If you’ve been following the world of mobile phone technology of late, you may be aware that Apple’s latest IPhones and AirTag locator tags bring something new to that platform. Ultra wideband radios are the new hotness when it comes to cellphones, so just what are they and what’s in it for those of us who experiment with these things?
Ultra wideband in this context refers to radio signals with a very high bandwidth of over 500 MHz, and a very low overall power density spread over that spectrum. Transmissions are encoded not by modulation of discrete-frequency carriers as they would be in a conventional radio system, but by the emission of wideband pulses of RF energy across that bandwidth. It can exist across the same unlicensed spectrum as narrower bandwidth channelised services, and that huge bandwidth gives it an extremely high short-range data transfer bandwidth capability. The chipsets used by consumer devices use a range of UWB channels between about 3.5 and 6.5 GHz, which in radio terms is an immense quantity of spectrum. Continue reading “What Is Ultra Wideband?”→
What could possibly be better than printing out a few low-resolution voxels on a MakerBot? A whole lot of things, but how about getting those voxels with your own synthetic aperture radar? That’s what [Gregory Charvat] has been up to, and he’s documented the entire process for us.
The build began with an ultra wideband impulse radar we saw a while ago. The radar is built from scraps [Greg] picked up on eBay, and is able to image a scene in the time domain, creating nice linear sweeps on a MATLAB plot when [Greg] runs in front of the horns.
With an impulse radar under his belt, [Greg] moved up the technological ladder to something that can produce vaguely intelligible images with his setup. The synthetic aperture radar made from putting his radar horns on the carriage of a garage door opener. The horns slowly scan back and forth along the linear rail, taking single impulse readings and adding them together in an image. In the video below, [Greg] is able to image a few pieces of copper pipe only a few inches in diameter. The necessary equipment for this build only cost [Greg] a few hundred bucks at the Dayton Hamvention, and a similar setup could be put together for even less.
If building an X band impulse synthetic aperture radar isn’t impressive enough. [Greg] also 3D printed one of his radar images on a MakerBot. That’s just applying stlwrite to the 2D radar image and feeding it into MakerWare. Gotta have that blog cred, doe. It also makes for the best headline I’ve ever written.