Millimeter-wave non-contact flip-chip transitions with Chebyshev filtering response using coupled microstrip resonators

The 77GHz automotive collision avoidance radar system is more important today. In this paper, a non-contact flip-chip transition design incorporating with the filter characteristic is proposed for the radar system. The transition is used to connect the RF signal path from a low-temperature co-fired ceramic (LTCC) substrate to a Teflon board. The concept of the transition is based on the design of coupled microstrip resonators, thereby accomplishing filtering transitions. The overall performance can also be improved, with bandwidth of 15 dB return loss from 74.4 GHz to 81.8 GHz, i.e., a 9.5% fractional bandwidth (FBW) and insertion loss of 1.3dB in the pass band.