Microwave characterization and modeling of multilayered Cofired Ceramic waveguides

This paper examines, with the aid of an Electromagnetic (EM) Field Solver (High Frequency Structure Simulator, HFSS [1]) the performance of via sidewall rectangular waveguide structures in a cofired ceramic substrate, and compares the modeled results to the modeled performance of a conventional solid conductor waveguide. The comparisons are made on the basis of insertion loss, reflection loss, and waveguide cutoff frequency. In addition, HFSS simulations were done to determine the crosstalk between two adjacent waveguides that share a common metal via fence sidewall, as well as two adjacent waveguides with separate, closely spaced, via sidewalls. In order to facilitate testing, a transition from stripline to cofired ceramic waveguide was developed Finally, we present measured results of a via sidewall rectangular waveguide structure fabricated as a Low Temperature Cofired Ceramic (LTCC) substrate, which shows very good agreement with the modeled performance.