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Public defence in Radio Science and Engineering, Lic.Sc.(Tech.) Veli Voipio

Public defences
Public defence from the Aalto University School of Electrical Engineering, Department of Electronics and Nanoengineering
This picture shows testing how well the ground penetrating measurements work. The depth of the lake and the layers in the lake bottom are expected to be visible in the measurement profile. The ground penetrating radar that was constructed during the dissertation work is in a plastic box in the middle of the raft. The author of the dissertation Veli Voipio is in the picture.
Photo: Armi Temmes

When

–

Where

Maarintie 8 & Online
Lecture hall TU1

Event language(s)

English

The title of the thesis: The Gopher Antenna: A New Type of Ground Penetrating Radar Antenna

Thesis defender: Veli Voipio
Opponent: Dr. Iraklis Giannakis, University of Aberdeen, UK
Custos: Prof. Ville Viikari, Aalto University School of Electrical Engineering, Department of Electronics and Nanoengineering

It is very challenging to design an antenna for the Ground Penetrating Radar. In order to produce a sharp, Gaussian pulse, the antenna must transmit a wide Gaussian spectrum from the generated pulse spectrum while the radiating center stays in the same position. The receiver antenna and circuit must function correspondingly. Normally this is achieved by using damping resistors, but this results in an inefficient system. Additionally, most Ground Penetrating Radars have a very wide beamwidth, but a narrower beamwidth may be desirable. 

This work introduces a new type of antenna structure, called Gopher antenna, which has a high efficiency and a roughly 60° beamwidth. The antenna consists of an L-antenna and a patch antenna that is coupled with the second resonant frequency of the L-antenna. The antenna utilizes the three lowest resonant frequencies of the L-antenna and the first resonant frequency of the patch antenna, and produces a contiguous spectrum over the three lowest resonant frequencies of the L-antenna. The antenna is also relatively small, lightweight, and has a good polarization purity. It can be used in existing Ground Penetrating Radar applications (construction, archaeology, near surface geophysics, humanitarian demining, etc.) and, moreover, it is also very feasible in drone applications, which are under busy development currently.

Keywords: antenna, FDTD, ground penetrating radar

Thesis available for public display 10 days prior to the defence at: https://aaltodoc.aalto.fi/doc_public/eonly/riiputus/

Contact:

Email [email protected]
Phone +358405150149


Doctoral theses in the School of Electrical Engineering: https://aaltodoc.aalto.fi/handle/123456789/53

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