**2. GPR system**

 Egypt desert water, land mines, and Egyptian ancient mummy detection are an important, and yet challenging problem remains to be solved and is a matter of concern for both civilian groups and military. Water depth, quantity, and volume are different from location to another, and landmines have huge variety in use with various sizes and materials. They are mostly designed in a circular, rectangular, butterfly, or cylindrical shapes as V69, PSM-1, Hamdy, and Mon 200 with dimensions 13, 7.6, 21, and 43 cm, respectively. On the one hand, the electrical properties of water purity are changed due to water quantities and mineral contained; on the other hand, the electrical properties of the mummy are varying according to biological materials involved as tissues, bones, scapula, and femur, respectively [23]. The average effective dielectric constant is equal to 6.5 and dielectric loss equal to 15 [24].

*Detection of Underground Water by Using GPR DOI: http://dx.doi.org/10.5772/intechopen.83594* 

Groundwater is a hidden natural resource. It is found in different proportions, in various rock types, and at various depths of ground surface. Previously, in the past, when there is no visible flow of water along the rivers or lakes, people used to dig small pits, in the river alluvium, then collect the groundwater coming through seepage to use in different purposes and for meeting the domestic needs. As well as the people of mountainous area, springs are the outcome of seepage from any groundwater system [25, 26].

More than 60% of the global population thrives by using only the groundwater resources. The groundwater, which was existing at shallow depths in the open wells, has gone deep due to overexploitation. Exploring these water sources becomes a challenging task to geoscientists [27–29].

 As the signal of the GPR is required to propagate through inhomogeneous media, the efficiency of the antenna should be taken into account. Thus, in order to enhance the efficiency, a compact shape of Vivaldi is designed [7]. The compactness in the shape of antenna is achieved by using two Vivaldi surface shapes with the same feeding network. Frequency-modulated continuous wave (FMCW) is another type than pulse wave also used for GPR and for through-the-wall applications. FMCW systems are transmitting a repetitive waveform with increasing or decreasing frequency [21]. UWB-FMCW systems require a linear sweep, which may be difficult to create. Lower-frequency signals are required to penetrate the ground effectively as the penetration depth decreases with increasing frequencies.

 GPR radar could be used for soil with different electrical properties to detect water underground [30, 31]. However, a broadband signal with good resolving power is required. Thus, the GPR antenna should operate on lower frequency and should have a very wide bandwidth. Also, the UWB antenna applied to communication system with high gain is highly desired [32].
