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REVIEW 4 major objections 6 minor 28 references

Confocal Ellipsoidal Reflectors with Phased Array Vivaldi Antenna Source for Imaging Systems

T0 review · 4 major / 6 minor · reviewed 2026-08-10 · deepseek-v4-flash

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Pith's one-line read A pair of confocal ellipsoidal mirrors fed by a Vivaldi phased array is claimed to image a 40 cm field at a 2 m standoff while cutting reflector blockage and refocusing with centimeter-scale feed motion.

desk verdict Incremental but useful low-blockage dual-reflector geometry; the FoV and refocusing claims are ray-optics projections dressed as full-wave results. read the letter →

arxiv 2501.15997 v1 pith:DGAMHS2A submitted 2025-01-27 physics.optics

Mohammad Hossein Koohi Ghamsari , Mahyar Mehri Pashaki , Mehdi Ahmadi-Boroujeni This is my paper · ORCID
classification physics.optics
keywords confocalellipsoidalreflectordual-reflectorantennablockagereductionnear-fieldimagingVivaldiphasedarraystandoffmillimeter-waverefocusing
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper proposes an on-axis dual-reflector design for near-field millimeter-wave imaging in which both reflectors are ellipses sharing a focus, with the main reflector displaced so the focused beam passes through a central hole instead of being blocked by the sub-reflector and feed. The authors argue this geometry cuts the blockage caused by backscattered waves, a problem that degrades standard Gregorian designs, and they verify the reduction with ray-tracing simulation. They then add a 28 GHz 4x4 Vivaldi phased-array source and use full-wave simulation to show that steering the array up to 30 degrees scans the focus about 19.7 cm to either side, giving a roughly 40 cm field of view at a 2 m standoff. They also show with ray tracing that shifting the source laterally by a few centimeters moves the standoff focus by tens of centimeters, making the imaging distance tunable. If correct, the structure offers a simple low-blockage optical front end for standoff millimeter-wave and terahertz imaging.

What carries the argument

The load-bearing object is the confocal ellipsoidal dual-reflector pair: both reflecting surfaces are ellipses, the main one described by $P_1M = 2F/(1+\cos\theta_m)$ and the sub-reflector by $OS \mp SP_1 = 2c/e$, aligned so they share focus $P_1$ and so the feed phase center sits at $O$. The geometry turns the standard blockage problem around: instead of an off-axis or asymmetric layout, the main reflector is decentered vertically by $D_B/2$ with a hole, and the tilted sub-reflector sends rays through the shared focus toward that hole, keeping the aperture and the focused beam on axis while removing most of the feed and sub-reflector obstruction. The focal-length relations $d_1 = \frac{r}{p}(1-\sqrt{1-p})$ and $d_2 = \frac{r}{p}(1+\sqrt{1-p})$, with $d_2 = d_1 + 2c$, connect the lateral feed displacement $\Delta f x$ to the standoff shift $\Delta s x$ through the magnification factor $M_S$, defined as the ratio of the main reflector's first focal length to the sub-reflector's first focal length. That relation is what makes refocusing by a few centimeters of feed motion possible.

What would settle it

Simulate or build the full 4x4 Vivaldi phased array together with the two confocal ellipsoidal mirrors at 28 GHz, and record the focal-plane intensity as the beam steers from -30 to +30 degrees. If the focus traverses a line about 40 cm long with the half-power beamwidth staying near the point-source value, the central claim stands; if the focus wanders off the expected line or the spot broadens as the array steers, the point-source phase-center assumption is violated.

