Millimeter-wave silicon MMIC interconnect and coupler using multilayer polyimide technology

This paper reports our latest progress in developing Low-loss and low-cross talk silicon MMIC interconnects for millimeter-wave applications. The propo sed silicon/metal/polyimide (SIMPOL) structure based on multilayer polyimid e technology is extremely effective in reducing noise crosstalk, and also p rovides very Low line loss, even at the millimeter-wave regime. The measure ment results of the developed SIMPOL structures demonstrate extremely low n oise crosstalk (<-40 dB) in the entire frequency range (up to 50 GHz), whic h is limited by the dynamic range of the measurement equipment, and excelle nt insertion loss (<-0.25 dB/mm) up to 45 GHz, In addition, the SIMPOL conc ept is applied for the first time successfully in the design and fabricatio n of branch-line hybrids at millimeter-wave frequencies, 30 and 37 GHz.