|
|
|
|
Home》Other Research Activities/
Phase Noise Calibration
|
|
 |
|
|
Phase Noise System
|
|
Our first phase noise measurement system was from Femtosecond Systems, Inc. which included a single channel phase noise detector, a phase noise standard (1, 5, 10, 100 MHz), a delay line unit, and one single channel signal analyzer. A low noise frequency standard LNFR-400 was used as a reference signal of the system to measure properties of active devices like oscillators and power supplies, or passive devices like long cables and distribution amplifiers. When in system noise floor test, it could measure up to -177 dBc/Hz (5 MHz PM, at Fourier frequency 100 KHz).
In time domain measurement, the traditional time interval counter works well only when τ is not less than 1 second. The phase noise measurement method shows its excellence at analyzing properties of passive devices and measuring the very short term stability (τ < 0.5 second), the latter can be achieved by using the specific mathematical conversion between frequency domain and time domain. Our lab has done some works on the calculations which proved to be useful in the very short term stability estimate.
In 2011, our laboratory purchased another measurement system from SpectraDynamics , Inc. due to malfunction of 10 MHz phase noise standard in the first one. Its frequency range of measurement is 2 MHz ~ 26 GHz with FFT spectrum DC ~ 40 MHz and the related noise standard is traceable to NIST (1 MHz ~ 1 GHz). When in system noise floor test, it could measure up to -175dBc/Hz (5 MHz PM, at Fourier frequency 100 KHz).
|
|
|
|
|
|
Fig1. Front panel of the microwave phase noise measurement system
|
|
|
|
|
|
Fig2. Noise floor test of the microwave phase noise measurement system
|
|
