Homemade VNA Delivers High-Frequency Performance on a Budget
1 min read
Summary
A vector network analyser is an instrument that measures frequency-dependent transmission characteristics such as gain, phase delay, and reflection coefficients.
Typically, VNAs are either cheap and limited or hugely expensive with full features, with little in between, although the popular NanoVNA has helped to close the gap at the lower end of the market.
Now, however, engineer Henrik Forsten has shared details of his build of a high-performance VNA that works between 10 MHz and 15 GHz and cost just $300 to build.
This is many times more than either the NanoVNA or Forsten’s previous budget VNA build, but it is far cheaper than commercial alternatives.
Key components are dual-channel broadband RF mixer chips, high-speed 12-bit ADCs, and a fast FPGA to handle data processing.
The design uses a custom six-layer PCB with large cutouts for directional couplers, which are isolated signals using coaxial cable lined with ferrite rings.
