A Wideband Vivaldi Antenna for Drone-Based Microwave Imaging System

Materials common in construction are reinforced concrete or cement-based materials. These materials occasionally develop cracks naturally due to deterioration throughout their lifecycle. The detection of cracks, erosion, voids, and gaps in walls and structural supports is critical in preventing structural failures. Microwave-based non-invasive techniques such as Non-Destructive Testing (NDT) is preferred to detect structural anomalies since there is no impact on the integrity of the structure or material due to the penetration capability of microwaves into dielectric materials. Current NDTs have several limitations and drawbacks, such as being heavy and bulky; however, they also share being expensive and restricted by maneuverability and scalability. An Unmanned Aerial Vehicle (UAV) or commonly known as a drone, can be equipped with a microwave imaging system capable of generating 3D subsurface images and remotely controlled to nondestructively scan buildings, bridges, and other infrastructures to detect anomalies. The drone can be maneuvered to access specific locations, both interior, and exterior, and reach certain heights while keeping personnel safe. The system would be scalable in hardware and software to fit certain applications or needs. The drone-based microwave imaging system is light-weight, consisting of one or multiple antennas, software-defined radios for transmitting and receiving signals, and microwave imaging algorithms to generate real-time 3D images. To achieve the light-weight design, the drone structure could be metallized and utilized as the antenna instead of mounting additional antennas and hardware. The 3D microwave images can help in assessing progress during the construction process or during inspections of existing structures for timely repairs. The use of this system can lead to more robust construction and structures and provide a lower-cost and precise solution than conventional NDTs.