High temperature superconducting planar filters for wireless communication

Exquisite properties of HTS filters employed in the base station receivers of cellular systems lead to reduced adjacent channel interference, increased coverage and better spectrum utilization, and hence increase the revenue for the communication service providers. There are approximately 1,500 HTS front-end mobile radio receivers working commercially in the USA and Asia, and they are predicted to make a significant impact on the third and fourth generations of wireless communication. This Chapter presents a brief history of superconducting materials and microwave properties of high-temperature superconducting (HTS) films, reviews designs and properties of HTS resonators and filters, shows cryogenic HTS base station receivers available on the market, and summarizes possible trends in this field