The Defence Research and Development Organisation (DRDO) has undertaken the development of a high-power antenna array with an electromagnetic (EM) transparent radome for wideband applications. This advanced system is set to be integrated with the Anusandhan Flying Test Bed (FTB), a crucial airborne platform for testing electronic warfare (EW), radar systems, and communication technologies. The initiative aligns with DRDO’s ongoing efforts to enhance India’s defense capabilities through cutting-edge airborne electronic systems.
Overview of the High-Power Antenna Array
The high-power antenna array is designed to operate across multiple frequency bands, ranging from Very High Frequency (VHF) to C-band, making it suitable for various applications including electronic intelligence (ELINT), radar warning receivers (RWR), and secure military communication systems. The antenna array, along with its mounting panel and radome, is engineered to meet stringent airborne operational requirements.
Key Frequency Bands
The antenna system supports six distinct frequency bands:
- Band 1: VHF Band (Low)
- Band 2: VHF Band (High)
- Band 3: VHF to UHF Band
- Band 4: UHF Band
- Band 5: L-Band to S-Band
- Band 6: S-Band to C-Band
This extensive frequency coverage enables the system to function across multiple defense applications, including electronic warfare, airborne surveillance, and communication relay.
Design and Development
DRDO has specified stringent design parameters to ensure the high-power antenna array meets operational and performance requirements. The system comprises directional and omnidirectional antennas, each developed for high-power transmission and minimal signal distortion.
Antenna Design Parameters
Each antenna is designed for optimized radiation coverage and power handling capabilities. The following parameters are integral to the system:
- Gain Performance: Ensures optimal signal strength across all frequency bands.
- Beamwidth Configuration: Designed to meet azimuth coverage of ±60° and elevation coverage from +5° to -40°.
- Polarization: Linear vertical polarization for all antennas.
- VSWR (Voltage Standing Wave Ratio): Maintains a ratio of less than 2:1 to ensure efficient power transmission.
- Mechanical Strength: Designed to withstand aerodynamic loads, vibrations, and mechanical impacts.
Each antenna undergoes rigorous simulation and analysis using electromagnetic software to validate its radiation pattern, return loss values, and field performance before fabrication and integration.
Electromagnetic Transparent Radome for Wideband Applications
To ensure optimal performance of the high-power antenna array, DRDO has designed an electromagnetic (EM) transparent radome. The radome serves as a protective enclosure while maintaining minimal signal attenuation.
Material Selection and Structural Properties
The radome is fabricated using composite materials such as quartz cyanate ester layers and Rohacell foam, ensuring high durability and low transmission loss. It meets the following key parameters:
- Operating Frequency: VHF to C-band.
- Transmission Loss: Less than 1 dB across the operating frequency range.
- Reflection Coefficient (S11): Better than -10 dB.
- Dielectric Constant: Between 2.5 and 4.0.
- Structural Strength: Withstands aerodynamic loads, bird strikes, and mechanical impacts.
- Weather Resistance: UV, rain, and ice-resistant properties enhance operational longevity.
Integration with Anusandhan Flying Test Bed
The Anusandhan FTB serves as DRDO’s airborne platform for real-world validation of radar, electronic warfare, and communication systems. The integration of the high-power antenna array into Anusandhan enhances its capability to test and evaluate next-generation avionics and electromagnetic warfare systems under dynamic flight conditions.
Antenna Mounting and RF Cabling
The antenna array is securely mounted on a metallic panel to ensure structural stability. DRDO has mandated the use of airborne-quality RF cables and connectors to minimize insertion loss and ensure high power handling. The mounting configuration is optimized to prevent electromagnetic interference (EMI) between individual antennas.
Applications in Defense Technologies
The high-power antenna array, combined with the EM transparent radome, plays a pivotal role in multiple defense applications:
Electronic Warfare (EW) and Signal Intelligence (SIGINT)
- Supports jamming, spoofing, and electronic countermeasures.
- Enables real-time signal monitoring and processing for threat analysis.
Radar and Surveillance Systems
- Enhances airborne radar capabilities for tracking and reconnaissance.
- Provides improved target detection and classification.
Secure Military Communication
- Facilitates encrypted voice and data transmission over long distances.
- Supports tactical data link (TDL) integration with airborne command systems.
Environmental and Qualification Testing
To ensure operational reliability, the system undergoes extensive qualification and environmental testing in compliance with military standards:
- Random Vibration Testing: Conducted along three axes for 5 minutes per axis.
- Thermal Cycling: Subjected to temperatures ranging from -54°C to +71°C for three cycles.
- Bird Strike and Hail Impact Analysis: Evaluated through simulated impact scenarios.
- Electromagnetic Compatibility (EMC) and EMI Testing: Ensures compliance with MIL-STD-461 standards.
Documentation and Compliance
As part of DRDO’s standard development process, all aspects of design, simulation, fabrication, and testing are meticulously documented. The system complies with CEMILAC and DGAQA standards, ensuring readiness for airborne deployment.
DRDO’s development of the high-power antenna array with an EM transparent radome marks a significant advancement in India’s airborne electronic warfare and radar capabilities. Integrated with the Anusandhan Flying Test Bed, this system facilitates comprehensive real-world testing of critical defense technologies. With its robust design, wideband frequency support, and high-power handling, the system is poised to enhance the operational effectiveness of future airborne electronic and radar systems in India’s defense sector.