RF Signal Generator Calibration by Segmented Port Groups
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Solution Overview
Problem
Calibrating large, distributed RF signal generator systems with numerous ports is challenging due to scalability issues, manual calibration requirements, and limitations in calibration device port capacity, leading to high effort and inefficiency.
Innovation Solution
A method and system that split the signal generator system into smaller groups, calibrate each group individually, and use system-wide correction terms to synchronize and align RF output ports, utilizing a calibration device like a vector network analyzer (VNA) to calculate relative errors and perform phase and power calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the signal generator system is built with a large number of RF ports to test multi-port DUTs, then the system can accommodate more ports, but the system becomes difficult to realize and is not scalable
Solution Approach 1:
The signal generator system is divided into multiple independent signal generator units, each with a manageable number of RF ports. These units can be individually calibrated and then combined to form a larger system, enabling the system to scale from 8 ports to 16, 24, or more ports without requiring complete system redesign or recalibration.
2Quantity of substance
If the signal generators are distributed across different racks to accommodate large numbers of ports, then the system can be implemented, but the cabling becomes cumbersome
Solution Approach 1:
Multiple signal generator units are merged into a single calibrated system through the patent's calibration method. The units are connected via RF cables forming a calibration loop, allowing them to be calibrated together as one integrated system, thereby reducing cabling complexity compared to treating them as separate distributed systems.
3Measurement precision
If manual calibration is performed on large distributed systems, then calibration can be done, but the calibration effort becomes very high
Solution Approach 1:
The calibration process is segmented into three efficient steps: (1) individual calibration of each signal generator unit, (2) calibration of reference ports across units, and (3) system-wide calibration using a calibration loop. This segmented approach reduces calibration time compared to traditional manual calibration of entire large systems.
Solution Approach 2:
Individual signal generator units are pre-calibrated before being combined into the full system. This preliminary calibration of components reduces the overall calibration effort required for the complete system, as individual units are already optimized before system integration.
4Quantity of substance
If the number of RF ports of the system exceeds the number of ports of the calibration device, then the system can be built, but traditional calibration methods become infeasible
Solution Approach 1:
The calibration method transitions from a traditional point-to-point calibration approach to a loop-based calibration approach. By connecting reference ports of multiple units in series to form a calibration loop, the system enables calibration of ports beyond the calibration device's port capacity, effectively adding a dimensional aspect to the calibration process.
Solution Approach 2:
Reference ports of signal generator units serve as intermediaries in the calibration loop. These reference ports enable the calibration device to indirectly calibrate ports that are not directly connected to it, allowing the system to calibrate more ports than the calibration device physically possesses.
Data Source
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AI summary
The disclosure relates to a method (10) for calibrating a signal generator system (20), comprising: connecting (11) RF output ports of a first group (21) of RF signal generators to a calibration device (26) and performing a first calibration measurement to calculate relative errors between a reference RF output port and the remaining RF output ports of the first group (21); connecting (12) RF output ports of at least a second group (22) of RF signal generators to the calibration device (26) and performing at least a second calibration measurement to calculate relative errors between a reference RF output port and the remaining RF output ports of the second group (22); connecting (13) the respective reference RF output ports of the first and at least the second group (21, 22) to the calibration device (26) and performing a third calibration measurement to calculate relative errors between the reference RF output ports of the first and at least the second group (21, 22); and calculating (14) system wide correction terms on the basis of the calculated relative errors.