K band RFPA size reductions

I find it interesting that as I progress through RF/Microwave design how sizes of the circuits shrink continuously with operating frequency ( medium power). The attached image ( blurred a trifle for proprietary reasons) shows a completed board for a 26.5 Ghz, 2 watt power amplifier. The active device design is done in GAN technology and the board substrate is a RO4350 with gold plating and impedance control ( read $$$ cost). Be that as it may, notice the comparative size in the image. Everything about this board is minute. The SMA connectors are minute, the thickness of the substrate is minute, etc. The design was done using Keysight ADS and (interestingly), QUCS and Octave ( as the math engine). The input and output impedances are 50 Ohm. Anyone interested in more details may contact me on spg@signalpro.biz. One interesting facet of the module design was the time spent in identifying the SMA connectors for 26.5 Ghz. I find it interesting that most suppliers seem to stop at 18 Ghz for component frequency performance. So 26.5 Ghz is a novelty now I suppose. It may not be for long though. Please visit the Signal Processing Group Inc. website for more interesting technical and business information.

A 26.5 Ghz power amplifier

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