排序方式: 共有3条查询结果,搜索用时 15 毫秒
1
1.
Ostapchuk A. A. Kocharyan G. G. Morozova K. G. Pavlov D. V. Gridin G. A. 《Izvestiya Physics of the Solid Earth》2021,57(5):659-670
Izvestiya, Physics of the Solid Earth - Abstract—Granular media determine the dynamics of many natural systems including faults in the Earth’s crust. The paper addresses the laboratory... 相似文献
2.
Igor S. Falkovich Alexander A. Konovalenko Anatoliy A. Gridin Leonid G. Sodin Igor N. Bubnov Nikolay N. Kalinichenko Sergey L. Rashkovskii Dmitriy V. Mukha Peter L. Tokarsky 《Experimental Astronomy》2011,32(2):127-145
We have developed an active dipole that is intended for use in new generation low frequency array applications. The preamplifier of the active dipole has very high linearity (input IP2 = 70 dBm, input IP3 = 31 dBm) and low noise temperature (100?C360 K). The frequency dependence of the dipole impedance and the match between the dipole and preamplifier have been optimized to achieve Galactic noise limited operation. The ratio between the antenna temperature due to Galactic noise and the noise temperature of the preamplifier is 10 ± 1.5 dB over the whole 10 to 70 MHz range. The total cost of the active cross-dipole is 220 euro. 相似文献
3.
Alexander?Alexandrovich?KonovalenkoEmail author Igor?Savelievich?Falkovich Nikolay?Nikolaevich?Kalinichenko Alexander?Alexandrovich?Gridin Igor?Nikolaevich?Bubnov Alain?Lecacheux Carlo?Rosolen Helmut?O.?Rucker 《Experimental Astronomy》2003,16(3):149-164
An effective wide-band (10 to 60 MHz) active antenna element has been developed. The cost of one short (3 m), thin dipole with built-in amplifier and metal construction is less than 45 euro. It was shown both theoretically and experimentally that the upper limiting frequency is at least 60 MHz, the dynamic range is 90 dB/V and the share of the amplifier noise to the background antenna temperature is about 10%. The developed active dipole was tested by building a 30-element antenna array and comparing its parameters with one of the subpart of the UTR-2 radio telescope having passive dipoles of 8.6 m in length and 1.8 m in diameter. The 3C461 ionospheric scintillation spectra observed in the experiments show that the sensitivities and noise-immunities of both antennas are close. This proves the availability using of a short cheap active dipole in new generation giant radio telescopes. 相似文献
1