Thomas Does Radio or Something

In eventual hope for getting on 2.3 GHz, I picked up a pair of very low cost surplus panel antennas originally intended for SISO 2.4 GHz ISM operation. These were likely for WISP or other internet range extension use. I'm going to presume that they're broadband enough to extend down into the narrowband amateur segment, but maybe I'll get the chance to test that before applying much power. Blank, smudged radome of a TP-24-20-18 antenna

In an effort to be prepared for figuring out how to work an integrated microwave SDR, I picked up three amplifier modules for 900, 1300, and 2400 MHz. They're all from the same eBay seller and presumably the same factory with matching enclosures, labeling, and design techniques. Lineup of the three amplifier modules (labeled 2.4G 10W, 1250, and 915) with the heatsink planned for future use.

After reading the W1GHZ GaAsFET LNA Bias entry, I wanted to see what the performance of these exposed-base optocouplers are. The concept comes from the IEEE Microwave Journal Application Notes: Photovoltaic Bias for Depletion-Mode Devices in Low-Noise Amplifier Applications (DOI 10.1109/MMM.2022.3226635). It's not open access, so I figured some publicly available characterization data would be cool to share. I have access to a dual-channel precision SMU (source-measure unit, Wikipedia ) and that's exactly what we need to characterize the photovoltaic behavior of optocouplers! Keysight B2902B SMU front panel during a 20 mA input, open circuit output measurement