China
Africa
Explore chapters and articles related to this topic
Multiband MIMO antennas
Published in Yadwinder Kumar, Shrivishal Tripathi, Balwinder Raj, Multifunctional MIMO Antennas, 2022
Harsh Verdhan Singh, D. Venkata Siva Prasad, Shrivishal Tripathi
Parasitic elements or etched slit antennas produce dual orthogonal modes by coupling in the ground plane and/or radiating patch, creating a wideband [33]. This technique utilizes supplementary coupling paths to improve isolation among the antenna elements [34, 35]. The dual coupling paths prevent the arriving signal from one element to another, which affects an enhancement in the decoupling level. The decoupling modules, such as the folded shorting strip meandered slot and the vertical parasitic strip, are known as parasitic elements and are obliquely connected [36–38]. The significant advantages of the parasitic or slot antenna are size, easy implementation, and an accessible design process involving the application of waveguides and/or printed circuit board technology. However, the location of the parasitic elements has to be precise, and it is not straightforward.
Integral Equation of Leontovich
Published in Boris Levin, Antennas, 2021
An ideal slot antenna is a slot cut in an infinitely large, ideally conducting, infinitely thin plane. The calculation of such antennas is performed using the duality principle [39]. In accordance with this principle, a slot antenna is a practical embodiment of a magnetic radiator, and the characteristics of a slot antenna can be determined based on the analogy between an electric and a magnetic radiator, if the characteristics of a metal (electric) radiator of similar size and shape are known. As shown in [40], if the slot is cut in a non-planar metal screen, the integral equation for voltage U between the edges of the slot coincides in appearance with the equation for current in an equivalent metal antenna of analogous shape and dimensions. However, the operator G(U), coming into this equation, which is linear with respect to U, depends on the shape of the screen, i.e., in a general case, it differs from the operator G(J) for a rectilinear metal antenna located in free space. Therefore, the question of the electrical characteristics of the slots cut in non-flat screens of different shape remains open.
Pattern Diversity Antennas for Base Stations
Published in Shiban Kishen Koul, G. S. Karthikeya, Millimetre Wave Antennas for 5G Mobile Terminals and Base Stations, 2020
Shiban Kishen Koul, G. S. Karthikeya
The concept of path loss compensation is introduced in this chapter, and two distinct pattern diversity architectures are presented in detail. First, a mmWave tapered slot antenna is introduced, which is integrated with metamaterial unit cells along with dielectric loading. In order to increase gain and its corresponding aperture efficiency, a stacked pattern diversity module is presented to achieve uniform illumination on the ground. Second, spatially modulated sub-wavelength metamaterial unit cells are investigated, which act as phase correcting elements that increase the gain yield for a minimal occupied volume, and the antenna element is used in a co-polarized stacked topology to achieve path loss compensation. The proposed antennas are deployed in a real-world scenario to study the received power profile on the ground illustrating the concepts introduced. The second design illustration is using 3D printed radome, and the third design is a progressive offset metamaterial integrated high aperture efficiency antenna presented along with its corresponding stacked pattern diversity module.
Compact Slotted Microstrip Antenna for 5G Applications Operating at 28 GHz
Published in IETE Journal of Research, 2022
P. Merlin Teresa, G. Umamaheswari
Microstrip patch antenna consists of a thin radiating surface mounted on one side of the dielectric substrate and ground plane on the other side. The most commonly employed microstrip antenna is a rectangular patch which looks like a truncated microstrip transmission line. It is approximately of one-half wavelength long [4]. A dielectric substrate is used in antenna designing, the length of the antenna decreases as the relative dielectric constant of the substrate increases. With the development wireless communication field has been demanded more compact size devices that can fabricate more integrated circuit within short space. Due to this, antenna designers are paying more attention on microstrip patch antenna for its several benefits such as compact size, low profile, high reliability, low cost, etc. With such benefits, microstrip patch antenna (MPA) has demerits too. Lower bandwidth is the major disadvantage. Due to these, antenna designers are paying more focus in designing compact size broadband antenna. The various bandwidth enhancement of MPA is slot configuration, multiple radiating element, parasitic patch, multiple feeding, and proximity couple. The applications of the slot antenna are used in broad range of applications from wireless and satellite communication system to medical system. Bandwidth is the major parameter which increases the user occupancy by adding more number of slots the bandwidth can be enhanced.
Cross-Polarization reduction of wideband slot antennas in planar printed configuration
Published in Electromagnetics, 2022
Khan Masood Parvez, SK Moinul Haque
We can find very few literatures where cross-polarization reduction and bandwidth enhancement have been addressed simultaneously. The modern antenna configurations are extensively described by Milligan (2005). Miniaturization and bandwidth enhancement techniques of slot antennas are purported in the literatures of Azadegan and Sarabandi (2007), Ghosh, Haque, and Mitra (2011) and Haque and Parvez (2017). The wide band slot antennas are illustrated by Wang and Chang (2008) and Sze and Wong (2001). It was shown that the metamaterial loading (Chen et al. 2018) can improve the bandwidth and gain of an L-shaped slot antenna. Wide band and cross-polarization suppression methods for slot antennas (Chen et al. 2017; Parvez and Haque 2021) and microstrip antennas (Kumar and Guha 2016; Kumar, Pasha, and Guha 2016; Liu et al. 2018) are illustrated. Often, it had been found that to achieve higher bandwidth, other antenna parameters such as cross-polarization increases and vice-versa.
A multibeam slot antenna using dual-layer metasurface
Published in Electromagnetics, 2021
Tingting Fan, Xinwei Chen, Guorui Han, Liping Han, Yufeng Liu, Wenmei Zhang
To widen the impedance bandwidth of the antenna, rectangular loop slots are employed as coupling apertures. Considering that the antenna is rotationally symmetric, it has same S-parameters when the four input ports are excited individually. In this part, we analyze performance of antenna by taking the port 1 as an example. Figure 2 plots the corresponding S11 and input impedance. For comparison, the results with rectangular slot (length 30 mm, width 13 mm) are also provided. In case of rectangular slot, antenna has a narrow impedance bandwidth from 3.35 to 3.85 GHz (500 MHz), as displayed in Figure 2a. However, when the rectangular loop slot is adopted, a wider impedance bandwidth of 2.14–3.54 GHz (1.40 GHz) is achieved. The mechanism why the loop slot can help to improve the bandwidth can be expounded by input impedance shown in Figure 2b. With regard to the antenna with rectangular slot, only around 3.6 GHz, input impedance approximates to (50 + j0) Ω. By introducing the rectangular loop slot, the input reactance is reduced, and the corresponding range expands to 2.14–3.54 GHz due to the enhancement of coupling. As a result, the bandwidth of the antenna is widened to 1.40 GHz.