My comment:
(a) It is hard to believe the report that it can intercept DF-21 (or any missile). I mean, 東風21型飛彈 DF-21 (excluding -21A, -21B, -21C and -21D) gas a range of "1,770 km (1,100 mi)" en.wikipedia.org for "DF-21." The en.wikipedia.org for "ballistic missile" lists four ranges: short-range ballistic missile (SRBM), medium-range ballistic missile (MRBM; 1,000 - 3,500 km), intermediate-range ballistic missile (IRBM), and intercontinental ballistic missile (ICBM) --in that order.
(b) "據了解,經研發團隊重新檢視後,重新針對飛彈彈頭尋標系統內的晶片進行升級,並整合國內Ka波段技術後,在尋標系統改用主動式Ka波段以及更新軟體後,整個尋標系統的偵測距離提升並超過20公里以上,大大提高飛彈在攔截目標的精準度。"
microwave https://en.wikipedia.org/wiki/Microwave
("a form of electromagnetic radiation with wavelengths ranging from one meter to one millimeter * * * Frequencies in the microwave range are often referred to by their IEEE radar band designations: S, C, X, Ku, K, or Ka band")