کنفرانس مهندسی برق ایران

صفحه اصلی / سی و سومین کنفرانس بین المللی مهندسی برق

A Wideband PLL with Programmable LC VCO with 5.1 to 7.9GHz Lock Range

نویسندگان :

Mohsen Azimikia¹ Arash Esmaili²

1- دانشگاه صنعتی ارومیه 2- دانشگاه صنعتی ارومیه

کلمات کلیدی :

PLL،LC VCO،Wideband،programable VCO

چکیده :

Abstract—LC VCOs are known to have good performance in terms of phase noise and jitter. However, their limited tuning range and area consumption due to the bulky inductors are their main disadvantages. The nonlinear behavior of the PLL during acquisition and also the change in the LC VCO gain for broadband applications make the design of broadband PLLs using LC VCOs a difficult task. Realizing that the phase noise of the PLL has an inverse proportion to the square of the quality factor encouraged us to use bonding wire as the inductor which has proven to have a high-quality factor. Since the absolute value of the inductance of the bonding wire has a great dependency on its form factor, we used a programmable LC VCO that utilizes a capacitor bank to switch between frequency bands. Using a coarse-fine scheme the digital words for the capacitor bank are obtained then the circuit switches to varactor for fine-tuning. Maintaining loop gain using a programmable charge pump a wideband PLL is designed with a tuning range of 5.1GHz to 7.9GHz in 0.18um CMOS technology. The measured jitter is below 300fF with a power consumption of 14.5mW for 7.9GHz output frequency.