When you search "HDTV antenna" on Amazon, you're going to see about 20 to 30 cheap flat-panel antennas made for city homes. Though they all look the same, I found the Channel Master Flatenna ...

This passive device lets you steer signal beams for over-the-air wireless test systems. Vaunix Technology, a manufacturer of modular RF/wireless test equipment, has introduced the LBM-7250-4 Lab Brick ...