Title :
A sub-sampling digital PM/AM noise measurement system
Author :
Nelson, C.W. ; Howe, D.A.
Author_Institution :
Time & Freq. Div., Nat. Inst. of Stand. & Technol., Boulder, CO, USA
Abstract :
A digital phase/amplitude modulation (PM/AM) noise-measurement system (DNMS) implementing field-programmable gate array (FPGA)-based digital down-converters (DDCs), and 250 MHz analog-to-digital converters (ADCs) is reported. Performance in the first, baseband Nyquist region shows white phase-noise floors of less than -180 dBc/Hz. With proper pre-filtering of the input signals to prevent undesired aliasing, high-bandwidth track-and-hold amplifiers (THA) extend the operating range of the DNMS to microwave frequencies. Preliminary testing with an 18 GHz THA shows residual white phase-noise floors at 10 GHz of less than -160 dBc/Hz.
Keywords :
amplifiers; amplitude modulation; analogue-digital conversion; field programmable gate arrays; filtering theory; measurement systems; noise measurement; phase modulation; phase noise; sample and hold circuits; signal sampling; white noise; DDC; DNMS; FPGA; THA; amplitude modulation; analog-to-digital converter; baseband Nyquist region; digital AM noise measurement; digital PM noise measurement; digital down converter; digital noise measurement system; field programmable gate array; frequency 10 GHz; frequency 18 GHz; frequency 250 MHz; phase modulation; sampling system; signal prefiltering; track-and-hold amplifier; white phase noise; Amplitude modulation; Clocks; Floors; Frequency measurement; Noise; Noise measurement; Phase measurement;
Conference_Titel :
Frequency Control Symposium (FCS), 2012 IEEE International
Conference_Location :
Baltimore, MD
Print_ISBN :
978-1-4577-1821-2
DOI :
10.1109/FCS.2012.6243736
