A Micromachined 1.37 THz Waveguide-Based 2 × 2 Beam Divider

The design, fabrication and measurement of a 2 × 2 local oscillator beam divider for pumping a hot electron bolometer based heterodyne array at 1.37 THz is presented. The WR0.65 rectangular waveguide-based
H
-plane and
E
-plane junctions are used to construct the feeding network. The divider comprises two 400-
$\mu $
m thick silicon wafers with multilayer deep reactive-ion etching micromachined circuits, and a Pickett–Potter horn array manufactured in aluminum (AI) using computer numerical control machining. The two silicon plates and the AI plate were assembled with a special process using multilayer stacking technology to ensure an assembling misalignment lower than 10 μm. The radiation patterns of the beam divider are measured at 1.34 THz and 1.37 THz and compared to simulations. This is the first prototype of the multilayer stacked waveguide-based 2 × 2 beam divider at 1.37 THz ever fabricated.