An apparatus is configured to detect skin cancer using THz radiation. A high frequency source generates a high-frequency signal. A power splitter divides the high-frequency signal between a transmission branch and a reception branch. A first frequency multiplier multiplies the frequency of the high-frequency signal. A transmission antenna emits the multiplied high-frequency signal as THz radiation. A frequency generator generates a low-frequency signal. A mixer mixes the high-frequency and low-frequency signals to generate a mixed-frequency signal. A second frequency multiplier multiplies the mixed-frequency signal. A reception antenna device receives the THz radiation and generates a THz signal. The mixing device mixes the THz signal with multiplied mixed-frequency signal to generate a measurement signal. The evaluation device evaluates the measurement signal.
