On the airport runway in the early morning, the radar antenna is quietly rotating. It is like an tireless sentinel, weaving a protective net with invisible radio waves. This device, known as X-band radar, is becoming a secret weapon against “black flying” drones. Let’s uncover the mystery of this technology and see how it safeguards the blue sky above us.

1, Radar that can speak

The name “radar” comes from the English abbreviation “RADAR”, which means “using radio detection and ranging”. Just like bats use sound waves to explore, radar perceives the world by emitting radio waves. Different frequency bands are equivalent to different “languages”.  The X-band is one of the high-frequency radio waves, with a frequency range between 8-12GHz, which is equivalent to vibrating 8-12 billion times per second.

Choosing this frequency band has its unique advantages. It has a higher resolution than the common S-band (2-4GHz) and can see smaller objects clearly. Meantime, it has better penetration than the higher frequency Ku band (12-18GHz). That because it can maintain good performance even in rainy and foggy weather. This compromise feature makes X-band radar a versatile tool for all-weather operation.

 

2, The Trilogy of Radar Operations

Launch detection signal

The radar antenna swings its arms like a symphony conductor, casting carefully designed radio beams into the sky. These beams travel at the speed of light and bounce back like echoes when encountering obstacles. Modern radar can complete hundreds of such “question and answer” operations per second, thousands of times faster than human blinking speed.

Capture weak echoes

When the radio waves touch the drone, some of the energy will return to its original path. The receiving antenna is like a sensitive ear, capable of capturing echoes with only one millionth of the emitted energy. Specially designed filters will eliminate interference signals such as birds and flying insects, focusing on finding drone features with metal structures.

Intelligent analysis and judgment

The advanced processor starts working by calculating the round-trip time of the signal to determine the distance, analyzing frequency changes, and measuring velocity (Doppler effect). If a suspicious target is detected, the system will automatically mark and display the motion trajectory on the electronic map, and the entire process only takes a few seconds.

 

3, Four ultimate strategies for combating drones

See through the disguised eyes

Ordinary cameras are easily obscured by night or clouds, while X-band radar can penetrate most non-metallic obstructions. In 2021, there was a drone interference incident at Shenzhen Airport, which relied on radar to lock onto targets in low visibility conditions and avoid a greater crisis.

A magnifying glass that captures details

Thanks to the wavelength accuracy of 3-5 centimeters.  Usually,the X-band radar can not only detect targets, but also recognize features such as rotor speed. This ability helps security personnel distinguish between model airplane toys and modified drones with threats, reducing false alarms and interference.

Mind reading technique for predicting actions

Through continuous tracking, the system can calculate the flight path and hovering position of the drone. During the 2023 Hangzhou Asian Games, the security team predicted the approach route of a suspicious drone 20 minutes in advance, gaining valuable time for emergency response.

Commander of team operations

Modern defense systems often have radar play the role of the ‘brain’. When an intruder is detected, it will automatically command the electromagnetic interference equipment to lock the signal, dispatch the drone interception network for capture, and the entire process does not require manual intervention. This coordinated defense system forms a three-dimensional protective net around important facilities.

 

4, Intelligent upgrade in progress

Technicians are teaching radar new skills. Through artificial intelligence training, the new generation system can remember tens of thousands of drone features with recognition accuracy exceeding 98%.  For example, in the 2024 Spring Festival travel rush guarantee, a certain intelligent radar system successfully detected a formation of unmanned aerial vehicles disguised as a flock of migratory birds, avoiding a potential crisis.

Miniaturization technology makes radar more accessible to people. Palm sized vehicle mounted radar has begun to be equipped on police patrol vehicles, helping grassroots police officers quickly locate “black flying” operators.  Consumer grade products are also under development and may enter residential security systems in the future, building air safety barriers for ordinary people.