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Terahertz paper
65438+1On October 27th, South China Morning Post reported that China National Defense Science and Technology Journal published a paper, reporting that Yao Jianquan team of Tianjin University realized reliable communication under hypersonic flight conditions by using terahertz technology. We know that hypersonic vehicles produce high temperature and ionized gas through air friction during flight, and at the same time produce electromagnetic shielding with air shock wave, thus isolating electromagnetic communication. Terahertz has strong penetration and obstacle avoidance ability, which can ensure the guidance and communication of hypersonic flying objects. So what is terahertz technology? It has the following characteristics:

(1) has wide spectrum resources and rich frequency resources for terahertz high-speed wireless communication. Terahertz electromagnetic wave is between microwave and far infrared, spanning radio waves and light waves in the traditional concept. Its wavelength is about 30 um-3 mm, which is much smaller than that of microwave and millimeter wave, so it can be used to detect smaller targets and locate them more accurately.

(2) It is rich in frequency and has a very wide bandwidth. It can emit nanosecond or picosecond pulses with thousands of frequencies, which greatly exceeds the scope of the existing stealth technology. Therefore, no matter the target of appearance stealth, paint stealth or plasma stealth, it can be "nowhere to hide"

(3) Multi-beam communication has strong communication tracking and capturing ability and flexible control, which provides better tracking and capturing ability for terahertz communication in space networking communication.

(4) Strong anti-jamming/anti-interception capability, good terahertz wave propagation directivity, narrow beam and great detection difficulty; Terahertz signal is difficult to excite and receive, and has better confidentiality and anti-interference ability.

(5) It has strong ability to overcome the communication black barrier in the near space, can effectively penetrate the plasma sheath, and can provide communication means for the measurement and control of high-speed aircraft in the near space.

From the above description, terahertz technology can also be anti-stealth. Stealth generally refers to coating a layer on the surface to absorb or scatter radar waves, which can greatly reduce the probability of being found and achieve the purpose of stealth. Therefore, stealth technology usually relies on shape, absorbing coating and forming plasma cloud to absorb or change the propagation direction of radar waves to achieve stealth. The anti-stealth principle of terahertz technology should be similar to that of infrared tracking and aiming system, and the target is found mainly by receiving the reflected signal of the target. Therefore, the coating, shape and plasma layer used for stealth purposes are ineffective for it. Therefore, it is almost ineffective for the next generation fighter to install terahertz radar.

Terahertz technology can not only be used for hypersonic guidance, communication and anti-stealth of the next generation fighter, but also be the core technology of the next generation high-speed wireless communication. Terahertz technology can reach hundreds of Gbps, and the current 5G is only about 20Gbps. Think about how fast it will be. American "Star Chain" plans to use terahertz technology to increase the existing speed of 100Mbps to 10Gbps. China has achieved a speed of several hundred Gbps on the ground.

Terahertz communication is an advantageous technical approach for future mobile communication (beyond 5G) and an important technical means for high-speed transmission of space information network, which has the application prospect of integration of defense and civilian technologies and coordinated development. China has made an important breakthrough in the key technology of terahertz high-speed wireless communication, which is basically in sync with the world technical level. Therefore, further efforts to develop terahertz high-speed communication technology are of great strategic significance for China to lead the development of international high-speed wireless communication technology and the future standardization process of mobile communication.