Optimized design of a novel broadband LTCC Balun for wireless application

This paper presents a miniaturized multi-layer Marchand Balun realized by low temperature co-fired ceramic (LTCC) technology for wireless application. In order to seize the advantage of LTCC technology on multi-layer substrates and make full use of three-dimensional space to develop small size device, the broadside coupled strip line is utilized to design the coupled region of the Marchand Balun. A method of changing the even mode impedances of the coupling region is proposed that can optimize the design of the Marchand Balun to get a better operating performance. This paper proves that the proposed method is feasible and the performance of the Marchand Balun is suitable for wireless application.