SMTR® module - Evolution towards airborne applications

Modern active electronically steered antennas (AESA) operate in different platforms and systems. Inside AIRBUS Defence & Space, the focus on X-band antennas today is on airborne and fighter nose radars, in satellite based SAR antennas (synthetic aperture radar) for earth observation, and ground surveillance and security radars. Active airborne antennas are assembled with hundreds or even thousands of transmit/receive modules. This paper will describe the evolution of the so-called standardized module solution based on LTCC package technology with special regard to airborne applications and the correlated needs. This evolution especially contains significant optimization steps concerning area, weight and cost. By realization of an SMTR® Module suitable to a folded plank concept a significant reduction of installation depth could be achieved. As the module weight is dominated by its package, technology evaluation and implementation of advantageous concepts and materials was performed, here. Cost reduction is always a key focus of T/R module evolution as the modules still allocate a big part of antenna's production cost. Some steps have been realised here both on technology and component level. The next generation of AESA antennas will result in a combination of different operating modes within the same antenna front end, including radar, communication (data links), and jamming (electronic warfare, EW). This leads to enhanced demands especially towards the MMICs. The RF section of today's T/R modules for AESA applications is typically based on GaAs technology. During the last 10 years there was much progress in the development of disruptive semiconductor materials, especially GaN and SiGe BiCMOS, which have the potential to challenge or even replace the GaAs technology, here. This paper will describe and show this evolution through the last years and shall give an outlook towards future developments with regard to airborne applications.