Inside India’s Secret Stealth Technology Race

Current Capabilities, Research Progress, Challenges and Future Roadmap

India has made significant progress in indigenous low-observable (stealth) technologies over the past decade. While operational details remain classified, publicly available information indicates that the country has moved beyond laboratory-scale research and is developing Radar Absorbent Coatings (RAC), Radar Absorbing Materials (RAM), Radar Absorbing Structures (RAS), flexible radar-absorbing rubber sheets, metamaterials, and electromagnetic signature management technologies for future aerospace, naval, and land platforms. 

The primary driver of these technologies is the need to improve survivability against modern AESA radars, integrated air defence systems (IADS), and precision-guided weapons.

 National Stealth Technology Ecosystem

India’s stealth material development is led by a network of DRDO laboratories, academic institutions, and defence public sector enterprises.

Overall Ecosystem

Why Militaries Should Adopt RAC

Modern conflicts increasingly feature layered surveillance and precision strike capabilities. Radar absorbent coatings provide a passive, always-on method of reducing detection probability and extending platform survivability. Key reasons include:

• Reduced Radar Detection Range – Shortens the adversary’s engagement timeline.
• Enhanced Mission Success – Improves the chances of reaching and completing objectives before being detected.
• Force Multiplication – Increases the effectiveness of existing platforms without major redesigns.
• Lower Casualties – Improves the survivability of personnel and valuable assets.
• Complement to Electronic Warfare – Strengthens layered protection when combined with jammers, decoys, and emissions control.
• Cost-Effective Modernization – Offers a practical upgrade path for legacy platforms that cannot be fully redesigned for stealth.
• Supports Multi-Domain Operations – Helps maintain operational freedom across air, land, and maritime environments.

DRDO’s Current RAC Technology Portfolio

Recent DRDO technology roadmaps and technology-transfer documents show that India is actively developing.  India’s ecosystem for Radar Absorbent Materials (RAM), Radar Absorbent Coatings (RAC), Radar Absorbing Structures (RAS), and stealth composites is steadily expanding but remains relatively specialised. DRDO laboratories continue to lead the development of core technologies, while a small number of private companies—most notably MarudharNeural Tech, Hyper Stealth Technologies Pvt. Ltd., and Meta Tattva Systems—have emerged as visible participants in signature-management products and multispectral camouflage.

Radar Absorbent Paint (RAP)

Designed for:

• Aircraft
• UAVs
• Land systems
• Strategic assets

Key features 

• More than 90% microwave absorption in target frequency bands.
• Polyurethane-based coating system with magnetic functional fillers.
• Spray-gun application on aluminium alloys and carbon-fibre composites.
• Resistance to hydraulic oil, aviation fuel, thermal shock, and vibration.
• Suitable for airborne and land platforms. 

Flexible Radar Absorbing Rubber Sheet (LHSF-RAbS)

DRDO has also developed lightweight, flexible RAM sheets that can be bonded onto complex surfaces.

Advantages:

• 90% microwave absorption
• Lightweight
• Flexible
• High tensile strength
• Compatible with metal and composite structures
• Applicable to airborne, land, and sea platforms 

Radar Absorbing Structures (RAS)

Rather than simply painting a surface, RAS integrates absorbing materials into structural components.

Applications include:

• Air intake ducts
• Wing skins
• Radome bulkheads
• Leading edges
• Pylons
• Honeycomb structure
• Splitter plates

This approach combines stealth with structural functionality. 

Key Challenges

Despite strong progress, several challenges remain:

• Achieving broadband absorption across L-, S-, C-, X-, Ku-, and Ka-bands.
• Maintaining performance under extreme temperatures, humidity, UV exposure, and abrasion.
• Balancing stealth with weight, durability, and maintainability.
• Scaling production while ensuring consistent electromagnetic properties.
• Establishing domestic manufacturing for advanced nanomaterials and specialized fillers.

Advanced Research Areas

DRDO’s published technology priorities include work on:

• Artificial electromagnetic (EM) materials
• Electromagnetic cloaking materials
• Metasurfaces and frequency selective surfaces (FSS)
• Adaptive and phase-changing stealth materials
• High-temperature radar absorbing materials for aircraft exhaust nozzles
• Low-frequency (L- and S-band) absorbing materials
• Multi-spectrum adaptive camouflage
• Plume infrared signature suppression 

These efforts indicate a shift from conventional coatings to multifunctional stealth materials that address radar and infrared signatures together.

