The invention relates to noise isolation in semiconductor devices, and a design structure on which a subject circuit resides. A design structure is embodied in a machine readable medium used in a design process. The design structure includes a deep sub-collector located in a first epitaxial layer, and a doped region located in a second epitaxial layer, which is above the first epitaxial layer. The design structure further includes a reach-through structure penetrating from a surface of the device through the first and second epitaxial layers to the deep sub-collector, and a trench isolation structure penetrating from a surface of the device and surrounding the doped region.