3-D Printed Millimeter-Wave and Terahertz Lenses with Fixed and Frequency Scanned Beam

Yi, Huan; Qu, Shi‐Wei; Ng, Kung Bo; Chan, Chi Hou; Bai, Xue

doi:10.1109/tap.2015.2505703

Cited by 171 publications

(105 citation statements)

References 31 publications

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“…Quantitatively, the contrast ratios between the measured intensities of two designated regions are all larger than 9.6 dB. The weak fields outside the two designated regions might be caused by the impedance mismatch at the air-dielectric interfaces, and this mismatch can be further reduced by introducing periodic antireflection structures 25 .…”

Section: Experimental Demonstration Of Three Basic Logic Operations mentioning

confidence: 94%

“…To let our proposed idea work at higher frequencies, we should at least consider scaling down the four key ingredients to higher frequencies, namely, the metasurfaces, the input light encoder (or the spatial light modulator), the light source and detector. These ingredients are accessible to experimental investigations with current technology 17,25,27 .…”

Section: Optical Logic Gates At Higher Frequenciesmentioning

confidence: 99%

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Performing optical logic operations by a diffractive neural network

et al. 2020

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Optical logic operations lie at the heart of optical computing, and they enable many applications such as ultrahighspeed information processing. However, the reported optical logic gates rely heavily on the precise control of input light signals, including their phase difference, polarization, and intensity and the size of the incident beams. Due to the complexity and difficulty in these precise controls, the two output optical logic states may suffer from an inherent instability and a low contrast ratio of intensity. Moreover, the miniaturization of optical logic gates becomes difficult if the extra bulky apparatus for these controls is considered. As such, it is desirable to get rid of these complicated controls and to achieve full logic functionality in a compact photonic system. Such a goal remains challenging. Here, we introduce a simple yet universal design strategy, capable of using plane waves as the incident signal, to perform optical logic operations via a diffractive neural network. Physically, the incident plane wave is first spatially encoded by a specific logic operation at the input layer and further decoded through the hidden layers, namely, a compound Huygens' metasurface. That is, the judiciously designed metasurface scatters the encoded light into one of two small designated areas at the output layer, which provides the information of output logic states. Importantly, after training of the diffractive neural network, all seven basic types of optical logic operations can be realized by the same metasurface. As a conceptual illustration, three logic operations (NOT, OR, and AND) are experimentally demonstrated at microwave frequencies.

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Section: Experimental Demonstration Of Three Basic Logic Operations mentioning

confidence: 94%

Section: Optical Logic Gates At Higher Frequenciesmentioning

confidence: 99%

Performing optical logic operations by a diffractive neural network

et al. 2020

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“…UC. The dielectric lens unit is established by using the antireflection (AR) structure as described in [30]. It is well known that the operating bandwidth of the AR structure is inherently narrow due to the presence of the quarter-wavelength air posts as the transition parts.…”

Section: B Implementation Of the Proposed Unit Cell (Uc)mentioning

confidence: 99%

A Reflectarray Antenna Designed With Gain Filtering and Low-RCS Properties

Mei

Zhang

Cai

et al. 2019

IEEE Trans. Antennas Propagat.

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This paper presents a reflectarray (RA) antenna operating at X-band with gain filtering and low radar cross section (RCS) properties. The unit cell (UC) for the proposed RA antenna design combines a band-notched absorber unit and a dielectric lens unit together, where the dielectric lens unit serving as a phase shift is coated on the absorber unit to achieve co-design. Importantly, it is required that the UCs should still maintain the high notch-band-edge selectivity property that the band-notched absorber originally has when the profile of the dielectric lens unit is varied to cover a full phase-cycle (2π) for the proposed RA antenna design. For demonstration, an absorber is presented with a high notch-band-edge selectivity and a wide absorption bandwidth performance in vertical and horizontal polarization, respectively; a dielectric lens based on square posts is rigorously designed to be coated on the absorber seamlessly to construct the desired UC. The simulated results show that the proposed RA antenna has a bandpass-like gain filtering performance and pencil-beam radiation patterns within the notch band, which is experimentally verified by the measured results. In addition, the measured results also reveal the RCSs of the proposed RA antenna are reduced significantly compared to counterparts of the conventional RA antenna in horizontal polarization and out of the notch band in vertical polarization. Index Terms-Reflectarray (RA) antenna, absorbing media, dielectric lens, phase shift, high gain, gain filtering, low RCS.

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“…A transmitarray is typically composed of a feed source that illuminates a single or multilayer quasi-periodic array, whose unit-cells are characterized by one or more variable geometrical parameters, through which it is possible to control the transmission coefficient phase of each cell and to obtain the desired radiation pattern [2]. The TA unit-cell can consist in metallic elements printed on different dielectric layers [3][4][5], in completely metallic slot-based layers separated by air gaps [6,7] or even in a dielectric structure perforated by one or several holes, as implemented in [8][9][10][11][12][13]. In comparison with reflectarrays, TAs present the advantage to not suffer for blockage, which require the use of off-set feeds in RA, and this increases the difficulty to implement efficiently the beam scanning.…”

Section: Introductionmentioning

confidence: 99%

Beam Scanning Capabilities of a 3D-Printed Perforated Dielectric Transmitarray

2019

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In this paper, the design of a beam scanning, 3D-printed dielectric Transmitarray (TA) working in Ka-band is discussed. Thanks to the use of an innovative three-layer dielectric unit-cell that exploits tapered sections to enhance the bandwidth, a 50 × 50 elements transmitarray with improved scanning capabilities and wideband behavior has been designed and experimentally validated. The measured radiation performances over a scanning coverage of ±27 ∘ shown a variation of the gain lower than 2.9 dB and a 1-dB bandwidth in any case higher than 23%. The promising results suggest that the proposed TA technology is a valid alternative to realize a passive multibeam antenna, with the additional advantage that it can be easily manufactured using 3D-printing techniques.

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3-D Printed Millimeter-Wave and Terahertz Lenses with Fixed and Frequency Scanned Beam

Cited by 171 publications

References 31 publications

Performing optical logic operations by a diffractive neural network

Performing optical logic operations by a diffractive neural network

A Reflectarray Antenna Designed With Gain Filtering and Low-RCS Properties

Beam Scanning Capabilities of a 3D-Printed Perforated Dielectric Transmitarray

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