mm-Wave Power Amplifiers in Silicon — State-of-the-Art and Several Recent Architecture/Circuit Examples
There is a rapidly growing need for high-performance mm-wave power amplifiers to address upcoming mm-wave 5G communication and numerous mission-critical multi-functional DoD applications. These next-generation mm-wave PAs are often expected to deliver nearly “perfect” performance. They should offer large output power to ensure sufficient link budget, broad bandwidth to support multi-standard communication or frequency reconfigurability/agility, high peak and back-off efficiency for energy saving, and also inherent linearity for Gbit/s complex modulations with minimum or even no digital pre-distortions (DPD). Compared to compound devices, silicon devices often exhibit inferior device-level performance, including power density, gain, efficiency, linearity, and reliability. However, besides their unparalleled fit for system-level integration, silicon technologies offer mature modeling, flexible metal options, and extensive digital control, making them an extremely versatile and attractive platform for design innovations. In this talk, we will review the state-of-the-art of silicon mm-wave PAs and compare them to recent compound semiconductor PAs. We will then present several recently reported silicon mm-wave PA design examples that essentially leverage architecture/circuit level innovations to overcome silicon device limitations and radically advance the state-of-the-art.