BlueHalo on Monday said it has acquired Citadel Defense in a deal that complements its existing capabilities in countering unmanned aircraft systems (C-UAS) with a family of radio frequency (RF)-based products to detect and mitigate threats from small drones.

Terms of the deal were not disclosed. Citadel has 30 employees.

Citadel, which is based in San Diego, is a small business that develops and manufactures the Titan family of C-UAS solutions that are based on an open software architecture and can autonomously detect, track, identify and defeat small drones using electronic countermeasures. Citadel’s C-UAS solutions are used by U.S. military services, including Special Forces, Customs and Border Protection, and others and can be set up quickly for fixed and dismounted operations for defense, border and critical infrastructure protection.

Titan is a smart jamming system that uses adaptive frequency jamming technology to detect and defeat drone threats without disrupting electronic signals nearby. Citadel uses artificial intelligence and machine learning technology to autonomously detect the uplinks and downlinks of a drone and its operator in high electronic noise environments.

BlueHalo, a portfolio company of the private equity firm Arlington Capital Partners, offers the LOCUST laser weapon system and its related target and acquisition system counter drones. The company also offers the RF-based ARGUS system for perimeter intrusion detection.

“Citadel has established itself as a leader in the C-UAS market and continues to innovate at a pace necessary to stay ahead of the rapidly evolving threat environment,” Jonathan Moneymaker, BlueHalo’s CEO, said in a statement. “The combination of Citadel and BlueHalo’s unique technologies, deep mission intimacy, and systematic approach to innovation will accelerate our technology roadmap and allow us to rapidly field technologies critical to the warfighter.”

Citadel will continue to be led by Christopher Williams, the company’s CEO.

BlueHalo provides engineering solutions and technology in the areas of space superiority and directed energy, air and missile defense, C4ISR, cyber and intelligence.