Digital display for half wave detector with cubic spline interpolation – part 1 and following articles laid out the design concepts of a power meter display.
Digital display for half wave detector with cubic spline interpolation – part 2 described a simple cubic spline interpolation model.
This article examines the problem a little deeper to arrive at an improved solution.
The chart above compares the response of an ideal peak detector (cyan) with an LTSPICE simulation of a BAT46 with 57kΩ load (orange x). Whilst the simulation approaches the ideal at peak RF voltage Vp greater than 3V, it departs greatly at very low Vp. Continue reading Digital display for half wave detector with cubic spline interpolation – part 4