%0 Journal Article %T Voltage-controlled oscillator at 6 GHz for Doppler radar in heart sensing applications %A Jovanovi£¿ Predrag %A Tasi£¿ Sini£¿a %A Jokanovi£¿ Branka %J Serbian Journal of Electrical Engineering %D 2009 %I Technical Faculty of ?a?ak %R 10.2298/sjee0903471j %X In this paper, the design of a low noise voltage controlled oscillator (VCO) for heart sensing applications is presented. It is designed using Ansoft Designer software to have a low level of phase noise, therefore a bipolar transistor is chosen. Many effects such as the behavior of large signals, the parasitic effects of packages, etc., are taken into account. Hence, through a nonlinear analysis, quite accurate simulation results are provided. %K VCO %K 6 GHz %K low phase noise %K high output power %K microstrip technology %U http://www.doiserbia.nb.rs/img/doi/1451-4869/2009/1451-48690903471J.pdf