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Extended reading notes

Core claim

The central claim is that a symmetric on-axis confocal ellipsoidal dual-reflector configuration can do near-field standoff imaging with much less blockage than a standard Gregorian system and with useful scanning and refocusing flexibility. In the proposed layout, the main reflector is an upright ellipse with a central hole, and the sub-reflector is a tilted displaced ellipse sharing the main reflector's first focus with the source point, so rays from the feed reflect off the sub-reflector, pass through the shared focus, and are focused by the main elliptical reflector at a second focus 2 m away. Ray-tracing shows no blocked rays where a same-size Gregorian design blocks many, and full-wave simulation with a point feed at 30 GHz confirms a concentrated Fresnel-region caustic. Replacing the point feed with a designed 4x4 Vivaldi phased array at 28 GHz, steering the array from -30 to +30 degrees sweeps the focal spot to about 19.7 cm on each side, i.e., a roughly 40 cm field of view. Table IV reports that moving the feed laterally by 0.5 to 2.5 cm refocuses the standoff image by tens of centimeters, depending on the magnification factor, so the same optics can be retuned without large mechanical motion.

Load-bearing premise

The analysis treats the finite 4x4 Vivaldi array as a point source with a fixed phase center at the feed location, so the reported 40 cm field of view and the refocusing shifts rest on the array's effective source not moving or distorting as it steers.

Editorial extensions

If this is right

  • If the simulated blockage reduction carries over physically, the imager's signal-to-noise ratio should improve because less power scatters back into the source and the detectors.
  • The 40 cm scan at 2 m, driven only by electronic beam steering in a small phased array, points to a compact front end that can inspect a broad standoff area without moving the large reflector.
  • Because the reflector surfaces are frequency-independent, the same geometry with a suitably scaled feed should transfer to terahertz standoff imaging, where blockage is especially costly.
  • A small lateral feed positioner combined with the magnification relation gives a quantitative tuning rule for refocusing across tens of centimeters of standoff, allowing depth coverage without changing the main optics.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • An end-to-end full-wave simulation of the 4x4 Vivaldi array together with the reflectors would test the point-source assumption directly; the paper currently verifies the array's beam steering and the reflector focusing in separate simulations.
  • The reported inverse relation between magnification and feed-displacement gain suggests a design rule: lower magnification buys larger standoff refocusing strokes, at the cost of tighter alignment tolerances.
  • The same on-axis low-blockage geometry could be adapted to compact radar ranges or synthetic-aperture setups, where backscatter from the optics contaminates the measured target response.
  • A direct scatterer test at the 2 m focus, recording received power as the array steers, would quantify both the 40 cm field of view and the blockage reduction in one measurement.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 6 minor

Summary. The paper proposes an on-axis dual-reflector confocal ellipsoidal architecture for near-field millimeter-wave and THz imaging. The main reflector is an elliptical conic with a central hole, and the sub-reflector is a displaced and tilted ellipse sharing a focus with the main reflector and the source. The authors claim that this geometry substantially reduces blockage relative to a standard Gregorian design, that a 4x4 Vivaldi phased-array feed at 28 GHz can scan a 40 cm field of view at 2 m standoff, and that lateral feed displacements of a few centimeters can tune the standoff focus by tens of centimeters. The supporting evidence consists of COMSOL ray-tracing comparisons for blockage, a full-wave COMSOL simulation of the reflectors with a 30 GHz point source, CST simulations of the Vivaldi unit cell and array, and analytical/ray-based tables for scanning and refocusing.

Significance. If the central claims are substantiated, the proposed geometry would offer a simpler on-axis low-blockage alternative to conventional Gregorian or offset reflector configurations for standoff imaging, avoiding the size and alignment complexity of off-axis designs. The paper includes useful quantitative design tables and a concrete Vivaldi array design with simulated reflection coefficients. However, the most important performance claims — the 40 cm field of view and the refocusing behavior — are currently supported only by a point-source full-wave simulation combined with separate array beam-steering data, and the blockage improvement is assessed only qualitatively. The work is a plausible engineering concept but does not yet fully demonstrate the end-to-end performance asserted in the abstract.

