{"title":"Development of a new atom-based SI traceable electric-field metrology technique","authors":"C. Holloway, Matt T. Simons, J. Gordon","doi":"10.23919/AMTAP.2017.8123709","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123709","url":null,"abstract":"We are developing a fundamentally new atom-based approach for electric (E) field metrology. This technique has the capability of becoming a new international standard for E-field measurements and calibrations. Since this new approach is based on atomic transitions of alkali atoms (mainly caesium and rubidium atoms), the probe is self-calibrating and has a capability of performing measurements over a large bandwidth (from 10's MHz to the THz range). This new approach will lead to a self-calibrated, SI traceable, E-field measurement, and has the capability to perform measurements on a fine spatial resolution in both the far-field and near-field. We will report on the development of this new metrology approach, including the first fiber-coupled vapor-cell for E-field measurements, which allows for easier and more flexible measurements. We discuss key applications, including self-calibrated measurements, millimeter-wave and sub-THz measurements, field mapping, and sub-wavelength and near-field imaging. We show results for free-space measurements of E-fields, for measuring the E-field distribution along the surface of a circuit board, and for measuring the directivity pattern of a horn antenna.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"384 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115221056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Free-space antenna far-field extraction from near-field measurements above metallic ground","authors":"R. A. Mauermayer, T. Eibert","doi":"10.23919/AMTAP.2017.8123696","DOIUrl":"https://doi.org/10.23919/AMTAP.2017.8123696","url":null,"abstract":"The unknown spherical mode coefficients of an antenna radiating above an infinite perfectly electrically conducting ground plane are determined from near-field measurements by considering the ground plane in the forward operator of the inverse problem which is efficiently solved for the antenna sources by employing the iterative generalized minimum residual solver (GMRES). However, two mechanisms may lead to deviations of the reconstructed sources from the free-space antenna sources. First, dependent on the height of the antenna above the ground, the forward operator might not be exactly invertible such that the sources can not be accurately determined. Second, the reconstructed sources are different from the free-space sources due to inevitable coupling effects between the antenna and the metallic ground. Based on numerical experiments, the capability of the applied spherical field transformation approach to extract the free-space antenna sources from measurements above a metallic ground plane is investigated in detail.","PeriodicalId":405864,"journal":{"name":"2017 Antenna Measurement Techniques Association Symposium (AMTA)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133193746","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}