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We discuss materials characterization and integration considerations for large‐format, antenna‐coupled, low‐noise, cryogenic, bolometer arrays for far‐infrared space‐based observatories. The suitability of Bi as an antenna termination resistor and annealed gold for microstrip and groundplane, in the context of using each to optimize signal and bandwidth of the receiver is addressed. Bismuth is chosen as a candidate termination resistor material because films can be made with the 10–100 Ω/□ needed to impedance‐match the antenna in a compact, stable, and reproducible manner. We characterize both the DC electronic transport and the THz optical properties of thermally evaporated (TE) and ion assisted thermally evaporated (IAE) Bi. It is found that the residual resistance ratio of the IAE Bi is an order of magnitude higher than that of TE Bi in the relevant impedance range. Furthermore, we show that we have produced IAE Bi films with linear response across the THz band. We discuss the possibility of employing other, much lower volume, absorber materials including TiAu and PdAu alloys. A comparison of the expected noise in a standard coupling resistor for each material is made. A technique of fabricating 150 nm gold films having a low temperature resistivity equal to 3.5×10−9 Ωm via thermal annealing is also presented. We model the response of these candidate films in an antenna circuit for THz radiation.