Microwave characteristics of interconnects for 4 GHz-band HTS power devices

Abstract

For applications of high-Tc superconducting HTS filters with microstrip line structure to microwave power devices in linear operations, it is important not only to achieve handling power sufficient for the devices not to break down, but also to decrease the intermodulation distortion (IMD) as much as possible. One of main causes of the IMD is the pattern of the HTS resonators. Other factors we have considered as a cause of IMD are I/O interconnects and thermal conditions inside a filter package. To clarify these influences, we fabricated and examined the model devices that consisted of a YBCO microstrip disk resonator chip with TM11 resonant mode, the I/O interconnects with metal electrodes, and packages with and without the introduction of He gas. As the results of the third-order IMD (IMD3) examinations of the model devices for 4GHz band, it is confirmed that the IMD can be reduced by improving the I/O interconnects and the gas atmosphere inside the power-filter package.