major comments (4)
  1. [Section III-A, Table III] The abstract and conclusion state that full-wave simulations proved a field of view of approximately 40 cm, but the only full-wave simulation of the reflector system (Fig. 3) uses a point source at 30 GHz. The FoV numbers in Table III are obtained by mapping the 4x4 Vivaldi array's beam-steering angles at 28 GHz to focus displacements, with no end-to-end full-wave simulation of the actual array illuminating the reflectors. To support the claim, the authors should either simulate the full array plus reflector system at 28 GHz for the extreme steering angles and compare focal-plane field distributions, or at minimum demonstrate that the array's phase center remains fixed at point O across the ±30 degree scan range and that the array's wavefront is well approximated as a point source. Without this, the 40 cm FoV claim is not demonstrated.
  2. [Section II-B, Fig. 2] The blockage-reduction claim is based solely on a qualitative visual comparison of ray-tracing images. The statement that a significant number of rays are blocked in the Gregorian structure is not backed by any quantitative metric. Since reduced blockage is a central claimed advantage, the authors should report a numerical blockage ratio (for example, the fraction of launched rays that are intercepted or reflected back, or the resulting change in aperture efficiency) for both geometries under identical conditions.
  3. [Section III-B, Eq. (4), Table IV] The refocusing results in Table IV are presented without a derivation of Eq. (4) or a supporting citation, and the symbols r and p are not defined in the text. In addition, the text states that ray-tracing simulations showed the standoff can be changed, but Table IV appears to be computed from Eq. (4) rather than from ray tracing. The authors should clarify which entries in Table IV come from ray tracing and which come from the analytical formula, provide a clear definition and derivation of Eq. (4), and state the criterion used for acceptable refocusing (for example, a beamwidth or aberration tolerance). The ordering of the delta_fx column in Table IV is also non-monotonic and should be reordered for readability.
  4. [Section III-A, Table I] The FoV is a prespecified design target (40 cm in Table I), and Table III reports a scanning range of ±19.7 cm, that is, 39.4 cm. The paper should frame this as a validation that the design meets its chosen specification, not as an independent prediction proved by full-wave simulation. Furthermore, the definition of FoV in Section II-A is qualitative (an acceptable range of aberrations before rays become increasingly divergent); the authors should specify the quantitative criterion used to decide that ±19.7 cm is the edge of the FoV, such as a maximum allowed half-power beamwidth growth or Strehl ratio degradation.
minor comments (6)
  1. [Section III-B] The heading contains the typo 'Tunning'; it should be 'Tuning'.
  2. [Section II-A, Eq. (4)] The symbols r and p in Eq. (4) are not defined in the text and should be defined explicitly (likely the radius and conic constant of the main reflector).
  3. [Section II-A, after Eq. (1)] The notation P1M, OS, and SP1 for distances is confusing because it can be read as products of points; use d(P1,M), d(O,S), and d(S,P1) or add a sentence defining the notation.
  4. [Table IV] The first column of Table IV is not in monotonic order (the sequence -2.5, -1.5, -0.5, 3.5, 1.5, 0.5); reorder the rows monotonically so the dependence is easy to read.
  5. [Fig. 3 caption] The caption does not specify the full-wave simulation details, such as the polarization/orientation of the point source, the boundary conditions, and the simulation frequency; adding these details would improve reproducibility.
  6. [Section I, references] The relationship between this work and the authors' earlier conference paper [10] should be clarified; the present manuscript should state explicitly what is new beyond [10].

Circularity Check

1 steps flagged · score 4.0 of 10

The 40 cm FoV is a design target listed in Table I and then reported as the simulated FoV, so the headline FoV claim is a target restatement rather than an independent prediction; the rest of the derivation is self-contained.

  1. self definitional [Section II-B (Table I) and Section III-A (Table III)]
    "According to this Table, the stand-off distance, where rays are focused, is considered 200 cm, and a FoV of approximately 40 cm is expected. ... Based on this table, by changing the phased array antenna beam angle by up to 30 degrees, the stand-off focusing point is scanned to about 19.7 cm, giving an approximate 40 cm desired FoV of Table I."

