Micromachined 3D millimeter-wave and terahertz devices

Micromachining is a very promising technology to manufacture miniature three-dimensional (3D) devices at millimeter-wave (mm-wave) and terahertz (THz) frequencies. After a decade´s development, this technology has begun to demonstrate its viability and capability. It has delivered devices with competitive performance to traditional metal machining or electroforming, for coaxial and waveguide structures with sub-millimeter dimensions. This paper will discuss three strands of work that tackle three main challenges - fabrications, designs and measurements - in this technology. Several passive devices will be presented to illustrate the progress made on the multilayered SU8 techniques. These include guided transmission structures and devices based on rectangular coaxial lines, waveguides and free-space frequency selective surfaces. The concerned frequency covers from 30 GHz to 1 THz.