Generalized Radar Range Equation Applied to the Whole Field Region

Area of Science:

• Electromagnetics
• Radar Systems Engineering
• Applied Physics

Background:

• Conventional radar range equations are inadequate for terahertz (THz) radar operating in the near-field due to limited source power and target scattering characteristics.
• Near-field operation is common in THz radar, necessitating a revised approach for accurate range calculations.

Purpose of the Study:

• To develop a generalized radar range equation applicable to both near-field and far-field regions for THz radar systems.
• To establish a robust near-field radar theory for improved radar cross section estimation and system design.

Main Methods:

• Numerical simulations were performed to derive a near-field radar cross section (RCS) formula for various targets.
• Parameters such as antenna gain and target RCS were modified to propose a generalized radar range equation.
• The effectiveness of the proposed equation was validated using THz radar working efficiency and near-field RCS simulation models.

Main Results:

• The proposed generalized radar range equation provides smaller calculation results in the near field compared to the conventional equation.
• The generalized equation yields identical results to the conventional equation in the far field.
• The equation was successfully applied to complex targets and demonstrated extensibility across a wider frequency band.

Conclusions:

• The generalized radar range equation is effective for the entire radiation area, encompassing both near and far fields.
• The established near-field radar theory supports radar cross section estimation in extremely high frequencies.
• This work facilitates the fine design of THz radar systems and broadens their application scope.