    Table I lists FoV=40 cm as a design parameter/expected value before any simulation. Section III-A then reports a ±19.7 cm scan range (~39.4 cm) and explicitly labels it 'an approximate 40 cm desired FoV of Table I', i.e., the verified FoV is the same quantity that was preset as the target. The only full-wave reflector simulation (Fig. 3) is a point source at 30 GHz; it does not scan the beam or quantify FoV. Table III is a beam-angle-to-displacement mapping, not a full-wave array simulation. Hence the abstract's statement that 'full-wave simulations proved a FoV of approximately 40 cm' presents the design input as an independently verified prediction; the FoV claim is the target restated by the chosen geometry, not a result derived from unconstrained first principles.

full rationale

The paper's central novelty—low-blockage on-axis confocal ellipsoidal pair and stand-off refocusing by lateral feed displacement—is derived from the conic geometry (Eqs. 1–4) and is not circular. The blockage comparison uses independent ray-tracing between the proposed and Gregorian designs. Table IV's refocusing values follow from the stated magnification factor and ellipse relations; no parameters are fitted to data. Self-citations [10] and [23] provide context only and are not load-bearing. The one partial circularity is the FoV claim: 40 cm appears as a design goal in Table I and is then reported as the simulated FoV, so it is a target-restatement rather than a free prediction. There is also a correctness gap—the full-wave reflector simulation uses a 30 GHz point source, while the Vivaldi array is 28 GHz and no end-to-end array-plus-reflector full-wave simulation is shown—but this is a validation weakness, not circularity. Overall score 4 reflects partial circularity in one headline claim, with the rest of the derivation self-contained.

Assumptions & free parameters 5 free parameters · 4 assumptions · 0 invented entities

The central design rests on standard conic-section optics and on hand-selected dimensions, plus the modeling assumptions that ray tracing captures blockage and that a point-source phase center represents the phased array. No new physical entities are introduced, and no parameters are fitted to external measurements. The largest uncharged costs are the phase-center assumption and the lack of a complete sub-reflector parameter set.

free parameters (5)
  • Main reflector diameter DM = 80 cm
    Chosen design input; determines aperture and standoff, not fitted to measured data.
  • Sub-reflector diameter DS = 35 cm
    Design input for blockage geometry; no independent derivation given.
  • Central hole diameter DB = 16 cm
    Design input to reduce blockage; the choice is not justified quantitatively.
  • Stand-off distance ds = 200 cm
    Target design value; the FoV and refocusing results depend on this choice.
  • Sub-reflector tilt angle beta and eccentricity e
    These define the sub-reflector orientation and are essential to replicate the geometry, but values are not reported in Table I or the text.
assumptions (4)
  • domain assumption Geometrical optics and ray tracing are valid for the 28-30 GHz reflector system at 2 m standoff.
    The design uses ray tracing in COMSOL as verification for blockage and refocusing without including diffraction or edge effects.
  • domain assumption The 4x4 Vivaldi array is adequately represented by a point-source phase center at O.
    Full-wave simulation in Fig. 3 uses a point source, while Table III uses array beam angles; no co-simulation of array and reflectors is shown.
  • standard math Elliptical conic-section focusing relations (Eq. 1-4) are standard and exact for ideal reflectors.
    The paper relies on conic-section reflection properties to predict focusing and refocusing without derivation.
  • domain assumption Commercial simulator outputs (COMSOL, CST) accurately model the electromagnetic behavior of the proposed structure.
    No experimental validation is provided, so the simulations are the only evidence for the claimed performance.

