The asymmetric strike capability of “unmanned” against “manned” drones has actually changed the “rules of the game” in modern warfare. Countries are exploring ways to restrain this game changer. Microwave weapons will become an effective means to counter UAVs and their swarms due to their advantages of light-speed attack, strong area-wide killing capability, and high cost-effectiveness.

As drones and their swarm system combat modes gradually become an important style of future warfare, the development of effective countermeasures has gradually received great attention from all countries. Taking the United States as an example, since 2015, the US military has paid increasing attention to the development of anti-drone systems. From fiscal year 2019 to 2021, the average annual investment is approximately US$500 million. In fiscal year 2023, the U.S. Department of Defense spent another $668 million on the research and development of counter-drone systems, and at least another $78 million on procurement.

The US military is testing drone swarms.

The process of countering UAVs can be mainly divided into two stages: discovery and attack. That is, first detect, track and provide early warning to the target UAV, and then adopt corresponding damage means to attack according to the actual situation. Commonly used damage methods include:

1) Using anti-aircraft artillery and anti-aircraft missiles for hard kills. Although this method has high technological maturity, it is also costly;

2) Capture drones by throwing nets from the ground or in the air and using physical capture methods. This method is low-cost and simple to implement, but the hit rate is low and the range is very limited;

3) Using combat drones to fight drones has the characteristics of high accuracy and small collateral damage, but the technical maturity is relatively low, and generally can only achieve point-to-point attacks, which is less lethal to the swarm system with self-healing capabilities. limited;

4) Use high-energy laser weapons to directly kill targets. This method has the characteristics of fast response, high precision, and high power. However, its effectiveness is greatly affected by the target material and weather, and its effect is average when dealing with a large number of swarms.

In contrast, microwave weapons under development may become the nemesis of drones, especially drone swarms. Microwave weapons refer to combat weapons equipped with High-Power Microwave (HPM) payloads, which can be mounted on a variety of platforms such as land-based, air-based, sea-based, and even missile-based. The damage principle of microwave weapons is similar to that of common microwave ovens, that is, it continuously emits electromagnetic pulses, coupling through the back door (holes, etc.) of the drone to disrupt the flight control system of the drone, or coupling through the front door (microwave receiving channel) to damage the drone. The measurement and control receiver may cause the UAV to lose control or be damaged depending on the amount of coupling energy.

“Phaser” high-power microwave weapon system.

Compared with other damage methods, microwave weapons have unique advantages in countering UAVs and their swarms.

First of all, it has a wide killing area, can kill multiple targets in the area at the same time, and does not require high accuracy of the guidance system. For example, the “Tactical High-Power Operational Responder” (THOR) anti-swarming electromagnetic weapon developed by the U.S. Air Force Research Laboratory can shoot down more than 50 drones at one time in actual tests.

Second, the attack time is short, microwaves propagate at the speed of light and have high energy density, which can cause damage to the target within microseconds. For example, the land-based “Onidas” system launched by the American company Epirus in 2020 successfully shot down all 66 drones in a prototype demonstration in February 2021 in just a few minutes.

Third, microwave has a longer wavelength than laser, is not sensitive to weather, and can be used all day long.

Finally, the cost-effectiveness ratio is extremely high. When countering drones, it only consumes electrical energy and can be used repeatedly.

Based on the above advantages, high-power microwaves can achieve wide-area damage and efficient confrontation against drones and their clusters, and have gradually become the “nemesis” of drones.