A Novel Hybrid Fast Switching Adaptive No Delay Tanlock Loop Frequency   Synthesizer
  This paper presents a new fast switching hybrid frequency synthesizer with wide locking range. The hybrid synthesizer is based on the tanlock loop with no delay block (NDTL) and is capable of integer as well as fractional frequency division. The system maintains the in-lock state following the division process using an efficient adaptation mechanism. The fast switching and acquisition as well as the wide locking range and the robust jitter performance of the new hybrid NDTL synthesizer outperforms conventional time-delay tanlock loop (TDTL) synthesizer by orders of magnitude, making it attractive for synthesis even in Doppler environment. The performance of the hybrid synthesizer was evaluated under various conditions and the results demonstrate that it achieves the desired frequency division. 
Ehab Salahat, Saleh R. Al-Araji, Mahmoud Al-Qutayri
cs.IT math.IT