Dual-band lightweight, low-cost RF front-end solutions for point-to-point wireless applications

The objective of this work is to achieve the integration of a state-of-the-art RF CMOS chip in lightweight multilayer-organic (MLO) substrates at millimeter-wave frequencies. To do this, first the substrates need to be characterized above 30 GHz. This was done through the Ring Resonator Method. Once the loss and dielectric properties were known, the layers for the MLO stack-up were chosen and two different antenna arrays were designed for the chip’s communication. Subsequently, a hybrid integration with a silicon interposer layer was developed in preparation for the future CMOS chip. This integration consisted of a combination of flip-chip bonding assisted by a non-conductive film (NCF) layer to secure the bonding. Finally, since the chip has two different operating frequencies, an exhaustive orientation study for the arrays was performed. The study revealed the best orientation for the antennas in order to minimize interaction between them in the package. The final package possesses the ability to simultaneously excite both array designs, and also includes all interconnects and transitions required by the RF CMOS chip. Although the main focus is at millimeter-wave frequencies, other novel techniques at different frequencies are discussed, such as utilizing microfluidic channels to reduce the size of RF designs, characterizing 3D-printing materials, and designing the first micro-dispensed antenna in Ka band. All of these help to highlight the ability and versatility of organic substrates at high frequencies.Ph.D