Papers by Author: Wen Dong Zhang

Abstract: Pb0.97La0.02(Zr0.95Ti0.05)O3 antiferroelectric thick films were prepared on platinized silicon substrates by sol–gel methods. Films showed polycrystalline perovskite structure with a strong (100) preferred orientation. The antiferroelectric nature of the films was confirmed by the double hysteresis behaviors versus applied field. The temperature dependence of dielectric constant and loss displayed the Curie temperature was 225oC.The current caused by the polarization and depolarization of polar was detected at coupling application of electric field and temperature. The phase transition characterization could be effectively adjusted by electric field and temperature.

Abstract: With the development of modem broadband radar, amount of reaserchers focus on broadband radar echo signal acquisitions and feature extraction of the target. Due to the large bandwidth as high as several MHz, the time interleaved ADC system is playing an important in radar echo systems, but this structure will bring in channel dismatch errors. The paper gave an explicit analysis of such three channel mismatch errors, and established the formulas of spectrum when all three mismatch errors exist together. Then presented the measure errors algorithm combined three errors according to the formulas of spectrum and the effective calibration algorithm．The algorithm was implemented in FPGA at last.