...under perpetual construction.
Here you can find some of the circuits I have built in the past, in particular a 12-bit and 18-bit parallel port analog-to-digital converters with complete schematics and C source code for Linux
A simple analog-to-digital converter that interfaces to a PC parallel port and providing 12 bit of resolution, with four differential input channels. Actual conversion throughput is about 2.5 ksamples/s
A high-resolution ADC : it can provide up to 18 bits plus sign, at 16 samples/s, with four differential or eight single-ended input channels.
Characterization of the QRP2000 USB-controlled synthesizer.
How to build a vector network analyzer without explicitly measuring phase, but only voltages.
How to design a bias-tee with nice performances, starting from an existing design by WB9JPS.
Brief overview on how to extract a model for the capacitance-vs-voltage curve of a varactor diode, starting with the graphs on the component datasheet.
How to extract a (small-signal) LDMOS model, starting from the device S-parameters, with some examples for common high-frequency LDMOS.
Characterization and modeling of a homemade "calibration kit" (reference impedances) to be used to calibrate a network analyzer.