Why this work is in the frame
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Bibliographic record
Abstract
Orbital angular momentum (OAM) techniques are exploited for a wide range of potential radiofrequency (RF) and electromagnetic applications, including megahertz-through-terahertz wireless systems, fiber-based and free-space optical communications and sensing, just like acoustic and any other wave-based counterparts. In those RF and electromagnetic applications, OAM wave is set to enable the development of high-speed and high-capacity communications, radar imaging, and sensing systems, among many others. In this chapter, a comprehensive comparison between plane wave and OAM wave propagation using a patch antenna as a radiator at 2.45 GHz is presented and discussed. This comparison allows the appreciation of the fundamental properties of the OAM wave when compared against its plane wave counterpart. For simplified comparison and discussion, we will use two abbreviated terms: PWPA for plane-wave patch antenna and OWPA for OAM wave patch antenna. PWPA refers to as planar patch antenna that produces plane waves in far-field, whereas patch antenna that delivers OAM waves in far-field is termed as OWPA. In this context, all physical quantities for wave propagation such as electric field, magnetic field, wave impedance, wave vector, velocity, pitch, and propagation constant are theoretically studied for OAM waves and compared with plane waves. First, OAM wave generation is studied through widely used uniform circular antenna array (UCAA) in literature. Then, plane wave patch antenna (PWPA) and OAM wave patch antenna (OWPA) are designed and verified through simulation and measurement. OWPA is designed with characteristic mode analysis (CMA) based on a lossy substrate to excite a twisting wave at a determined patch location. With this in mind, a comparative investigation of PWPA and OWPA is conducted for different physical parameters. Cylindrical near-field scan clearly shows a helical wave motion for OWPA, whereas a normal plane wave motion for PWPA. Furthermore, the comparison of plane wave and OAM wave propagation is demonstrated using the combination of a Tx–Rx antenna pair. It is observed that the overall signal from OWPA can be received with two PWPAs at an angle as OWPA has a dispersive beam. Moreover, the receiving antenna with a large aperture and plane wave horn antenna (PWHA) in the line of sight (LOS) range can also be used to receive the overall signal from OWPA. The received signal in PWPA–PWPA, OWPA–OWPA, OWPA–PWPA–PWPA, OWPA–PWHA Tx–Rx pairs is thoroughly compared and studied. Measured and simulated results for transmission are −30 dB for 0 dB input signal in OWPA–PWPA–PWPA and OWPA–PWHA cases, which are reasonably justified within the sensitivity/dynamic range of short-distance communication and radar sensing receivers.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| 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 | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.006 | 0.000 |
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 it