Title :
Dual-ferrite slot line for broadband, high-nonreciprocity phase shifters
Author :
El-Sharawy, El-Badawy ; Koza, Christopher J.
Author_Institution :
Dept. of Electr. Eng., Arizona State Univ., Tempe, AZ, USA
fDate :
12/1/1991 12:00:00 AM
Abstract :
A phase shifting structure that exhibits both broadband operation and high nonreciprocity is presented. This structure comprises a slot line between two oppositely magnetized ferrite substrates. A full-wave spectral-domain analysis is used, where Green´s functions are formulated using a transmission matrix approach. By eliminating the use of relatively thick high-dielectric substrates, a bandwidth of 3:1 and a differential phase of 50°/cm are feasible. The geometry of the present structure can be optimized to increase both the nonreciprocity and the bandwidth. The characteristic impedance of the slot line is presented and shows a strong dependence on the slot width and the state of ferrite magnetization. The addition of thin layers of high-dielectric material increases the differential phase to over 100°/cm without significantly reducing the bandwidth. These layers were found to reduce the variation of characteristic impedance versus the ferrite magnetization
Keywords :
Green´s function methods; electric impedance; ferrite applications; phase shifters; waveguide components; waveguide theory; Green´s functions; broadband; characteristic impedance; dual ferrite slot line; ferrite magnetization; full-wave spectral-domain analysis; high-dielectric material; high-nonreciprocity phase shifters; oppositely magnetized ferrite substrates; slot width; thin layers; transmission matrix approach; Bandwidth; Dielectric substrates; Ferrites; Geometry; Green´s function methods; Impedance; Magnetic materials; Magnetization; Phase shifters; Planar transmission lines;
Journal_Title :
Microwave Theory and Techniques, IEEE Transactions on
