The quadrature sampling (QSD) or "Tayloe" detector, created by Dan Tayloe (N7VE) is a detector and preamplifier. Its features are based on an extremely compact and simple design The device's feature set includes: • Less than 1 dB of conversion loss • A high third-order intercept (+30 dBm). The basic product detector is shown below. Note the detector's simplistic design. The incoming RF signals are routed via a common resistor, R, and a commutating RF multiplexer, to one of four detection capacitors, C. This one-of-four multiplexer is commutated at a rate of four times the desired detection frequency. The 4x commutating frequency causes each capacitor to see a quarter cycle of the input RF at the desired detection frequency.