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Cite this review

Pith. "Pith review of Confocal Ellipsoidal Reflectors with Phased Array Vivaldi Antenna Source for Imaging Systems." pith.science (2026). https://pith.science/paper/DGAMHS2A

@misc{pith2026250115997,
  author       = {Pith},
  title        = {Pith review of: Confocal Ellipsoidal Reflectors with Phased Array Vivaldi Antenna Source for Imaging Systems},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/DGAMHS2A}},
  note         = {Machine review of arXiv:2501.15997}
}
read the original abstract

In this paper, an on-axis dual-reflector confocal ellipsoidal structure is presented for near-field imaging systems. In the proposed structure, the backscattered electromagnetic wave problem, known as the blockage effect, is reduced considerably using an elaborate design of the sub-reflector and precise alignment of the reflectors. The proposed geometry is analyzed, followed by a design example for the stand-off distance of 2 m. The blockage reduction characteristic is verified using ray-tracing simulation. Next, the scanning performance of the structure is investigated utilizing a Vivaldi phased array antenna as the source designed at the central frequency of 28 GHz. The full-wave simulations proved a field-of-view (FoV) of approximately 40 cm. Furthermore, tuning the proposed reflectors configuration standoff distance is examined with a point source. The ray-tracing simulations showed that stand-off distance can be easily changed up to tens of centimeters with just a few centimeters of source point lateral displacement.

Figures

Figures reproduced from arXiv: 2501.15997 by the authors.

Figure 1
Figure 1. Symmetric dual-reflector confocal ellipsoidal configuration. The [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 3
Figure 3. Full-wave simulation of the dual-reflector confocal ellipsoidal Fresnel [PITH_FULL_IMAGE:figures/full_fig_p003_3.png] view at source ↗
Figure 2
Figure 2. Comparing the ray-tracing simulation results of the proposed structure [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figures from the paper (2 more)
Figure 5
Figure 5. Figure 5: Refocusing performance of the proposed structure by displacing the [PITH_FULL_IMAGE:figures/full_fig_p004_5.png]
Figure 4
Figure 4. Figure 4: Phased array Vivaldi antenna. (a) The proposed unit cell of the Vivaldi [PITH_FULL_IMAGE:figures/full_fig_p004_4.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

28 extracted references · 27 canonical work pages

  1. [1]

    The evolution of antenna technology: Reflectors and microstrips,

    C. A. Balanis, “The evolution of antenna technology: Reflectors and microstrips,” IEEE Antennas and Propagation Magazine , 2024

    work page 2024

  2. [2]

    Broadband dual-polarized folded dipole antenna with simple feed structure,

    X. Shi, J. D. Peng, K. Huang, and L. H. Ye, “Broadband dual-polarized folded dipole antenna with simple feed structure,” Microwave and Optical Technology Letters, vol. 65, no. 6, pp. 1735–1740, 2023

    work page 2023

  3. [3]

    Millimeter-wave wideband±45° dual-polarized wide-angle scanning phased array an- tenna,

    W. Jiang, S. Liao, P. Liu, Q. Xue, and W. Che, “Millimeter-wave wideband±45° dual-polarized wide-angle scanning phased array an- tenna,” IEEE Antennas and Wireless Propagation Letters , 2024

    work page 2024

  4. [4]

    C. A. Balanis, Antenna theory: analysis and design . John wiley & sons, 2016

    2016

  5. [5]

    The novel method for deployable parabolic reflector based on uchiwa origami,

    A. K. Baghel, V . U. Oliveira, P. Pinho, and N. B. Carvalho, “The novel method for deployable parabolic reflector based on uchiwa origami,” in 2024 18th European Conference on Antennas and Propagation (EuCAP). IEEE, 2024, pp. 1–4

    work page 2024

  6. [6]

    Multibeam compact dual reflectarray antenna for high-throughput satellites in ka-band,

    D. Martinez-de Rioja, E. Martinez-de Rioja, Y . Rodriguez-Vaqueiro, A. Pino, C. Mosquera, J. A. Encinar, and G. Toso, “Multibeam compact dual reflectarray antenna for high-throughput satellites in ka-band,” in 2024 18th European Conference on Antennas and Propagation (EuCAP). IEEE, 2024, pp. 1–4

    work page 2024

  7. [7]

    Efficient anomalous reflector design using array antenna scattering synthesis,

    S. K. Vuyyuru, R. Valkonen, D.-H. Kwon, and S. A. Tretyakov, “Efficient anomalous reflector design using array antenna scattering synthesis,” IEEE Antennas and Wireless Propagation Letters , vol. 22, no. 7, pp. 1711–1715, 2023

    work page 2023

  8. [8]

