In IQSTAR 1.5 release, modulated signal measurement can use the Spectrum option of the PNA-X vector network analyser of Keysight Technologies, to measure ACPR and Spectrum directly from the VNA at the DUT reference plane using the a- and b-waves. When using a VNA, the modulated signal measurement module requires IQS100B-11 as a prerequisite.
The growing complexity of wireless systems imposes a thorough and detailed characterization of RF power amplifiers using wideband signals. IQSTAR enables high-speed and signals quality measurements to extract the DUT performances (EVM, ACPR, CCDF, PAPR…)
With full control of the vector signal generator, it is possible to set the modulation scheme manually with adequate settings and have IQSTAR recall the required state on the instrument. Otherwise, it is possible to generate an IQ waveform using IQSTAR Waveform Generator or any third-party software and use it directly in IQSTAR by loading a text file containing the columns “I” and “Q”.
The Vector Network Analyzer or Signal analyzer, with appropriate options and power meters, is used to measure different parameters like:
- Adjacent Channel Power Ratio (ACPR)
- Error Vector Magnitude (EVM)- using Signal Analyzer only
- Complementary-Cumulative-Distribution-Function (CCDF)- using Signal Analyzer only
- Peak-to-Average Power Ratio (PAPR)- using Signal Analyzer only
IQSTAR Modulation measurements support multiple combinations of vector signal generators and signal analyzers from different vendors, allowing the test engineers to switch between instruments seamlessly and reduce the cost of ownership as he does not have to learn a new instrument user interface.
Power amplifier characterization using modulated signals requires instruments with different options to enable the modulation and demodulation personalities based on the modulated signal used. These options are necessary when signal demodulation is needed to measure the required parameters, like EVM. Moreover, Test engineers may need different EVM measurements (EVMavg, EVM peak, EVM rms) and developing drivers sustaining different instruments from different vendors and with multiple personalities becomes difficult to support. Therefore, IQSTAR 1.5 embeds a user data configuration allowing the user to set the instrument in the right personality and fetch the parameter using SCPI commands.
Multiple parameters can be measured in different configurations giving the user access to all the instrument’s capabilities.