Gain and Bandwidth Enhancement of Ferrite-Loaded CBS Antenna Using Material Shaping and Positioning

Author

Amiri, Mikal Askarian ; Balanis, Constantine A. ; Birtcher, Craig R.

Author_Institution

Sch. of Electr., Comput. & Energy Eng., Arizona State Univ., Tempe, AZ, USA

Volume

12

fYear

2013

fDate

2013

Firstpage

611

Lastpage

614

Abstract

Loading a cavity-backed slot (CBS) antenna with ferrite material and applying a biasing static magnetic field can be used to control its resonant frequency. Such a mechanism results in a frequency-reconfigurable antenna. However, placing a lossy ferrite material inside the cavity reduces the gain and impacts the impedance bandwidth. This letter develops guidelines, based on a nonuniform applied magnetic field and nonuniform magnetic field internal to the ferrite specimen, for the design of ferrite-loaded CBS that enhance its gain and tunable bandwidth by shaping the ferrite specimen and judiciously locating it within the cavity. To validate the modeling, simulations were performed using ANSYS´s Maxwell 3D and HFSS, and they were compared to measurements conducted in the Arizona State University (ASU) anechoic chamber.

Keywords

Maxwell equations; anechoic chambers (electromagnetic); antennas; impedance matching; magnetic field measurement; ANSYS Maxwell 3D; ASU anechoic chamber; Arizona State University anechoic chamber; HFSS; bandwidth enhancement; biasing static magnetic field; cavity-backed slot antenna; ferrite-loaded CBS antenna; gain enhancement; impedance bandwidth; material positioning; material shaping; Cavity-backed; ferrite; gain; impedance match; tunable bandwidth;

fLanguage

English

Journal_Title

Antennas and Wireless Propagation Letters, IEEE

Publisher

ieee

ISSN

1536-1225

Type

jour

DOI

10.1109/LAWP.2013.2260519

Filename

6511976