A new low-loss microstrip structure on LTCC substrate

Abstract

We have devised and implemented a new low-loss microstrip transmission structure on LTCC substrate by including void cavities in the dielectric layer between conductor strip and ground plane. Measurements of lambda/4 T-resonators with the novel microstrip structure reveal total loss of 0.0126 dB/mm and Q-factor of 267 at 15.85GHz. The dielectric loss is analyzed as small as 0.0005 dB/mm at the frequency, and that is equivalent to an improvement of a factor of 18 compared to the conventional LTCC microstrip structure. The proposed microstrip structure with the embedded void cavities is suited for low loss LTCC based RF-MCM applications.