BiCMOS integrated waveguide with artificial dielectric at submillimeter wave frequencies

In this paper we present a synthetic waveguide integrated in a commercial BiCMOS back-end-of-line, employing artificial dielectrics (ADs) to reduce the component size. The AD is realized by employing floating pillars using the various layers available in the technology, thus fulfilling metal density rule and boosting the effective permittivity of the host medium (i.e., SiO2) to 12.5. The impact of the AD translates in a 56% width reduction of the waveguide, for the same cutoff frequency. The structure provides 1.6dB of losses per guide wavelength (λg) at 300GHz and more than 30dB suppression below 180GHz, avoiding the need of filters in multiplication stages.