Direct RF and Heterodyne Receivers for Congested and Contested Electromagnetic Environments

Abstract

Recent advances in high-speed RF-sampling data converters and integrated digital channelization are enabling direct radio-frequency (Direct RF) digitization and instantaneous-wideband receiver architectures. These architectures offer the potential for improved probability of intercept against agile emitters, reduced sensing-to-response latency, and increased multi-mission flexibility in increasingly congested electromagnetic environments. At the same time, contested environments impose stringent constraints arising from front-end linearity, blocking, spurious responses, sampling-clock jitter, converter dynamic range, and real-time processing capacity. This paper presents a system-level comparison of Direct RF and heterodyne receiver architectures using a common Monte Carlo simulation framework in which both architectures are evaluated against identical realizations of the electromagnetic environment. Seven operationally motivated aspects are examined: probability of intercept, sensing-to-response latency, detection performance under emitter congestion, compute-limited scalability, blocking robustness, spectral exploitation efficiency, and multi-emitter deinterleaving performance. The analysis identifies the architectural trade space between persistent wideband observation and sequential spectrally selective reception, highlighting the roles of instantaneous bandwidth, finite digital-processing capacity, and analogue front-end protection. The resulting comparison motivates hybrid receiver architectures that combine selective analogue protection with wideband digitization and scalable digital processing for future electromagnetic operations.