Wideband probe‐type microstrip‐to‐waveguide transition integrated in LTCC

A wideband probe‐type microstrip‐to‐waveguide transition integrated in a low‐temperature co‐fired ceramic (LTCC) is presented and experimentally verified. To enhance the bandwidth, an air‐hole matching structure besides the probe is buried in an LTCC substrate, which is implemented by drilling square holes on different substrate layers. The microstrip‐to‐waveguide transition is fabricated to verify a design with compact size. The measured results show a good agreement with simulated results.