Terahertz monolithic integrated coplanar band‐pass filter based on slotline mode.

In this letter, a terahertz monolithic integrated planar band‐pass filter based on coplanar waveguide (CPW) resonators has been proposed. By adopting the feeding line in form of a slotline, the need for air‐bridges in traditional CPW filters is eliminated, achieving good integrability and reducing fabrication difficulty. To further improve the filtering performance, the defected ground structure is used in the design, introducing a finite transmission zero at the lower sideband. The filter is manufactured on the semi‐insulation silicon carbide (SiC) substrate, to fit the existing advanced GaN‐on‐SiC monolithic integration system. Measurement reveals the fractional band‐width of 5.7% at the center frequency of 279 GHz, with an insertion loss of 5.1 dB. With a volume of 500 × 400 × 50 μm (0.45 × 0.36 × 0.045 λ0), the proposed filter improves the performance of the planar filter operating at the terahertz band effectively. [ABSTRACT FROM AUTHOR]