volume | PIER Journals

Abstract

This paper presents a compact, low-cost, frequency-domain bistatic radar system using two identical square microstrip patch antennas fabricated on an FR-4 substrate (εr = 4.4, thickness = 1.6 mm). The antenna incorporates a suspended air-gap configuration to enhance bandwidth and radiation efficiency, and is designed to resonate near 3.3 GHz. The antenna was designed and optimised using CST Microwave Studio and experimentally validated using a Vector Network Analyser (VNA). Simulation results demonstrate a peak gain of 6.6 dBi and radiation efficiency of 83.2%. The fabricated antenna exhibits a measured peak gain of 7.0 dBi at 3.23 GHz and a |S₁₁| ≤ −10 dB bandwidth from approximately 3.0 to 3.5 GHz, with a measured resonance minimum of −14.3 dB at 3.27 GHz. The bistatic radar system operates over a swept frequency range of 2.8 to 3.8 GHz, acquiring complex S₂₁ parameters at each discrete frequency step. The received S₂₁ data is processed using background subtraction to suppress antenna coupling and background clutter, followed by an Inverse Fast Fourier Transform (IFFT) for range-domain target localisation. The proposed system is experimentally validated in single-target and multiple-target scenarios. Closely spaced targets are further characterised using a CLEAN iterative deconvolution algorithm as a post-processing step. Consistent target localisation across all scenarios is confirmed by two-dimensional radar images obtained from cross-range scanning. The results demonstrate the feasibility of a low-cost bistatic radar platform for short-range sensing applications including security scanning, remote target localisation, and multi-target detection

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Dr. Ankita Malhotra

Dr. Priyal Veera

Dr. Aryan Bhalkar

Dr. Rajiv Datta

Dr. Shubham Tayade

Professor Amit A. Deshmukh