Phase Noise Spectrum Measurement for USRP

Phase noise is a common hardware impairment, resulting from the frequency instability of voltage-controlled oscillators (VCO). To improve the phase noise performance of a VCO, they are typically connected to a control circuit. This control circuit is known as phase locked loop (PLL). It is commonly used as a frequency synthesizing circuit for the carrier frequency in mobile communication transceivers. Universal Software Radio Peripherals (USRP) are widely used in mobile communication research. While Datasheets of USRP's such as the X310 and their PLL component are publically available [Link], the phase noise (magnitude) is only given at discrete frequency offsets. The raw data of phase noise spectrums is typically not available. For researchers that investigate the phase noise phenomena or want to utilize USRP's in Testbeds for phase synchronous transceivers, this data is of interest. Therefore, recorded phase noise spectrum measurements are provided.