Target Products
Several Base Station Remote Radio Heads (RRH) and Antenna Integrated Radios (AIR)
Purpose
Determine if the Power Amplifier Module (PAM) uses Doherty combiner architecture and simulate its performance under dynamic loads.
Procedure
- The product teardown was undertaken and RF Amplifier Module circuit board was isolated.
- Performed a detailed circuit extraction and analysis to determine the microwave integrated circuit (MIC) topology of the PA module:
- Main amplifier input and output matching networks
- Peaking amplifier input and output matching networks
- Doherty combiner geometry
- The dielectric material used were determined by measurement
- Based on the above circuit extraction a simulation was performed using ADS (2-D numerical analysis, Momentum) to generate the S parameters.
- Harmonic balance technique was used for non-linear simulation of the PA circuit topology.
- Simulation results were analyzed.
Result
- The main and the peaking amplifiers were identified and their functions deduced.
- The circuit was successfully mapped to a variant of Doherty architecture.
- Load modulation was proven based on the simulation results.
