A buried conductive layer is formed underneath a buried insulator layer of a semiconductor-on-insulator (SOI) substrate. A deep isolation trench laterally surrounding a portion of the buried conductive layer is formed, and is filled with at least a dielectric liner to form a deep capacitor trench isolation structure. Contact via structures are formed through the buried insulator layer and a top semiconductor layer and onto the portion of the buried conductive layer, which constitutes a buried conductive conduit. The deep capacitor trench isolation structure may be formed concurrently with at least one deep trench capacitor. A patterned portion of the top semiconductor layer may be employed as an additional conductive conduit for signal transmission. Further, the deep capacitor trench isolation structure may include a conductive portion, which can be electrically biased to control the impedance of the signal path including the buried conductive conduit.