Low phase noise phase locked loop frequency synthesizer design for breast cancer detection

Abstract

Harmonic Motion Microwave Doppler Imaging (HMMDI) method is recently proposed as a non-invasive hybrid breast imaging technique for tumor detection. In this method, local harmonic motion is generated in the tissue using a focused ultrasound probe. A narrow-band microwave signal is transmitted to the tissue. The Doppler component of the scattered signal, which depends on the dielectric and elastic properties of the vibrating region, is sensed [1]. Since the measurements obtained from HMMDI is directly related with phase noise, there are some studies to reduce phase noise of RF transmitting signal. In this work having a pure signal with ultra-low phase noise (−140dBc/Hz@1MHz) is one of the main goals to achieve the desired results at the proceeding steps. In addition the signal should be in (2–6GHz) frequency ranges. Therefore, modelling a low phase noise PLL operating in high frequency ranges with the help of measurements and microwave simulation tool (ADS) planned. According to the simulation results the proposed VCO provided a Phase Noise of about −137.64dBc/Hz @1MHz that is very acceptable in comparison to other provided complex VCO structures [2-5]. In addition generate 2.76 GH oscillating frequency.