Irbis-E Flanker Family Radar

The Irbis multifunctional radar employs a 900mm passive phased array antenna mounted on a hydraulic actuator. With electronically steering, it can scan sectors of 60 degrees in both azimuth and elevation. Using the hydraulic actuator (mechanical steering), the azimuth coverage boosts to 120 degrees. It can detect and track up to 30 airborne targets with a Radar Cross Section (RCS) of three square meters at ranges of 400 kilometers using track-while-scan mode while engaging two targets with semi-active radar homing missiles or up to eight targets with active radar homing missiles. In the air-to-surface mode the Irbis provides clues allowing to attack two surface targets with precision-guided weapons while tracking up to four targets on the ground and scanning the horizon searching for airborne threats that can be engaged using active radar homing missiles.

Irbis-E is an advanced multi-mode, hybrid passive electronically scanned array radar system developed by Tikhomirov NIIP for the Su-35BM multi-purpose fighter aircraft. NIIP developed the new radar based on the Bars radar system provided to Su-30MKI/MKM/MKA aircraft.

Tikhomirov NIIP has provided the ability to spot super-low-observable targets with RCS = 0.01 square meters at ranges out to 90 kilometers. This capability might allow Su-35 aircraft to engage cruise missiles and unmanned aerial vehicles as well as fifth generation stealth fighter aircrafts such as the F/A-22 Raptor and F-35 Lightning II. NIIP and GRPZ will take care of the Irbis production with the first radar system slated for installation on the Su-35 in August 2007.

Design

Irbis-E development started in 2004 and the first radar prototype entered flight tests on board an Su-30M2 aircraft acting as a test bed in early 2007. The resulting radar system provides air-to-air, air-to-sea and air-to-ground (ground mapping, Doppler beam sharpening and Synthetic Aperture Radar modes) modes with improved performance in intense clutter (radar) environments compared to its predecessor, the Bars system. In addition, Irbis has been designed to detect low and super-low observable/stealth airborne threats.

This is an X band multi-role radar with a passive phased antenna array (PAA) mounted on a two-step hydraulic drive unit (in azimuth and roll). The antenna device scans by an electronically controlled beam in azimuth and angle of elevation in sectors not smaller than 60°. The two-step electro-hydraulic drive unit additionally turns the antenna by mechanic means to 60° in azimuth and 120° in roll. Thus, in using the electronic control and mechanical additional turn of the antenna, the maximum deflection angle of the beam grows to 120°.

The Irbis-E is a direct evolution of the BARS design, but significantly more powerful. While the hybrid phased array antenna is retained, the noise figure is slightly worse at 3.5 dB, but the receiver has four rather than three discrete channels. The biggest change is in the EGSP-27 transmitter, where the single 7-kilowatt peak power rated Chelnok TWT is replaced with a pair of 10-kilowatt peak power rated Chelnok tubes, ganged to provide a total peak power rating of 20 kilowatts. The radar is cited at an average power rating of 5 kilowatts, with 2 kilowatts CW rating for illumination. NIIP claim twice the bandwidth and improved frequency agility over the BARS, and better ECCM capability. The Irbis-E has new Solo-35.01 digital signal processor hardware and Solo-35.02 data processor, but retains receiver hardware, the master oscillator and exciter of the BARS. A prototype has been in flight test since late 2005.