This thesis presents the design and implementation of a millimeter-wave Gunn
diode oscillator operating at 35 GHz (Ka (R) 26.5-40 GHz Band). The aim of the
study is to produce a high frequency, high power signal from a negative resistance
device situated in a waveguide cavity by applying a direct current bias. First the
physics of Gunn diodes is studied and the requirements that Gunn diode operates
within the negative differential resistance region is obtained. Then the best design
configuration is selected. The design of the oscillator includes the design of the
waveguide housing, diode mounting and the bias insertion network. Some
simulation tools are used to predict, approximately, the behaviour of the oscillator
and the bias coupling circuit. For tuning purposes, a sliding backshort and a triplescrew-
tuner system is used. For different bias values and different positions of the
tuning elements oscillations are observed. A much more stable and higher
magnitude oscillations were obtained with the inclusion of &ldquo / resonant disc&rdquo / placed
on top of the diode. 15 dBm power was measured at a frequency of 28 GHz.
Laboratory measurements have been carried out to determine the oscillator
frequency, power output and stability for different bias conditions.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/2/12608759/index.pdf |
| Date | 01 August 2007 |
| Creators | Luy, Ulku |
| Contributors | Toker, Canan |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
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