USE OF SCAN IMPEDANCE AND SCAN ELEMENT PATTERN

摘要

Scan Impedance usually controls the bandwidth and matching capabilities of wideband arrays. But it is difficult to measure, as all elements must be properly excited. Scan Element Pattern, whether measured on transmit with one element excited, or on receive, always yields relative scan performance, and frequency squared behavior. On transmit the driven element impedance is benign, but it is not Scan Impedance. On receive the impedance is Scan Impedance, but it is difficult to measure. Computer simulations are used to elucidate these characteristics.