Tag Archives: Radar

Homemade 6 GHz Radar, v3

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The third version of [Henrik Forstén] 6 GHz frequency-modulated continuous wave (FMCW) radar is online and looks pretty awesome. A FMCW radar is a type of radar that works by transmitting a chirp which frequency changes linearly with time. Simple continuous wave (CW) radar devices without frequency modulation cannot determine target range because they lack the timing mark necessary for accurately time the transmit and receive cycle in order to convert this information to range. Having a transmission signal modulated in frequency allows for the radar to have both a very high accuracy of range and also to measure simultaneously …read more

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Doppler Module Teardown Reveals the Weird World of Microwave Electronics

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Oscillators with components that aren’t electrically connected to anything? PCB traces that function as passive components based solely on their shape? Slots and holes in the board with specific functions? Welcome to the weird and wonderful world of microwave electronics, brought to you through this teardown and analysis of a Doppler microwave transceiver module.

We’ve always been fascinated by the way conventional electronic rules break down as frequency increases. The Doppler module that [Kerry Wong] chose to pop open, a Microsemi X-band transceiver that goes for about $10 on eBay right now, has vanishingly few components inside. One transistor for …read more

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Making a Cheap Radar Unit Awesome

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[JBeale] squeezed every last drop of performance from a $5 Doppler radar module, and the secrets of that success are half hardware, half firmware, and all hack.

On the hardware side, the first prototype radar horn was made out of cardboard with aluminum foil taped around it. With the concept proven, [JBeale] made a second horn out of thin copper-clad sheets, but reports that the performance is just about the same. The other hardware hack was simply to tack a wire on the radar module’s analog output and add a simple op-amp gain stage, which extended the sensing range well …read more

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The Sensors Automating Your Commute

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In a bout of frustration I recently realized that the roads have all updated — most people have no idea how — and this sometimes hurts the flow of traffic. This realization happened when an unfortunate person stopped in a left turn lane well before the stop line. The vehicle didn’t trigger the sensor, so cycle after cycle went by and the traffic system never gave the left turn lane a green light, thinking the lane was unoccupied. Had the driver known about this the world would have been a better place. The first step in intelligent automation is sensing, …read more

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RADAR Controlled Speakers

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[Scott] had a simple problem – he was tired of leaning over his work bench to change the volume on his speakers. He desired a system that would readily allow him to switch the speakers on and off from a more comfortable distance. Not one to settle for the more conventional solutions available, [Scott] whipped up a RADAR-activated switch for his speaker system.

The build relies on a surprisingly cost-effective RADAR module available off the shelf, running in the 5.8GHz spectrum. At under $10, it’s no big deal to throw one of these into a project that requires some basic …read more

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Automotive Radar and the Doppler Effect

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With more and more cars driving themselves, there is an increasing demand for precise environment aware sensors. From collision avoidance to smooth driving, environmental awareness is a must have for any self-driving cars. Enter automotive radar: cool, precise and relatively cheap. Thanks to a donated automotive radar module, [Shahriar] gifts us with a “tutorial, experiment and teardown.”

Before digging into the PCB, [Shahriar] explains the theory. With just enough math for the mathmagically inclined and not too much for the math adverse, [Shahriar] goes into the details of how automotive radar is different from normal stationary radar.

Only after a …read more

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Radar Sensors Put to the Test

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[Andreas Spiess] picked up a few inexpensive radar sensors. He decided to compare the devices and test them and–lucky for us–he collected his results in a video you can see below.

The questions he wanted to answer were:

  • Are they 3.3 V-compatible?
  • How much current do they draw?
  • How long to they show a detection?
  • How far away can they detect the motion of a typical adult?
  • What is the angle of detection?
  • Can they see through certain materials?
  • Can the devices coexist with other devices in the same area? What about WiFi networks?

Good list of questions, and if …read more

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The Right Circuit Turns Doppler Module into a Sensor

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Can you buy a working radar module for $12? As it turns out, you can. But can you make it output useful information? According to [Mathieu], the answer is also yes, but only if you ignore the datasheet circuit and build this amplification circuit for your dirt cheap Doppler module.

The module in question is a CDM324 24-GHz board that’s currently listing for $12 on Amazon. It’s the K-band cousin of the X-band HB100 used by [Mathieu] in a project we covered a few years back, but thanks to the shorter wavelength the module is much smaller — just an …read more

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