Frequency-Locked Detector Threshold Setting Criteria Based on Mean-Time-To-Lose-Lock (MTLL) for GPS Receivers

Frequency-Locked Detector Threshold Setting Criteria Based on Mean-Time-To-Lose-Lock (MTLL) for GPS Receivers

Frequency-locked detector (FLD) has been widely utilized in tracking loops of Global Positioning System (GPS) receivers to indicate their locking status. The relation between FLD and lock status has been seldom discussed. The traditional PLL experience is not suitable for FLL. In this paper, the threshold setting criteria for frequency-locked detector in the GPS receiver has been proposed by an...

Injection locked oscillator lock detector

Frequency detector for fast frequency lock of digital PLLs

Introduction: A wide tuning range for a PLL can be achieved by incorporating a frequency-locked loop (FLL) in parallel with the PLL. The key building block of an FLL is the frequency detector (FD) that determines the difference between the oscillator’s divided clock (CKV) and the reference clock (REF). There are many ways to accomplish frequency lock in digital PLLs, but all of them suffer from...

A Study of GPS Carrier-Phase Time Transfer Noise Based on NIST GPS Receivers

To do a better time comparison between high-precision clocks (such as a Cesium-fountain clock and Hydrogen-maser clock), we want to study and eventually lower the GPS carrier-phase time transfer noise. The GPS carrier-phase time transfer noise comes from four sources: GPS satellite, GPS signal path, ground receiving equipment (receiver and antenna), and data-processing algorithm. This paper foc...

Phase - Locked Loops for High - Frequency Receivers and Transmitters – Part

In this second part, we will focus on a detailed examination of two critical specifications associated with PLLs: phase noise and reference spurs. What causes them and how can they be minimized? The discussion will include measurement techniques and the effect of these errors on system performance. We will also consider output leakage current, with an example showing its significance in openloo...