Design and Evaluation of On-Chip Terahertz Wave Power Combiner for Beyond 5G/6G

We designed a terahertz wave power combiner which combines high-frequency currents from each photomixer in a micro strip line and investigated the feasibility of terahertz wave power combining. The designed terahertz power combiner was fabricated on silicon carbide (SiC) substrate because of its high thermal conductivity, which prevents thermal damage to the UTC-PD at high photocurrent. The UTC-PDs was activated with a bias voltage of −1.0 V and a photo current of 8 mA. Experimental results show that the output power of four photo mixers is multiplied by 11 dB (approximately 13 times) compared to that of a single photomixer, which confirms a great advantage of arrayed photomixers as a current source. In addition, the THz waves was higher without narrowing the beam width, compared to using the method of arrayed antennas with UTC-PDs.