Millimetre-wave power sensor design

Dinh, Duc Dang (2017). Millimetre-wave power sensor design. University of Birmingham. Ph.D.

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Abstract

This study is to maintain and extend the power standards at National Physical Laboratory (NPL) in the United Kingdom. The calibration service of microwave power sensors at high frequencies is endangered because a limited number of traceable waveguide power sensors is available at 50 GHz and above. In this thesis, the technologies of sensing microwave power in waveguides are reviewed, and the bolometric power sensor is investigated further, as its principle is suitable for the traceability requirement at NPL. The conventional design technique of bolometric sensor based on transmission line theory is generalised and two power sensor designs are introduced. The X-band sensor was fabricated, measured at the University of Birmingham and calibrated at NPL. Excellent linearity and high effective efficiency of the design was obtained. The high frequency power sensor designs based on the proposed technique can be scalable to 300 GHz and above, and a W-band sensor is introduced as an example.

In order to add more flexibility in selecting frequency and bandwidth, a novel design of microwave power sensor with integrated filter function is described. An analytical power sensor synthesis technique using coupling matrix is presented for the first time. An X-band power sensor with integrated third order Chebyshev filter function was designed and manufactured. Experiential measurements in Birmingham and NPL are in good agreement with simulation and theoretical expectation.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):