The THz spectrum is being explored due to its inherent large bandwidth to fulfill the throughput requirements for future wireless systems. However, there are intrinsic challenges for the exploitation of this spectrum for wireless communications, particularly concerning current technological capabilities. Moreover, it remains a big question if THz systems can be made efficient. In this contribution, we present a system analysis to show the potential of overcoming these challenges using quasi-optical antennas integrated with wideband SiGe-BiCMOS electronics and a suitable baseband design that can lead to the Tbit/sec and energy-efficient wireless transmission.