Phased Amplitude Matched Hybrid RF-Manifold for X-Band AESA Radar

Abstract

The Active Electronically Scanned Array (AESA) radars are far superior to the former Passive Electronically Scanned Arrays (PESA) due to their multi-function capability, graceful degradation, robustness, and long operation life. The key enabling sub-system to obtain these features is the phased array front-end that typically consists of more than 1000 transmit-receive modules (TR modules or TRMs) that provide beam agility, low side-lobe levels, high power, and long-range capability to the radar. These TRMs ideally require input signals with equal amplitude and phase from the preceding sub-system so that the desired phase shifts and attenuation can be applied correctly. However, such 1:1000 dividers, also called the RF Manifold, poses several research challenges. Generic power dividers include a passive approach only, which weakens the signal to the extent that it cannot be amplified by TRMs. Due to these limitations and gain degradation as the signal propagates away from an input, a hybrid approach of passive division and active components is adopted. The active part consists of amplifiers to re-coup the lost power due to passive division. However, they add to amplitude and phase variability. This thesis focuses on developing a hybrid RF Manifold for a wideband -Band AESA radar that can provide phase and amplitude-matched outputs. The other feature of this research will be the techniques to achieve wide bandwidth, increase isolation between ports, and size miniaturization.