Active and Passive Beamforming in Phased Array Radar with Intelligent Reflecting Surface

Motivated by the improved detection performance in multi-input multi-output (MIMO) radar systems, we apply the intelligent reflecting surface (IRS) in the phased radar. To deal with this, we consider a more practical radar antenna model and IRS element model, and the near-field channel model between phased radar and IRS is assumed. An active radar beamforming and passive IRS beamforming are proposed aiming at maximizing the signal-to-noise ratio. Meanwhile, the SNR gain by introducing IRS in phased radar is analyzed which shows that the IRS deployment has great impacts on the SNR improvement. Simulation results illustrate that the proposed method can achieve better SNR performance with proper IRS deployment. The IRS cannot be located far from the phased radar and the angle between the radar and the IRS should be carefully tuned, otherwise, the benefit is limited.