A. Muñoz-Acevedo

Electronically Reconfigurable Transmitarray at Ku Band for Microwave Applications

An electronically reconfigurable transmitarray device at 12 GHz is presented in this work. This paper highlights the functioning of this kind of device and thoroughly examines the proposed reconfigurable transmitarray. The architecture is discussed along with the design and selection of all the constituting elements and the prototypes for all of them. In order to add reconfigurability to the transmitarray structure, 360° reflective phase shifters were designed, prototyped and validated for direct application. Eventually, a demonstrative prototype for an active transmitarray with phase shifters was assembled, and radiation pattern measurements were taken in an anechoic chamber to demonstrate the capabilities of this structure.

An Efficient Hybrid GO-PWS Algorithm to Analyze Conformal Serrated-Edge Reflectors for Millimeter-Wave Compact Range

A method to analyze parabolic reflectors with arbitrary piecewise rim is presented in this communication. This kind of reflectors, when operating as collimators in compact range facilities, needs to be large in terms of wavelength. Their analysis is very inefficient, when it is carried out with fullwave/MoM techniques, and it is not very appropriate for designing with PO techniques. Also, fast GO formulations do not offer enough accuracy to reach performance results. The proposed algorithm is based on a GO-PWS hybrid scheme, using analytical as well as non-analytical formulations. On one side, an analytical treatment of the polygonal rim reflectors is carried out. On the other side, non-analytical calculi are based on efficient operations, such as M2 order 2-dimensional FFT. A combination of these two techniques in the algorithm ensures real ad-hoc design capabilities, reached through analysis speedup. The purpose of the algorithm is to obtain an optimal conformal serrated-edge reflector design through the analysis of the field quality within the quiet zone that it is able to generate in its forward half space.

Overview of Novel Post-Processing Techniques to Reduce Uncertainty in Antenna Measurements

The error analysis has been investigated since 1975 since recent publications, as shown in references as (Newell et al., 1975) where the classical 18 terms for planar near field systems where established. It is also worth mentioning the more recent studies developed inside the actions under the “Antenna Measurement” activity of the “Antenna Centre of Excellence (ACE)” within the sixth framework research program of the European Union. In particular, that work pretended to establish common error calculation criteria in spherical near-field and far-field antenna measurement systems. The results of that research were summarized in an exhaustive deliverable (Alexandridis et al., 2007), which detailed the observations stated by several research institutions. In that deliverable it was agreed that the causes of uncertainties and errors in a spherical near-field antenna measurement are divided in six categories: