We disclose an arrayed antenna for reception of electromagnetic radiation from a millimeter-wave or terahertz range. In an example embodiment, individual antenna cells in the arrayed antenna are configured for coherent detection of the received electromagnetic radiation and are electrically connected with one another in a manner that causes each of the antenna cells to positively contribute to the overall gain of the arrayed antenna. In some embodiments, the arrayed antenna may have a network of electrical conductors that is configured to (i) collect and deliver the electrical output signals generated by the individual antenna cells to an output terminal of the arrayed antenna, (ii) deliver an electrical local-oscillator signal from a common local-oscillator source to the individual antenna cells, and (iii) deliver electrical DC power from a common power supply to electrical circuits in the individual antenna cells.