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In this study, a new spiral dual-band antenna integrated with an optical system for a small CubeSat spacecraft was proposed. It is challenging to design an antenna with a limited space on a CubeSat platform. To improve the space utilization, an antenna was designed based on the concept of not occupying the sides of the CubeSat. A feature of the proposed antenna system is its compactness, dual-band operation in the L-and S-bands, and possibility of integration with spacecraft cameras. As a result of the study, reflection coefficients of -18 dB and -23 dB and gain of 6.8 dBi and 7.4 dBi, respectively, were achieved at resonant frequencies of 1.7 GHz and 2.45 GHz. The conical shape of the spiral antenna allows the optical system to increase the coverage area, and a simple deployment system with feedback ensures the mission safety. These properties make the proposed antenna suitable for CubeSat systems.INDEX TERMS CubeSat antenna, dual-band antenna, Earth observation, helix antenna

In this work, we discuss deployment of a new setup of high-frequency antennas for detection of air showers. It is considered to employ two types of high-frequency antennas for the new setup, the first type of antenna is the SALLA type, which is used in the Tunka-Rex experiment, and the second type is a narrow-radiational high-frequency Uda-Yagi antenna. The comparison of radiation patterns, frequency range and noise level in the mountains and at the university altitude levels is presented.

In this work, ternary composites of NiZn ferrite/carbonyl iron/carbon black (Ni0.5Zn0.5Fe2O4/CI/CB) were prepared via two stages. Firstly, Ni0.5Zn0.5Fe2O4 was prepared by a self-combustion method using sucrose as a fuel. After that, the operation was continued via mixing CB, CI, and Ni0.5Zn0.5Fe2O4 through grinding balls. Three various weight ratios of Ni0.5Zn0.5Fe2O4/CI/CB (1:1:1, 1:1:2, and 2:1:1) with various thicknesses (2–4–6 mm) were prepared. The absorbers were prepared by dispersing (Ni0.5Zn0.5Fe2O4/CI/CB) composites with a weight ratio within a paraffin wax matrix of 40 % w/w. X-ray diffractometry and FTIR spectroscopy were used in order to characterize the samples. The morphology of the powders was investigated by SEM. The functional characterization was accomplished by measuring the microwave absorption properties in the fre-quency band of 8.8–12 GHz. The microwave absorption materials (MAMs) showed wide bandwidths under –10 dB in the range of 2.81–3.20 GHz and reasonable surface density in the range of 3.625–4.041 kg/m2. The absorber of 3.20 GHz bandwidth had a minimal reflection loss of –19.4 dB at the matching frequency of 9.92 GHz with a thickness of 6 mm.

In this article, the author examines the activities and policies of Khaknazar Khan, who ruled in the 40-80's. XVI century, at the time of the revival of the Kazakh Khanate and the personal human qualities of the Khan, the problems of Khaknazar Khan's relationship between the rulers of Muerennakhr in the 70s of the mentioned century are also considered. At this time, the political situation of Mauerannakhr was complicated, the process of power struggle divided into two political groups-the Baba Sultan group in Tashkent and the Abdallah Khan group in Bukhara. In the interests of the Kazakh people, Khaknazar Khan supported the ruler of Bukhara. He died during the struggle with Baba Sultan.