Direct speed output
Measure vehicle speed from 1 to 240 km/h without requiring an external radar signal processor.
24 GHZ DOPPLER VEHICLE SPEED SENSOR
HC-TR20 Radar Speed Sign Sensor
Measure approaching or departing vehicle speed at over 200 metres. HC-TR20 is a compact Doppler radar module for radar speed signs, curve warnings and roadside safety systems.
PCBA standard supplyRS485 + 3.3 V TTL UART9600 bps
HC-TR20PRODUCT OVERVIEW
Vehicle speed data for signs and roadside warnings
HC-TR20 integrates the microstrip antenna, RF circuit and signal processing into a compact module that directly outputs vehicle speed and direction for downstream controllers.
Approach or departure
Configure detection for approaching vehicles, departing vehicles or both directions.
Long detection distance
Detect vehicles at more than 200 metres when alignment, target and site conditions support the range.
Compact integration
Use the 69 × 53 × 5 mm PCBA in a speed sign, warning controller or custom roadside enclosure.
SPEED OUTPUT & INTEGRATION
Simple data for embedded roadside systems
HC-TR20 sends measured speed through RS485 or 3.3 V TTL UART at 9600 bps. It can also provide high- or low-level active warning outputs for controller integration. For the detailed communication protocol and integration documentation, please contact our technical team.
SENSINGHC-TR20 radarMeasure radial vehicle speed
→
OUTPUTSpeed + directionRS485 · TTL UART · warning signal
→
INTEGRATIONYour controllerDisplay · warn · log · configure
APPLICATIONS
Focused on speed feedback and road warnings
Radar speed signsSend live vehicle speed to an LED driver-feedback display.
Curve warning systemsDetect approaching speed before a bend and activate a warning output.
Intersection approach warningTrigger roadside safety equipment when a vehicle enters the monitored approach.
Custom roadside devicesEmbed the PCBA and speed output in an OEM traffic-safety controller.
Application note: HC-TR20 is a single-speed-output sensor for feedback and warning systems, not a multi-target tracking radar.
PRODUCT CONFIGURATIONS
Standard PCBA or optional enclosure
The HC-TR20 normally ships as the compact PCBA module. If your project requires the protective enclosure shown below, specify it before ordering.
TECHNICAL SPECIFICATIONS
HC-TR20 performance
Use these values for initial system design. Final distance and accuracy depend on vehicle reflection, radar alignment, installation stability and site conditions.
Confirm project fit| Parameter | Specification |
|---|---|
| Vehicle detection distance | More than 200 m |
| Speed measurement range | 1 to 240 km/h |
| Speed measurement error | Within ±1 km/h when the vehicle direction is aligned with the radar beam axis |
| Transmit frequency | 24.075 to 24.175 GHz; 24.125 GHz typical |
| Output power (EIRP) | 18 dBm typical; 20 dBm maximum |
| Transmit antenna gain | 16 dBi |
| Receive antenna gain | 18.4 dBi |
| Transmit beam (3 dB) | ±22° horizontal; ±8° vertical |
| Receive beam (3 dB) | ±11° horizontal; ±8° vertical |
| Communication | RS485 and UART (3.3 V TTL), 9600 bps |
| Power supply | 9 to 24 V DC; 75 mA typical at 12 V |
| Operating temperature | −20 to +85 °C |
| Storage temperature | −40 to +125 °C |
| PCBA dimensions | 69 × 53 × 5 mm |
| Optional enclosure dimensions | 100 × 85 × 20 mm |
INSTALLATION & CONNECTION
Align the beam with the vehicle path
Doppler radar measures the radial component of speed. Install HC-TR20 on a stable structure and keep the beam as close as practical to the vehicle travel direction for the best accuracy.
Minimize the angle between the radar beam axis and vehicle movement direction.
Select the output direction that matches the speed-sign or warning application.
Use 9600 bps serial communication or the configured warning output.
Use a suitable field enclosure or request the optional product enclosure before ordering.
PROJECT SUPPORT
Match the speed sensor to your roadside controller
Share the sign or warning application, target distance, installation angle, supply voltage, interface and preferred speed unit. Our team can help confirm the configuration.
01Application02Mounting angle03Serial interface04Field test
TECHNICAL FAQ
Common HC-TR20 questions
What does the HC-TR20 output?
HC-TR20 directly outputs measured vehicle speed and direction. Speed units can be configured as km/h, mph or m/s, and warning signal outputs are also available.
Does the standard product include an enclosure?
The standard supply is the 69 × 53 × 5 mm PCBA module. The protective enclosure is optional and should be specified before ordering.
Can it distinguish approaching and departing vehicles?
Yes. The radar can be configured for approaching targets, departing targets or both directions.
Is HC-TR20 a multi-target tracking radar?
No. HC-TR20 is designed to provide vehicle speed and direction for signs and warning systems. Use an HC-M series radar when coordinates, trajectories, classification or multi-target tracking are required.
How does the radar connect to a controller?
It supports RS485 and 3.3 V TTL UART at 9600 bps. For the detailed communication protocol, please contact our technical team and share your integration requirements.
What information should I provide before ordering?
Provide the application, required distance, road geometry, mounting angle, supply voltage, interface, speed unit and whether you need the optional enclosure.
DISCUSS AN HC-TR20 PROJECT
Send us your sign or warning-system requirements.
We will use your application, target distance, mounting angle, interface and enclosure requirements to recommend the next technical step.