Broadband electromagnetic characterization of a 100     Ω traveling-wave electrode by measuring scattering parameters

• Published in: Physical review special topics. PRST-AB. Accelerators and beams Vol. 16; no. 7; p. 072001
• Main Authors: Consoli, Fabrizio, Balleyguier, Pascal, Di Giacomo, Marco
• Format: Journal Article
• Language: English
• Published: College Park American Physical Society 01.07.2013
• Subjects: Broadband; Electrodes; Electromagnetic properties; Electromagnetic radiation; Group velocity; Propagation velocity; S parameters; Scattering; Transmission lines
• ISSN: 1098-4402; 1098-4402; 2469-9888
• DOI: 10.1103/PhysRevSTAB.16.072001

The Single Bunch Selector (SBS) will be used on the Spiral2 linear accelerator to reduce the rate of high energy bunches reaching the target with, in principle, no residual particles from the suppressed bunches. For this purpose, a pulsed electromagnetic wave will travel along the 100Ω microstrip meander line electrode of the SBS. In this work we describe the broadband accurate characterization of the electrode electromagnetic features. The method applied here leads to the analytical determination of complex characteristic impedance, propagation constant, and group velocity from a measurement of the 50Ω scattering parameters on the meander transmission line. Particular care is given to the de-embedding phase of the transitions required to connect the meander electrode to the measurement device.