Seeed Studio Launches Sub-$7 mmWave 24GHz Human Static Presence Module Lite
https://www.hackster.io/news/seeed-studio-launches-sub-7-mmwave-24ghz-human-static-presence-module-lite-438ed4090a2e

New, cheaper sensor has a shorter range than its predecessor but comes with new distance and speed measuring capabilities.

If you’re partial to browsing AliExpress, Banggood, or eBay for unusual hardware, you may have seen the HB100 Doppler Radar modules. These are a PCB with a metal can on board, and their reverse side has a patch antenna array. They work on a frequency of 10.525 GHz, and [OH2FTG] has characterized a few of them to see how close they lie to that figure.

These devices have a superficially very simple circuit that makes extensive use of PCB layout for creating microwave inductors, capacitors, and tuned circuits. There’s a FET oscillator and a diode mixer, and a dielectric resonator coupling the output and input inductors of the FET. This component provides the frequency stability, but its exact frequency depends on what lies within its electric field. Thus the screening can does more than screening, and has a significant effect on the frequency and stability of the oscillator.

The higher quality HB100s have a small tuning screw in the top of the can which in turn adjusts the frequency. This should be tweaked in the factory onto the correct point, but is frequently absent in the cheaper examples.

https://www.youtube.com/watch?v=C5xWcHKanUE

DIY radar speed sign looks and works like the real thing
https://blog.arduino.cc/2021/06/29/diy-radar-speed-sign-looks-and-works-like-the-real-thing/

McNelly’s design relies on an Arduino Nano and a Doppler radar module that sends out 10.525GHz radio pulses continuously and measures how much the reflected frequency has changed.

The sign also uses a giant seven-segment display for showing the speed to passersby.

http://johnmcnelly.com/arduino-radar-speed-sign/

https://github.com/CoolNamesAllTaken/radar-speed-sign

The Ttime is based on pulse lengths read with pulseln() function that returns the length of the pulse in microseconds.

unsigned int Ttime = nbPulsesTime / AVERAGE;
unsigned int Freq = 1000000 / Ttime

where the number “1000000″ is obtained? thank you for your attention.

Using loop antennas crafted on an embroidery machine and a modified Doppler sensor board, soft fabrics can get gesture sensing smarts.

Using loop antennas crafted on an embroidery machine and a modified Doppler sensor board, soft fabrics can get gesture sensing smarts.

The electronics are made up of a customised sensing board split into two parts: A modified HB100 Doppler Radar Motion Detector forms the sensor half, while modified Adafruit Bluefruit LE Micro development board handles data collection and transmission to a remote laptop for data processing via the Random Forest machine learning algorithm.

Built around Infineon’s BGT24LTR11, the compact Grove Doppler Radar takes aim at advanced driver assistance system (ADAS) projects

This blog reveals how to classify pedestrians and bicyclists based on their micro-Doppler characteristics using a deep-learning network and time-frequency analysis.