Radar Warning Receiver (RWR) and Jammer are very important part of Electronic Warfare Suite. RWR and Jammer work in combination with each other.
Defence Avionics Research Establishment (DARE) an arm of DRDO had developed Tarang-1/1B/2 RWR and most of India’s fleet of Mig-21, Mig-27, Mig-29 and Su-30 MKI had been fitted with this. But Tarang is an analog RWR and unable to catch low probability intercepts (LPIs).
Of late DARE had developed R118 Dhruti, a wide band digital RWR for Su-30MKI. The digital receiver makes it possible to differentiate overlapping signals, differentiate single pulses among CW within a frequency band. In simple terms it can differentiate multiple radar threats with frequencies close to each other and can also differentiate radar emissions from the background noise.
As for as jammer is concerned, earlier most of Indian fleet was fitted with Israeli Elta EL/L-8222 Airborne Self Protection Jammer. They have been upgraded to wideband EL/L-8222WB pods.
But at Aero India, 2017 Alpha Design demonstrated a High Band Jammer (HBJ) pod for Su-30MKI. It will be better integrated with the RWR Tarang than the original Russian SAP-518 pods, which some say are of the quality used for commercial airliners not fighter jets.
Moreover Russia does not share source codes or demands huge sums for that otherwise Indian RWR could have been integrated with SAP-518 pods too.
Indigenous Indian Radar Warning Jammer (RWJ) which will subsequently be equipped on Tejas fleet too, consists of a Unified Receiver Exciter Processor (UREP) with advanced digital receiver/ Digital Radio Frequency Memory (DRFM) with Microwave Power Module (MPM) based transmitter.
Working on DRFM principle means it receives, detects, classifies the signal waveform, stores them, adds a delay and sends it back to the adversary emitter to be picked up thereby giving incorrect range data and even azimuth if the scan patterns are known.
High Band Jammer (HBJ) has three major components : the integrated Electronic Warfare Suite, the active array phased transmit-receive unit, and the cooling system. While the first two have been developed, the complex cooling system is being worked upon, with DARE presently sourcing an Israeli system.
DARE scientists are confident that by early 2019 this problem will be resolved. It will spawn a whole generation of new series of jammers and EW suites that can be used on subsequent models of Tejas like MK2.
We think that rests the scores of questions that we receive on Jammers for Tejas from our followers in India.
