مقایسهٔ روش‌ها

	حلقه قفل فاز	تحلیل پارامتر S
حوزه	مهندسی برق	مهندسی برق
خانواده	Process / pipeline	Process / pipeline
سال پیدایش	1966	1965
پدیدآور	Floyd M. Gardner	Kaneyuki Kurokawa
نوع	Feedback control loop for frequency and phase synchronization	Wave-based description of RF/microwave network behavior
منبع بنیادین	Gardner, F. M. (1966). Phaselock Techniques. Wiley & Sons.	Kurokawa, K. (1965). Power waves and the scattering matrix. IEEE Transactions on Microwave Theory and Techniques, 13(3), 194-202.
نام‌های دیگر	PLL, Phase lock, Frequency synchronizer	S-parameter, Scattering parameters, Network parameters
مرتبط	3	3
خلاصه	A Phase-Locked Loop (PLL) is a feedback control system that synchronizes an output oscillator to match the phase and frequency of an input signal. Introduced by Gardner in 1966, PLLs are ubiquitous in communications, radar, clock distribution, and power systems. The PLL continuously adjusts its oscillator frequency to minimize the phase error with the input, achieving lock. PLLs are fundamental to modern electronic systems.	S-Parameters (Scattering Parameters) characterize RF and microwave networks by their transmission and reflection of voltage waves. Introduced by Kurokawa in 1965, S-parameters are ideal for high frequencies where wave effects dominate. Unlike impedance (Z), admittance (Y), or hybrid parameters, S-parameters are directly measurable with network analyzers, naturally account for characteristic impedance, and are intuitive for cascade analysis. S-parameters are the standard language of RF engineering.