Development of an ultra-wideband Vivaldi antenna array for radar measurement of snow thickness and density

We present an ultra-wideband 2-18 GHz Vivaldi antenna array for airborne radar measurement of snow thickness and density. Estimation of snow parameters, such as density or snow-water-equivalent requires the knowledge of volume and surface scattering from snow (H. Rott et al., Int'l Symp. on Geoscience and Remote Sensing, pp. 144-147, 2009). Due to the resolution requirement and the sensitivity of the S/C-band (2-8 GHz) and Ku-band (12-18 GHz) radar backscatter to physical properties of the snow, the frequency band of interest is chosen to be 2-18 GHz (G. Parrella et al., IEEE Int'l Symp. on Geoscience and Remote Sensing, pp. 4410-4413, 2012). In view of this, we have developed a 10 × 10 ultra-wideband 2-18 GHz dual-polarized Vivaldi antenna array. The array is based on the design proposed by Kindt and has been extended to operate from 2 to 18 GHz (R. W. Kindt and W. R. Pickles, IEEE Trans. on Antennas and Propagation, 60, 3, pp. 1320-1328, 2012). As an experimental verification of the dual-polarized antenna array design, we have fabricated and tested a single 10-element slice of the array. Due to the absence of the other polarized element, this single-polarized antenna array provides a VSWR 2:1 across the bandwidth from 2.6 to 18 GHz. Our experimental results show that the prototype array performs closely to the simulation results in terms of both VSWR and radiation patterns. A comparison of the simulated and measured results will be presented. Measurement results of the full dual-polarized array are also expected to be presented at the conference.