    Design of fresnel-region millimeter-wave metasurface beam shaper using deep learning,

    M. H. K. Ghamsari, E. Imanbeygi, and M. Ahmadi-Boroujeni, “Design of fresnel-region millimeter-wave metasurface beam shaper using deep learning,” in 2024 32nd International Conference on Electrical Engi- neering (ICEE). IEEE, 2024, pp. 1–5

    work page 2024

Show all 28 references
  1. [9]

    Reflection-phase calculation of circularly polarized folded reflectarray antennas with low profile, high efficiency, and arbitrary aperture distribution,

    M. Sano, R. Kuse, and T. Fukusako, “Reflection-phase calculation of circularly polarized folded reflectarray antennas with low profile, high efficiency, and arbitrary aperture distribution,” IEICE Communications Express, 2024

    2024

  2. [10]

    A confocal ellipsoidal reflector system for millimeter-wave applications,

    M. H. K. Ghamsari, M. Ahmadi-Boroujeni, and S. Babanejad, “A confocal ellipsoidal reflector system for millimeter-wave applications,” in 2022 6th International Conference on Millimeter-Wave and Terahertz Technologies (MMWaTT). IEEE, 2022, pp. 1–4

    2022

  3. [11]

    Double-layer frequency selective surface-based corner reflector for indoor self-localization systems in the w-band,

    J. S ´anchez-Pastor, M. Sch ¨ußler, R. Jakoby, and A. Jim ´enez-S´aez, “Double-layer frequency selective surface-based corner reflector for indoor self-localization systems in the w-band,” in 2024 18th European Conference on Antennas and Propagation (EuCAP) . IEEE, 2024, pp. 1–5

    2024

  4. [12]

    S. Rao, L. Shafai, and S. K. Sharma, Handbook of Reflector Antennas and Feed Systems Volume III: Applications of Reflectors. Artech House, 2013

    2013

  5. [13]

    Sub-thz spatially modulated beam splitting reflectors for potential ris implementations,

    D. T. Phan, J. Palosaari, D. Kong, T. Siponkoski, S. Myllym ¨aki, M. E. Leinonen, A. P ¨arssinen, J. Juuti, and P. J. Soh, “Sub-thz spatially modulated beam splitting reflectors for potential ris implementations,” in 2024 18th European Conference on Antennas and Propagation (E...

    2024

  6. [14]

    Low-profile and broadband dual-linearly polarized offset dual-reflector antenna for w- band applications,

    J. Taillieu, D. Gonz ´alez-Ovejero, R. Sauleau et al. , “Low-profile and broadband dual-linearly polarized offset dual-reflector antenna for w- band applications,” IEEE Transactions on Antennas and Propagation , 2024

    2024

  7. [15]

    J. W. Baars, The paraboloidal reflector antenna in radio astronomy and communication. Springer, 2007, vol. 348

    2007

  8. [16]

    Optimization of small reflector antennas for radio astronomy,

    A. Soliman and S. Weinreb, “Optimization of small reflector antennas for radio astronomy,” in 2016 United States National Committee of URSI National Radio Science Meeting (USNC-URSI NRSM) . IEEE, 2016, pp. 1–2

    2016

  9. [17]

    Analysis, design and measurement of a low sidelobe level lightweight array antenna for surveillance radar applications,

    A. G. Toshev, “Analysis, design and measurement of a low sidelobe level lightweight array antenna for surveillance radar applications,” in 18-th International Conference on Microwaves, Radar and Wireless Communications. IEEE, 2010, pp. 1–4

    2010

  10. [18]

    Poynting streamline for energy flow and aperture efficiency of reflector antennas: Application and analysis,

    J. Diao, “Poynting streamline for energy flow and aperture efficiency of reflector antennas: Application and analysis,” IEEE Antennas and Propagation Magazine, 2024

