Research On The Application Of YBCO Superconductors In Antenna

To amylase the influence of high-Q high temperature superconducting (HTS) layer on antenna frequency bandwidth, two identical 400MHz dipole antenna distinguished by their YBCO and copper radiation strips were fabricated. The relational graph between return loss (S11) and frequency shows that the two antennas have the same bandwidth while S11 is–10dB and the YBCO antenna has a 20 percent wider band width than the copper one while S11 is–15dB. Then two YBCO solenoid applications which contained super low frequency (SLF) transmitting antenna and SLF undersea receiving magnetic loop antenna were proposed. The YBCO solenoid was used to improve the current distribution and reduce the power loss of transmitting antenna. And since the application of HTS YBCO solenoid, the SLF undersea receiving magnetic loop antenna becomes more sensitive to tiny signals and the self noise decrease to a very low level. The equivalent thermal noise field (ENF) of HTS magnetic antenna is 30 to 40dB lower than the same shape copper one. The exact anylisis approach included HTS strip alternating current loss,calculative theory and experimental foundation introduction, by means of simulating the magnetic field influence of the iron core to YBCO tape under a changing current environment, we got the total tape loss of a whole solenoid coil by integrating experimental data of short tape samples, Which is less than one in a thousand than the same spec copper antenna. Then we optimized the parameters of magnetic loop antenna and analyzed the axial magnetic field change due to different antenna parameters. On YBCO membrane antenna application, a wide frequency band HTS micro strip antenna with MgO substrate and YBCO boss-eyed radiating part was designed. By adjusting the MgO substrate thickness and the probe radius, a 20 percent relative bandwidth came out. The double-faced YBCO membrane can serve as aperture coupled feeding part of the antenna array. Especially in the outer space, the high efficiency HTS feeding part works without cooling system as the temperature around is lower than Tc.