Applications – Aircraft

Benefits:

• Reduced frontal RCS
• Improved survivability in contested airspace
• Better penetration of integrated air-defense systems

Indian Navy

Modern indigenous warships incorporate:

• Angled superstructures
• Composite masts
• Signature reduction measures

While specific coating formulations are not disclosed, stealth design principles are integral to newer surface combatants. Modern warships use radar-absorbing coatings alongside angled structures to reduce radar signatures, making detection and targeting more difficult.

Benefits include:

• Reduced detectability
• Delayed missile targeting
• Increased survivability during maritime operations

Armoured Vehicles

RAC can help:

• Delay detection by battlefield surveillance radars
• Reduce susceptibility to some radar-guided reconnaissance and targeting systems
• Improve concealment in conjunction with camouflage

Assessment

From open-source evidence, the current status can be summarized as follows:

One of the strongest publicly available indicators is the Integrated Mobile Camouflage System (IMCS).

In 2023, the Indian Army placed its first procurement order for IMCS for mechanised forces under the iDEX programme. The system, developed by an Indian start-up, includes:

• Low-emissivity coatings 
• CAM-IIR coatings 
• Mobile camouflage materials 
• Reduction of thermal and radar signatures of armoured fighting vehicles 

The system is specifically intended for mechanised formations and is designed to make AFVs more difficult to detect by radar and thermal sensors. 

UAVs

Small drones often have low inherent radar signatures, and applying RAC can further reduce detectability, especially for ISR and special missions.

Advantages

Passive Protection

Requires:

• No electrical power
• No operator intervention
• No RF emissions

Always active.

Platforms Likely to Benefit – For Indian Air Force aircraft, the public evidence varies considerably by platform. It is useful to separate confirmed operational use, confirmed technology development, and expected future integration.

DRDO leadership has publicly stated that radiation/radar-absorbing composite materials are being developed to meet AMCA’s stealth requirements. 

Future UAVs

Future reconnaissance and combat UAVs are expected to integrate RAC to:

• Reduce detection range
• Increase survivability
• Improve penetration of defended airspace.

Technology Readiness

Strategic Importance

Indigenous RAC technologies offer several strategic advantages:

• Reduced dependence on imported stealth materials.
• Lower life-cycle costs through local maintenance and repair.
• Enhanced survivability for aircraft, ships, UAVs, missiles, and land systems.
• Strengthened capability to support future indigenous platforms such as AMCA and Ghatak.
• Opportunities for collaboration with Indian industry through DRDO technology-transfer initiatives. 

Modern battlefields are dominated by advanced radar systems capable of detecting, tracking, and engaging targets from long distances. As radar technology evolves—with AESA radars, multi-static radars, and AI-assisted tracking—the need to reduce a platform’s detectability has become increasingly important. One of the most effective passive survivability measures is the application of Radar Absorbent Coating (RAC).

Unlike active electronic warfare systems that emit signals to jam or deceive enemy radars, RAC works silently by reducing the amount of radar energy reflected back to the enemy radar, thereby decreasing the platform’s Radar Cross Section (RCS).

What is Radar Absorbent Coating (RAC)?

Radar Absorbent Coating is a specially engineered paint or coating containing electromagnetic absorbing materials such as:

• Ferrite particles
• Carbon nanotubes
• Graphene composites
• Conductive polymers
• Iron ball paint
• Metamaterial structures (latest generation)

These materials convert incident radar energy into minute amounts of heat instead of reflecting it back to the radar antenna.

Working Principle

When radar waves strike a conventional metallic surface:

• Around 80–95% of the energy is reflected.
• Enemy radar receives a strong return.
• Target is detected easily.

With Radar Absorbent Coating:

• Radar energy enters the coating.
• Electromagnetic energy is attenuated.
• Internal losses convert RF energy into heat.
• Only a small percentage is reflected.

Result:

Lower Radar Cross Section (RCS)

Lower RCS directly translates into shorter detection ranges.

Detection Range Reduction

Radar detection follows the radar range equation:

[Detection\ Range \propto (Radar\ Cross\ Section)^{1/4}]

This means:

Even modest reductions in RCS can significantly compress the enemy’s engagement timeline.

How RAC Improves Survivability

Delays Enemy Detection

A radar operator receives a weaker return signal.

