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Master Thesis, 30 hp: Antenna Array Calibration

Location
Järfälla, Sweden
Closing date
31 January 2022
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Background

Solutions based on phased array antenna technology with individual transmit- and receive channels for each antenna element,  “digital arrays”, have many advantages in both Electronic Warfare, EW and radar applications.  In particular, a large number of different ‘high-resolution’ methods for simultaneous estimation of parameters such as, incident angles and Doppler frequencies, of several targets can be applied. The increased number of degrees of freedom inherent in a solution based on a digital antenna array also enables estimation of noise, jamming and clutter characteristics. With this information, jammer (-s) and clutter can subsequently be adaptively suppressed. However, in practice, perfect calibration of an antenna array can seldom be achieved. Also, as calibration typically, but not necessarily,  prohibits simultaneous operation of the system,  it may not be possible to perform calibration as frequently as would have been desirable in order to keep the resulting errors below some specified level.  Consequently, calibration errors may gradually build up due to time-varying characteristics of the actual antenna system.

Calibration or model errors include unknown deviations from the nominal array response in terms of gain- and phase characteristics as well as sensor locations. Also, uncertainties in antenna coupling and transmitter-/receiver response may contribute to reduced performance.

Furthermore, broadband signals are used in many systems, implying possible complications since an antenna array response typically varies significantly with frequency.                                                                                   

Consequently, it is important to obtain some measure of the sensitivity of the considered methods/ algorithms used for target parameter estimation to various forms of array model errors.

Description of the master thesis

  • Implement a model in Matlab that can be used to quantify the sensitivity of various high resolution parameter estimation methods with respect to typical antenna array errors. In addition, it shall be possible to model effects using broadband signals.
  • In a subsequent step use this model as a tool for development and evaluation of methods with increased robustness to different forms of array model errors, also for the case with broadband signals.
  • This Matlab model shall be designed so that it is possible to use it as a model of the antenna array based experimental “Wida transmitter and receiver”. 
  • Implement and evaluate performance of algorithms for estimation of target incident angle(-s) and Doppler frequenc(y/ies) in the Wida system. Compare resulting performance with those obtained using the corresponding Matlab model. 
  • Write a report.

This project is suitable as a M.Sc. thesis work in Electrical Engineering or Engineering Physics.

Your profile

Required skills and areas of interest :

  • Successfully completed courses in Digital Signal Processing, Adaptive Filter Theory, Modulation Theory, Algebra or equivalent.
  • System Modeling and Parameter Estimation Theory.   
  • Good skills in programming, preferably Matlab.

Desired skills:

  • Knowledge of basic RF receiver- and transmitter architectures.
  • Basic skills in Microwave Engineering.
  • Experience with practical measurement techniques.

This position requires that you pass a security vetting based on the current regulations around/of security protection. For positions requiring security clearance additional obligations on citizenship may apply.

Contact

Joel Midstjärna

joel.midstjarna@saabgroup.com

Last application day

2021-01-31

Kindly observe that this is an ongoing recruitment process and that the position might be filled before the closing date of the advertisement.

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