Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization

Phase reconstruction is in general a non-trivial problem when it comes to devices where the reference is not accessible. A non-convex iterative optimization algorithm is proposed in this paper in order to reconstruct the phase in reference-less spherical multiprobe measurement systems based on a rot...

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Main Authors: Rubén Tena Sánchez, Fernando Rodríguez Varela, Lars J. Foged, Manuel Sierra Castañer
Format: Article
Language:English
Published: MDPI AG 2021-04-01
Series:Sensors
Subjects:
Online Access:https://www.mdpi.com/1424-8220/21/7/2459
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author Rubén Tena Sánchez
Fernando Rodríguez Varela
Lars J. Foged
Manuel Sierra Castañer
author_facet Rubén Tena Sánchez
Fernando Rodríguez Varela
Lars J. Foged
Manuel Sierra Castañer
author_sort Rubén Tena Sánchez
collection DOAJ
description Phase reconstruction is in general a non-trivial problem when it comes to devices where the reference is not accessible. A non-convex iterative optimization algorithm is proposed in this paper in order to reconstruct the phase in reference-less spherical multiprobe measurement systems based on a rotating arch of probes. The algorithm is based on the reconstruction of the phases of self-transmitting devices in multiprobe systems by taking advantage of the on-axis top probe of the arch. One of the limitations of the top probe solution is that when rotating the measurement system arch, the relative phase between probes is lost. This paper proposes a solution to this problem by developing an optimization iterative algorithm that uses partial knowledge of relative phase between probes. The iterative algorithm is based on linear combinations of signals when the relative phase is known. Phase substitution and modal filtering are implemented in order to avoid local minima and make the algorithm converge. Several noise-free examples are presented and the results of the iterative algorithm analyzed. The number of linear combinations used is far below the square of the degrees of freedom of the non-linear problem, which is compensated by a proper initial guess. With respect to noisy measurements, the top probe method will introduce uncertainties for different azimuth and elevation positions of the arch. This is modelled by considering the real noise model of a low-cost receiver and the results demonstrate the good accuracy of the method. Numerical results on antenna measurements are also presented. Due to the numerical complexity of the algorithm, it is limited to electrically small- or medium-size problems.
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spelling doaj.art-e913102370874ef5b4cf674acb3bf1cd2023-11-21T13:58:02ZengMDPI AGSensors1424-82202021-04-01217245910.3390/s21072459Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex OptimizationRubén Tena Sánchez0Fernando Rodríguez Varela1Lars J. Foged2Manuel Sierra Castañer3Information Processing and Telecommunications Centre, ETSI Telecomunicación, Universidad Politécnica de Madrid, 28040 Madrid, SpainInformation Processing and Telecommunications Centre, ETSI Telecomunicación, Universidad Politécnica de Madrid, 28040 Madrid, SpainMicrowave Vision Group, Pomezia, 00071 Rome, ItalyInformation Processing and Telecommunications Centre, ETSI Telecomunicación, Universidad Politécnica de Madrid, 28040 Madrid, SpainPhase reconstruction is in general a non-trivial problem when it comes to devices where the reference is not accessible. A non-convex iterative optimization algorithm is proposed in this paper in order to reconstruct the phase in reference-less spherical multiprobe measurement systems based on a rotating arch of probes. The algorithm is based on the reconstruction of the phases of self-transmitting devices in multiprobe systems by taking advantage of the on-axis top probe of the arch. One of the limitations of the top probe solution is that when rotating the measurement system arch, the relative phase between probes is lost. This paper proposes a solution to this problem by developing an optimization iterative algorithm that uses partial knowledge of relative phase between probes. The iterative algorithm is based on linear combinations of signals when the relative phase is known. Phase substitution and modal filtering are implemented in order to avoid local minima and make the algorithm converge. Several noise-free examples are presented and the results of the iterative algorithm analyzed. The number of linear combinations used is far below the square of the degrees of freedom of the non-linear problem, which is compensated by a proper initial guess. With respect to noisy measurements, the top probe method will introduce uncertainties for different azimuth and elevation positions of the arch. This is modelled by considering the real noise model of a low-cost receiver and the results demonstrate the good accuracy of the method. Numerical results on antenna measurements are also presented. Due to the numerical complexity of the algorithm, it is limited to electrically small- or medium-size problems.https://www.mdpi.com/1424-8220/21/7/2459antenna measurementsphase reconstructionpost-processingmultiprobereference-less
spellingShingle Rubén Tena Sánchez
Fernando Rodríguez Varela
Lars J. Foged
Manuel Sierra Castañer
Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization
Sensors
antenna measurements
phase reconstruction
post-processing
multiprobe
reference-less
title Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization
title_full Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization
title_fullStr Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization
title_full_unstemmed Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization
title_short Reconstruction of Relative Phase of Self-Transmitting Devices by Using Multiprobe Solutions and Non-Convex Optimization
title_sort reconstruction of relative phase of self transmitting devices by using multiprobe solutions and non convex optimization
topic antenna measurements
phase reconstruction
post-processing
multiprobe
reference-less
url https://www.mdpi.com/1424-8220/21/7/2459
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AT larsjfoged reconstructionofrelativephaseofselftransmittingdevicesbyusingmultiprobesolutionsandnonconvexoptimization
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