Vertical LTCC Integrated Rectangular Waveguide and Transitions for Millimeter-Wave Applications

A new vertical guiding structure in low-temperature cofired ceramics (LTCC) substrates is proposed. This vertical LTCC integrated waveguide (V-LIW) allows transmitting signals and realizing components in the body of the LTCC substrate perpendicular to its surface. This vertical integration leads to considerable footprint reduction while opening the door to higher frequency coverage as well as easy implementation of E -plane structures. Discontinuities in V-LIW and transitions between the proposed V-LIW and conventional horizontal guiding structures such as coplanar waveguides, standard rectangular waveguides, and substrate integrated waveguides are also introduced. Applications to the design of V-band and W-band filters, couplers, and power dividers are presented. Several prototypes are fabricated with measurement results showing a good agreement with simulation data.