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.
Width of the step tolerable for offset of the aperture in a transducer between post-wall and hollow standard waveguides
We have proposed the transducer with the step width is to be wide than the conventional model for strong tolerance against the aperture offset in the fabrication in terms of the reflection. For the model where the step length is 1.5 wavelengths, it has small effect by the aperture offset. We will confirm it by an experiment
Cutaneous myiasis caused by the housefly, Musca domestica
Summary We report a case of cutaneous myiasis by the housefly. Musca domestica.