S-Parameter Method and Its Application for Antenna Measurements


IEICE TRANSACTIONS on Communications   Vol.E97-B    No.10    pp.2011-2021
Publication Date: 2014/10/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.E97.B.2011
Type of Manuscript: Special Section INVITED PAPER (Special Section on Recent Progress in Measurement and Design Techniques on Antennas, Propagation and Wireless Systems)
S-parameter method,  input impedance,  radiation pattern,  reflection coefficient,  

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This paper focuses on the S-parameter method that is a basic method for measuring the input impedance of balanced-fed antennas. The basic concept of the method is summarized using the two-port network, and it is shown that the method can be enhanced to the unbalanced antennas using a formulation based on incident and reflected waves. The compensation method that eliminates the influence of a measurement jig and the application of the S-parameter method for the measurement of a radiation pattern with reduced unbalanced currents are explained. Further, application of the method for measuring the reflection and coupling coefficients of multiple antennas is introduced. The measured results of the input impedance of a dipole antenna, radiation patterns of a helical antenna on a small housing, and S-parameters of multiple antennas on a small housing are examined, and the measured results obtained with the S-parameter method are verified.