Design and Analysis of Air Gap Microstrip Slot Antenna Using Aperture Coupling

A microstrip slot antenna for C Band has been proposed with compact structure and suppressed back radiation. In this paper, the feeding technique used is aperture coupling with a modification that patches and the feed line are positioned below the substrate and the slot is etched above the substrate. The position of the patches along the slot axis is kept at the negative peak of the standing wave distributions to generate the voltage null on the slot line so as to have a 180Âº phase shift in the centre of the patch hence achieving better front to back ratio. Also the gain of 6.774dB is achieved in this design. The results are validated by simulation measurements.

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Design and Simulation of the Air-Gap L-Shaped Feeding Arc Slot Antenna

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.926-930.1281 ◽

2014 ◽

Vol 926-930 ◽

pp. 1281-1284

Author(s):

Ping Li ◽

Yong Zhong Zhu ◽

Yuan Yuan Guo ◽

Yu Peng

Keyword(s):

Air Gap ◽

Slot Antenna ◽

Omnidirectional Antenna ◽

Profile Height ◽

Airborne Electromagnetic ◽

Informational System

In the efforts to improve the capability of duty service and contingency-handing of informational system and deal with the communications security of helicopter, according to the request of the airborne electromagnetic equipment miniaturization and conformal, design of an air-gap L-shaped feeding arc slot antenna. This antenna is an omnidirectional antenna, its profile height under 0.03 working wavelength, the size under 0.5 working wavelength and the transmission gain exceed 3dB.

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A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-201505 ◽

2020 ◽

pp. 1-15

Author(s):

Jianqi Li ◽

Yu Zhou ◽

Jianying Li

Keyword(s):

Magnetic Field ◽

Conformal Mapping ◽

Permanent Magnet ◽

Flux Density ◽

Analytical Method ◽

Electromotive Force ◽

Analytical Calculation ◽

Air Gap ◽

Permanent Magnet Machines ◽

Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

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Effects of contact gap on nondestructive evaluation using magnetic measurement for ferromagnetic steel

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-209411 ◽

2020 ◽

Vol 64 (1-4) ◽

pp. 969-975

Author(s):

Hiroaki Kikuchi ◽

Yuki Sato

Keyword(s):

Magnetic Flux ◽

Nondestructive Evaluation ◽

Effective Permeability ◽

Magnetic Circuit ◽

Magnetic Measurement ◽

Air Gap ◽

Motive Force ◽

Hysteresis Curve ◽

Evaluation Technique ◽

Ferromagnetic Steel

We investigated effects of contact gap on magnetic nondestructive evaluation technique using a magnetic single-yoke probe. Firstly, we evaluated hysteresis curves and impedance related to permeability of the material measured by a single-yoke probe, when an air gap length between the probe and specimens changes. The hysteresis curve gradually inclines to the axis of the magneto-motive force and magneto-motive force at which the magnetic flux is 0 decreases with increasing the gap length. The effective permeability also decreases with increasing the gap thickness. The incremental of gap thickness increases the reluctance inside the magnetic circuit composed of the yoke, specimen and gap, which results in the reduction of flux applying to specimen.

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