Multi-Frequency Phase Retrieval for Antenna Measurements

TL;DR

This paper introduces a multi-frequency phase retrieval method for antenna measurements that leverages spectral phase relationships across frequencies to improve phase reconstruction accuracy from magnitude-only data.

Contribution

The paper proposes a novel multi-frequency phase retrieval approach that uses spectral phase information to enhance phase reconstruction in antenna measurements.

Findings

Improved phase reconstruction accuracy using multi-frequency data.

Method works with far-field probe configurations.

Enhanced independent phase information extraction.

Abstract

Phase retrieval problems in antenna measurements arise when a reference phase cannot be provided to all measurement locations. Phase retrieval algorithms require sufficiently many independent measurement samples of the radiated fields to be successful. Larger amounts of independent data may improve the reconstruction of the phase information from magnitude-only measurements. We show how the knowledge of relative phases among the spectral components of a modulated signal at the individual measurement locations may be employed to reconstruct the relative phases between different measurement locations at all frequencies. Projection matrices map the estimated phases onto the space of fields possibly generated by equivalent antenna under test (AUT) sources at all frequencies. In this way, the phase of the reconstructed solution is not only restricted by the measurement samples at one frequency, but by the samples at allfrequencies simultaneously. The proposed method can increase the amount of independent phase information even if all probes are located in the far field of the AUT.