Figure - available from: IET Microwaves, Antennas & Propagation
This content is subject to copyright. Terms and conditions apply.
Simulated and measured normalised radiation patterns of the proposed wideband low profile log‐periodic array (a) 2 GHz, (b) 4 GHz, (c) 6 GHz, (d) 8 GHz
Source publication
A novel low profile log‐periodic array with vertically polarised end‐fire radiation patterns is proposed in this study. It totally consists of 22 antenna elements with three different types of monopole antennas. Specifically, conventional monopoles were utilised at the high end band, while monopoles with different types of top‐hat loadings were des...
Similar publications
A phase‐shifted circularly polarised ring microstrip antenna (PS‐CP‐RMSA), which can switch between three different phases, is proposed. The phase of a circularly polarised antenna can be shifted by changing the angle of rotation. Taking advantage of this property, the proposed PS‐CP‐RMSA comprises a circularly polarised ring microstrip antenna (CP...
In this paper we present a shared-aperture polarisation reconfigurable microstrip array designed to resonate at 11.5 GHz with a gain bandwidth of 2 GHz (~17%). The polarisation reconfigurability (both linear and circular) is achieved using two orthogonal and independently-fed sub-arrays that are intertwined together on the same aperture. Each subar...
In this paper, a mode and circular-polarization (CP) simultaneously reconfigurable patch array antenna for orbital angular momentum (OAM) beams generation is presented and experimentally investigated. The array antenna simply consists of a 1:4 power divider and four antenna elements, each of which is fed with two switchable ports and a quadrature p...
This work presents a unidirectional, co-circularly polarized (CP), printed antenna with highly decoupled or isolated transmit (T
<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub>
) and receive (R
<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub...
In this paper we present a shared-aperture polarisation reconfigurable microstrip array designed to resonate at 11.5 GHz with a gain bandwidth of 2 GHz (~17%). The polarisation reconfigurability (both linear and circular) is achieved using two orthogonal and independently-fed sub-arrays that are intertwined together on the same aperture. Each subar...
Citations
... Attempts at lumped element loading by using inductive or capacitive loads have already been made in a number of works, even for slot-antenna radar applications, as in Zhao et al. (2018). Most relevant to ours Sheng and Chen (2019) and Liang and Wu (2018), used an inductance to suppress such undesired modes but in a 2-dipole configuration, while He et al. (2019) using a capacitive load aimed mostly at improving the reflection coefficient of the designed antenna. The choice of an RLC load as a bandstop circuit in this work is made both for simplicity of design as well as for practical reasons relating to phase stability. ...
Log‐Periodic Dipole Antennas have been known to provide good performance over large fractional bandwidths. However, optimized designs of log‐periodic antennas, in particular for radioastronomy and remote sensing, need to tackle the spurious radiation of secondary dipole harmonics that can compromise the gain smoothness and therefore the ability to detect natural spectral features emitted by the probed sources. A new, low‐cost method applicable also at a post‐design stage is proposed in this paper, which relies on loading some of the dipoles with appropriate lumped circuit elements in order to avoid this unwanted feature while preserving the desired performance characteristics. Application is found on the log‐periodic dipole antenna selected for the low‐frequency instrument of the SKA (Square Kilometer Array), and general guidelines are described for other designs. An experimental test using a transmitting VHF antenna and the antenna under test with new RLC loaded dipoles confirms our solution.
This article is protected by copyright. All rights reserved.
... In recent years, it is popular in the design of wideband flushmounted endfire antenna owing to its wide applications in the aircraft, missile, and unmanned aerial vehicles. Many novel designs also have been proposed based on these metal platform [1][2][3][4][5][6][7][8][9][10][11]. However, comparing with the horizontally polarized endfire antenna [1], the vertically polarized endfire antenna has drawn extensive attention due to its integrating design with metal platform directly. ...
... The antenna shows an extremely wide bandwidth from 2 to 18 GHz, and a low profile of 0.053λ L . On this basis, a capacitor-loaded hat is proposed to realize a very narrow transverse physical dimension [5]. Surface wave antenna is a good candidate to satisfy the requirements of low-profile, wideband and endfire pattern. ...
