Planar Electric Dipole Research Articles

Magnetic-electric dipole circularly polarized antenna with unidirectional radiation pattern with improved characteristics

Abstract In this paper, a compact unidirectional antenna consisting of a planar electric dipole and a shortened connecting element is introduced. This antenna is excited by a Γ-shaped feeding line. A wide impedance bandwidth in the frequency range of 1.3–3.3 GHz is observed in the output performance. Sufficient main lobe and low level back lobe have been introduced as other characteristics of the structure, based on radiation patterns. The antenna design process is evaluated step-by-step and using parametric study based on the antenna geometry. One of the main features of the desired antenna is the realization of circular polarization in a high percentage of the operational bandwidth 1.5–3.3 GHz. The radiation patterns of the orthogonal planes E-field and H-field along with the left-handed and right-handed circular polarization patterns for the desired antenna have been extracted and analyzed. A three-dimensional structure in the form of stacked stepped disks (SSD) is introduced to increase overall performance of antenna. There is an acceptable similarity between the E-field and H-field page patterns, which shows the accuracy of the design process. On the other hand, for studying the circular polarization, left-handed and right-handed patterns based on the main beam direction and orthogonal polarization level have acceptable performance. The maximum overall gain of the antenna in the designed frequency band is near to 13 dB.

A wideband magnetoelectric dipole antenna for 4G/5G communication

AbstractIn this letter, a wideband magnetoelectric (ME) dipole antenna for 4G/5G communication is proposed. The bandwidth of the antenna is greatly enhanced by loading two pairs of metallic circular loops on the planar electric dipole. With the loops, the antenna impedance bandwidth in terms of 10 dB is improved from 48.3% (1.98–3.24 GHz) to 86.8% (1.465–3.71 GHz), that is, 79.7% bandwidth enhancement is achieved. The surface current of the proposed antenna is analyzed in detail. It shows that when the length of the loops approaches half a wavelength, the loops contribute new resonant modes, thereby increasing the impedance bandwidth. A prototype is fabricated and measured. The measured results are in good agreement with the simulated counterparts. Meanwhile, the antenna gain ranges from 7.42 to 12.8 dBi across the operational frequency region. Stable radiation patterns with low crosspolarization levels are obtained in both E‐ and H‐plane.

Design of a compact magneto‐electric dipole antenna

AbstractIn this letter, a compact magneto‐electric (ME) dipole antenna is designed and analyzed without compromising too much good performance of the ME dipole. In particular, the second‐order Minkowski‐like fractal structure is loaded on the planar electric dipole to effectively miniaturize the aperture size of the antenna. A prototype was fabricated and measured. The antenna volume is reduced by 24.6% when compared with the counterpart before the fractal. Meanwhile, the proposed antenna can achieve a bandwidth of 56% in terms of −10 dB ranging from 1.58 to 2.81 GHz. The radiation pattern of E‐ and H‐planes are basically identical. The cross‐polarization level is less than −25 dB, and the front‐to‐back ratio is larger than 14 dB. The maximum antenna gain can be up to 10.1 dBi. The measured results are in good agreement with the simulated ones.

A Coupled-Fed Broadband Dual-Polarized Magnetoelectric Dipole Antenna for WLAN and Sub-6 GHz 5G Communication Applications

This paper presents a novel coupled-fed broadband dual-polarized magnetoelectric dipole antenna for wireless local area network (WLAN) and 5G communication applications. The proposed magnetoelectric dipole antenna is composed of a planar electric dipole and shorting pins as a magnetic dipole to obtain a broad operation frequency band. Two coupled microstrip lines perpendicular to each other are coupled through a cross-shaped slot to excite the vertical and horizontal polarizations. The proposed antenna features a simple structure, high gain, and high polarization isolation. The measured impedance bandwidth of the proposed antenna is 1.8–4.2 GHz (fractional bandwidth of 80%). The measured realized antenna gain value is 3.7–8.5 dBi, and polarization isolation level is 25 dB at the operation frequency band.

Wideband end‐fire circularly polarised complementary source antenna for millimetre‐wave applications

A millimetre-wave end-fire circularly polarised (CP) complementary source antenna is proposed. Circular polarisation is obtained by combining a quarter-wave shorted patch and a planar electric dipole. A direct-feeding method based on the use of substrate integrated coaxial line (SICL) is developed for wideband excitation of the antenna. The antenna element achieves a −10-dB impedance bandwidth of more than 32.4% and a 3-dB AR bandwidth of 30.1% with a stable gain around 5.5 dBic. To demonstrate higher antenna gain, a 1 × 4 CP antenna array fed by an SICL power divider is designed. Measurement of the fabricated prototype verifies that the CP antenna array achieves a gain up to 10.5 dBic. The competitive performances including wide bandwidth, stable gain, and simple planar configuration make the proposed CP antenna attractive for millimetre-wave applications such as the fifth-generation (5G) mobile communications and the next generation WiFi systems.

