AN UNBALANCED SINUOUS ANTENNA FOR ULTRA-WIDEBAND POLARIMETRIC GROUND-PENETRATING RADAR

Sinuous antennas are capable of producing ultra-wideband radiation with polarization diversity in a low-profile form factor, making them a good fit for close-in sensing applications such as ground-penetrating radar (GPR). This work proposes an unconventional method of operating a four-port sinuous antenna-driving each arm independently and unbalanced- to achieve a quasi-monostatic antenna system capable of polarimetry while separating transmit and receive channels, as is common in GPR systems. The quasi-monostatic configuration of the antenna reduces system size as well as increasing sensitivity to near-surface targets by preventing extreme bistatic angles. A prototype four-port sinuous antenna is fabricated and integrated into a GPR testbed. The polarimetric data obtained with the antenna is then used to distinguish between buried target symmetries.