UWB Vivaldi Antenna Array Lower Band Improvement for Ground Penetrating Radar Applications

Abstract

This paper concerns a ground penetrating radar system (GPR) presenting beam forming ability. This ability is due to a great flexibility in the emission of wavefronts. The innovative concept is to use an array of antennas which can reconfigure itself dynamically, in order to focus on a desired target. This antennas system can act as a new microwave sensor to detect and characterize buried targets in an inhomogeneous medium which is the case study in various application fields such as geophysics, medical, planetology,… Its electronics are in development with the DORT (Time reversal technique) method integration for optimizing the localization of buried target. This paper aims are to present the antenna optimization used in the GPR applications. Typical antennas used in GPR are generally Vivaldi ones directly on the ground. Especially, in the context of the space mission ExoMars 2020, the radar antenna is set on a mobile station at a distance of about 30 cm from the ground to avoid any contact. However, they are limited by their important size, due to the lowest frequency of their bandwidth. Results of this work concern an increase of the antenna bandwidth by shifting the lowerband limit, making it a UWB type without changing its size. As low frequency waves can spread deeper into probed medium, this optimization can improve the radar data inversion performances.

Partially dielectric loaded planar Vivaldi array antenna for forward‐looking GPR applications

“…Compared to the literature, the designed antenna's useable bandwidth starts from a very low frequency. 17 In this way, it will be advantageous for radar applications that require access to forest areas or deeply buried target detection. In addition, the gain of the upper part of the bandwidth increased without changing the antenna size or volume by using partial dielectric loading between the array elements.…”

“…In comparison to Wang and colleagues, 8,9,15,16 the proposed antenna is advantageous because of its smaller size, lower number of antenna elements, better gain, and bandwidth performance. Compared to the literature, the designed antenna's useable bandwidth starts from a very low frequency 17 . In this way, it will be advantageous for radar applications that require access to forest areas or deeply buried target detection.…”

1-Tx/5-Rx Through-Wall UWB Switched-Antenna-Array Radar for Detecting Stationary Humans

“…In this research, the through-wall switched-antenna-array radar scheme consists of one transmitting (Tx) and five receiving (Rx) Vivaldi antennas. The advantages of Vivaldi antennas are high antenna gain (10 dBi), narrow-angle directivity, and ultra-wide frequency band [26][27][28][29][30][31][32][33]. In through-the-wall image radar, the MIMO technology can be applied for higher-resolution radar imaging, but suffers from delayed data acquisition due to multiple transmitting and multiple receiving during operation [12][13][14][15][16][17][18][19][20][21], and the large number of MIMO elements contributes to higher fabrication costs and complexity.…”

“…In this research, the through-wall switched-antenna-array radar scheme consists of one transmitting (Tx) and five receiving (Rx) Vivaldi antennas. The advantages of Vivaldi antennas are high antenna gain (10 dBi), narrow-angle directivity, and ultra-wide frequency band [26][27][28][29][30][31][32][33]. Table 1 tabulates the dimensions of Tx and Rx Vivaldi antennas.…”

Compact Elliptical UWB Antenna for Underwater Wireless Communications

“…The recent narrow-band [ 21 , 22 , 23 , 24 , 25 ] antennas with a lower gain and a bigger size are designed with a complicated structure even though the Photonic Band Gap (PBG) structure could be a promising periodic structure to compensate those drawbacks. There are wide-band and ultra-wideband antennas in [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ] with less working BW, and a lower gain along with more substantial dimensions compared to the operating frequency for underwater communications. However, their implemented patch shape antennas complicated the design more.…”