Passive Tuner Calibration for Wideband Load Pull Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Passive load pull measurement systems face significant accuracy issues due to impedance deviation over wide modulation bandwidths, which are not adequately addressed by existing technologies, especially when using passive tuners, leading to measurement errors in high-data transmission applications.
Innovation Solution
Calibrating passive tuners at multiple frequencies within the modulation bandwidth to accurately determine the impedance seen by the Device Under Test (DUT) and de-embedding measured data at each frequency, using a Vector Network Analyzer and spectrum analyzer to ensure accurate power measurement across the bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If passive tuners are used in load pull measurement systems, then device complexity and cost are reduced, but measurement precision deteriorates due to impedance deviation over wide modulation bandwidths
Solution Approach 1:
The patent applies preliminary action by performing calibration at multiple frequencies across the modulation bandwidth before actual measurements. The system pre-determines impedance values at multiple frequencies and stores them for later use, eliminating the need for complex real-time impedance compensation during measurements.
Solution Approach 2:
The patent changes the calibration parameter from a single frequency to multiple frequencies across the modulation bandwidth. By calibrating at multiple frequency points and interpolating between them, the system maintains measurement accuracy without requiring complex real-time adjustment mechanisms.
2Loss of time
If single-frequency calibration is used, then calibration time and complexity are reduced, but measurement reliability deteriorates due to impedance variations across modulation bandwidth
Solution Approach 1:
The system performs preliminary calibration at multiple frequencies and stores the results for reuse across multiple measurements. This preliminary action ensures reliability without repeating the time-consuming multi-frequency calibration for each measurement, as the calibrated impedance data can be interpolated and applied to multiple DUT measurements.
Solution Approach 2:
The patent applies partial action by performing calibration at a sufficient number of frequency points across the modulation bandwidth rather than at every possible frequency. This provides adequate coverage to ensure measurement reliability while avoiding excessive calibration time, finding an optimal balance between the number of calibration points and measurement accuracy.
3Ease of operation
If impedance deviation over modulation bandwidth is ignored, then measurement process is simplified, but measurement precision deteriorates in wideband modulation systems
Solution Approach 1:
The system performs preliminary characterization of impedance variation across the modulation bandwidth and stores this data for later compensation. This allows the measurement process to remain simple while incorporating accuracy corrections, as the impedance compensation data is pre-computed and automatically applied during measurements.
Solution Approach 2:
The patent introduces an intermediary calibration dataset that mediates between the simple passive tuner and the accuracy requirements. The calibrated impedance values at multiple frequencies serve as an intermediary reference that enables accurate power measurements without requiring complex real-time impedance control during the actual measurement process.
Data Source
AI summary
A load pull system and method for calibrating the system and conducting measurements on a Device Under Test (DUT). The system includes at least one passive tuner; and a modulated signal connected to the DUT input. The passive tuner is calibrated at multiple frequencies within the modulation bandwidth of the modulated signal. The impedance and measured quantities such as power at the DUT reference plane are determined using tuner s-parameters at multiple frequencies within the modulation bandwidth.