... It is observed that our proposed antenna has a smallest longitudinal dimension, while keeping a low profile, broad bandwidth, and high gain. The antennas in [4] and [5], based on folded top-hat monopole array, have large longitudinal dimension and small peak gain though its bandwidth is more than 160% and keeps low profile. Compared with the endfire surface wave antenna [7] which has a broad bandwidth, the proposed antenna shows higher peak gain and smaller longitudinal dimension. ...
In this paper, a metasurfing (MS) concept is demonstrated and applied in the design of the low profile and wideband endfire antenna on metallic surface environments. The MS comprises an array of varying patch printed on homogeneous host medium, and fed by a surface wave launcher (SWL). Each row patch is designed according to the operating wavelength and by altering the surface reactance of the MS the surface-wave mode can be manipulated into the free-space wave mode. Meanwhile, two row of rectangle patches with same size are located on between the surface wave launcher (SWL) and non-uniform MS, which is regarded as an impedance modulation to obtain a good impedance matching. The VSWR of the proposed antenna is below 2.5 from 3.8 GHz to 16.7 GHz in the measured results, which are in good agreement with the simulated results and the thickness of proposed antenna is only 5 mm (0.065kL, kL is the free-space wavelength at the lowest operating frequency). Moreover, a stable end-fire beam and low side lobe level (SLL) is obtained in a wide frequency band, and the group delay and the time-domain result also are shown to prove the good wideband transmission.
In this article, a broadband semicircular antenna array geometry was examined, along with its design and configuration in the submillimeter wave range (9.35-42.89 GHz). The work has been divided into two prime phases; in the first phase of work, an innovative angular-phased 1 : 4 broadband power divider has been presented in which its isolation, insertion, and return losses are investigated. In the next phase, the proposed power divider was used to configure a 4-element antenna array, and its theoretical analysis was carried out. The angular path difference in the array was used to introduce phase difference in between the antenna elements to minimize the mutual coupling and to optimize the narrow beamwidth. Using geometry and fundamental array theory, the array factor of a novel broadband array configuration has been derived and analytically investigated.
A broadband, unidirectional, phased array is proposed. Single antenna element of the prototyped array is a broadband windmill-like shaped antenna. Four elements of this antenna are fed by a power divider and are configured in a novel semicircular-shaped, angular-phased array. A phase difference of
$\pi $
/4 was introduced by optimizing the angular path difference among four antenna elements in the array. Total 21.5% of size reduction is achieved by introducing angular-phased array in comparison with the conventional linear-phased array. The array of radius 65 mm is prototyped on the Rogers RO4232 substrate for the operating frequency range 9.35–42.89 GHz. The proposed array configuration can maintain an average gain of 8.54 dB and average radiation efficiency of 69.71% in the entire operating frequency range while exhibiting a peak gain of 11.86 dB. The presented array exhibits highly directional behavior in the endfire direction, with the 3-dB angular beamwidth in the range from 15.1
$^\circ$
to 76.7
$^\circ$
. To the best of the authors’ knowledge, any comparable state-of-art has not been reported yet in the literature that could provide such a large impedance bandwidth in sub-mmWave range. The proposed array may find its applications for future indoor and outdoor short-range communication networks.
A compact fully metallic antenna with high endfire gain and vertical polarization is presented for applications that require the antenna to be mounted on large metallic platforms. The proposed structure includes one driven element on a ground plane, in addition to several parasitic directors and reflectors. The antenna behaves like a Yagi array, but with vertical polarization, where multiple directors and reflectors are used to enhance the endfire gain in the plane that contains the ground surface. The driven element is an upside-down U-shaped metallic strip with short vertical sides connected to the ground plane. The radiation is predominantly emitted from these vertical sides giving the antenna its vertical polarization radiation. Directors and reflectors are designed based on the driven element, with directors having the center of the U-shaped strip connected to the ground plane and reflectors without shorting pins in the middle. A prototype is fabricated with a volume of 104
$\times 55\times $
6 mm
<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>
. The measured bandwidth is 18% (5.32–6.38 GHz). The variation of endfire gain is 2 dB around the nominal gain of 10.3 dBi across the bandwidth.
