Passive infrared sensor systems and methods

A passive infrared (PIR) sensor system, comprising:

• a PIR sensor configured to produce an output signal in response to receiving infrared (IR) radiation;
• an electronic shutter positionable in a field of view (FOV) of the PIR sensor, wherein the electronic shutter comprises a pair of substrates and a liquid crystal (LC) element positioned between the pair of substrates, wherein the electronic shutter comprises a first state providing a first transmissivity of IR radiation through the electronic shutter and a second state providing a second transmissivity of IR radiation through the electronic shutter that is less than the first transmissivity;
• and
• a shutter actuator configured to apply an actuation signal to the electronic shutter to actuate the electronic shutter between the first state and the second state.

A passive infrared (PIR) sensor system, comprising:

• a PIR sensor configured to produce an output signal in response to receiving infrared (IR) radiation;
• a mechanical shutter positionable in a field of view (FOV) of the PIR sensor;
• and
• a shutter actuator comprising a Lavet motor that comprises a stator comprising a pair of arms, a rotor positioned between the pair of arms of the stator, and a solenoid coil positioned about one of the arms of the stator;
• wherein the shutter actuator is configured to displace the mechanical shutter across an IR sensing element of the PIR sensor to at least partially block the IR radiation received by the PIR sensor in response to receiving an actuator signal.