Comparative Analysis of Three FDA System Receiving Beam Models

Enabled by advanced signal processing methodologies, the transmitter and receiver end of frequency diverse array (FDA) systems can be decoupled for independent theoretical analysis. This study methodically classifies and generalizes three fundamentals receive beamforming modes for FDA architectures: narrowband coherent processing, wideband pseudo-coherent processing, and wideband fully-coherent processing. Comprehensive theoretical derivations complemented by numerical simulations are performed to characterize their beamforming properties. The analytical framework is structured as follows: First, a transmit beamforming model derived from classical linear array theory is formulated, with particular attention to its intrinsic space-time coupling characteristics. Subsequently, the operational mechanisms of receive beamforming are rigorously examined under three distinct signal processing paradigms, differentiated through matched filtering techniques and cross-correlation operations. Numerical simulations reveal two critical findings: (1) While the main lobe structures preserve consistent spatial morphology across all modes, (2) the sidelobe regions manifest significant time-frequency feature disparities attributable to distinct signal processing frameworks. These observations demonstrate remarkable agreement with the proposed analytical predictions. The generalized receive beamforming models establish a unified theoretical foundation for FDA systems, providing foundational insights to advance their implementation in next-generation radar architectures and spectrally efficient communication systems.