2020-10-21T19:21:09Z http://oa.upm.es/cgi/oai2
oai:oa.upm.es:42261 2016-07-23T11:01:15Z 7374617475733D707562 7375626A656374733D74656C65636F6D756E69636163696F6E6573 747970653D636F6E666572656E63655F6974656D
Time and spatial filtering for echo reduction in antenna measurements Sierra Castañer, Manuel González Blanco, María Pilar López Morales, Manuel José Saccardi, Francesco Foged, Lars Jacob Telecommunications During the last years, new algorithms, based on time filtering, spatial or modal filtering, have been designed for echo reduction techniques applied to antenna measurements. These algorithms have been used for different applications where the effect of the echoes is important, as far field system, VHF or UHF applications, automotive systems, small antennas, etc. The authors, in previous papers, have analysed the effect of different algorithms: time filtering (fft, non uniform dft or matrix pencial), modal filtering based on Spherical modes (MV-Echo) and spatial filtering based on Integral Equations (Insight) and holographic techniques (fft and dft) to cancel the effect of the reflections. This comparison has been applied to the measurements of a dipole antenna (SD1900) using a StarLab system. It is observed that each of the algorithms is better for different situations, depending on the source of the echo. For instance, time filtering techniques are good for reflections coming from different distances with respect the direct ray, but not so good for close reflections. In addition hey need a large frequency band to work properly. Spatial algorithms can correct the effect of positioners or other structures close to the antenna under test, but they are better for planar near field acquisitions and worse for classical single probe spherical near field where the antenna is rotated and probe is fixed (e.g. roll-over-azimuths systems). Moreover, they require extra information of the AUT geometry. This paper presents first a comparison of each algorithm and then, a combination of time and spatial techniques based on uniform or non-uniform DFT to take advantage of the benefits of each algorithm for different origins of the reflections. E.T.S.I. Telecomunicación (UPM) http://creativecommons.org/licenses/by-nc-nd/3.0/es/ 2015 info:eu-repo/semantics/conferenceObject Presentation at Congress or Conference Antenna Measurement Techniques Association (AMTA) | Antenna Measurement Techniques Association (AMTA) | 11/10/2015 - 16/10/2015 | Long Beach, California, USA PeerReviewed application/pdf eng TEC-2011-28789-C02-01 S2013/ICE-3000 info:eu-repo/semantics/openAccess http://oa.upm.es/42261/