Special episode 11: Using ADS to perform nonlinear test on RF power amplifier 3 (using WCDMA signal with a bandwidth of 5MHz for ACLR test)
Other tests:
Fanwai 9: Using ADS to conduct nonlinear tests on RF power amplifiers 1 (taking IMD3 testing as an example)
Fanwai 10: Using ADS to conduct nonlinear tests on RF power amplifiers 2 (Using 64QAM signals with a bandwidth of 20MHz for ACLR, EVM, CCDF test)
1. Basic theory
The non-linear performance of power amplifiers is very important, especially for mobile devices that are widely used today. Because of its various complex signal modulations, the actual nonlinear performance of a power amplifier is best tested with a modulated signal rather than a single or two-tone signal.
ACLR refers to the adjacent channel leakage ratio, which means the ratio of the transmit power leakage to the first or second adjacent channel carrier power and the transmit power. It mainly tests the performance of WCDMA transmission indicators. The requirement of ACLR is that the first carrier frequency is 35dB (that is, positive Negative 5MHZ), the second carrier frequency is 45dB (plus or minus 10Mhz), the unit is expressed in dbc.
For general tests, as long as the test value is within the range required by the agreement, it is ok! This is equivalent to a rigid index.
2. ADS-based WCDMA signal test
The template path used:
D:\ADS2023\examples\Signals_and_Systems\Wireless\WCDMA3G\WCDMA3G_PA_Test_wrk
Use this schematic: WCDMA3G_PA_UE_ACLR
Put the PA to be tested into it:
Set the frequency and envelope of the simulation Simulator:
Just run the simulation.
3. ADS-based WCDMA signal test results
The simulation frequency here is 3GHz, and the input power is 20dBm. The results are as follows:
It can be seen that the designed PA meets the requirements of WCDMA. Let’s observe the specific frequency spectrum:
