Embedded Suspended Stripline Substrate Technology (ESSS) as a Catalyst for Low-loss PCB Structures in the Ka-Band

A novel PCB embedded suspended stripline arrangement is proposed in order to improve the RF performance compared to classical planar technologies. The advantages are demonstrated through the design and characterization of a 2nd-order filter at Ka-band having 4.5% fractional bandwidth (FBW). The simulated Q-factor is around 455 which is significantly higher compared to what is achievable in microstrip. The manufactured sample shows deviations in the expected range given by the manufacturing tolerances from the simulated results. However, a similar high Q-factor of 410 in Ka-band was obtained.