    2024

  11. [19]

    Spher- ical ports as a direct interface for full-interaction po/mom-to-fem: Application to lower-frequency satellite-remote-sensing reflector-based antennas,

    P. Robustillo, J. Rubio, R. G ´omez-Alcal´a, and J. C ´orcoles, “Spher- ical ports as a direct interface for full-interaction po/mom-to-fem: Application to lower-frequency satellite-remote-sensing reflector-based antennas,” IEEE Transactions on Antennas and Propagation , 2024

    2024

  12. [20]

    A wideband reflector-based mm- wave/thz nearfield line scanner for rapidly sensing materials in en- velopes,

    C. Rappaport and M. Geraghty, “A wideband reflector-based mm- wave/thz nearfield line scanner for rapidly sensing materials in en- velopes,” in 2024 18th European Conference on Antennas and Prop- agation (EuCAP). IEEE, 2024, pp. 1–3

    2024

  13. [21]

    Active millimeter-wave standoff and portal imaging techniques for personnel screening,

    D. M. Sheen, D. L. McMakin, T. E. Hall, and R. H. Severtsen, “Active millimeter-wave standoff and portal imaging techniques for personnel screening,” in 2009 IEEE Conference on Technologies for Homeland Security. IEEE, 2009, pp. 440–447

    2009

  14. [22]

    A phase- controlled parabolic reflector for wideband microwave focal-plane imag- ing,

    T. Wang, S. Luan, M. Yang, Y . Li, S. Xie, and Y . Yang, “A phase- controlled parabolic reflector for wideband microwave focal-plane imag- ing,” IEEE Antennas and Wireless Propagation Letters , 2024

    2024

  15. [23]

    Design and optimization of gregorian-based reflector systems for thz imaging system optics,

    M. H. K. Ghamsari, M. Ahmadi-boroujeni, and S. Babanejad, “Design and optimization of gregorian-based reflector systems for thz imaging system optics,” in 2022 4th West Asian Symposium on Optical and Millimeter-wave Wireless Communications (WASOWC) . IEEE, 2022, pp. 1–5

    2022

  16. [24]

    Confocal ellipsoidal reflector system for a mechanically scanned active terahertz imager,

    N. Llombart, K. B. Cooper, R. J. Dengler, T. Bryllert, and P. H. Siegel, “Confocal ellipsoidal reflector system for a mechanically scanned active terahertz imager,” IEEE Transactions on Antennas and Propagation , vol. 58, no. 6, pp. 1834–1841, 2010

    2010

  17. [25]

    Zooming and scanning gregorian confocal dual reflector antennas,

    J. A. Martinez-Lorenzo, A. Garcia-Pino, B. Gonzalez-Valdes, and C. M. Rappaport, “Zooming and scanning gregorian confocal dual reflector antennas,” IEEE Transactions on antennas and propagation , vol. 56, no. 9, pp. 2910–2919, 2008

    2008

  18. [26]

    Bifocal dual reflector system for active terahertz imaging,

    D. Zhou, L. Hou, Y . Yuan, Y . Zang, X. Tu, J. Chen, and P. Wu, “Bifocal dual reflector system for active terahertz imaging,” Applied optics, vol. 57, no. 12, pp. 3224–3230, 2018

    2018

  19. [27]

    Deformable mirror for wavefront shaping of infrared radiation,

    M. Eichenberger, F. Giorgianni, N. Sauerwein, C. Vicario, and C. P. Hauri, “Deformable mirror for wavefront shaping of infrared radiation,” Optics Letters, vol. 43, no. 9, pp. 2062–2065, 2018

    2018

  20. [28]

    Exper- imental comparison of anomalous reflectors implemented with local and non-local design approaches,

    S. Kosulnikov, A. Dıaz-Rubio, A. Osipov, and S. Tretyakov, “Exper- imental comparison of anomalous reflectors implemented with local and non-local design approaches,” IEEE Transactions on Antennas and Propagation, 2024

    2024

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