Sub-Terahertz Band Dielectric Waveguide Power Dividers Based on Multimode Interference

This work presents dielectric waveguide power dividers based on multimode interference (MMI) in the sub-terahertz band. $\boldsymbol{1}\times \boldsymbol{2}$ and $\boldsymbol{1}\times \boldsymbol{3}$ power dividers are designed and simulated. The proposed power dividers include a feed dielectric waveguide, a transmission dielectric waveguide, and several output dielectric waveguides. It is investigated that the $\boldsymbol{E}_{\boldsymbol{11}}^{\boldsymbol{x}}$ mode in the feed wave-guide excites the $\boldsymbol{E}_{\boldsymbol{n1}}^{\boldsymbol{x}}$ mode in the transmission waveguide and then outputs the $\boldsymbol{E}_{\boldsymbol{11}}^{\boldsymbol{x}}$ mode in the output waveguides. The proposed power dividers are composed of only one layer of dielectric material, which is simple in design and inexpensive. The proposed $\boldsymbol{1}\times \boldsymbol{2}$ power divider has a center frequency of 100 GHz, the insertion loss of 0.9dB at 100GHz, the return loss greater than 26dB, and the isolation greater than 12.5dB at 86–120 GHz. The proposed 1 × 3 power divider has a center frequency of 100 GHz, the insertion loss of 0.75dB at 100GHz, the return loss greater than 25dB, and the isolation greater than 10dB at 93–118 GHz.