The research and development in 0.1-1.0 THz frequency region is extremely significant for wide range of applications, for instance, for wide band telecommunication and imaging systems, material spectroscopy, and medical imaging and treatments. In spite of the problems in technology and high prices for basic components (phase shifters, directional couplers, etc.), the THz systems meet expanding interest of consumers. Dielectric rod waveguides (DRW) are promising transmission lines, when low loss dielectric materials are used, and can be combined with semiconductor devices (oscillators, detectors, mixers, etc.) in the hybrid and/or monolithic integrated circuits. Considerable achievements in this area have been obtained in RAD, Aalto. These developments offer a new opportunity for passive and active component performance, as it allows to decrease the insertion losses. Besides, DRWs have no cut-off frequency enabling broad band operation. Existing materials with controllable parameters are usually very lossy at low THz frequencies, which results in a limitation of the operational frequency. Therefore, carbon nanotubes (CNT) and graphene can be an appropriate solution. We propose to use micro-electromechanical systems (MEMS) in order to produce a novel phase shifter based on an electronically reconfigurable varactor. CNTs and/or graphene are ideally suited as a flexible varactor. Such a phase shifter can be developed by introducing a varactor to the DRW. Both CNTs and graphene components can be integrated into the DRW antenna or to the antenna array surfaces in order to obtain the antenna array for future THz beam steering applications. The applications in communications come from the great interest to the ultra-fast wireless communication links for future wireless systems, providing data rates of more than 10 Gbit/s. However, the output power of semiconductor photomixers is typically only a few microwatts at 1 THz. The efficiency can be greatly increased by using a stack of n-i-pn-i-p superlattice photomixers with extremely small size where ballistic conductivity can be employed. It is well known that the CNTs and graphene have the highest ballistic conductivity. Preliminary experiments show potential of graphene as a photodiode. However, mechanism of photoconductivity is not clear yet. We propose to replace the semiconductor with CNT and/or graphene photodiode. Moreover graphene layer has unique 2-d electron gas properties which allow to build an traveling wave amplifier. Both passive (e.g. phase shifters) and active (DRW with an active layer) components can be integrated into the DRW antenna to obtain a compact transceiver module for THz applications.