On Ultra-Wideband Multifunctional Aesa Systems with First Experimental Measurements

This paper focuses on the development of an ultrawideband Active Electronically Scanned Array (AESA) based Multifunctional RF-System (MFRFS) demonstrator, employing a full-polarimetric aperture and making use of Gallium-Nitride (GaN) Transmit-Receive Modules (TRMs) with True Time Delays. Key elements of the investigations include the design and construction of the AESA frontend, its assembly, integration and initial testing in a controlled laboratory environment, as well as experimental antenna measurements in an anechoic chamber, suitable for ultra-wideband electronic scanning without beam squint effects. The system exhibits characteristics such as low Noise Figure and high RF-power density comparable to modern fighter Radars, but over a larger frequency range from <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$C$</tex> to upper Ku band, highlighting its suitability for multifunctional RF applications. Additional assessments encompass ultra-wideband radiating element and aperture measurements including singleelement adjustments for amplitude and delay matching, Plank and multi-channel TRM construction, and excessive environmental testing to ensure robustness and reliability of the design.