To cope with the mission requirements for monitoring Earth's dynamic processes, future Synthetic Aperture Radar (SAR) systems will need to meet different performance requirements. The driver is to increase the acquisition frequency and to provide capabilities to monitor large areas. In addition, the imaging parameters show a high degree of heterogeneity depending on the application. In Terms of SAR instrument performance this translates into a large swath and access range to increase the coverage and a lower power consumption to increase the orbit duty cycle. Further, the instrument must be capable of operating in various modes. In this context the use of large reflectors combined with digital feed arrays for SAR is receiving increased interest. This paper suggests a spaceborne SAR system utilizing a deployable reflector together with a digital feed array, shortly states its design and addresses the various performance optimization issues.