Emerging wireless technologies focus on operational frequencies significantly above the sub-6-GHz frequency bands for higher data rate or for better resolution. Application of antenna arrays is nowadays a commonly accepted approach for these new technologies. However, as the bandwidth demand continues to increase, the interface between the antenna and the active electronics starts to emerge as a bottleneck. It becomes very challenging to cover sufficient bandwidth to support multiple channels, or in some cases even a single channel, while keeping the antenna geometry simple, and the packaging and assembly cost low. In MiRAIN, we propose a new approach to design the antenna/amplifier interfaces at millimeter-wave frequencies. We will make use of reverse-saturated SiGe HBT switch topology, featuring a high off-resistance, to create tunable matching networks. The tunable networks will make it possible to adapt an amplifier to switch between multiple frequencies, or to adapt to impedance variations due to the location of the antenna within an array, or during electronic beamsteering. Furthermore, we will develop a new design approach that combines the design of the amplifier core, the re-configurable matching network and the antenna itself, instead of using pre-matched structures. At the end of the project, an array demonstrator will be realized that consists of an antenna array and MiRAIN ICs with an amplifier core, the tunable matching network, a phase shifter and a digital interface. The principle of tunable matching network will be applied to the design of a multi-band phase shifter. The ICs will also include test ports that will detect the incident and reflected power to and from the antenna, while this information will be used to adapt the amplifier to the impedance variations. The final goal will be to demonstrate electronic beam-steering at multiple frequency bands within 25 to 30 GHz range.