SFCW Radar with an Integrated Static Target Echo Cancellation System

Area of Science:

• Electrical Engineering
• Radar Systems
• Signal Processing

Background:

• Continuous Wave (CW) radar systems, including Ground-Penetrating Radar (GPR) and Through-Wall Imaging Radar (TWIR), suffer from receiver saturation and background noise due to strong echoes from stationary targets.
• Current methods like automatic gain control mitigate saturation but do not remove the underlying static target reflections from the signal.
• The need exists for an effective method to automatically remove static targets in moving radar platforms to enhance signal clarity and data interpretation.

Purpose of the Study:

• To propose and validate a novel method for real-time multiple static target Echo Cancellation (EC) in Frequency Modulated Continuous Wave (FMCW) or Swept Frequency Continuous Wave (SFCW) radar systems.
• To design an integrated system using active Integrated Circuit (IC) components for efficient static echo removal.
• To demonstrate the system's effectiveness in suppressing static targets without impacting the detection of dynamic targets or requiring high-dynamic-range receivers.

Main Methods:

• Development of an echo cancellation system integrated into an SFCW radar operating between 500 MHz and 2.5 GHz.
• Utilizing active IC components to generate and sum a corresponding echo cancellation signal for each frequency step with the received echo.
• Designing the system for a moving radar platform, assuming a constant distance between the surface and targets.

Main Results:

• Simulated static target echoes were suppressed by up to 38 dB using a cable as a known target.
• Experimental results in a real-world scenario with a moving radar platform demonstrated up to 20 dB attenuation of static targets.
• The proposed EC system showed minimal impact on the radar's size and power consumption, and did not affect the detection of dynamic targets.

Conclusions:

• The proposed echo cancellation system effectively removes multiple static targets in real-time for SFCW radar systems.
• The method offers a significant advantage by eliminating the need for high-dynamic-range receivers and preventing saturation.
• This technique presents a promising solution for compact implementation in SFCW radars and other CW radar types for improved performance.