An Integrated Millimeter-Wave Broadband Microstrip-to-Waveguide Vertical Transition Suitable for Multilayer Planar Circuits
An integrated broadband vertical microstrip-to-rectangular waveguide (RWG) transition at Ka-band is presented. This transition is especially suitable for multilayer planar circuits, by utilizing a section of multilayer three-dimensional (3-D) stepped substrate integrated waveguide (SIW) structure, along with a taper transition. A simplified initial transition model from 3-D stepped SIW to waveguide is first optimized, thereafter, a full microstrip-to-waveguide transition is constructed and further optimized. For demonstration, some back-to-back transition prototypes are fabricated by multilayer PCB processing. The experimental results show that the return loss better than 15 dB is obtained from 33 to 36.7 GHz, with the minimum net insertion loss about 0.7 dB for a single transition at 35 GHz.
A full Ka-band microstrip-to-waveguide transition using side-inserted magnetic coupling semicircular ring
A novel microstrip-to-waveguide transition utilizing a semicircular microstrip ring is presented. This transition is based on the side-inserted structure of magnetic field excitation in a rectangular waveguide. It has filled in blank of structures with which a rectangular waveguide can be excited from its narrow wall. It is also compact, and has advantages of full Ka-band availability, low insertion loss, structural flexibility and easy fabrication. Field coupling, impedance matching and compensation structures are included in this design. Structural characteristics of this transition and design of its individual components are analyzed in detail. Simulation and measurement of this transition are also discussed. The Ka-band back-to-back transition with RT-duriod 5880 substrate demonstrates the whole bandwidth with overall insertion loss between 0.95dB and 1.94dB, and return loss better than 11dB, respectively.
Compact in-line waveguide-to-microstrip coaxial probe transition for millimeter-wave
A novel in-line waveguide-to-microstrip transition using coaxial probe structure in the U-band is proposed. This transition has the advantages of low loss, compact structure and hermetic package. A metal post is inserted into the center E-plane of the waveguide to prompt the conversion of electromagnetic wave. Experimental results of the transition verify the validity of the design. A net transition loss of 1dB is obtained within a wide frequency range from 42GHz to 50 GHz. The length of overall transition is less than 0.7 λg, which is wavelength of the operation center frequency.