Design of UHF Thin Film Transformer and Research of its S-Parameter Performance

Abstract

A novel spiral stacked thin film transformer was designed based on Si IC technology in this paper. And also, the stacked air core and ferrite core thin film transformers with different turns ratio were prepareed. Then, the S-parameter performance of these two kinds of transformers were measured. The measurement results show that the magnetic core thin film transformer has a better electronic transmission performance. It obtains maximum transmission efficiency 93.7% at the frequency range from 10MHz to 20GHz, and the air core transformer obtains maximum 89% at the same frequency range. Many testings show that ferrite core thin film transformer with turns ratio 1:1 can obtain the transmission efficiency over 60% at the frequency range from 2GHz to 16GHz.