24GHz mmWave Radar Sensor – Human Static Presence Detection Module

Introduction

The 24GHz Millimeter-Wave (mmWave) Radar Sensor is an advanced human static presence detection module designed for security, safety, and smart automation applications. Detecting human presence in an Area of Interest (AOI) is essential in environments such as homes, offices, hotels, and high-security areas.

Among various detection technologies, radar technology is one of the most reliable and efficient methods for detecting human presence. Radar systems use radio waves to detect objects and determine their position, speed, and angle. A radar system consists of a transmitter that emits electromagnetic (microwave) waves. These waves reflect off objects and return to the receiver, helping determine the object’s location and movement.

In addition to motion detection, modern mmWave radar technology can even detect subtle human biological signatures such as breathing patterns and heartbeats.

Advantages Over Traditional PIR Sensors

Compared to traditional PIR (Passive Infrared) sensors, the Human Static Presence Module offers significantly higher sensitivity. It can detect:

Standing individuals
Moving persons
Falling movements
Micro-movements such as breathing

Because it operates using millimeter-wave transmission, it continues functioning even when partially obstructed by materials such as plastic or thin barriers. Unlike PIR sensors, which respond only to motion and may stop detecting when movement ceases, this module continuously monitors human presence.

This makes it highly suitable for applications in living rooms, hotel rooms, offices, healthcare facilities, and correctional institutions.

What is an mmWave Radar Sensor?

mmWave (millimeter-wave) radar sensors operate within the frequency range of 30GHz to 300GHz. Due to their extremely short wavelengths, they provide:

Sub-millimeter accuracy
High-resolution detection
Small antenna size
Penetration through materials such as plastic, drywall, and clothing
Reliable operation in rain, fog, dust, and snow

The 24GHz radar module uses FMCW (Frequency Modulated Continuous Wave) and CW signals. The working process includes:

The sensor transmits FMCW and CW radio waves into the detection area.
These waves reflect off moving, micro-moving, or stationary targets.
The internal MMIC circuit converts reflected waves into electrical signals.
Data processing algorithms analyze the signals to determine human presence and activity.

24GHz Radar Module Overview

This radar module is designed for microcontroller-based applications. It operates with low power consumption and offers wide detection coverage.

Operating Voltage: 3.3V – 5V
Current Consumption: 80–90mA
Maximum Detection Range: Up to 9 meters
Wide Beam Angle Coverage

Interface (2.0 mm, 4-Pin)

VCC – 5V Power Supply
GND – Ground Connection
URX – TTL Serial Receive
UTX – TTL Serial Transmit

Technical Specifications

Frequency: 23.5GHz – 24.5GHz
Modulation Method: FMCW
Detection Distance: >4m (static), >8m (moving)
Installation Height: 3m (static detection radius >2m)
Power Supply: 3.3V – 5V
Current: 80mA
Output Serial Level: 3.3V
Detection Cycle: Adaptive
Antenna Half-Power Angle: Horizontal ±22°, Vertical ±24°
Data Format: Serial Port ASCII Output

Key Features

Reliable Technology: Infineon mmWave FMCW industrial radar technology
Doppler Radar Principle: Uses Near Distance Sensor (NDS) technology operating at 24GHz
Intelligent Algorithm: Distinguishes between occupied and unoccupied conditions automatically
Privacy Protection: Provides detection without capturing personal identity
Flexible Installation: Works properly even with partial obstructions
Safe Operation: Outputs harmless 10 dBm energy power
High Accuracy: More than 95% detection accuracy with reduced interference
High Robustness: Functions effectively under varying temperature, humidity, dust, airflow, and lighting conditions
High-Performance Antenna: Detects micromotions with Horizontal 90° / Vertical 60° coverage

Measurement Distance

Motion Detection: Up to 12 meters
Micromotion Detection: Up to 5 meters
Body Presence Detection: Up to 3 meters

Response Time

Unoccupied to Occupied: Within 0.5 seconds
Occupied to Unoccupied: Above 1 minute

Customizable Radar Module

The radar module supports secondary development, allowing customization of radar parameters, communication protocols, antenna configuration, and functional features. This makes it suitable for smart home systems, IoT devices, security monitoring, healthcare monitoring, and industrial automation applications.