No abstract

Sinuous antennas exhibit many desirable properties for ground penetrating radar (GPR) applications such as ultrawide bandwidth, polarization diversity, and a low-profile form factor. However, sinuous antennas are dispersive since the active region moves with frequency along the structure. This is an undesirable quality for pulsed-radar applications since the radiated pulse will be distorted. Such distortion may be detrimental to close-in sensing applications such as GPR. This distortion may be compensated in processing with accurately simulated or measured phase data. However, antenna performance may deviate from that simulated or measured due to the dielectric loading of the ground. In such cases, it may be desirable to employ a dispersion model based on antenna design parameters which may be optimized in-situ. Dispersion compensation models previously investigated for other antennas may be similarly applied to sinuous antennas. This paper explores the dispersive properties of the sinuous antenna and presents a simple model that may be used to compress dispersed pulses.

No abstract

Sinuous antennas are capable of producing ultra-wideband radiation with polarization diversity. This capability makes the sinuous antenna an attractive candidate for UWB polarimetric radar applications. Additionally, the ability of the sinuous antenna to be implemented as a planar structure makes it a good fit for close-in sensing applications such as ground-penetrating radar (GPR). In this work, each arm of a four-port sinuous antenna is operated independently to achieve a quasi-monostatic antenna system capable of polarimetry while separating transmit and receive channels-which is often desirable in GPR systems. The quasi-monostatic configuration of the sinuous antenna reduces system size as well as prevents extreme bistatic angles, which may significantly reduce sensitivity when attempting to detect near-surface targets. 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.