Master Thesis: Compound Transistor Structures for broadband PA applications i Göteborg

Background

Recent development in distributed power amplifiers have shown good potential to obtain high efficiency in back-off for a wide bandwidth, making these interesting options for communication systems utilizing high peak-to-average modulated signals. A general drawback of distributed power amplifier is the gain in the GHz domain. Too low gain would counteract on the high efficiency properties since a powerful, hence power consuming, driver would be needed. One approach to boost the gain in distributed power amplifiers is to use “compound transistor structures”, e.g. ‘Cascode’ or ‘Darlington’ structures.

Objectives

The purpose of the thesis is to identify and investigate different compound transistor structures suitable for gain boosting distributed and efficient power amplifiers. Intended frequencies for the investigation is primary up to 10GHz but part of the investigation is also to explore frequency limitations of the different structures identified. Other objectives of the work can be summarized as follows:

• Identify suitable compound transistor structures, e.g. ‘Cascode’, ‘Darlington’ or ‘Darlington Cascode’

• Identify a minimum set of evaluation criteria for the intended application (Distributed Efficient Power Amplifier). These could for instance include gain, stability, frequency limitations and impedance levels. An understanding of the Distributed Efficient Power Amplifier and what parameters of this that are important will need to be developed in parallel.

• Evaluate the identified structures based on the developed evaluation criteria.

• Validate performance for at least one of the most promising structures in the intended power amplifier structure using ADS.

Qualifications

Master of science program student in electronics with knowledge in microwave circuit design. Knowledge in ADS environment would be an asset but is not a strict requirement.

If you have any specific questions you are welcome to send an email to recruiter Therese Blom at therese.blom@ericsson.com. 

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Primary country and city: Sweden (SE) || || Göteborg || 21094

Req ID: 220788