Internship / Design and production of an "Envelope Tracking" PMR radio transmission system (m/f)

Description de l'offre

Internship / Design and production of an "Envelope Tracking" PMR radio transmission system (m/f)

Airbus DS SLC Elancourt

Airbus Defence and Space is a division of Airbus Group, formed by combining the business activities of Cassidian, Astrium and Airbus Military. The new division is the No. 1 defence and space company in Europe, the second largest space business worldwide, and among the top ten defence companies on the planet. It employs some 40,000 employees, generating revenues of approximately €14 billion per year.

Airbus Group is a global leader in aeronautics, space and related services. In 2015, the Group - comprising Airbus, Airbus Defence and Space and Airbus Helicopters - generated revenues of € 64.5 billion and employed a workforce of around 136,600.

Our people work with passion and determination to make the world a more connected, safer and smarter place. Taking pride in our work, we draw on each other's expertise and experience to achieve excellence. Our diversity and teamwork culture propel us to accomplish the extraordinary - on the ground, in the sky and in space.

Description of the job

Airbus Defence and Space (Elancourt) is looking for an intern for a 5 to 6-month internship.

The secure Professional Mobile Radio (PMR) networks used by the French law enforcement agencies or the fire service are migrating to wideband technologies to provide, in addition to voice, a wireless high-speed data transfer service.

The Long Term Evolution (LTE) standard was chosen for its new radio communication systems. Consequently, the transmission systems of the PMR devices are becoming increasingly complicated to design, in particular the power amplifier, due to the use of non-constant envelope modulation. The LTE modulation uplink with a Peak-to-Average Power Ratio (PAPR) of 6-7 dB involves a compromise between efficiency, linearity and bandwidth for the power amplifier.
Mobile phones supporting LTE technology integrate functions used to optimise the consumption of this RF (Radio Frequency) amplifier.
The technique used in commercially available mobile phones which seems to be the most promising for PMR devices is referred to as "Envelope Tracking" architecture.

You will analyse, and then implement an Envelope Tracking structure to optimise the efficiency of an RF power amplifier that has already been designed, while complying with the linearity constraints for LTE PMR applications.

This internship will start on 2nd January 2017 (subject to some flexibility).

Internships at Airbus Group

Profil recherché

Tasks & accountabilities

Your tasks will include:

·  Carrying out a bibliographical study, as well as a synthesis on the state of the art of Envelope Tracking architecture:

- variants of envelope modulator architecture,
- design constraints (compromise between efficiency/linearity/bandwidth),
- simulation in ADS of envelope modulators and the complete system with the power amplifier.

·  Producing an Envelope Tracking system:

- definition and production of a PCB,
- development and validation of the system using various types of measurement equipment (Signal generator, Spectrum analyser, Network analyser, Oscilloscope).

Required skills

You are in the final year of engineering school, completing a Master's degree or in the 5th year of university, specialising in Engineering/ Electrical engineering, Hyperfrequency

You have good knowledge of analogue systems such as operational amplifiers and DC/DC converters and of RF power amplifiers.

You have skills in:

·  ADS Keysight,
·  Power and Analogue Electronics (Operational Amplifier, DC/DC converter),
·  RF electronics (Knowledge of basic structures for power amplifiers),
·  Handling of measurement equipment (Signal generator, Spectrum analyser, Network analyser, Oscilloscope).

You are proactive and renowned for thoroughness and an ability to work independently.

You are a good team player and have excellent interpersonal skills.

English: advanced level
French: advanced level