TIDUF89 September   2024

 

  1.   1
  2.   Description
  3.   Resources
  4.   Features
  5.   Applications
  6.   6
  7. 1System Description
    1. 1.1 Detection Theory
    2. 1.2 Multi-Pass Architecture
  8. 2System Overview
    1. 2.1 System Design Theory
      1. 2.1.1 Long Detection Range
        1. 2.1.1.1 Antenna Design for Long Detection Range
        2. 2.1.1.2 SNR Compensation for Long Detection Range
        3. 2.1.1.3 Smart Detection Logic
      2. 2.1.2 Low Power Consumption
        1. 2.1.2.1 Efficient Chirp Design
        2. 2.1.2.2 Deep Sleep Power Modes
        3. 2.1.2.3 Hardware Accelerator
      3. 2.1.3 Low False Alarm Rate
        1. 2.1.3.1 Typical Causes of False Alarms
        2. 2.1.3.2 False Alarms Outside the Detection Zone
        3. 2.1.3.3 False Alarms Within the Detection Zone
        4. 2.1.3.4 Adaptive State Machine
  9. 3Hardware, Software, Testing Requirements, and Test Results
    1. 3.1 Hardware Requirements
    2. 3.2 Software Requirements
    3. 3.3 Test Setup
      1. 3.3.1 Test 1 - Detection Range
      2. 3.3.2 Test 2 - False Alarm Rate
      3. 3.3.3 Test 3 - Power Consumption
    4. 3.4 Test Results
  10. 4Design Files
    1. 4.1 Schematics
    2. 4.2 Bill of Materials
  11. 5Tools and Software
  12. 6Document Support
  13. 7Support Resources
  14. 8Trademarks
  15. 9About the Authors

2.1.1.1 Antenna Design for Long Detection Range

The IWRL6432AOP device achieves very long detection range over a wide field of view through effective circuit and antenna design. As seen in the IWRL6432AOP, data sheet the IWRL6432AOP has a single transmitter Effective Isotropic Radiated Power (EIRP) of 15dBm. EIRP is the maximum of the sum of the conducted power and the antenna gain over the entire field of view of the antenna. EIRP refers to the maximum amount of power that the device can radiate, which is most typically at 0° in azimuth and elevation, referred to as bore sight. A large EIRP means that at bore sight, the radar can detect objects that are very far away.

While the EIRP gives the maximum radiated power, the IWRL6432AOP, data sheet also shows radiation plots of the RX and TX antennas across azimuth and elevation. The IWRL6432AOP exhibits a wide field of view (FOV) and achieves ±70 degrees in the azimuth and ±40 degrees in the elevation.

The combination of a high EIRP and a wide FOV make the IWRL6432AOP an effective radar in all environments. For example, in a crowded city, the distance from a home to the street can be short, but the sidewalk in front of the house can be quite long, which can benefit a short detection range and a wide field of view. However, in the countryside, there can be a long road leading up to the home, which can benefit a long detection range and a narrower field of view. To create a design that can work for all setups, video doorbell providers need to have both a wide-field of view and a long front-facing detection range. The IWRL6432AOP is able to achieve these specifications at a variety of power levels.