windows, to name a few. The entire infrasound detection system consists of the following components: a speaker (infrasound sensor) as a microphone input, an order-frequency filter, an analog to digital (A/D) converter, and finally, an MCU used to analyze the recorded signal. Each time a potential intruder tries to enter into a house, she or he tests whether it is closed and locked, uses tools on openings, or/and applies pressure, and therefore he or she creates low-frequency sound vibrations. Before the intruder breaks in, the infrasound detector automatically catches sight of the intruder's actions The purpose of such a system is to detect burglars before they enter the house to avoid both theft and vandalism. The sensitivity is dependent on the size of a home and the presence of animals. Ultrasonic detectors These active detectors transmit ultrasonic sound waves that are inaudible to humans using frequencies between 15 kHz and 75 kHz. The Doppler shift principle is the underlying method of operation which detects a change in frequency due to object motion. This detection occurs when the object must cause a change in the ultrasonic frequency to the receiver relative to the transmitting frequency. The ultrasonic detector operates by the transmitter emitting an ultrasonic signal into the area to be protected. Solid objects (such as the surrounding floor, walls, and ceiling) reflect sound waves, which the receiver will detect. Because ultrasonic waves are transmitted through air, hard-surfaced objects tend to reflect most of the ultrasonic energy, while soft surfaces tend to absorb the most energy. When the surfaces are stationary, the frequency of the waves detected by the receiver will be equal to the transmitted frequency. However, a change in frequency will occur as a result of the Doppler principle, when a person or object is moving towards or away from the detector. Such an event initiates an alarm signal. This technology is not active in many properties because many alarm professionals consider this obsolete. Microwave detectors This device emits microwaves from a transmitter and detects any reflected microwaves or reduction in beam intensity using a receiver. The transmitter and receiver are usually combined inside a single housing (monostatic) for indoor applications and separate housings (bistatic) for the protection of outdoor perimeters high-risk sites and critical infrastructures such as fuel storage, petrochemical facilities, military sites, civil and military airports, nuclear facilities and more. To reduce false alarms this type of