เปรียบเทียบวิธี

	Phase-Locked Loop	Transmission-Line Matrix Method
สาขาวิชา	วิศวกรรมไฟฟ้า	วิศวกรรมไฟฟ้า
ตระกูล	Process / pipeline	Process / pipeline
ปีกำเนิด	1966	1971
ผู้ริเริ่ม	Floyd M. Gardner	Peter Johns
ประเภท	Feedback control loop for frequency and phase synchronization	Transmission line network analogous to electromagnetic fields
แหล่งต้นตำรับ	Gardner, F. M. (1966). Phaselock Techniques. Wiley & Sons.	Johns, P. B., & Beurle, R. L. (1971). Numerical solution of 2-D scattering problems using a transmission-line calculator. Proceedings of the IEE, 118(9), 1203-1208.
ชื่อเรียกอื่น	PLL, Phase lock, Frequency synchronizer	TLM, Transmission line matrix
ที่เกี่ยวข้อง	3	3
สรุป	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.	The Transmission-Line Matrix (TLM) method is a direct discretization of Maxwell equations using an equivalent transmission line network. Introduced by Johns and Beurle in 1971, TLM models electromagnetic fields as voltage and current waves propagating on coupled transmission lines. The method is intuitive, numerically stable, and efficient for both transient and frequency-domain electromagnetic problems. TLM remains competitive with FDTD and FIT for many RF and microwave applications.