China
Africa
Explore chapters and articles related to this topic
Polymer Composites for Stealth Technology
Published in Anandhan Srinivasan, Selvakumar Murugesan, Arunjunai Raj Mahendran, Progress in Polymer Research for Biomedical, Energy and Specialty Applications, 2023
Deepthi Anna David, Vidhukrishnan Naiker, Jabeen M. J. Fatima, Thomas George, Pritam V. Dhawale, Mrudul Vijay Supekar, P. M. Sabura Begum, Vijay Kumar Thakur, Prasanth Raghavan
Stealth technology which is the low observable technology (LO technology), is a subfield of military tactics as well as the passive and active electronic countermeasures that encompasses a variety of techniques to conceal (invisible or less visible) troops, ships, submarines, planes, missiles, ground vehicles, and satellites from detection by radar, sonar, infrared, and other means. Camouflage, or the ability to blend an object's appearance into the visual background, was the earliest use of this notion. Using the detection technology like radar, sonar, surface-to-air missiles, and others have become more powerful, and thus, the amount to which ground vehicles, aircrafts, and ships have been affected in reaction has risen. Chemicals or high dielectric materials were used on the military uniforms to diminish the impact of their infrared signature. However, the contemporary stealth vehicle is built to have selective spectral signature or treating the surface of the aircraft with materials or construct the aircraft with the right selection of materials which could absorb the radar signals. Predominantly there are two methods for making vehicles invisible to radar.The aircraft can be designed in such a way that the electromagnetic radiations it emits are deflected away from the radar systems.Materials that absorb radar signals can be used to cover the aircraft, which is simply called radar absorbing materials (RAMs).
Latest Trends in the Field of Printed Antennas
Published in Binod Kumar Kanaujia, Surendra Kumar Gupta, Jugul Kishor, Deepak Gangwar, Printed Antennas, 2020
Radar cross section (RCS) is one of the important parameters in stealth technology which is widely used in military applications. That is why a low value of RCS is necessary in the case of antenna designing. In early days, the reduction in RCS was obtained by conventional methods such the use of ferrite substrate [47], radar-absorbing materials [48] and resistive loads [49]. In the case of RCS reduction in antennas, researchers have to face two major challenges: (i) the reduction in RCS in the complete frequency band and (ii) maintaining the radiation property and reflection coefficient properties of the radiator after making the modifications to the reference antenna. RCS highly depends on the incident angle of EM wave, so maintaining the RCS reduction approximately constant over a wide range of incident angles is another challenge in this field. The use of frequency-selective surface (FSS) is a very effective tool for reducing the RCS value along with maintaining the radiation property and reflection coefficient properties. Boundary conditions on a FSS structure are given as follows [50]: E→inc+E→scat=ZsI^s
Investigation in reduction of radar cross section due to plasma release from target in active stealth technology
Published in Arun Kumar Sinha, John Pradeep Darsy, Computer-Aided Developments: Electronics and Communication, 2019
Swathi Nambari, Sasibhushana Rao Gottapu, Kolluri Sri Ranga Rao
With the advancement of technology, wars are being fought without human presence, and can utilize weapons that can be launched by aircrafts, ships, Unmanned Aerial Vehicles (UAV), and so forth. These objects, to accomplish their targets, should not be recognized by enemy radars which may result in launching counter measures. To avoid the detection by enemy radars various technologies are being developed. Stealth technology is one such important technology which is significant in making an object undetectable to enemy radar and it is a low observable technology. Accomplishing stealth features requires decreasing active and passive signatures of the target. Changing these signatures can enhance the survivability of defense systems. In Stealth technology, numerous signatures are to be overseen for an object, in which most Radar systems utilize radar cross section (RCS) for segregating targets and characterizing them as Stealth.
UHMWPE textiles and composites
Published in Textile Progress, 2022
Ashraf Nawaz Khan, Mohit Gupta, Puneet Mahajan, Apurba Das, R. Alagirusamy
Another application is in the field of radar absorbing structure (RAS). The radome is a protective cover for a radar (radio detection and ranging) antenna and the materials; used in its manufacture need to possess good mechanical properties and a low dielectric constant. However, the RAS itself needs to be made of the same kind of material but having high electro-conductive properties to improve electromagnetic wave absorption characteristics, so nano-conductive particles are incorporated into the UHMWPE fabric to protect the RAS against external loads. Consequently, with advancements in modern radar systems, stealth technology requires further improvements to minimise detectability. Given that the detectable distance of the radar is directly proportional to the radar cross-section (RCS) (Lee, Choi, & Lee, 2015). The RCS can be reduced in different ways such as those used in the low-observable design based on a combination of stealth shaping, radar-absorbing material (RAM), and a radar-absorbing structure (RAS) (as shown in Figure 110).
An ultrathin and broadband radar absorber using metamaterials
Published in Waves in Random and Complex Media, 2021
Bi Cheng Zhou, Dong Hong Wang, Jiang Jiang Ma, Bao Yi Li, Ya Juan Zhao, Ke Xun Li
In summary, we designed and fabricated an ultrathin and broadband metamaterial-based microwave absorber. The simulation results show that the broadband MMA exhibits almost completely above 90% absorption in the frequency range 11.07–23.36 GHz for normal incidence. The absorption characteristics of this absorber can be tuned and shifted to our interested frequency range by means of adjusting the scale of the unit. We further studied electromagnetic field distributions and surface currents which will illustrate the mechanism of microwave absorption in the desired range of frequencies. The proposed absorber has been studied and experimentally verified for different oblique angles and for different angles of polarization. The simulation results are basically consistent with the experimental verification. Therefore, the proposed absorber has potential applications to reduce radar cross section (RCS) in stealth technology.
Development of a composite EM wave absorber for the leading edge of low observable aircraft
Published in Advanced Composite Materials, 2019
Won-Jun Lee, Sang-Min Baek, Young-Sik Joo
However, an anti-stealth radar system, such as a bi-static radar, attempts to determine the intentionally reflected EM waves of the stealthy aircraft. The bi-static radar separates the transmitting and receiving antenna to defeat ‘stealth shaping technology.’ Thus, the material and structure with EM wave-absorbing characteristics to suppress the wave reflection becomes the key to stealth technology.