Design and Study of a New Ultra-wideband Pattern Diversity Antenna, for High-Gain Application
Bibliographic record
Abstract
A new Ultra-Wideband (UWB) pattern diversity antenna is proposed, designed and investigated in this thesis. The antenna is capable of radiating in directive and omni-directional modes. Three different versions of the design are studied to show the performance for different applications. The first design consists of a single radiating element fed from two sides by coaxial probes over a shaped ground plane. In-phase excitation of the ports produces omni-directional radiation patterns and out-of-phase excitation results in directive radiation in the boresight of the antenna. The shape of the radiator is a disk, which is modified in geometry to improve the isolation of the ports. The antenna shows impedance bandwidth from 6.8 GHz to more than 15 GHz. The second design is a dual-element version of the same antenna to equalize the radiation patterns in the E- and H-planes. The antenna requires four ports and has an impedance bandwidth from 7.4 GHz to more than 15 GHz. A microstrip power divider is then included, in the third design, which in addition to decreasing the number of extra circuits for feeding, decreases the lower frequency to 4.5 GHz, without changing the radiation patterns significantly throughout the bandwidth. A prototype of this antenna was fabricated and measured, and the results are presented. In the fifth chapter, an electromagnetic polarization filter is designed for the single element UWB antenna, to reduce the cross-polarization level. 7 dB reduction in the maximum level of cross-polarization is achieved, throughout the frequency band 8 - 11 GHz. The following chapter is dedicated to the study and performance of the microstrip-fed UWB antenna, when used as a feed for prime-focus reflectors. It is shown that the designed antenna is capable of feeding the reflector with efficiency as high as 75%, and more than 60%, over a wide bandwidth of 5.5 - 9 GHz.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.001 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".