A Wide Tuning Range CMOS Quadrature Ring Oscillator with Improved FoM for Inductorless Reconfigurable PLL

Ramesh K. POKHAREL  Shashank LINGALA  Awinash ANAND  Prapto NUGROHO  Abhishek TOMAR  Haruichi KANAYA  Keiji YOSHIDA  

IEICE TRANSACTIONS on Electronics   Vol.E94-C   No.10   pp.1524-1532
Publication Date: 2011/10/01
Online ISSN: 1745-1353
DOI: 10.1587/transele.E94.C.1524
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Microwave and Millimeter-Wave Technology)
Category: Active Devices and Circuits
frequency tuning sensitivity,  feed forward technique,  figure of merit,  phase noise,  ring oscillator,  reconfigurable wireless system quadrature outputs,  0.18 µm CMOS,  

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This paper presents the design and implementation of a quadrature voltage-controlled ring oscillator with the improved figure of merit (FOM) using the four single-ended inverter topology. Furthermore, a new architecture to prevent the latch-up in even number of stages composed of single-ended ring inverters is proposed. The design is implemented in 0.18 µm CMOS technology and the measurement results show a FOM of -163.8 dBc/Hz with the phase noise of -125.8 dBc/Hz at 4 MHz offset from the carrier frequency of 3.4 GHz. It exhibits a frequency tuning range from 1.23 GHz to 4.17 GHz with coarse and fine frequency tuning sensitivity of 1.08 MHz/mV and 120 kHz/mV, respectively.