In-flight performance analysis of direct RF sampling architecture applied to VHF band avionics

Abstract

For the future aviation industry, one of the most important requirements is simplifying the RF avionics, whilst increasing the security and performance of the current systems. Among the solutions, Direct RF Sampling (DRFS) architecture can be considered as one of the most promising. With the advantages of Local Oscillator (LO) mixer reduction and multisystem architecture compatibility, Direct RF architectures can significantly reduce the RF components between the antenna and the receiver, while at the same time support multiple avionics in parallel in just one single platform. As part of the AVIO-505 project, applications of DRFS architecture in VHF band avionics have been studied, specifically in VHF Omnidirectional Range (VOR), Instrument Landing System (ILS), VHF Radio, Emergency Locator Transmitter (ELT) and ACARS. Along with the laboratory experiments in a controlled environment using certified equipment (Aeroflex IFR-4000), a series of flight tests on a Cessna 172 have been conducted. As the main objectives of this paper, the results of these tests are presented and analyzed, which demonstrate the feasibility and capability of this innovative architecture in avionics. Furthermore, the potential of this architecture in other bands is discussed with an example in Automatic Dependent Surveillance-Broadcast (ADS-B)-In application, in which the jitter problem and its solution are presented in detail.