The FAA-450 Antenna Analyzer is an open source project built from STM32-F7 Discovery board. This project originated from “EU1KY Antenna Analyzer V3”, which features a colour TFT LCD, Capacitive Touchscreen, HF/VHF(UHF) frequency coverage, built-in TDR function, and multiple scanning curves besides with SWR. These features may outperform many expensive antenna analyzers present on the market. The analyzer utilizes the DSP technology to analyze the sampled and lower converted (10KHz) V & I signal and derive their magnitude ratio and phase difference. The calibrated measured results could be very accurate for amateur radio purpose.
Moreover, the device is able to work up to 450 MHz for some less accurate measurements.(Using 3rd harmonics of both signal and LO above 150 MHz, or above 200 MHz if properly confgured).
I bought it ready assembled from #^https://www.elekitsorparts.com/product/faa-450-antenna-analyzer-eu1ky