0.9mW 7GHz and 1.6mW 60GHz frequency dividers with locking-range enhancement in 0.13μm CMOS

Frequency dividers are key components for frequency synthesis in wireless and wireline communication systems. Among different types of frequency dividers, LC-based injection-locked frequency dividers (ILFDs) feature highfrequency operation at low power consumption, but their locking range is quite narrow due to the high-Q nature of the resonator. Recently, design techniques to enhance the locking range of ILFDs have been reported. Injection into two coupled LC oscillators [1] and sandwiched injection into two identical LC oscillators [2] are proposed, but these techniques are suitable for dividers with quadrature outputs. Inductive-peaking and transconductance enhancement techniques [3, 5] are also used but they require extra inductors and thus larger chip area. In this paper, a simple but effective technique is presented to improve the locking range of ILFDs without extra inductive components while consuming low power