In this thesis, RF sections of a multi tier instantaneous frequency measurement (IFM) receiver which can operate in 2 &ndash / 18 GHz frequency band is designed, simulated and
partially realized. The designed structure uses one coarse tier, three medium tiers and one fine tier for frequency discrimination. A novel reflective phase shifting technique
is developed which enables the design of very wideband phase shifters using stepped cascaded transmission lines. Compared to the classical phase shifters using coupled
transmission lines, the new approach came out to be much easier to design and fabricate with much better responses. This phase shifting technique is used in coarse
and medium tiers. In fine frequency measurement tier, I/Q discriminator approach is used because reflective phase shifters would necessitate unacceptably long delay
lines. Two I/Q discriminators are designed and fabricated using Lange directional couplers that operate in 2-6 GHz and 6-18 GHz, resulting in satisfactory response. Additionally, 6 GHz HP and 6 GHz LP distributed filters are designed and fabricated to be used for these I/Q discriminators in fine tier. In order to eliminate possible
ambiguities in coarse tier, a distributed element LP-HP diplexer with 10 GHz crossover frequency is designed and fabricated successfully to be used for splitting the
frequency spectrum into 2-10 GHz and 10-18 GHz to ease the design and realization problems. Three power dividers operating in the ranges 2-18 GHz, 2-6 GHz and 6-18
GHz are designed for splitting incoming signals into different branches. All of these dividers are also fabricated with satisfactory response. The fabricated components
are all compact and highly reproducible. The designed IFM can tolerate 48 degrees phase margin for resolving ambiguity in the tiers while special precautions are taken
in fine tier to help ambiguity resolving process also. The resulting IFM provides a frequency resolution below 1 MHz in case of using an 8-bit sampler with a frequency
accuracy of 0.28 MHz rms for 0 dB input SNR and 20 MHz video bandwidth.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/3/12612044/index.pdf |
| Date | 01 June 2010 |
| Creators | Pamuk, Gokhan |
| Contributors | Yildirim, Nevzat |
| 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 public access |
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