China
Africa
Explore chapters and articles related to this topic
Introduction to Microelectromechanical Systems
Published in Shiban Kishen Koul, Sukomal Dey, Radio Frequency Micromachined Switches, Switching Networks, and Phase Shifters, 2019
Shiban Kishen Koul, Sukomal Dey
Electronic beam steering is a primary issue in modern phased arrays systems and is extensively used in military and commercial applications such as wireless communications and radar systems. Many studies and experiments have been performed on the electronic beam steering principle. The most popular and useful method is to use phase shifters in combination with an antenna array [44,45], as shown in Figure 1.12. The method of beam steering is broadly classified as time delay, frequency scanning and phase scanning. The phase shifters produce phase shifts between the elements of an antenna array and can steer the beam to the desired direction. Phase shifters are very critical and essential components in the beam steering, because they are the general devices used in phased arrays and they account for nearly half of the cost of an entire electronically scanned phased array.
Optical micro-electrical-mechanical phased array
Published in Guangya Zhou, Chengkuo Lee, Optical MEMS, Nanophotonics, and Their Applications, 2017
The beam steering and stabilization features, while very critical to many electro-optical systems, are still very much limited in performance. Systems in these related optical applications are restricted by the nature of mechanical beam steering and the stabilization that comes with it. Mechanical beam steering suffers from a lack of rapid pointing ability, requires high mechanical complexity, and demands higher cost, while having a lower reliability. Therefore, it is desirable for nonmechanical approaches to increase the pointing speed, provide random access pointing, decrease system complexity, increase overall reliability, and reduce costs. Optical phased arrays (OPAs) have generated a growing interest in many application areas regarding beam forming and beam steering [1]. Applications of OPAs range from 3D displays, printing, optical data-storage, and telecommunication to military and other industrial applications. Specifically among them, light detection and ranging (LIDAR) is a key enabling technology for target detection, surveying and mapping, self-driving cars, and other autonomous vehicles [2].
Photonic Integrations of Near-Infrared Indoor Optical Wireless Communications
Published in Ke Wang, Indoor Infrared Optical Wireless Communications, 2019
As discussed above, the beam steering device allows the dynamic tuning of light propagation direction in the free space according to practical requirements, and hence, it is highly demanded in high-speed indoor OWC systems. A number of technologies have been studied to realize beam steering devices, and they mainly include the micro-electromechanical system (MEMS), the liquid crystal and the optical phased array principles. We will review the MEMS- and the liquid crystal-based schemes in this section, and introduce the optical phased array principle in the next section.
A Brief Review on mm-Wave Antennas for 5G and Beyond Applications
Published in IETE Technical Review, 2023
Paikhomba Loktongbam, Debasish Pal, A. K. Bandyopadhyay, Chaitali Koley
To increase the gain, different gain enhancement techniques are used. These special techniques for gain enhancement include the usage of a parabolic hole [138] in the substrate, usage of superstrate [139,140] usage of AMC (Artificial magnetic conductor) [141–143], usage of EBG (Electronic bandgap structures) [144,145] etc. The MEMS (Micro Electromechanical system) based antennas, co-designed with CMOS, have the advantages of flexibility and re-configurability compared to conventional mm-wave on-chip antennas. These antennas are particularly useful in those applications where beam steering is a must. Beam steering needs an antenna array whose elements are switched electronically with a pre-determined phase shift pattern. MEMS-based switches are used with MEMS-based mm-wave antennas. These combinations are then co-designed with CMOS for an easy interface. Some critical challenges remain as open problems like parasitic coupling, placement of on-chip inductors, ESD (electrostatic discharge), etc. Therefore, this area is still very much open for high-end research. Table 6 enlist quite a few papers developed for the antenna on-chip applications.
Low-profile electronic beam-scanning metasurface antenna for Ka-band applications
Published in Waves in Random and Complex Media, 2023
Aqeel Hussain Naqvi, Sungjoon Lim
Multi-functional antennas have become increasingly popular due to the advent of next-generation communication technology and growing demands for wireless communication systems. Beam-steering has been implemented in various next-generation communication systems, including autonomous vehicle scanning systems, radars, drone tracking, and satellite communication (SATCOM). European Space Agency (ESA) designated 27.5–31 GHz as the frequency band for SATCOM (civil and military) applications. Electromagnetic (EM) waves have traditionally been controlled by combining complex phase shifters and bulky cascading activators. Metamaterials have enabled many exotic developments, including invisibility cloaks [1], lenses [2], and perfect absorbers [3]. Two-dimensional metamaterial counterparts have been extensively studied for their powerful ability to manipulate EM waves due to low profile, low cost, high integration and easy fabrication [4,5], metasurfaces. Consequently, many potential applications have received significant interest in recent years.
Design and development of T-Shaped antenna structure for wireless communication
Published in Waves in Random and Complex Media, 2022
A single element is used to start the design of a 1X2 phased array elliptical inverted T-shaped slotted sectored patch antenna, and beam steering is added. The stubs and slots create multiband and wide-bandwidth elements in a single element. An elliptical-shaped aperture beyond the radiating patch, as well as stubs and DGS, increase the antenna bandwidth. The phased array allows the antenna to have high gain and beam-steering capabilities. The antenna array's dimensions are intended to fit inside any current small smartphone. The suggested antenna is built on an FR4 substrate with a dielectric constant of 4.2 and a thickness of 0.0058 mm. The DGS is double bracket-shaped slots etched in the ground to change the current distribution. Antenna design, simulation, optimization, and analytical assessments are performed using the CST Studio Suite. The goal is to disrupt the present distribution on the stubs of a radiating patch linked to the DGS ring slot through an indirect connection. The antenna impedance qualities are controlled by various design factors such as slot width, ring diameter, split ring percentage, and slot placement.