Networking and Communication Engineering

T. Chtioui ¹, Ben Issa ¹, A. Fakhfakh ¹, M. Samet ¹

Affiliations
1 National School of Engineering of Sfax, 3.5 Street of Soukra, 3038 University of Sfax, TN

Abstract

This paper proposes a wide tuning Injection-Locked Frequency Divider (ILFD) and describes its operation principle. The circuit is made of a differential CMOS-tank oscillator in 0.35 μm process and is based on the direct injection topology. A theoretical prediction of the Locking range is developed and a graphical optimization of the circuit is done. The simulated results obtained with optimum parameter sizing show that at 2.5 V supply voltage, the divider free-running frequencies are from 2.27 to 2.53 GHz. The locking range of the proposed ILFD is about 548 MHz from the incident frequency 4.524 to 5.074 GHz. The power consumption is 9 mW and the phase noise of the locked output is -128.6 dBc/Hz at 1 MHz offset frequency.

Keywords

Graphical Optimization Method, Injection-Locked Frequency Divider (ILFD), Locking Range, VCO.

Full Text

     

D. Ben Issa ¹, M. Samet ¹, A. Kachouri ¹

Affiliations
1 National School of Engineering of Sfax, 3.5 Street of Soukra, 3038 University of Sfax, TN

Abstract

A multi-bands voltage controlled oscillator (VCO) based on LC resonator circuit is presented in this work. Two methods of optimization are applied to multi-band VCO circuit in order to confirm and to compare their results. These optimization techniques are the geometric program (GP) and graphical method. Theory results of each optimization method agree on the optimum component size of the multi-band VCO circuit. The operation range of the VCO is extended to cover eight frequency bands from 3.1GHz to 4.8GHz of which the tuning range is 42.5%. The phase noise is -118dBc/Hz, -123dBc/Hz and -123dBc/Hz at 1 MHz offset frequency from carrier frequency of 3.432GHz, 3.96GHz and 4.488GHz, respectively. The power consumption of multi-band VCO is 18mW from a 2.5V supply voltage. Simulated results show the performances of these methods, in fact, low phase noise and low power are obtained with the optimum components size of achieved result of optimization methods.

Keywords

VCO, Phase Noise, Geometric Program, Graphical Optimization Method.

Full Text