Pablo Padilla de La Torre

Dual circular polarized steering antenna for satellite communications in X band

In this work, a dual circular polarized steering antenna for satellite communications in X band is presented. The antenna consists of printed elements grouped in an array. This terminal works in a frequency band from 7.25 GHz up to 8.4 GHz (15% of bandwidth), where both bands, reception (RX) and transmission (TX) are included simultaneously and Left Handed Circular Polarization (LHCP) and Right Handed Circular Polarization (RHCP) are interchangeable. The antenna is compact, narrow bandwidth and reaches a gain of 16 dBi. It has the capability to steer in elevation to 45±, 75±, 105± and 135± electronically with a Butler matrix and 360± in azimuth with a motorized junction.

Comparison of Different Methods for the Experimental Antenna Phase Center Determination Using a Planar Acquisition System

This work provides the comparison of difierent methods for the experimental determination of the phase center location of an antenna. The phase center position is determined by means of measured data obtained with a planar scanning system and computed with difierent methods: a least-squares flt method with and without weighting coe-cients and a directivity-based plane wave spectrum (PWS) analysis method. A study of the phase center position for difierent microwave antennas is provided. The results of the difierent methods are presented and compared, along with the confldence interval of the phase center values due to the uncertainties of the acquisition system.