Take A Deep Dive Into A Commodity Automotive Radar Chip

January 17, 2023 by Dan Maloney 24 Comments

When the automobile industry really began to take off in the 1930s, radar was barely in its infancy, and there was no reason to think something that complicated would ever make its way into the typical car. Yet here we stand less than 100 years later, and radar has been perfected and streamlined so much that an entire radar set can be built on a single chip, and commodity radar modules can be sprinkled all around the average vehicle.

Looking inside these modules is always fascinating, especially when your tour guide is [Shahriar Shahramian] of The Signal Path, as it is for this deep dive into an Infineon 24-GHz automotive radar module. The interesting bit here is the BGT24LTR11 Doppler radar ASIC that Infineon uses in the module, because, well, there’s really not much else on the board. The degree of integration is astonishing here, and [Shahriar]’s walk-through of the datasheet is excellent, as always.

Things get interesting once he gets the module under the microscope and into the X-ray machine, but really interesting once the RF ASIC is uncapped, at the 15:18 mark. The die shots of the silicon germanium chip are impressively clear, and the analysis of all the main circuit blocks — voltage-controlled oscillator, power amps, mixer, LNAs — is clear and understandable. For our money, though, the best part is the look at the VCO circuit, which appears to use a bank of fuses to tune the tank inductor and keep the radar within a tight 250-Mz bandwidth, for regulatory reasons. We’d love to know more about the process used in the factory to do that bit.

This isn’t [Shahriar]’s first foray into automotive radar, of course — he looked at a 77-GHz FMCW car radar a while back. That one was bizarrely complicated, though, so there’s something more approachable about a commodity product like this.

Continue reading “Take A Deep Dive Into A Commodity Automotive Radar Chip” →

Hackaday Links: January 15, 2023

January 15, 2023 by Dan Maloney 18 Comments

It looks like the Martian winter may have claimed another victim, with reports that Chinese ground controllers have lost contact with the Zhurong rover. The solar-powered rover was put into hibernation back in May 2022, thanks to a dust storm that kicked up a couple of months before the start of local winter. Controllers hoped that they would be able to reestablish contact with the machine once Spring rolled around in December, but the rover remains quiet. It may have suffered the same fate as Opportunity, which had its solar panels covered in dust after a planet-wide sandstorm and eventually gave up the ghost.

What’s worse, it seems like the Chinese are having trouble talking to the Tianwen-1 orbiter, too. There are reports that controllers can’t download data from the satellite, which is a pity because it could potentially be used to image the Zhurong landing site in Utopia Planitia to see what’s up. All this has to be taken with a grain of dust, of course, since the Chinese aren’t famously transparent with their space program. But here’s hoping that both the rover and the orbiter beat the odds and start doing science again soon.

Continue reading “Hackaday Links: January 15, 2023” →

Another Magnetron Teardown

December 22, 2022 by Al Williams 22 Comments

[Electronoobs] has a healthy respect for the voltages and ceramics inside a microwave oven. But he still found the courage to tear one apart and show us the insides and characterize some of the components. You can see the video of the teardown below.

The danger of the voltage is obvious. However, there is also a ceramic insulator inside. Some of them are made from aluminum oxide, but others are made with beryllium oxide. You probably don’t want to inhale either one, but beryllium oxide, if powdered, can cause serious health problems. Obviously, you need to be careful if you decide to rip your oven open. Of course, the other danger is if you put the oven back together and try to use it. You need to ensure all the shielding is back in the proper place.

The video shows the operation of several of the components using test equipment and, in some cases, some surrogate components. The animation of an LC oscillator is very easy to understand. However, when he actually cuts into the magnetron with a rotary tool, you can really see how the device works. Some animations make it even clearer.

We haven’t seen a magnetron teardown for a few years. You can do many things with a magnetron from radar to vacuum deposition of films.

Continue reading “Another Magnetron Teardown” →

Casting Metal With A Microwave And Vacuum Cleaner

September 29, 2022 by Bryan Cockfield 39 Comments

Metalworking might conjure images of large furnaces powered by coal, wood, or electricity, with molten metal sloshing around and visible in its crucible. But metalworking from home doesn’t need to use anything more fancy than a microwave, at least according to [Denny] a.k.a. [Shake the Future]. He has a number of metalworking tools designed to melt metal using a microwave, and in this video he uses them to make a usable aluminum pencil with a graphite core.

