Reactive RF Jamming Systems
FPGA-powered · Field-tested · 18 μs reaction time
Defender-series jammers neutralize drone threats and disrupt modern telecommunications using proprietary FPGA-based reactive jamming. Operators define frequency ranges, power allocation, and jamming mode per mission — deployed to the jammer via software, no hardware changes.
Mission
Trusted Jamming Solutions for Defense and Security Operations
Since 2015, B4 Limits has developed FPGA-based jamming solutions for defense and security applications. Our engineering team holds advanced degrees in RF engineering and signal processing. We are a registered NATO supplier (NCAGE 99YVH) and have delivered jamming systems for incarceration facilities and counter-UAS operations. Every Defender unit undergoes rigorous field testing before deployment.
Our Advantages
Reactive Jamming
Semi-reactive detects threats and jams the entire configured range within 18 μs — medium power-to-range ratio. Reactive responds in 36 μs, jamming only the detected signal — maximum power-to-range ratio.
Smart Power for Maximum Range
FPGA-based signal generation enables precise power allocation per threat frequency, delivering effective jamming at up to 3 km omnidirectional or up to 10 km with directional antennas against C1-class drones. Power is directed where it matters, not wasted on empty spectrum.
Software-Defined Operation
Jamming behaviour is defined by operator-created profiles uploaded via Leo control software. Each frequency range is independently configured — power, algorithm, and jamming mode. New threat: create a new profile, deploy in the field. No firmware updates, no hardware changes.
Operator Safety by Design
Fiber-optic separation keeps operators at a safe distance from the jammer during active operations. Defender systems are designed for remote deployment, minimizing personnel exposure to RF emissions.
Open Integration via REST & SAPIENT
Defender integrates into existing C-UAS architectures via REST API or NATO SAPIENT protocol. This positions the Defender as the defeat/engage layer within a complete detect-track-classify-engage kill chain, working alongside third-party radar, EO/IR, and RF detection systems.
Up to 8 Hours of Continuous Operation
Custom-engineered batteries optimized for the Defender power profile deliver up to 8 hours of continuous jamming at full output. Battery management extends both operational runtime and long-term equipment lifecycle.
Our Jamming Solution
Traditional jammers broadcast continuously across all frequencies, wasting power on empty spectrum. Defender's FPGA-based architecture enables three distinct operational modes — letting operators choose between maximum coverage (Active), balanced efficiency (Semi-Reactive), and precision targeting (Reactive) based on the threat environment.
Active
Semi - Reactive
Reactive
Field-proven
Deployed, tested, and validated in real operational environments.
Defender Product Lineup
Every Defender jammer is built on the same FPGA-based reactive architecture — detecting threat transmissions and generating targeted jamming within 18 μs. Each unit is configured to the operational requirement and field-tested against live drone targets before delivery.
The product line spans two platform series. The Modular series scales from a single portable module to a multi-module array — combining units to reach the power, bandwidth, and coverage area of fixed-installation systems while remaining field-reconfigurable between missions. The Manpack series provides a self-contained man-portable jammer for dismounted operations, facility protection, and rapid deployment scenarios. Both series share the same reactive jamming modes, software ecosystem, and integration capabilities, and can operate together in a synchronized network.
Defender Modular Series
Scalable jamming platform — combine modules to match any mission scale
FPGA-based reactive jamming system that scales from a single man-portable module to a multi-module array operating as one coordinated jammer. Add modules to increase power, frequency coverage, and simultaneous bandwidth. Deploy modules co-located for concentrated jamming power or distribute them across terrain for wide-area coverage — all synchronized and managed as a single system through Leo control software.
Each module can optionally operate as a standalone jammer with full reactive capability. When combined, modules synchronize as a single system — scaling power and bandwidth with each module added while remaining field-deployable and reconfigurable between missions. Platform specifications are per module — total system power, bandwidth, and coverage multiply with the number of connected modules.
Single module capabilities:
Applications:
Defender Manpack Series
Man-portable configurable jamming system — 32 kg, IP66
Compact FPGA-based reactive jamming platform in a ~32 kg man-portable chassis. Configured per project for telecom denial, counter-UAS defeat or any combination — from narrowband precision targeting to wideband multi-threat coverage. Reactive mode concentrates all available power on detected threats, delivering effective range typically reserved for vehicle-mounted systems.
Applications:
Leo
Jammer control and monitoring softwareLeo provides centralized command and control for all networked Defender jammers. Role-based access separates configuration authority (profile creation and configuration) from field operation (one-touch activation of pre-set jamming profiles). Optimized for ruggedized tablet deployment with minimal processing requirements. Supports encrypted jamming profile distribution to prevent unauthorized configuration changes.
Lemur
Operator training and qualification platformLemur is a browser-based training platform that fully emulates Leo in a safe, RF-free environment. Operators progress through automated, structured exercises covering system startup, profile configuration, jamming activation and more. Supports self-paced individual training with built-in automatic assessment.
Company
B4 Limits was founded in 2019 by engineers with RF jamming expertise dating back to 2015. The team's first deployments served incarceration facilities, delivering proven cellular jamming systems that remain in active operation. In 2021, development began on the Defender counter-UAS platform — a 3-year program that produced a new generation of FPGA-based reactive jammers. Today, B4 Limits is a registered NATO supplier (NCAGE 99YVH, D-U-N-S 850906664) designing and manufacturing all hardware, firmware, and software in-house at our facility in Białystok, Poland.
EU-Funded R&D
Defender development co-financed by the European Union
The Defender reactive jamming platform was developed with co-financing from the European Regional Development Fund under the Smart Growth Operational Programme (POIR). The project advanced FPGA-based signal processing and reactive jamming algorithms from research through to field-validated production systems.
European Union
Republic of Poland