Microstrip Ferrite Coupled Line Isolators

Study of Nonreciprocal Devices Using Three-Strip Ferrite Coupled Line

“…Nonreciprocal devices are important components of the modern microwave systems [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. In order to obtain the nonreciprocal effects one needs to utilize the ferrite materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] or active elements such as amplifiers [19].…”

“…In order to obtain the nonreciprocal effects one needs to utilize the ferrite materials [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] or active elements such as amplifiers [19]. The integrated nonreciprocal devices are in general realized in microstrip [2][3][4][5][6][7][8][9][10][11][12] or slot line [15][16][17][18] technology, with the ferrite material magnetized longitudinally or transversely. Recently, the longitudinally magnetized microstrip [2][3][4][5][6][7][8][9][10][11] or slot [17,18] ferrite coupled lines (FCL) are being developed and employed to realize integrated nonreciprocal devices.…”

“…The integrated nonreciprocal devices are in general realized in microstrip [2][3][4][5][6][7][8][9][10][11][12] or slot line [15][16][17][18] technology, with the ferrite material magnetized longitudinally or transversely. Recently, the longitudinally magnetized microstrip [2][3][4][5][6][7][8][9][10][11] or slot [17,18] ferrite coupled lines (FCL) are being developed and employed to realize integrated nonreciprocal devices. Generally, the FCL section is a four port circuit build with a standard coupled lines (CL) composed of three conductors and with ferrite slab located above or below the lines.…”

“…However, in such structures high insertion losses associated with long ferrite slab (often several wavelengths) are being observed. Recent researches on these devices concern improvement of their parameters such as bandwidth and losses [3][4][5][6][7][8][9][10]17]. Taking into consideration the Faraday effect that appears in the structure, the optimal behavior of FCL section is obtained for ferrite interaction with linearly or circularly polarized waves [3,12].…”

Investigations of Cylindrical Ferrite Coupled Line Junction Using Hybrid Technique

“…This optimal effect is achieved when the ferrite material is placed in the region where the wave is linearly polarized and occurs in cylindrical waveguide with coaxially located ferrite rod or suspended stripline junction. In order to construct devices such as circulators [7,19], gyrators [20] or isolators [17] 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.…”