Investigations of nonreciprocal devices employing cylindrical ferrite coupled line junction

Investigations of Four-Port Circulator Utilizing Cylindrical Ferrite Coupled Line Junction

“…It consists of a cascade connection of magic-T junction, cylindrical coupled slotline junction (CFCL) and multilayer transformer from coupled slotlines to microstrip lines. In the design of the circulator the CFCL junction proposed in [10] and described in Section 3.1 was applied. Taking into account the dimensions of CFCL junction the feeding structures, i.e., magic-T junction and output transformer were designed and presented in Sections 3.2 and 3.3, respectively.…”

“…In the design of four-port circulator the CFCL section presented in [10] was utilized. The angular dimensions of junction were slightly modified to obtain π/4 Faraday rotation angle for the length of ferrite section L = 26 mm at operation frequency f 0 = 8.2 GHz.…”

“…9). The configuration of the structure is similar to the one presented in [10]. However, in comparison to [10] the substrate and overlay with low permittivity (ε r = 3.5) were assumed, which allows for better matching of cylindrical section with planar one.…”

“…The novel class of integrated nonreciprocal devices such as isolators or circulators are the one realized with the use of longitudinally magnetized ferrite coupled lines section (FCL) [1][2][3][4][5][6][7][8][9][10][11]. Significant interest in these devices results from their advantages such as weak biasing magnetic field and wide operation bandwidth [2].…”

“…According to the coupled-mode model [12] in such section the gyromagnetic coupling occurs resulting in Faraday rotation effect. In order to construct devices such as circulators [1-6, 9, 11], gyrators [7] or isolators [8,10] the FCL section has to be cascaded with reciprocal section providing input signals to the FCL which are either in phase or out of phase.…”