Micro-wave data converters for space applications

In advanced applications such as satellite telecommunications, digital radar, frequency hopping data links and micro-wave communications, powerful signal processors able to handle broadband signal vectors are becoming more common. The bottleneck is now the availability of high sampling rate and high linearity data converters, ADCs (Analog to Digital Converter) for reception and DACs (Digital to Analog Converter) for transmission. Advanced high bandwidth and high data rate data converters are revolutionizing the way that microwave communication systems are designed. The ability to perform direct microwave synthesis in the L, S and lower C bands brings higher flexibility and lower part count without any performance degradation. Some of these data converters are now available with space grade quality and as such are being used in many satellite applications. This paper describes an innovative 12bit 3GSps DAC, EV12DS130A, with an output bandwidth of 6GHz which gives good performance up to lower C band. It describes the design features of the device along with a novel output shaping scheme which extends the performance up to higher frequencies. The paper also covers the interfacing to the device which can often be problematic for space grade Application Specific Integrated Circuits (ASICs). A novel timing verification feature is described along with a timing mode which can reduce the input data rate but allows data output at higher clock speeds. A companion 10bit 1.5GSps ADC, EV10AS180A is also described, which offers good performance into the L band and along with the EV12DS130A can provide a complete space grade transceiver solution. Also covered are aspects of these components' performance under radiation testing.