How the PIR sensor became 90 degrees detection?

The PIR (Passive Infrared) sensor detects motion by sensing changes in infrared radiation emitted by objects, primarily humans and animals. Traditionally, PIR sensors have a narrow detection angle, but by using a combination of multiple sensor elements and advanced optics, manufacturers can achieve a wider detection field, often up to 90 degrees. This is accomplished through the use of lens systems, such as Fresnel lenses, which refract and focus infrared signals onto the sensor, allowing for greater coverage and improved motion detection capabilities.