Ai-Thinker has launched two millimeter-wave radar-based human sensing modules: Rd-03 and Rd-03D. Both utilize 24GHz FMCW (Frequency-Modulated Continuous Wave) technology but differ significantly in performance, features, and applications. This article provides a comprehensive comparison to help users select the ideal solution for their needs.
Key Parameters Comparison
| Parameter | Rd-03 | Rd-03D |
| Core Chip | S3KM1110 | S5KM312CL |
| Frequency Band | 24GHz~24.25GHz | 24GHz~24.25GHz |
| Modulation Bandwidth | 1GHz (per channel) | 0.25GHz (per channel) |
| Max Detection Range | 5m (ceiling) / 10m (wall) | 8m (wall-mounted) |
| Angular Coverage | Azimuth ±60° | Azimuth ±60°, Elevation ±30° |
| Power Supply | 3.0~3.6V (3.3V typ.) | 5V |
| Current Consumption | 50mA (avg.) | 92mA (avg.) |
| Communication | UART (115200bps default) | UART (256000bps default) |
| Dimensions | 20×20mm (DIP-5 pins) | 15×44mm (1×4P socket) |
Key Differences:
-
Bandwidth: Rd-03 offers higher bandwidth (1GHz) for better interference resistance, while Rd-03D focuses on multi-target tracking with optimized algorithms.
-
Power Design: Rd-03 suits battery-powered devices; Rd-03D requires stable 5V input.
-
Data Rate: Rd-03D’s UART supports 256kbps for faster data transmission.
Functional Features Comparison
Rd-03 Highlights
-
Human Presence Detection: Detects both moving and static targets.
-
Customizable Parameters: Adjust sensing range, sensitivity, and delay via UART.
-
Anti-Interference: Configurable shielding zones to reduce false triggers.
-
Cost-Effective: DIP package compatible with standard 2.54mm headers.
Rd-03D Highlights
-
Multi-Target Tracking: Real-time tracking of multiple objects with speed and distance measurement.
-
High Precision: 0.75m resolution and ±0.15m accuracy.
-
3D Sensing: ±30° elevation coverage for complex spatial layouts.
-
Plug-and-Play: Default configurations enable quick deployment.
Functional Comparison:
-
Rd-03 excels in “presence detection” for simple applications (e.g., lighting control).
-
Rd-03D targets advanced scenarios requiring “multi-target analysis” (e.g., security systems).
Application Scenarios Comparison
Rd-03 Use Cases
-
Smart Lighting: Auto on/off based on human presence.
-
Digital Signage: Wake up screens when audiences approach.
-
EV Charging Stations: Monitor vehicles or users.
Rd-03D Use Cases
-
Smart Home: Track occupant movements for HVAC optimization.
-
Retail Analytics: Count foot traffic and analyze hotspots.
-
Safety Alerts: Detect falls in bathrooms or unauthorized intrusions.
Installation & Design Comparison
| Aspect | Rd-03 | Rd-03D |
| Mounting Options | Wall or ceiling mounting | Wall mounting only |
| Antenna Design | 1T1R (1 transmit, 1 receive) | 1T2R (enhanced reception) |
| Interference Mitigation | Avoid metal obstructions | Supports multi-radar coordination |
| PCB Compatibility | Standard 20×20mm layout | Elongated design (15×44mm) |
Design Tips:
-
Rd-03 fits compact devices (e.g., embedded fixtures).
-
Rd-03D requires careful antenna alignment to avoid elevation blockage.
Conclusion & Selection Guide
Rd-03 Advantages- Low power consumption (50mA) for battery-driven projects.
- Lower cost and easier prototyping.
- Advanced multi-target tracking capabilities.
- High-speed communication for real-time applications.
- Basic Detection (e.g., lighting): Choose Rd-03.
- Complex Tracking (e.g., security): Choose Rd-03D.