Bandwidth-Enhanced Low-Profile Magneto-Electric Dipole Antenna With Shorting Parasitic Elements

This paper presents a low-profile magneto-electric (ME) dipole antenna with an enhanced impedance bandwidth realized by the loading of shorting parasitic elements. The antenna contains a horizontal planar electric dipole antenna, a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Gamma $ </tex-math></inline-formula> -shaped shorted patch antenna, a pair of parasitic L-shaped shorted patches, and a direct feed. By loading of the parasitic L-shaped patches such that they are shorted to the ground, the proposed antenna attains a significant bandwidth enhancement while maintaining excellent broadside radiation characteristics. An antenna prototype with a low profile of only <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$0.11\lambda _{0}$ </tex-math></inline-formula> was fabricated and tested ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> is the free-space wavelength referring to the center frequency). The antenna achieves a measured impedance bandwidth of 75.64% (1.34–2.97 GHz) for a voltage standing wave ratio (VSWR) of less than 2. Within the operating band, the measured gain ranges from 6.23 to 8.49 dBi. Additionally, stable radiation patterns on both E- and H-planes with a high front-to-back ratio of more than 20.5 dB are achieved.

HIGH GAIN MAGNETO-ELECTRIC DIPOLE ANTENNA WITH NOVEL FEED DESIGN

A novel high gain unidirectional antenna composed of a planar electric dipole and a shorted patch is designed and discussed. The antenna has been excited by an arrow shaped feed. For the frequency range 1.8 GHz-2.6 GHz, the antenna is able to exhibit peak gain of 11.4 dBi, low back lobe radiations, almost identical E plane and H plane radiation patterns, high directivity of 11.6 dBi and antenna efficiency ≥ 90%. The antenna has a great potential to be used in various wireless communication applications requiring high gain and directivity in S-band.

Miniaturization of Magnetoelectric Dipole Antenna by Using Metamaterial Loading

This communication presents a novel miniaturized magnetoelectric dipole antenna by introducing magnetic metamaterial loading. The proposed antenna, excited by a $\Gamma $ -shaped probe, consists of a planar electric dipole and a quarter-wave shorted patch antenna. To miniaturize the antenna, the metamaterial loading is fully arranged inside the shorted patch antenna and the matching portion of the $\Gamma $ -shaped probe. The loading is formed by a stack of modified rectangular split-ring resonators, which are placed very closely in parallel. With the presence of the metamaterials, the effective permeability of the substrate is increased, and therefore the antenna finds a significant size reduction. Most importantly, the impedance and radiation characteristics of the antenna are not compromised too much. The antenna loaded with metamaterials exhibits an impedance bandwidth of 44% ranging from 1.7 to 2.67 GHz and a boresight gain of about 8.5 dBi. The volume size is reduced by 48% when compared with the original design having an impedance bandwidth of 47%.

A Novel Magneto-Electric dipole antenna for Ku band

In this paper a new kind of Magneto-Electric dipole antenna, composed of a planar electric dipole and a shorted patch has been designed to generate an end-fire radiation pattern in Ku band. The antenna provides a wide impedance bandwidth of 23.9% and peak directivity of 8.7dBi. Antenna also provides low cross polarization level in the entire range of operation. The antenna has a great scope to be used in airborne RADAR applications in Ku band.

60 GHz Plated Through Hole Printed Magneto-Electric Dipole Antenna

A wideband unidirectional antenna, which is composed of a planar electric dipole and a magnetic dipole formed by a vertically-oriented shorted patch antenna, is presented for millimeter wave applications. The antenna is realized by a plated through hole printed technique with the use of a microwave substrate and is excited by a T-shaped coupled strip feed. An impedance bandwidth of 33% (S11 ≤-15 dB) from 50 to 70 GHz is achieved. Stable radiation patterns with low cross polarizations and a stable antenna gain of ~7.5 dBi are achieved across the entire operating bandwidth. This single antenna element yields advantages of wideband, good directional radiation pattern and low fabrication cost.

Imaging of a small dielectric sphere buried in a half space

A MUSIC-type non-iterative, single-frequency imaging method is investigated, in line with recent works by the authors and colleagues on the sub ject. A small dielectric sphere is buried within the lower half of a two-half-space medium and illuminated from the upper one by a planar electric dipole array. Data of the imaging, the Multi-Static Response Matrix (MSR) involving the dyadic Green function of the medium and exploited via singular value decomposition, are either exact or asymptotic ones. Exact ones are computed by the Coupled Dipole Method (CDM). Asymptotic ones account for coupling to the interface via a Polarization Tensor (PT) calculated in closed form in the bispherical coordinate system attached to the (two-body) sphere-interface system. Comparisons between field data and between images of the inclusion inferred from them are discussed. Among other items, the capabilities of localization of the imaging procedure are exhibited. Whenever the inclusion is far enough from the interface, simplifying the PT to the one of an inclusion in free space is shown to be reliable. Use of a leading-order approximation of the Green function to speed up the imaging procedure is also investigated.