Analysis of Time and Frequency Response for Single/Multi-Tone Stimulus Harmonic Phase-Reference Based on Prime Number Algorithm

• Main Authors: He Yu, Cong Wang, David A. Humphreys, Maoliu Lin, Luqman Ali, Fanyi Meng
• Format: Article
• Language: English
• Published: MDPI AG 2020-11-01
• Series: Electronics
• Subjects: digital real-time oscilloscope (DRTO); harmonic phase-reference; multi-tone; prime number algorithm; sub-Nyquist spurs; nonlinear vector network analyzer (NVNA)
• Online Access: https://www.mdpi.com/2079-9292/9/11/1836

We present a spectrally-dense phase-reference and its calibration for nonlinear vector network analyzers (NVNAs) using a step recovery diode (SRD) comb-generator with a multi-tone stimulus. Frequency selection for multi-tone stimulus based on prime number algorithms was used with the Digital Real-Time Oscilloscope (DRTO) to avoid the sub-Nyquist spurs components and to increase the effective sampling rate so that the waveform can be observed in greater detail. The measured results were calibrated to minimize drift and jitter and achieved excellent agreement between the prime number and the exact frequency strategies except at the sub-Nyquist frequencies. The analysis indicates that the prime number selected frequencies show significantly improved performance by avoiding the DRTO distortion components. We have verified the validity of the method described in this paper by experimental measurement results.