What is a Millimeter Wave Security Scanner?

A Millimeter wave (mmWave) security scanner is a whole-body imaging device that utilizes high-frequency millimeter waves to create a detailed 3D image of the body and identify concealed objects. They are starting to replace X-Ray based scanning solutions at airports. A mmWave scanner generates millimeter waves through a series of small, disc-like transmitters (Tx) stacked vertically in two separate columns. When a person steps into the scanner, each transmitter emits pulses of mm Waves, which pass through clothing, reflect off the skin or any concealed solid and liquid objects, and returns to the receiver (Rx). Since multiple transmitter-receiver discs are stacked vertically and rotate around the individual, the system can capture a full-body scan from head to toe and front to back.

Advanced algorithms process these reflections, generating a high-resolution 3D image that highlights anomalies and is transmitted to an operator for review. These scanners effectively detect concealed weapons, explosives, and contraband in a non-invasive and efficient manner, making them ideal for security screening at airports, government facilities, and other high-security locations.

With the integration of AI and machine learning, the accuracy of these scanners will continuously improve. As they are exposed to more data over time, these systems will learn to better understand how different objects reflect signals, allowing them to more accurately identify and categorize potential threats. This ongoing learning process will make the scanners increasingly effective and reliable.

Millimeter wave (mmWave) refers to electromagnetic waves with wavelengths between 10 millimeters and 1 millimeter and frequencies ranging from 30 GHz to 300 GHz. These scanners usually use the frequency spectrum above 70 GHz. Due to their short wavelengths, mmWave signals enable can be focused into narrow, highly directional beams, there providing high scanning accuracy with high-resolution imaging. Signals in this frequency range can penetrate clothing but not through the skin or dense materials, making them ideal for use in security scanners as they can detect objects without revealing detailed body contours, thus addressing privacy concerns.

A key advantage of mmWave technology in security applications is its ability to detect both metallic and non-metallic concealed objects, including plastic explosives, ceramic weapons, narcotics, and contraband. Unlike traditional X-Ray based metal detectors, mmWave scanners use non-ionizing radiation and low power signals (10,000 times less power than a cellphone), making them safe for human exposure. 

Advantages of millimeter Wave Security Scanners 

mmWave security scanners offer rapid, high-resolution imaging, which makes them a crucial technology for modern security applications. Key advantages include:

Non-Invasive Screening: mmWave scanners eliminate the need for physical screening, providing a respectful and comfortable screening process as well as addressing privacy concerns.

High-Speed and Accuracy: These scanners can quickly detect both metallic and non-metallic objects with high precision, minimizing delays at security checkpoints. A typical mmWave scanner, depending on its capabilities, can scan anywhere between 300 to 800 person per hour.

Safety and Health Considerations: Unlike the X-ray scanner that involves exposure to ionizing radiation, mmWave technology utilizes non-ionizing radiation, which is safe for humans.

Ability to Detect Concealed Objects: mmWave scanners excel at detecting a wide range of concealed objects, including plastics, ceramics, and liquids, which are missed by metal detectors.

The use of mmWave scanners is being expanded beyond airports and other high-security areas and now the technology is being increasingly adopted at train stations, stadiums, and other high-footfall areas. Researchers are constantly focusing on reducing cases of false alarms and enhancing material differentiation capabilities by improving detection efficiencies.