A 3-D Phased Array Transmitter With Circuit and Package Codesign of a Phase Shifter and a Power Amplifier at W Band

This study proposes the design, fabrication, and testing of a 3-D integrated transmitter operating at the W band. Detailed analyses of the performance variations before and after packaging of the phase shifter (PS) and power amplifier (PA) are provided, along with specific design processes. The circuit and packaging of the PS and PA are codesigned to maintain their performance and minimize proximity effects during 3-D integration at millimeter-wave frequencies. The PS achieves a −6.4-dB loss at 100GHz, with a phase root mean square (rms) error of 1.11° and a gain rms error of 0.855dB. The PA achieves a maximum gain of 19.5dB at 103GHz, with a bandwidth from 99.2 to 106.7GHz and a saturated output power of 13dBm. Both the PS and PA are individually packaged using proprietary silicon-based micro-electro-mechanical system (MEMS) through-silicon-trench technology and multilayer photosensitive composite film. Finally, a 3-D integration of the transmitter system is realized using microbumps based on 3-D transition structures.