This paper presents the design and characterization results of the key RF components of calibrated passive radiometer (Dicke-radiometer) operating in the D-band frequency range and realized in an advanced 90 nm SiGe BiCMOS technology. A single-pole double-throw (SPDT) switch is presented utilizing PIN diodes, with a measured insertion loss of 2 dB and an isolation of 20 dB at 140 GHz. The LNA provides a gain of 30 dB with 3 dB bandwidth of 28 GHz and minimum noise figure of 6.2 dB, demonstrating state-of-the-art performance. The square-low power detector achieves responsivity of 10 kV/W and noise equivalent power (NEP) <3 pW/VHz. The low total DC power consumption (40 mW), along with the small footprint of the presented components make them highly suitable for integration in large scale imaging arrays.