Radar wideband digital beamforming based on time delay and phase compensation

Abstract

In conventional phased array radars, analogue time delay devices and phase shifters have been used for wideband beamforming. These methods suffer from insertion losses, gain mismatches and delay variations, and they occupy a large chip area. To solve these problems, a compact architecture of digital array antennas based on subarrays was considered. In this study, the receiving beam patterns of wideband linear frequency modulation (LFM) signals were constructed by applying analogue stretch processing via mixing with delayed reference signals at the subarray level. Subsequently, narrowband digital time delaying and phase compensation of the tone signals were implemented with reduced arithmetic complexity. Due to the differences in amplitudes, phases and time delays between channels, severe performance degradation of the beam patterns occurred without corrections. To achieve good beamforming performance, array calibration was performed in each channel to adjust the amplitude, frequency and phase of the tone signal. Using a field-programmable gate array, wideband LFM signals and finite impulse response filters with continuously adjustable time delays were implemented in a polyphase structure. Simulations and experiments verified the feasibility and effectiveness of the proposed digital beamformer. ARTICLE HISTORY

Comprehensive Review: Effectiveness of MIMO and Beamforming Technologies in Detecting Low RCS UAVs

“…The enhanced accuracy of narrowband beamforming in such applications ensures the reliable monitoring and management of UAVs in various operational contexts. Conversely, wideband beamforming with its broader frequency range offers better resolution and is more adept at operating in complex or cluttered environments, making it a potentially more effective technique in advanced radar systems [52][53][54]. The wider frequency range of wideband beamforming is advantageous for special scenario applications such as through-the-wall radar detection and groundpenetrating radar, due to its improved ability to better handle multipath propagation effects.…”

A New Radar Signal Recognition Method Based on Optimal Classification Atom and IDCQGA

“…For feature extraction, delay autocorrelation and phase difference characteristics, instantaneous characteristics, statistical characteristics, and transform domain characteristics are the most widely used [4]. The delay autocorrelation and phase difference between different modulation types can effectively identify the phase modulation signal by comparing the periodic differences of waveforms [5]. Instantaneous characteristics, such as instantaneous amplitude, instantaneous frequency and instantaneous phase, can clearly express the changing rules of non-stationary signals [6].…”