On-Wafer Microrectangular Coaxial Delay Line by Using MEMS-Casting Process

In this work, a serpentine microrectangular coaxial delay line (MRCDL) operating from dc to Ka -band is realized based on MEMS-Casting (MEMS-C) process. As an emerging technology, the MEMS-C process provides a low-cost, rapid, and one-time prototyping approach for manufacturing the proposed MRCDL. Besides, the single-crystal quartz with low permittivity and low loss tangent is used to fill the MRCDL and supply high reliability. One prototype is fabricated for demonstration. The measured results show a maximum 2.42-dB loss in the 410-ps delay circumstance, with 23.5-ps delay flatness in the range of dc to Ka -band. Moreover, the loss characteristic is comparable to the Cu-based air-filled MRCDL in a similar electrical delay situation, due to the dramatically shortened physical length benefiting from the low-loss filled dielectric. Obviously, the proposed microrectangular coaxial line (MRCL) design indicates an interesting solution to microwave and millimeter-wave microdevices and systems.