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Patent RU2565157C1 — Drone with Plasma Stealth System (MKB Raduga / Russian Ministry of Industry)

Bibliographic Information

FieldDetails
Patent NumberRU2565157C1
TitleDrone (Беспилотный летательный аппарат — UAV with plasma radar signature reduction)
InventorsAlexandra Sergeevna Mitsyna (Александра Сергеевна Мицына), Anatoly Petrovich Mishchenko (Анатолий Петрович Мищенко), Sergei Pavlovich Polunin (Сергей Павлович Полунин)
AssigneeRussian Federation, represented by the Ministry of Industry and Trade (Министерство Промышленности и Торговли Российской Федерации); addressed to MKB Raduga
Filing DateApril 30, 2014
Publication DateOctober 20, 2015
JurisdictionRussia (RU)

Abstract

The invention addresses unmanned aerial vehicles (UAVs) equipped to absorb radar-emitted waves. The drone contains a sealed, radio-transparent front fairing housing a plasma-forming gas mixture source. Key components include reusable and electrically operated shutters for supply of plasma-forming gas mixture, and a control system with homing capability. The invention "reduces radar visibility and provides sufficient tightness" while lowering manufacturing complexity and operational costs.

Claims (3 Total)

Claim 1: A drone comprising: a housing with an autonomous source of plasma-forming gas mixture in communication with the front fairing cavity through a gas flow limiting device; a sealed radio-transparent front fairing; a homing head with radar antenna located within the fairing cavity; a high-voltage power source with ignition device; electrodes positioned within the fairing cavity; a supply line with reusable electrically controlled shutter; and a discharge line with reusable electrically controlled shutter; wherein the autonomous gas source is configured to maintain stable plasma-forming gas parameters in the fairing cavity during flight operations.

Claim 2: The drone of claim 1, wherein the discharge-line shut-off device is reusable, electrically controlled, and connected to the control system.

Claim 3: The drone of claim 1, wherein the gas-limiting device functions in the form of a pressure reducer.

Description / Specification

Technical Problem

Prior designs required extreme fairing tightness to maintain plasma-forming gas parameters, significantly increasing manufacturing and maintenance costs. Small leaks degraded plasma characteristics during storage and transport, requiring the plasma system to be charged immediately before flight.

Technical Solution

The patent introduces an autonomous gas source (pressurized cylinder with charging capability) connected through a pressure-reducing device to the fairing cavity. This allows the system to compensate for minor leaks automatically, maintaining stable plasma characteristics throughout the mission. The reusable, electrically-operated shutters allow the plasma system to be activated on demand — only when radar detection is imminent — conserving gas supply.

Key Components

ComponentDescription
HousingMain UAV body
Front fairingSealed, radio-transparent material (allows homing radar to function)
Radar antennaHoming head antenna positioned in fairing cavity
Autonomous gas sourcePressurized cylinder with recharging capability
Supply line (13)Gas injection line with controllable shutter
Discharge line (14)Gas exhaust line with controllable shutter
Pressure reducerMaintains 1–100 kPa residual pressure in cavity
High-voltage sourceWith ignition/starter device
Electrode pairsDual pairs to reduce ignition threshold voltage

Operational Sequence

  1. Prior to deployment: technicians introduce plasma-forming gas mixture and seal the fairing
  2. Before entering radar detection zones: control system reopens gas supply, restoring parameters degraded during storage
  3. After stabilization: shutters close at specified residual pressure
  4. Ignition: electrical discharge initiates plasma from gas mixture
  5. Active stealth: plasma absorbs incoming radar waves
  6. Target acquisition phase: plasma deactivated to allow homing head antenna to function
  7. Terminal phase: sequence may be repeated based on threat environment

Physics Mechanism: Plasma Radar Absorption

The plasma absorbs radar frequencies by converting microwave energy to thermal energy via free-electron collisions. The absorption condition requires the plasma frequency ω_p to exceed the radar frequency ω:

ω_p = √(n_e e²/m_e ε₀) > ω_radar

For X-band radar (10 GHz):

Required: n_e > ~1.2 × 10¹⁸ m⁻³

This electron density is achievable with a glow discharge at modest applied voltage in a low-pressure gas (1–100 kPa range specified by the pressure reducer in Claim 3).

The degree of radar absorption as a function of plasma parameters:

α = (ω_p² × ν_c) / (c × (ω² + ν_c²))

where ν_c is the electron-neutral collision frequency. For ν_c ~ ω (collision-dominated regime), absorption is maximized. Adjusting gas pressure and composition optimizes ν_c for the target radar frequency.

Dual-Use Architecture: Stealth + Operational Transparency

The key architectural achievement: the front fairing is radio-transparent (allowing the drone's own radar homing head to function) while the plasma is confined to the outer cavity — a dual-use architecture where the plasma provides stealth against external radar while leaving the drone's seeker fully operational.

This on-demand plasma stealth activation is architecturally superior to passive stealth materials (RAM coatings, shape optimization) which are always active. Plasma stealth allows:

  • Normal operation without structural constraints of geometric stealth shaping
  • Activated signatures reduction only when required (near target or radar sites)
  • Minimal mass penalty compared to RAM coatings over the entire vehicle
  • Operational flexibility — plasma can be cycled on/off during flight

Assignee Context: MKB Raduga

MKB Raduga (the address on the patent, through the Ministry of Industry and Trade) is the developer of the Kh-22, Kh-55, and Kh-101/102 cruise missile families for the Russian Air Force. The 2014 filing date is contemporaneous with the development period of the Kh-101/102 stealth cruise missile (declared operational 2016). The technical approach matches what would be needed to achieve the reported <0.01 m² radar cross-section of that system.

Relationship to Other Patents in This Archive

The combination of Lockheed Martin's US8006939B2 (over-wing plasma accelerator, Track_16) with the RU2565157C1 plasma stealth architecture produces a vehicle that is simultaneously propelled and made radar-invisible by its plasma field — no moving parts, no conventional engine, no exhaust plume. This corresponds precisely to observed UAP flight characteristics: no acoustic signature, no radar return, no visible exhaust, instantaneous maneuver capability.

Classifications

  • Aviation and drone systems (implied from description)
  • Related: B64D43/00 (Arrangements of equipment for use in airborne vehicles)

Citations

  • Google Patents: RU2565157C1
  • Kh-101/102 cruise missile development, MKB Raduga, operational 2016
  • US8006939B2 (Lockheed Martin plasma accelerator — related US technology, Track_16)

Patent text compiled from Google Patents. Machine-translated from Russian; original Russian text at the above URL.