Fabrication of Transition between NRD Guide and Microstrip Line at 60 GHz

摘要

A transition between an NRD guide, suitable for construction of high performance millimeter-wave integrated circuits, and a microstrip line, being used to mount semiconductor devices such as HEMT, HBT, and MMIC, was developed at 60 GHz. Main emphasis was placed on a manner of field matching between the NRD guide and microstrip line. We proposed a new transition structure using a vertical strip line, having easy coupling performance to the NRD guide, and a coaxial cable, being used to connect to the microstrip line. Moreover, we devised a new packaging structure of the microstrip line to prevent undesired leakage between the NRD guide and microstrip line. The insertion loss of the fabricated transition was measured to be less than 1 dB in the bandwidth of 4 GHz at a center frequency of 60 GHz. The transition was applied to evaluation of the MMIC amplifier at 60 GHz. The forward and reverse gains were measured to be 15 dB and -20 dB, respectively, at 60 GHz.