Research On Super High Frequency HTS Multiplexer And NBCO HTS Filter

High-temperature superconducting(HTS)filters find wide use in mobile communi-cations,satellite technology,radio astronomy and meteorology radar,due to its excellent performance of low insertion loss,high selectivity,and deep out-of-band depression.Super high frequency(SHF)HTS multiplexer as receive front-end module can efficiently improve the sensitivity and anti-interference ability of the Satellite communication system and the application of HTS material with higher T_ccan make the system more stable and more reliable.The thesis focuses on the design and fabrication of super high frequency HTS multiplexer and characterization of NBCO HTS filter,including an X-band HTS band pass filter,an X-band HTS triplexer,a Ku-band HTS quintplexer and an NBCO HTS band pass filter.This thesis analyzes the coupling coefficient of different resonator configurations,removes the effects of the parasitic coupling in super high frequency HTS filter,and an X-band HTS band pass filter without uncontrollable zero points is designed.The thesis proposes a new method to design multiplexer which separates the coupling of each channel from the group delay response of the multiplexer,and a Ku-band HTS multiplexer is successfully realized by performing the proposed new method.The thesis applies the model of bond wires to the design,and an X-band HTS triplexer with excellent performance is fabricated.This thesis detailed characterizes the HTS band pass filter.The relationship be-tween the insertion loss and the temperature is qualitatively analyzed by applying the phenomenology of Superconductivity.The critical temperature and London penetration depth of the HTS film are derived through curve fitting of the relationship between the center frequency and the temperature.The temperature dependence of the frequency response,critical power,I P3 of the NBCO HTS filter is investigated in the thesis and comparisons are made with YBCO HTS filter of the same configuration,which provides experimental basis for the future applications of NBCO HTS film.