摘要 |
<p>A new structure for phase-locked loop (PLL) system is disclosed. As with conventional PLLs, the present invention consists of phase detection, loop filter and voltage-controlled oscillator units. An alternative phase detection structure, inspired by concepts from adaptive filtering and dynamical systems theory, is presented which substantially enhances the performance of the loop in terms of stability and dynamic performance. Presented phase detection scheme obviates the need for sophisticated loop filters, so much so that a first order filter suffices for most applications. In addition to the normal function of a PLL, the present system directly generates estimates of the amplitude, phase and frequency of the input signal. This feature extends the range of applications of the system beyond well-known applications of PLL in various disciplines of electrical engineering.</p> |