Investigations of nonreciprocal devices employing cylindrical ferrite coupled line junction

This paper presents application of a novel cylindrical ferrite coupled line (CFCL) junction to integrated nonreciprocal devices. In such a junction, high gyromagnetic coupling occurs. This gives possibility to design a pi/4 Faraday rotation CFCL junction with the ferrite rod having shorter length and lower saturation magnetization than the planar structures commonly known in literature. By utilizing the proposed cylindrical junction in integrated nonreciprocal devices, it is possible to reduce not only their dimensions but also the insertion losses occurring in such structures. In this paper, we present an application of CFCL junction to integrated isolator. The results of numerical simulations are verified experimentally, and good agreement is observed.