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Article List
2022, 20(5):419-423.
DOI: 10.11805/TKYDA2021050
Abstract:
An E-band continuous wave Traveling Wave Tube Amplifier(TWTA) for communication is presented. The TWTA integrates the E-band folded waveguide traveling wave tube with the miniaturized high-voltage power supply. It can be powered by low voltage supply in the outer part. The main properties of TWTA include operating frequency 81~86 GHz, saturated output power >80 W, small signal gain >38 dB, total efficiency >22%, size of 38 cm×20 cm×6.3 cm and airborne environmental adaptability. The TWTA bears the advantages of high power, high efficiency, miniaturization, and high reliability.
An E-band continuous wave Traveling Wave Tube Amplifier(TWTA) for communication is presented. The TWTA integrates the E-band folded waveguide traveling wave tube with the miniaturized high-voltage power supply. It can be powered by low voltage supply in the outer part. The main properties of TWTA include operating frequency 81~86 GHz, saturated output power >80 W, small signal gain >38 dB, total efficiency >22%, size of 38 cm×20 cm×6.3 cm and airborne environmental adaptability. The TWTA bears the advantages of high power, high efficiency, miniaturization, and high reliability.
2022, 20(5):407-413.
DOI: 10.11805/TKYDA2021346
Abstract:
Aiming at the phase jitter caused by environmental factors such as temperature and vibration changes in the process of optical fiber time-frequency transmission, a high-precision phase stability stress technology based on Proportional-Integral-Derivative(PID) feedback control is proposed. Michelson interferometer is employed for real-time phase detection. The real-time compensation is carried out through piezoelectric ceramics. This method can effectively overcome the bottleneck in compensation accuracy and speed of traditional phase discrimination and delay line. After calculation of environmental factors and PID compensation simulation, the transmission delay measurement accuracy of this method in 800 m optical fiber transmission is 2.2 fs, the transmission delay stability is <8.8 fs, and the initial state time is within 0.088 s under the external axial tension less than 100 N.
Aiming at the phase jitter caused by environmental factors such as temperature and vibration changes in the process of optical fiber time-frequency transmission, a high-precision phase stability stress technology based on Proportional-Integral-Derivative(PID) feedback control is proposed. Michelson interferometer is employed for real-time phase detection. The real-time compensation is carried out through piezoelectric ceramics. This method can effectively overcome the bottleneck in compensation accuracy and speed of traditional phase discrimination and delay line. After calculation of environmental factors and PID compensation simulation, the transmission delay measurement accuracy of this method in 800 m optical fiber transmission is 2.2 fs, the transmission delay stability is <8.8 fs, and the initial state time is within 0.088 s under the external axial tension less than 100 N.
2022, 20(5):414-418.
DOI: 10.11805/TKYDA2021133
Abstract:
With the increasing demand of Low Earth Orbit(LEO) communication satellite services, LEO satellites need to use Ka band for communication. In order to solve the problem of co-frequency interference between LEO satellite and Geostationary Orbit(GEO) satellite when Ka band is utilized, the spatial separation method based on link separation angle is adopted to analyze the angle interval of interference avoidance. The influence of different interference scenarios and ground station distribution on the interference angle interval is studied, and the interference avoidance measures are put forward for LEO satellites within the angle interval.
With the increasing demand of Low Earth Orbit(LEO) communication satellite services, LEO satellites need to use Ka band for communication. In order to solve the problem of co-frequency interference between LEO satellite and Geostationary Orbit(GEO) satellite when Ka band is utilized, the spatial separation method based on link separation angle is adopted to analyze the angle interval of interference avoidance. The influence of different interference scenarios and ground station distribution on the interference angle interval is studied, and the interference avoidance measures are put forward for LEO satellites within the angle interval.
2022, 20(5):424-430.
DOI: 10.11805/TKYDA2021128
Abstract:
Millimeter wave transmission in particulate environment is a fundamental topic in the communication community. In order to make controllable measurement, a dual-reflector Gaussian beam transmission system is designed based on the quasi-optical theory. This system consists of a pair of multi-flare angle horns, and two ellipsoidal focusing reflectors. The multi-flare angle horns are employed to generate Gaussian beam with 96% Gaussianity, and the focusing reflectors transform the incident beam to be identical to the input beam. In addition, the measurement on the system loss is conducted in the range of 75~110 GHz by using a vector network analyzer and extenders. It is found that the system loss is in the range of 2~4 dB, showing a satisfactory transmission performance. The preliminary study on water-spraying paves the way for future controllable measurement.
Millimeter wave transmission in particulate environment is a fundamental topic in the communication community. In order to make controllable measurement, a dual-reflector Gaussian beam transmission system is designed based on the quasi-optical theory. This system consists of a pair of multi-flare angle horns, and two ellipsoidal focusing reflectors. The multi-flare angle horns are employed to generate Gaussian beam with 96% Gaussianity, and the focusing reflectors transform the incident beam to be identical to the input beam. In addition, the measurement on the system loss is conducted in the range of 75~110 GHz by using a vector network analyzer and extenders. It is found that the system loss is in the range of 2~4 dB, showing a satisfactory transmission performance. The preliminary study on water-spraying paves the way for future controllable measurement.
