Design of a Generic Test Item

The ever-increasing sophistication of modern military aircraft avionic systems also poses a greater risk of susceptibility to Electromagnetic Environmental Effects (E3) from both natural and man-made sources. Of interest are not only the induced Radio Frequency (RF) currents flowing on the aircraft skin and radiated fields penetrating directly into the aircraft, but what effects these currents and fields may have on electronic circuit components. This paper describes a Generic Test Item (GTI); a device that is able to quantify and help visualise the effects of electromagnetic interference on avionics equipment at the signal level. This portable, battery operated device uses an ARDUINO compatible development board with an ATMEL microcontroller to simulate electrical signals within an aircraft cavity and alerts the operator to possible signal corruption due to the electromagnetic environment. The GTI presented in this paper is a prototype, limited to simulating RS422 and Transistor-Transistor-Logic (TTL) digital signals only. However, the concept can be extended to a wide range of protocols.