Abstract: A method for operating an electromagnetic compatibility testing system includes for selected frequencies, adjusting incrementally the lengths of each of the plurality of length-adjustable elements for selected combinations of length ratios between the driven element and other length-adjustable elements, including length ratios where the driven element is longer than the other length-adjustable elements, for each selected frequency storing in a table one of the incremental lengths at one of the selected combinations of length ratios having one of the lowest VSWR and a VSWR lower than a threshold value that has highest signal strength, for each selected frequency adjusting the lengths of each of the length-adjustable elements to the stored lengths, driving RF energy at the selected frequency at a EMC test power level into the EMC antenna generating an e-field in the equipment under test, and measuring behavior of the equipment under test in the presence of the e-field.

Abstract: A method for operating an electromagnetic compatibility testing system includes for selected frequencies, adjusting incrementally the lengths of each of the plurality of length-adjustable elements for selected combinations of length ratios between the driven element and other length-adjustable elements, including length ratios where the driven element is longer than the other length-adjustable elements, for each selected frequency storing in a table one of the incremental lengths at one of the selected combinations of length ratios having one of the lowest VSWR and a VSWR lower than a threshold value that has highest signal strength, for each selected frequency adjusting the lengths of each of the length-adjustable elements to the stored lengths, driving RF energy at the selected frequency at a EMC test power level into the EMC antenna generating an e-field in the equipment under test, and measuring behavior of the equipment under test in the presence of the e-field.

Abstract: A phased antenna array includes a plurality of variable length radiators arrayed in a geometric pattern. A length control mechanism is mechanically coupled to each one of the variable length radiators and responsive to radiator length control data to control the length of the variable length radiator. A variable phase delay circuit is coupled to each of the variable length radiators and responsive to phase delay control data to control a phase delay of a radio frequency signal coupled to the variable phase delay circuit. A controller has phase delay circuit control outputs coupled to each one of the variable phase delay circuits, and length control circuit coupleds to each one of the length control mechanisms. The controller is configured to send radiator length control data to each one of the length control mechanisms and to send phase delay data to each one of the variable phase delay circuits.