Instead of detecting a platform at:

• 200 km

Detection may occur at:

• 120–150 km

This reduction shortens the adversary’s decision-making window.

Compresses the Kill Chain

Enemy sequence:

Search → Detect → Track → Identify → Engage → Destroy

RAC affects the earliest stages by delaying detection and making reliable tracking more difficult, leaving less time for weapon employment.

Increases Missile Survival

Modern radar-guided missiles require:

• Stable target tracking
• Fire-control radar lock
• Mid-course updates
• Terminal guidance

Reduced radar returns can make these processes less reliable, particularly at longer ranges or in cluttered environments.

Increases Stand-off Capability

Aircraft, ships, or ground vehicles can operate closer to threat areas before being detected, improving mission flexibility.

Enhances Electronic Warfare

When RAC is combined with:

• DRFM jammers
• Digital decoys
• Chaff
• Towed decoys
• Electronic support measures

the overall survivability is greater than using any one technique alone.

Lower Lifecycle Cost

Compared with sophisticated active electronic warfare suites:

• Lower operating costs
• Minimal crew workload
• Broad applicability across multiple platforms

Limitations

RAC is not a “cloak of invisibility.”

Challenges include:

• Performance varies with radar frequency.
• Coatings can degrade due to weather, abrasion, or heat and require maintenance.
• Alone, they cannot defeat modern multi-sensor detection systems that combine radar, infrared, electro-optical, acoustic, and passive RF sensing.
• Best results are achieved when integrated with shaping, electronic warfare, decoys, and disciplined operational tactics.

Advanced Radar Signature Management for UAVs, Aircraft, and Maritime Platforms

The character of modern warfare is being reshaped by the rapid proliferation of advanced surveillance networks, Active Electronically Scanned Array (AESA) radars, integrated air defence systems, and AI-enabled multisensor fusion. In such an environment, survivability is no longer determined solely by speed, manoeuvrability, or electronic warfare; it increasingly depends on reducing a platform’s detectability across multiple domains. Radar signature management has therefore become a critical enabler of operational success.

Radar Absorbent Coating (RAC) represents a practical, passive, and cost-effective solution that complements existing stealth technologies. By reducing Radar Cross Section (RCS), delaying detection, complicating target acquisition, and compressing an adversary’s engagement timeline, RAC enhances the survivability of UAVs, aircraft, naval vessels, and ground platforms operating in contested battlespaces. Unlike extensive structural redesigns, RAC can be integrated onto existing platforms with minimal modification, making it an attractive capability for both legacy fleets and next-generation systems.

India has made notable progress in developing indigenous radar-absorbing materials and coatings through sustained research by DRDO and its partner laboratories. At the same time, innovative Indian companies such as MarudharNeural Tech Solutions (MNTS) are translating these advances into field-deployable solutions that address emerging operational requirements. The development of lightweight, durable, and mission-configurable Radar Absorbent Coatings reflects the growing maturity of India’s defence technology ecosystem and supports the national vision of self-reliance in critical military capabilities.

As highlighted during discussions with Mr. Ashish Mathur, Director of MarudharNeural Tech Solutions (MNTS), the future of survivability lies not in a single technology but in an integrated approach that combines advanced materials, stealth-oriented design, electronic warfare, adaptive camouflage, artificial intelligence, and multispectral signature management. Radar Absorbent Coatings are an important component of this layered survivability architecture, enabling platforms to remain operationally relevant against increasingly sophisticated detection and engagement systems.  The importance of public-private collaboration in achieving “Atmanirbhar Bharat” in stealth and low-observable technologies.

Looking ahead to 2035, advances in nanocomposites, graphene and carbon nanotube-based absorbers, metamaterials, adaptive electromagnetic skins, and multifunctional protective coatings will further transform low-observable technologies. These innovations are expected to support the next generation of Indian combat aircraft, unmanned systems, naval platforms, and armoured vehicles, while providing upgrade opportunities for existing fleets.

In an era where remaining undetected can determine mission success or failure, Radar Absorbent Coatings should no longer be viewed merely as protective paints, but as strategic force multipliers. Their adoption across India’s defence ecosystem will not only improve platform survivability and mission effectiveness but also strengthen indigenous technological capabilities, reduce dependence on imported stealth solutions, and contribute significantly to the operational readiness of the Armed Forces in future high-intensity conflicts.