A Two-Dimensional Electronically-Steerable Array Antenna for Target Detection on Ground

Target-detection with a proof-of-concept electronically-steerable array (ESA) antenna is demonstrated in this paper. First, the clutter level is investigated by using vertically-and horizontally-polarized electric fields. Two metallic cylinders with different sizes are subsequently used as targets and are characterized using standard 15-dBi horn antennas. The bigger cylinder reflects about 3 dB higher power than the smaller one. A 2x2 ESA antenna is designed, fabricated and tested for two-dimensional beam steering. Unlike standard horn antennas that exhibit no electronic steering, the 2x2 ESA is able to identify a target location by steering the beam angle from -40 to +40 degrees, when the target is placed at -25, 0, and +25 degrees. The reflected power from each target is 5 dB less when illuminated by the proof-of-concept 2x2 ESA than when illuminated by the standard horn antenna. This is due to the 5.2 dB gain difference between the two antennas. The findings of this work show the potential of ESAs in target detection technology

Wireless power transfer to a small, remote control boat

Over the past few decades, researchers have explored and implemented methods of wireless power transmission to operate devices that traditionally have been powered using plug-in power supplies and batteries. It is with this objective in mind that we built a boat, which is powered wirelessly from a field of harvestable energy. This project sought to develop a wirelessly powered remote control boat to be a proof of concept for the idea of wireless power transfer. Our criteria for success is that the boat should receive sufficient power to run anywhere in a 2.5 meter squared area. Having defined the field in which power will be required by our boat, we will fill this field with microwave RF energy. Finally, using a rectifying antenna, or rectenna, the energy will be harvested and delivered to the boat’s motors. We first developed three different topologies for our motor boat. For each boat, we made the minimization of power consumption a priority, while still maintaining speed and control. Operating between 100 and 200 milliwatts, each of the three topologies has a unique advantages and disadvantages with respect to its power consumption, speed, and controllability, and each has the ability to be powered wirelessly. From here, we plan to combine the rectenna with the boat, and deliver the power to our system. We will then characterize the radiation pattern of our power-receiving monopole antenna, and quantify the efficiencies of our various rectifier topologies