Packaging of High-Gain Multichip Module in Multilayer LCP Substrates at $W$ -Band

In this paper, we packaged a multichip module (MCM) in multilayer liquid crystal polymer (LCP) substrate using V-shaped wire bond and 3-D-printed housing. In the proposed module, two low-noise amplifiers (LNAs) are cascaded in series to obtain high gain and low noise figure, and multilayer circuit is designed to achieve high assembly density. To minimize mode mismatch between microstrip lines on LNA and LCP with low dielectric constant, V-shaped wire bond was designed for LNA integration, achieving low insertion loss and low reflection at W-band. To verify this bonding design experimentally, a singlechip module was first integrated and characterized, successfully achieving a gain of more than 26.5 dB from 80 to 100 GHz. Then, the MCM was investigated and packaged, in which substrate integrated waveguides and via barriers are introduced to eliminate the potential substrate modes, and 3-D-printed plastic housing coated with gold is designed to capsulate the LNAs and isolate them in free space. The measured data demonstrate a high gain of 50 dB, a low noise figure of less than 6 dB, and linear phase from 80 to 97 GHz.