Integrated front-ends up to 200 GHz

In this paper, we present results of work done in packaging highly integrated circuits based on 100nm mHEMT technology. We present several examples of fully integrated receivers and sources for frequencies bands 90-130 GHz and 160-210 GHz. The circuits are packaged into waveguide blocks, characterized and compared to on-wafer measurements. Waveguide to microstrip transitions based on 50 um alumina substrate, and including via holes, are used to effectively interface the MMICs to a rectangular waveguide at RF without using tuning structures to resonate wire-inductance. Noise and return loss are characterized on wafer and after packaging. Typical increase of 0.7 dB in the NF is observed at 90-130 GHz after the packaging and 1 dB at 160-210 GHz. We address the issue of MMICs with high level of integration resulting in large cavities in the package causing instabilities for certain biasing conditions. Some of the packaged modules are characterized at both room and cryogenic temperatures.