Calibration of Wideband LFM Radars based on Sliding Window Algorithm

TL;DR

This paper introduces a novel calibration method for wideband LFM radar systems using a sliding window algorithm, effectively correcting frequency-dependent errors and time delays based on the unique properties of LFM signals.

Contribution

It presents a new calibration technique leveraging the LFM signal's characteristics, applicable to various beamforming systems beyond radars.

Findings

The method accurately calibrates frequency-dependent errors.

Simulation results confirm improved beamforming accuracy.

The approach is versatile for different systems using LFM signals.

Abstract

This paper addresses the challenges of wideband signal beamforming in radar systems and proposes a new calibration method. Due to operating conditions, the frequency dependent characteristics of the system can be changed, and amplitude, phase, and time delay error can be generated. The proposed method is based on the concept of sliding window algorithm for linear frequency modulated (LFM) signals. To calibrate the frequency-dependent errors from transceiver and the time delay error from true time delay elements, the proposed method utilizes the characteristic of the LFM signal. The LFM signal changes its frequency linearly with time, and the frequency domain characteristics of the hardware are presented in time. Therefore, by applying matched filter to a part of the LFM signal, the frequency dependent characteristics can be monitored and calibrated. The proposed method is compared with the conventional matched filter based calibration results and verified by simulation results and beampatterns. Since the proposed method utilizes LFM signal as calibration tone, the proposed method can be applied to any beamforming systems, not limited to LFM radars.