Dynamic Visualization of Antenna Patterns and Phased-Array Beam Steering [Education Column]

Antenna education is often hindered by the fact that radiation patterns are hard to visualize (RF electromagnetic waves are invisible), and require complicated, expensive equipment to measure. To solve this problem, we have built a wall that illuminates when RF energy is directed at it. This allows immediate visualization of an antenna´s radiation pattern, and of concepts such as wireless propagation, polarization, gain, and even phased-array beam steering. A low-power LED rectenna array is used to create the visualization wall. We have also developed a multicolor LED rectenna that changes color depending on incident power. Also included is a phased-array antenna with a crystal oscillator and power amplifi er on the same board. This board allows the user to control the phase of signals fed to each of four columns of a 16-element patch array using only a rotary selector switch. This allows instructors to demonstrate the principles of phased-array beam steering in real time, all with a self-contained system cost of less than $1500.