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.
Novel Low-Loss Millimeter-Wave Transition From Waveguide-to-Microstrip Line Suitable for MMIC Integration and Packaging
This letter presents a unique low-loss transition from microstrip to full height rectangular waveguide at W-band. This microstrip transition can be made as a part of the mm-wave monolithic microwave integrated circuit (MMIC) of arbitrary size, and thus, avoid the use of bond wires at the high-frequency port of the MMIC circuit. As a result, the MMIC can be coupled directly to the waveguide. The working principle of the transition is based on electromagnetic coupling, where the coupling between the microstrip mode and the TE10 waveguide mode is achieved via a resonant cavity. A perfect magnetic conductor (PMC) surface is placed over the cavity to facilitate the smooth coupling of electromagnetic energy from the microstrip line to the cavity and then from the cavity to the waveguide. The PMC surface also suppresses the unwanted waveguide mode coupling to the oversized MMIC substrate. The measured back-to-back transition works over the frequency band of 80–114 GHz (relative BW of 35%) with minimum return loss of 13.5 dB. The total insertion loss of the manufactured prototype is found to be varying from 0.54 to 0.803 dB, which implies a single transition loss of less than 0.27–0.4015 dB in W-band.
Waveguide to microstrip probe transition for Ka-band transceiver applications
In this paper, we described the specific design procedures of Ka-band waveguide to microstrip transition using probe. Also, we fabricated the transition which has a low insertion loss, a low cost, and a simple structure for use in Ka-band transceiver systems.