave frequencies. Applications in wireless networks can also be addressed by using this kind of antennas. In this study, a comparison between the performance of an antenna under bending conditions (using a three-dimensional support) and its uncrumpled version is presented. We evaluate the crumpling effect on the resonant frequency, the bandwidth and the radiation patterns. A good agreement is observed between measurements and simulations data, even when the antenna is crumpled.

Analysis of Ultra-Wideband Elliptical Monopole with Modified Ground for Applications in Radiometric Measurements

Elliptical monopole antennas are commonly proposed in the literature especially for their ultra-wideband performance. In this work an elliptical monopole is studied with regard to the ellipticity ratio lower bound and a simplified formula for the major axis length is derived for maintaining wideband performance. The monopole is intended for black body radiometric (passive) measurements in the 1-5 GHz band so a number of conditions have to be met. Modifications to the ground plane were explored in order to minimize the total dimensions of the structure to fit in the front end of a microwave radiometer probe and enhance the performance in the lower frequencies of the band of interest. The antenna is intended for measurements in close proximity so the near field behavior of the structure is studied. The measured VSWR of the proposed structure is in good agreement with the simulated values.

A planar ultrawideband elliptical monopole antenna with reflector for breast microwave imaging

A printed elliptical monopole antenna operating at 1–4 GHz frequency for biomedical imaging applications is presented in this article. To reduce the reflection of the microwave signal from breast, glycerin is used as the coupling medium (εr = 9, σ = 0.4 S/m, tan δ = 0.28) whose electrical properties are close to those of breast tissue. Directional patterns and reduced back radiations are achieved using a reflector. The antenna has wide impedance bandwidth from 1 GHz to over 6 GHz (over 140%), suitable for radar-based imaging. The antenna demonstrates S21 > −60 dB from 1 to 4 GHz in the coupling medium. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:808–813, 2014

Slot cut printed elliptical UWB monopole antenna

ABSTRACTA novel compact ultra‐wideband slot cut elliptical printed monopole antenna is proposed. The measured bandwidth (BW) from 1.6 GHz to more than 22 GHz (>170%) has been obtained. The gain, radiation efficiency and radiation patterns, over the entire BW, remain similar to that of a printed elliptical monopole antenna with reasonable agreement between simulated and measured results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:631–635, 2014

Triple band-notched UWB monopole antenna with two resonator structures

We propose a novel configuration of a triple band-notched ultra-wideband (UWB) antenna. The designed structure is based on an elliptical monopole antenna combined with a complementary split ring resonator (CSRR) structure and a spiral resonator. The spiral resonator can achieve the dual-band notched performance at WiMAX band and ITU 8 GHz by adjusting the length and width of a spiral line. Besides, the CSRR can obtain the notched band at WLAN 5 GHz by changing the radius of a ring slot. The designed antenna shows that a VSWR of less than 2 was satisfied with a resonant frequency in the range of 1.34–11.4 GHz with a 78.96%, except for triple notched bands. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:4–6, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27275

TUNABLE FILTENNA USING VARACTOR TUNED RINGS FED WITH AN ULTRA WIDEBAND ANTENNA

A tunable flltering antenna (flltenna) realized using rings fed with an ultra-wideband (UWB) planar, elliptical monopole antenna is proposed. An array of slotted rings with varactors is placed in close proximity of the planar monopole to obtain the low proflle tunable flltenna. The array of rings can be viewed as a small tunable frequency selective surface. The design produces a tuning range of about 3.8{ 4.4GHz over a varactor reverse bias voltage of 1{4V.

A broadband antenna using the modified ground plane with a complementary split ring resonator for 5‐GHz WLAN band‐notched performance

AbstractIn this article, a new configuration of a broadband antenna is proposed.The designed antenna is an elliptical monopole antenna with a complementary split ring resonator structure that is inserted in the ground plane for rejecting the 5‐GHz WLAN band (5.15–5.35 and 5.725–5.825 GHz). In addition, impedance matching technique implemented by rectangular slot applied to the ground plane is suggested. The technique can be an effective method to achieve the wider bandwidth. The designed antenna shows that a VSWR less than 2 was satisfied with a resonant frequency in the range of 2.67–12 GHz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:6–3, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26512

Novel band-notched ultra-wideband elliptical monopole antenna with dual radiating elements

A novel ultra-wideband design of planar elliptical monopole antenna with dual radiating elements is presented. The proposed antenna consists of two elliptical radiating elements and a ground plane. The antenna has a super-wideband from 2.8 to 15 GHz for voltage standing wave ratio less than 2, except the notched band at 4.8–5.9 GHz for filtering the wireless local area network signal. Based on the contribution of the shorting position d to the notch bandwidth, a particular notch-band range can be designed by adjusting the size of the minor elliptical radiating element. The radiation pattern of the proposed antenna in the yz-plane is omni-directional. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1427–1430, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26023

A Printed Elliptical Monopole Antenna With Modified Feeding Structure for Bandwidth Enhancement

A printed extremely wideband antenna is studied and results presented. The proposed antenna is composed of a trapezoid ground plane and an elliptical monopole patch which is fed by a modified tapered CPW line. The simulated and measured results agree well and it indicates the antenna has a measured impedance bandwidth from 1.02 GHz to 24.1 GHz with a VSWR ≤ 2. It is shown that the antenna radiation pattern is nearly omni-directional over the entire frequency band and the antenna is suitable for wireless communication applications.