The frequency range of synthetic aperture radar is being extended to the promising THz spectrum as it provides high spatial resolution. The spectrum broadens the SAR applications to sub-mm resolution imaging and localization, non-destructive testing, and material characterization. Although the spectrum suffers from high atmospheric attenuation and free space path loss limiting the sensing range, it has emerging short-range applications. State-of-the-art THz SAR imaging is demonstrated primarily up to 1.1 THz with electronic transceiver modules. This paper presents one of the first demonstrations of 3D SAR imaging at 1.5 THz. The frequency band of 1.1-1.5 THz is considered for imaging a metallic target at a reference range of approx. 40 cm. The enhancement in terms of imaging quality compared to SAR image for the frequency band, 0.85-1.1 THz, is also presented.