A deadly next-generation Uttam active electronically scanned array radar is in making for upcoming Light Combat Aircraft (LCA) Tejas Mk2.
he realization phase of LCA Tejas MK 2 (Earlier called Medium Weight Fighter) is going on in full swing. The latest information is about the Uttam Active Electronically Scanned Array (AESA) Radar, that is about to enter the fabrication phase. Tejas MK2 will be little over one meter longer than Tejas Mk1 and its wingspan will be increased marginally by 30 centimetres. Overall, the dimensions of the two fighter jets will not be significantly different. It was reported that nose cone area of Tejas MK2 will be smaller than Tejas Mk1 and still this fighter jet will feature AESA radar with more Transmitter and Receiver Modules (TRM). Larger the number of TR modules, longer the range as the beam formed is fine.
Update on Uttam AESA of Tejas Mk2
As per the latest update LRDE is exploring options to transfer the technology to a private sector company. The defence private sector contractor will be responsible for build to specification type of arrangement. LRDE will supply the technology and specifications and the selected private sector company will fabricate this Radar unit.
The initial plan is to fabricate two units of this AESA radar, the first prototype of Tejas Mk2 will be rolled out in March 2022 and it will take its first flight in about 12 months from there. Thus, the timelines of this fabrication suggest that, Radar unit may be available in just about same time as first flight of Tejas Mk2. As this Radar is direct modification of Uttam AESA, thus the testing cycle will be much smaller.
The data available in the public domain suggests that upgraded Uttam AESA of Tejas Mk2 will have 912 – 968 TRM. The arrangement will be Quad modules like in baseline Uttam; these quads then will be arranged in planks.
- Quad: A typical TRM consists of a transmitter and receiver module referred as dipole. This dipole antenna element is configured in multilayer configuration of 4X1 i.e. four transmitter and receivers are packed into one module referred as quad.
- Plank: These Quad modules as shown in the image above are arranged in planks. A typical plank can have multiple quad modules arranged linearly. The planned planks on Uttam AESA MK2 will have 8 QTRM based planks and 6 QTRM based planks.
These planks with 8 and 6 QTRM will have 32 and 24 TR modules respectively arranged in packed formation. This high-density packing will allow this AESA radar to have more TR modules and occupy smaller area in the nose cone.
These Antenna Array Units (AAU) should be delivered, Certified and Integrated on a Tejas Mk2 Aircraft within 32 weeks. This indicates that AAU will be available for the first flight of the first prototype. The Tejas Mk2 likely will enter the fight trials in 2023 and production in 3-5 years from there based on the results of trails. This timeline allows this new AESA radar to get matured and form the baseline for the further improved radar of AMCA.
Importance of this Radar
Uttam AESA is a modular and scalable radar unit. The radar unit designed for the LCA Tejas MK1A can be easily modified for the requirements of Indian Airforce. This Radar system can be scaled up for the potential application on Super Sukhoi, Mig29 UPG or even Mirage 2000.
The radar system will allow the Indian airforce to integrate just about anything at the disposal to enhance the capabilities of the existing systems significantly.
Just for the comparison, the Tejas Mk2 will have a radar with more TRM than RBE2 of Rafale fighter jet.
- Baseline Uttam AESA – 736 TR modules
- RBE2 of Rafale – 838 – 1100 TR modules (based on the variant)
- AN/APG-68 offered on F21 – Around 1000 TR modules
- Uttam MK2 – 912 – 968 TR modules
Though the range and the ability to track the stealthy targets is not limited to number of TR modules, there are numerous other factors involved. 912-968 TR modules is an impressive number.
In addition, since Tejas Mk2 will have a coating of Radar absorbent material. Thus, this aircraft will have a smaller RRS. So, in comparison Tejas Mk2 can locate its target at much longer distance and make detection difficult for the adversaries. This will allow Tejas Mk2 to see its enemy first and fire at them first.
Range of Uttam AESA Mk2
Calculating the range of a fighter jet radar is a complex affair, it depends on multiple factors. Although by the use of peak power, range of various fighter jets can be compared. The current radar of Tejas EL/M – 2032 has a peak power of 10 W per TR module. Assuming the peak power is retained then improved Uttam should have 912 X 10 = 9120 W of peak power. In comparison current Uttam AESA will have 736 X 10 = 7360 W of peak power. This indicates Uttam Mk2 will have approximately 20% more peak power then baseline Uttam, resulting similar increase in detection range.
The other advantage that increased number of TR modules and channels offer is increased number of target tracking. The radar will be able to track more targets in track while scan mode. This will allow Tejas to prioritize the targets and take on multiple aircrafts in air demonstrating air dominance capabilities.