Frequency Extender RF Testing for Modulated Signal Linearity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current separate setups for CW and modulated signal testing in RF systems face challenges due to differences in signal characteristics, increased complexity, cost, and inaccuracies, particularly during on-wafer measurements, and are inadequate for modulated signal S-parameters measurements and load pull measurements.
Innovation Solution
A unified measurement system integrating IF VSG and IF VSA with VNA-EXTs for generating and analyzing RF modulated signals, eliminating the need for mixers and enabling precise characterization under both CW and modulated signal conditions, with linearization algorithms to mitigate nonlinear behavior.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If separate setups are used for CW and modulated signal testing, then measurement capability for both signal types is achieved, but device complexity and cost increase
Solution Approach 1:
The patent combines CW and modulated signal testing capabilities into a single unified measurement setup using a vector network analyzer with frequency extender. The system integrates both testing modes by using the same core instrumentation (VNA, frequency extender, signal source, receiver) to perform both CW and modulated signal measurements, eliminating the need for separate dedicated setups for each signal type.
Solution Approach 2:
The measurement system is designed to perform multiple functions using a single setup. The vector network analyzer with frequency extender can universally handle both continuous-wave characterization and wideband modulated signal testing, making the system multi-functional and adaptable to different measurement requirements without needing separate specialized equipment.
2Adaptability or versatility
If separate setups are used for CW and modulated signal testing, then comprehensive measurement capability is achieved, but measurement accuracy deteriorates during on-wafer measurements
Solution Approach 1:
By merging CW and modulated signal testing into a single unified setup, the system maintains consistent measurement conditions and calibration states throughout on-wafer measurements. The same VNA, frequency extender, and probe configuration are used for both signal types, eliminating calibration drift and setup variations that occur when switching between separate setups, thereby improving measurement accuracy.
3Speed
If frequency multipliers are used for generating high-frequency RF signals, then frequency extension capability is achieved, but nonlinear distortions increase
Solution Approach 1:
The system employs feedback mechanisms through the vector network analyzer's receiver to measure and characterize the nonlinear distortions generated by frequency multipliers. The VNA measures S-parameters and other characteristics under both CW and modulated signal excitation, enabling the system to identify and compensate for distortion effects, thereby maintaining signal quality despite the use of frequency multiplication for high-frequency generation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables precise characterization of RF components under modulated conditions, facilitating active and passive load pull measurements, and improving measurement accuracy and efficiency by minimizing nonlinear distortions.
Implementation Method 1
One group of frequency extenders relies on frequency multiplication as a means for generating high-frequency RF signals. In such devices, an output signal frequency is an integer harmonic (multiple) of an input signal frequency.
Implementation Method 2
Another group of frequency extenders operates on a principle of heterodyne mixing, in which a local oscillator (LO) signal is mixed with an RF signal to produce an intermediate frequency signal IFX i.e. IFX=RF±LO
Implementation Method 3
Typically, the superheterodyne receiver captures an output RF signal, down converts it to a lower frequency intermediate frequency (IF) signal and then digitizes the IF signal using an analog-to-digital converter (ADC)
Data Source
AI summary
A measurement system is described for the comprehensive characterization of millimeter-wave/sub-THz devices under both continuous-wave (CW) and modulated signal excitation. CW measurement setups, which include a vector network analyzer (VNA) and VNA frequency extenders (VNA-EXT) are enhanced by the integration of an IF vector signal generator (VSG) and IF vector signal analyzer (VSA). The measurement system incorporates a processing unit configured and operable to process a modulated test signal to mitigate nonlinear behavior. A linearization algorithm is used to linearize the frequency multipliers within the VNA-EXT, ensuring error-free RF modulated signal generation at a device under test (DUT) input reference plane.