Título: Microstrip Antennas - Circular polarisaton


Descripción automática: In this video, the presenter introduces the topic of microstrip antennas with circular polarization within the context of an online course module from the host's technical university. The discussion begins by explaining how observers, far along the positive side of the z-axis in a coordinate system, might perceive an electromagnetic wave that propagates along the same axis. By employing two linearly polarized feeding currents at the origin—aligned with the x-axis and y-axis respectively—a plane electromagnetic wave with two orthogonal components can be generated.

The presenter goes on to discuss the role of the ratio (k) and phase difference (phi) of the currents in achieving different polarizations. Particular attention is given to the conditions under which these configurations result in either right or left circular polarization. It's noted that by introducing a quarter-wavelength line at one of the ports, the phase of the current in that port is delayed by 90 degrees, allowing for the generation of circular polarization in the broadside direction.

Further, the video includes an explanation of how feeding ports with equal voltage but slightly different input impedances can result in circular polarization, utilizing the concepts of resonance and input reactance symmetry. This principle is also applied to achieving circular polarization with just one feed point, through various adjustments like feed location and minor physical alterations.

The concept of sequential rotation is discussed as a method for obtaining circular polarization by using patches with inherent linear polarization, resulting in enhanced circular polarization for an array. The quality of circular polarization is quantified through the axial ratio, with a perfect circular polarization having an axial ratio of one. The presenter exemplifies this with an analysis of a dual-polarized edge with a Butterworth-slot feed design, showing how it achieves wide bandwidths with respect to a standard axial ratio reference. The summary of this video offers insights into the fundamental concepts and techniques used to design and analyze microstrip antennas with circular polarization.

Autor/a: Peixeiro Custódio

Curso: Este vídeo es el 31/62 del curso European School of Antennas. [ Ссылка ]


+ Universitat Politècnica de València UPV: [ Ссылка ]
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#microstrip antennas #circular polarisation

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