Master Thesis: Passive Intermodulation Distortion in Multi-Band High Power Base Station Transceivers
Passive intermodulation (PIM) is an emerging problem in modern radio transceivers, which refers to the unwanted distortion produced by the passive RF components and results in undesired interference to the radio receivers. Specifically, with certain radio band combinations or downlink frequency channel allocations, nonlinear distortion produced by the passive components can result in spurious intermodulation terms that may appear in the own receiver (RX) operating band, causing the receiver sensitivity degradation. Radio transceivers operating in frequency division duplexing (FDD) mode and at high transmit power are particularly vulnerable to the PIM interference. The sources of PIM typically include nonlinear internal RF front-end components, such as cables, connected, filters, and switches. However, external sources such as corroded metal objects can also give rise to the PIM.
In general, various metal objects act like a diode which can trigger PIM due to the mixing of two or more strong RF signals in such a nonlinear junction. However, the amplitude of the resulting PIM signals can vary significantly depending on an object’s physical properties. Moreover, the antenna polarization also has an impact on the PIM power. Keeping these in view, the purpose of this work is to analyze and characterize the PIM phenomenon for different PIM sources, as well as to investigate the impact of antenna polarization on the PIM induced power.
To be able to successfully carry out the work, the candidate is expected to possess following skills:
- Telecommunications theory and familiarity with the radio systems
- MATLAB programming
- Ability to conduct literature reviews and be able to evaluate the appropriateness of different methods.
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Primary country and city: Sweden (SE) || || Stockholm || Stud&YP
Req ID: 261489