I’ve for some time now wanted to do more RF design. Although I have taken some RF design courses, I haven’t actually made a single RF design before. But you can’t learn without doing and inspired by the MIT coffee can radar designed by Gregory Charvat, I figured that building a radar should be a doable project that would offer some challenge while also having some real world use.
The simplest radar is a continuous wave Doppler radar, which continuously transmit a constant frequency signal. This signal reflects from a moving target and Doppler shift causes reflected signal to change frequency. This reflected signal is then received and mixed with the transmitted signal. Mixer product is the difference of the frequencies which is proportional to the speed of the target. This kind of radar is very simple to make, in fact there are even some children’s toys. Unfortunately it can’t detect the range of the target and isn’t that exiting.
6 GHz frequency modulated radar - [Link]
Elias, Øyvind and Jonas writes:
If we add up all our radar experience, the three of us have 9 years of experience with this technology. Our company have existed for three years now and we can see that the technology has a lot of potential.
We love radar technology. Why? Because it can see through stuff. Yes, that is right. A radar uses electromagnetic pulses that can travel through materials. Just like wifi signals and cellphone signals.
This means you can create a device that the police can use to get information about what is going on behind a door before entering a house. Or you can measure the vital signs of a person lying in a hospital bed from a distance. Or you can make a robust altimeter for drones that is not affected by wind, temperature or fog.
Dipper- a small, affordable and open source UWB radar - [Link]
In the heart of the D1 radar sensor is a radar chip based on Ultra-Wideband (UWB) radar technology from Novelda (www.novelda.no). An UWB radar sensor sends out electromagnetic pulses and looks at the pulses that are reflected back. When an electromagnetic pulse hits the wall in the video above, a part of the pulse is reflected back to the radar and a part of it penetrates the wall and is reflected from the cabinet behind the wall.
See-through-wall robot - [Link]
Much as humans and other animals see via waves of visible light that bounce off objects and then strike our eyes’ retinas, radar “sees” by sending out radio waves that bounce off targets and return to the radar’s receivers. But just as light can’t pass through solid objects in quantities large enough for the eye to detect, it’s hard to build radar that can penetrate walls well enough to show what’s happening behind. Now, MIT Lincoln Lab researchers have built a system that can see through walls from some distance away, giving an instantaneous picture of the activity on the other side.
The researchers’ device is an unassuming array of antennas arranged into two rows — eight receiving elements on top, 13 transmitting ones below — and some computing equipment, all mounted onto a movable cart. But it has powerful implications for military operations, especially “urban combat situations,” says Gregory Charvat, technical staff at Lincoln Lab and the leader of the project. [via]
Radar can see through walls - [Link]
The “Cantenna Radar” is a radar project that we (Tony Hyun Kim, Nevada Sanchez, Paresh Malalur) assembled from a kit provided by Lincoln Labs for an IAP 2011 course at MIT. The name “Cantenna” derives from the fact that the antenna actuators are actually recycled coffee cans! Photographs and basic schematic of the device are shown below:
Coffee can radar – [Link]