Abstract
This paper describes the development, the design and the measurement of a circularly polarized ultra-miniature antenna. The modelled device takes advantage of the magnetic properties of ferrite materials to achieve the desired specifications. Indeed, the antenna is operating at a frequency where the effective permeability is greater than 1 and the permeability has a negative real part, i.e. in the zone between the μ and μ <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">eff</i> resonances of the ferrite. The dimensions of the designed antenna are about λ0/23.6×λ0/20.7×λ0/29.4 at 2.42GHz and a good circular polarization is achieved at the central operating frequency of the device, with a boresight axial ratio of 1.6dB. This paper is based on the modal study of a ferrite cavity which will be presented and detailed in a first step. The physical properties of the antenna and related material (dimensions, ferrite internal magnetic field, the saturation magnetization, etc.) will be deduced from this modal study and from the resolution of the wave equation inside a cylindrical ferrite cavity. All the antenna performances in terms of impedance matching, axial-ratio and radiation pattern are reported and commented. This concept is finally validated by the measurement of a prototype.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.