Time Domain RF Signal Reconstruction via Frequency Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current measurement instruments for characterizing wideband periodic RF signals face challenges such as high noise floors, limited vertical resolution, and high costs, especially when attempting to acquire time domain information, while frequency domain instruments lack time domain data due to intermediate frequency bandwidth limitations.
Innovation Solution
A method using a narrowband coherent receiver to capture amplitude and phase of wideband periodic RF signals in the frequency domain, transforming these representations to the time domain, enabling fine time-resolution measurements with multiple ports for simultaneous signal analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a wideband measurement instrument is used to acquire the entire bandwidth of a wideband periodic RF signal in a single shot, then time domain measurement capability is achieved, but the noise floor increases and vertical resolution decreases
Solution Approach 1:
The patent divides the wideband frequency range into multiple contiguous narrowband segments. Each segment is measured separately using a narrowband VNA, allowing the instrument to maintain high sensitivity and low noise floor for each individual measurement. The segmented frequency data is then combined to reconstruct the complete wideband signal characteristics in the time domain.
2Object-affected harmful factors
If a narrowband VNA is used to measure periodic RF signals, then sensitivity and signal-to-noise ratio are improved, but the intermediate frequency bandwidth is limited to tens of MHz or less
Solution Approach 1:
The measurement bandwidth is segmented into multiple narrowband portions that can be sequentially acquired by the narrowband VNA. Each segment falls within the instrument's limited IF bandwidth capability, allowing high-sensitivity measurements to be performed across the entire wideband range through multiple sweeps.
Solution Approach 2:
The patent transitions from direct time-domain measurement to frequency-domain measurement with subsequent transformation. By measuring in the frequency domain and applying inverse Fourier transform, the system achieves time-domain characteristics without requiring the measurement instrument to have wide instantaneous bandwidth.
3Ease of manufacture
If a narrowband VNA or spectrum analyzer is used, then cost is reduced, but time domain information is lost since only spectrum power is acquired
Solution Approach 1:
The patent introduces an intermediary computational process (inverse Fourier transform) that converts frequency-domain spectral measurements into time-domain signal representations. This mathematical transformation acts as a mediator that recovers time domain information from frequency domain data without requiring expensive wideband time-domain measurement instruments.
4Measurement precision
If a wideband VNA is used to acquire the entire bandwidth, then time domain characteristics can be measured, but the instrument cost becomes prohibitively expensive
Solution Approach 1:
The patent segments the wideband measurement task into multiple narrowband measurements that can be performed sequentially by an affordable narrowband VNA. This segmentation allows cost-effective instrumentation to achieve capabilities that would otherwise require expensive wideband instruments.
Solution Approach 2:
The measurement process uses periodic sweeping across multiple frequency segments. The narrowband VNA performs repeated measurements at different frequency ranges, accumulating data that is later combined to provide complete wideband time domain characteristics.
Data Source
AI summary
A system and method are provided for making time domain measurements of a wideband periodic radio frequency (RF) signal using a narrowband measurement instrument operating in a frequency domain. The method includes receiving the periodic RF signal at a single port corresponding to a receiver of the measurement instrument; determining a complex absolute signal having amplitudes and phases of spectral components of the periodic RF signal over an entire bandwidth of the periodic RF signal in the frequency domain; and reconstructing a time domain signal corresponding to the periodic RF signal by transforming the complex absolute signal from the frequency domain to the time domain.