Before getting to the microwave kiln, the pencil mold needs to be prepared. A 3D-printed pencil is first created with the graphite core, and then [Denny] uses a plaster of Paris mixture to create the mold for the pencil. The 3D printed plastic is left inside the mold and placed in the first microwave kiln, which is turned on just enough to melt the plastic out of the mold, leaving behind the graphite core. From there a second kiln goes into the microwave to melt the aluminum.

Once the molten aluminum is ready, it is removed from the kiln and poured in the still-warm pencil mold. This is where [Denny] has another trick up his sleeve. He’s using a household vacuum cleaner to suck the metal into place before it cools, creating a rudimentary but effective vacuum forming machine. The result is a working pencil, at least after he wears down a few razor blades attempting to sharpen the metal pencil. For more information about how [Denny] makes these microwave kilns, take a look at some of his earlier projects.

Continue reading “Casting Metal With A Microwave And Vacuum Cleaner” →

Industrial Robot Repurposed To Make S’Mores

July 31, 2022 by Ryan Flowers 14 Comments

It’s summer time in the Northern Hemisphere, and that means campfires for cooking hot dogs, keeping the mosquitoes away, and of course, making s’mores. For our far-flung friends, that’s a fire roasted marshmallow and a square of chocolate smashed between two graham crackers. So called because when you’re done, you’ll want s’more. It’s an easy enough recipe that any child can tell you how to make it. But what if you’re not a child? What if you don’t even have hands, because you’re an industrial robot? This is the challenge that [Excessive Overkill] has taken on in the video below the break.

Starting with a Fanuc S-420 i W industrial robot built in 1997, [Excessive Overkill] painstakingly taught his own personal robot how to make S’Mores. Hacking the microwave with pneumatic cylinders to get the door open was a nice touch, and so are the vacuum grippers at the business end of the S’More-bot.

We know, we said you were supposed to make them on a campfire — but who wants to risk cooking their vintage robotic arm just to melt some chocolate?

There’s a lot of story behind this hack, and [Excessive Overkill] explains how they acquired, transported, and three phase powered an out of date industrial robot in another of their videos. Of course, this is Hackaday so it’s a subject that’s come up before in the reverse engineering of an industrial robot that we covered some time back.

Continue reading “Industrial Robot Repurposed To Make S’Mores” →

Microwave Sampler Is Like Time Domain Mixer

January 13, 2022 by Al Williams 17 Comments

[Gregory] is building some microwave gear and wanted to convert a 3.3 GHz signal to a 12 MHz intermediate frequency. You might think of using a mixer, but you’d need a local oscillator of nearly 3.3 GHz which is not only hard to build, but also will be very close to the signal of interest which is not a great idea. Instead, [Gregory] opted for a sampler, which uses an effect you usually try to avoid — aliasing — to allow downconversion with a much smaller local oscillator. You can see the design in the video below.

In the case of converting 3.3 GHz to 12 MHz, the local oscillator is around 100 MHz. How does that work? Watch the video and find out. The final project will triple the 3.3 GHz signal and we presume the 12 MHz downconvert is to easily phase lock the frequency using a PLL (phase-locked loop).

Continue reading “Microwave Sampler Is Like Time Domain Mixer” →

A Microwave Frequency Doubler

October 18, 2021 by Al Williams 14 Comments

It is an age-old problem. You have a 2.5 GHz source and you want it at 5 GHz. You need a frequency doubler. [All Electronics Channel] has an interesting video that talks not only about the theory of such a device but shows a practical one made with copper strips on a blank PCB substrate.

A fun thing about microwaves is that even little strips of copper are circuit elements since the wavelength at 2.5 GHz is only 12cm. That means a quarter-wave stub is only 3 cm — just over an inch.

The construction technique used is simple and, as he points out, experimenting with a real circuit will give you much more feel for how these circuits work than just reading and working out the math.

The multiplier drives an amplifier into nonlinearity which, of course, generates harmonics. Then a bandpass filter selects the second harmonic. If you haven’t dealt with stub circuits before, you might want to read up on how a piece of copper connected at one end can act like an inductor, a capacitor, or even a tuned circuit.

If you want more detail on the copper tape technique, we can help. If you don’t want to double frequency, maybe you would prefer to try voltage.

Continue reading “A Microwave Frequency Doubler” →