The next generation of communications satellites will use steerable phased-array antennas to allow in-flight alterations to the antenna beam shapes. The beam-forming networks of these antennas require digitally switchable attenuation-free phase shifters and phase-free attenuators. These control components must operate typically over 8% bandwidths at X- and Ku-bands with switching accuracies of 5° and 0.5 dB. The paper reports work carried out at British Aerospace Systems Ltd. on the development of such devices using both MIC (microwave IC) and MMIC (monolithic microwave IC) technologies.