mm-Wave and Sub-THz Frequency Multiplier Chain Design: Harmonic Generation, Impedance Optimization, and Buffering Techniques

Frequency multiplier chains are a key enabler for mm-wave and sub-THz signal generation, where fundamental VCOs are severely limited in tuning range and phase noise performance. This workshop presents practical design methodologies for frequency multiplier chains, focusing on harmonic generation mechanisms, optimal source and load impedance design for maximum power transfer, and gain-boosted buffer stages to efficiently drive cascaded multipliers. Key topics include frequency doubler and tripler architectures with buffer integration, biasing and harmonic enhancement techniques, and design trade-offs among conversion gain, efficiency, and bandwidth, supported by both simulated and measured results.