Linear and Circular Polarization Antenna Arrays for Harmonic Radar System: Passive Non-linear Tag Tracking Application
Wireless signal communications engineering has evolved over several decades, and has significantly challenged the wireless systems industry, to achieve a consistent electromagnetic signal over a larger distance with consistent signal in the presence of noisy surroundings. This research proposes a high performance, low-power planar design, and demonstration of circularly polarized harmonic antenna arrays for 4 and 8 GHz harmonic radar system which is equipped, and the antenna’s circular polarization performance was tested using a passive nonlinear harmonic tag (snowflake) in a noisy environment. This work mainly concentrates on investigation of the wave polarization, gain estimation and impedance matching of the antenna arrays that will be potentially assembled to the second-order harmonic radar system operating at 4 and 8 GHz, which plays a critical role in tag localization and post processing methods. The passive snowflake tag design was implemented in the simulation to determine the current distribution and gain plot patterns in comparison to a classic dipole antenna tag structure. In experiments: a combination of fundamental circular polarized (Left-Hand and Right-Hand) antennas were demonstrated to find Axial Ratio (A.R.) ≤ 3 dB band. A novel tag localization measurement, with various combinations of linear and circular polarized harmonic antenna arrays was utilized to perform and obtain the circular polarized received signal power in dBm v/s angle rotation by every 10° on a rotating platform setup. Finally, the wireless tag tracking result was achieved by using the designed circularly polarized antennas and the passive non-linear tag orientation setup.