Design and Measurement of Power-Coupling Structure for Parallel Operation of Two Folded Groove Waveguides

In this article, we design an input–output energy-coupling method for the parallel operation of two terahertz folded groove waveguides (FGWs)—a conversion from TE
₁₀
mode to two modes of TE
₁₁
. The mode is first converted in the H-plane of standard waveguide WR4 from TE
₁₀
to TE
₁₁
, and which is then subsequently converted into two TE
₁₁
modes through a Y-branch step impedance transformation. The novel energy-coupling structure was manufactured and measured so that the S parameter
$\text{S}_{{11}}$
is less than −10 dB in the frequency range of 170–260 GHz. And in the frequency range of 190–250 GHz, the simulated and measured transmission coefficient
$\text{S}_{{21}}$
tends to be consistent. Moreover, using the coupling structure, the dispersion characteristics of the parallel operation of two FGWs was measured.