The direct current injection (DCI) method, sometimes also referred to as direct drive, for aircraft high-intensity radiated field (HIRF) certification is evaluated. The method aims at reducing the necessity of resource-intensive radiated field testing at frequencies below the very high frequency band. Surface currents of a fuselage model are evaluated both analytically for incident fields and using DCI techniques. Resulting conductor currents occurring inside the fuselage model are measured and compared for both the incident field and DCI measurement techniques. The comparison approach is a direct one, meaning that no transfer function is applied between the methods.Index Terms-Aircraft, direct current injection (DCI), direct drive, high-intensity radiated field (HIRF).

No abstract

HIRF transfer functions results are rarely available to the public. Generally, the data provided in applicable guidance material are used for estimation of internal HIRF environment in an air vehicle. An exemplary set of HIRF transfer functions for a small aircraft is presented here. Results for the aircraft (10.4-m wingspan and 8.3 m of length) are compared with regard to state of the art approaches applied for aircraft HIRF certification campaigns. This is done in appropriate frequency ranges and by the use of applicable test methods with regard to requirements in place. For all major types of contemporary test methods, results are generated by measurement and numerical computer modeling. Principles of outcomes are discussed and compared to current practice in place. This concerns the shapes of the transfer functions on one hand and the order of magnitudes of obtained levels on the other hand. The obtained results show significant deviations from generic transfer functions currently applied in aircraft industry. The coupling to the interior of the aircraft observed here was higher than indicated by the applicable generic transfer functions. Numerical computer modeling is used here to verify the obtained outcomes by principle.Index Terms-Direct current injection (DCI), high intensity radiated fields (HIRF), low level direct drive (LLDD), low level swept current (LLSC), low level swept field (LLSF), method of moments (MoM).

An entire set of high-intensity radiated field transfer functions including the main types of contemporary test methods is presented. Consequently, the applied frequency range for this task expands over many decades, from the kilohertz range up to 40 GHz. A major aim is to demonstrate the application of numerical computer modeling for such a task. Results of measurements and various solvers are compared to each other. As the activity serves also for the validation of such applications, the scenario is investigated by the use of a fuselage model with limited complexity. Index Terms-Asymptotic, computational electromagnetics (CEM), direct current injection (DCI), finite-difference time domain (FDTD), high-intensity radiated fields (HIRF), low-level direct drive (LLDD), low-level swept current (LLSC), low-level swept field (LLSF), method of moments (MoM), power balance (PWB).

Time Domain (TD) and Frequency Domain (FD) simulations of aircraft internal electromagnetic environment were carried out using a digital mockup of a real small aircraft. Results are compared with the experimental High Intensity Radiated Fields (HIRF) certification test carried out in a semianechoic chamber