Abstract
This paper presents the work of a miniaturized 60-GHz balun chip with isolation and matching performance fabricated in 0. 18-mu m SiGe BiCMOS process. The use of isolation circuit as key building blocks within a 60-GHz transformer balun leads to an improved isolation performance between output ports, while simultaneously achieving the matching performance of them. Moreover, compared to the conventional isolation circuit, the artificial left-handed transmission line is introduced to remove the bulky distributed elements, and the capacitive loading compensation technique is utilized for both matching and miniaturization. Both electromagnetic simulation and measurement results of the proposed 60-GHz transformer balun chip design with isolation and matching characteristics are given with good agreement. From measurement results, better than 25-dB isolation and 18-dB return loss of the output ports have been achieved at 60 GHz, with an occupied area of 0. 022 mm(2).