Method and system for making time domain measurements of periodic radio frequency (RF) signal using measurement instrument operating in frequency domain

A system operating in a frequency domain for making time domain measurements of a periodic radio frequency (RF) signal, the system comprising:

• a coherent receiver of a plurality of coherent receivers configured to measure pulses in a plurality of reconstructed periodic RF signals in a time domain, wherein the plurality of reconstructed periodic RF signals are displayable simultaneously in the time domain, enabling direct comparison of amplitudes over time, wherein the coherent receiver is configured to receive the periodic RF signal in the frequency domain, wherein an entire bandwidth of the periodic RF signal is wider than an available bandwidth of the coherent receiver, and wherein the received periodic RF signal comprises a plurality of spectral components;
• and
• a processing unit comprising a processor device and a memory storing instructions that, when executed by the processor device, cause the processing unit to:
• determine a phase response of the coherent receiver;
• determine an amplitude response of the coherent receiver;
• measure phases of spectral components of the periodic RF signal using the phase response of the coherent receiver;
• measure amplitudes of the spectral components of the periodic RF signal using the amplitude response of the coherent receiver;
• determine a complex absolute signal from the periodic RF signal by combining the measured phases with the measured amplitudes of the spectral components of the periodic RF signal across the entire bandwidth of the periodic RF signal in the frequency domain;
• reconstruct the periodic RF signal in the time domain by transforming the complex absolute signal from the frequency domain to the time domain;
• detect at least one characteristic of the periodic RF signal in the reconstructed periodic RF signal in the time domain;
• and
• cause the at least one characteristic to be displayed on a display.

A non-transitory computer readable medium storing instructions for making time domain measurements of a periodic radio frequency (RF) signal received through a narrowband coherent receiver of a plurality of narrowband coherent receivers in a narrowband measurement instrument operating in a frequency domain for measuring pulses in a plurality of reconstructed periodic RF signals in a time domain, wherein the plurality of reconstructed periodic RF signals are displayable simultaneously in the time domain, enabling direct comparison of amplitudes over time, wherein an entire bandwidth of the periodic RF signal is wider than available bandwidth of each narrowband coherent receiver of the plurality of narrowband coherent receivers, wherein the instructions, when executed by a processor, cause the processor to execute steps comprising:

• determining a phase response of the narrowband coherent receiver receiving the periodic RF signal in the frequency domain;
• determining an amplitude response of the narrowband coherent receiver receiving the periodic RF signal in the frequency domain;
• measuring phases of spectral components of the periodic RF signal using the phase response of the narrowband coherent receiver;
• measuring amplitudes of the spectral components of the periodic RF signal using the amplitude response of the narrowband coherent receiver;
• determining a complex absolute signal from the periodic RF signal received in the frequency domain at the narrowband coherent receiver by combining the measured phases with the measured amplitudes, such that the complex absolute signal comprises the amplitudes and the phases of the periodic RF signal across the entire bandwidth of the periodic RF signal in the frequency domain;
• reconstructing the periodic RF signal in a time domain by transforming the complex absolute signal from the frequency domain to the time domain;
• detecting at least one characteristic of the periodic RF signal in the reconstructed periodic RF signal in the time domain;
• and
• causing the at least one characteristic to be displayed on a display.