(a) Fundamental layout of the compact integrated THz spectrometer based on Schottky diodes coupled to frequency-selective antenna structures. The chip is 2.4 mm × 1.4 mm wide. Each detector element can be read out and biased individually. The 50 GHz detector element is for monitoring possible strong interfering signals at comparably low frequencies. The remaining seven elements from 0.1 to 0.7 THz are used to sample the spectral behavior. (b) Application as detector for THz fingerprint spectra. When irradiated with a broadband THz spectrum such as a superradiant pulse from an ultra-short relativistic electron bunch, different frequency components can be detected in parallel and relative changes can be monitored with high precision.