Revisiting the Appearance of Grating Lobes for Antennas With Circular Periodicity

Manohar, Vignesh; Rahmat‐Samii, Y.

doi:10.1109/tap.2019.2920252

Cited by 8 publications

(5 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The SL contrast is overall higher for the circular SA structure due to its circular symmetry. Grating lobes appear differently in circular arrays as their relative strength is governed by the number of elements in the structure whereas the grating lobe level is equivalent between all lobes in a rectangular array [6].…”

Section: Performance Analysismentioning

confidence: 99%

Array design using rotational symmetry for high performance optical phased arrays

Kandid

2023

Smart Photonic and Optoelectronic Integrated Circuits 2023

View full text Add to dashboard Cite

Optical phased arrays (OPAs) have seen frequent implementation in applications requiring beam steering such as light detection and ranging (LiDAR) and free-space optical communications. These applications require narrow beamwidths and large steering ranges which are seldom found simultaneously. Grating sidelobes found in the far field patterns limit the steering range of an OPA due to the uniformly pitched elements spacing of > λ/2. Here we implement an array design that exploits the rotational symmetry of adjacent subarrays to suppress the sidelobes for both planar and circular sub-array lattices, greatly enhancing the OPA's steering range.

show abstract

Section: Performance Analysismentioning

confidence: 99%

Array design using rotational symmetry for high performance optical phased arrays

Kandid

2023

Smart Photonic and Optoelectronic Integrated Circuits 2023

View full text Add to dashboard Cite

show abstract

“…To date, integrated OPAs typically use one-dimensional (1D) linear arrays [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ] and two-dimensional (2D) planar arrays with either rectangular [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ] or circular [ 21 , 22 , 23 , 24 , 25 , 26 ] arrangements. For 1D arrays, wavelength-dependent grating nano-antennas are typically used for beam steering.…”

Section: Introductionmentioning

confidence: 99%

“…Circular OPAs are promising alternatives to 1D linear and 2D rectangular arrays, where a circular array can offer a large steering range and high resolution concurrently [ 21 , 22 , 23 , 24 , 25 , 26 ]. For circular OPAs, the high resolution and wide scanning can be obtained with efficient sidelobe suppression.…”

Section: Introductionmentioning

confidence: 99%

“…For this, we numerically investigated two different circular arrays arranged radially. Compared to the other circular arrangements [ 21 , 22 , 23 , 24 , 25 , 26 ], our proposed OPAs are fed by a central circular grating coupler with a high coupling efficiency. Leveraging radially positioned nano-antennas and an efficient central grating coupler, the circular OPAs can yield an aliasing-free azimuthal FOV of 360°.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Circular Optical Phased Arrays with Radial Nano-Antennas

et al. 2022

View full text Add to dashboard Cite

On-chip optical phased arrays (OPAs) are the enabling technology for diverse applications, ranging from optical interconnects to metrology and light detection and ranging (LIDAR). To meet the required performance demands, OPAs need to achieve a narrow beam width and wide-angle steering, along with efficient sidelobe suppression. A typical OPA configuration consists of either one-dimensional (1D) linear or two-dimensional (2D) rectangular arrays. However, the presence of grating sidelobes from these array configurations in the far-field pattern limits the aliasing-free beam steering, when the antenna element spacing is larger than half of a wavelength. In this work, we provide numerical analysis for 2D circular OPAs with radially arranged nano-antennas. The circular array geometry is shown to effectively suppress the grating lobes, expand the range for beam steering and obtain narrower beamwidths, while increasing element spacing to about 10 μm. To allow for high coupling efficiency, we propose the use of a central circular grating coupler to feed the designed circular OPA. Leveraging radially positioned nano-antennas and an efficient central grating coupler, our design can yield an aliasing-free azimuthal field of view (FOV) of 360°, while the elevation angle FOV is limited by the far-field beamwidth of the nano-antenna element and its array arrangement. With a main-to-sidelobe contrast ratio of 10 dB, a 110-element OPA offers an elevation FOV of 5° and an angular beamwidth of 1.14°, while an 870-element array provides an elevation FOV up to 20° with an angular beamwidth of 0.35°. Our analysis suggests that the performance of the circular OPAs can be further improved by integrating more elements, achieving larger aliasing-free FOV and narrower beamwidths. Our proposed design paves a new way for the development of on-chip OPAs with large 2D beam steering and high resolutions in communications and LIDAR systems.

show abstract

“…To remove the grating sidelobes and improve the beam-steering performance, circular OPAs have been proposed and represent an important choice [31][32][33][34][35][36][37][38][39][40][41]. Surprisingly, only limited preliminary work on photonic implementation of circular array has been reported to date [39][40][41], apart from bio-inspired solutions [31], non-photonic-based concepts [32], and optimization-driven circular schemes [33][34][35][36][37]. Indeed, compared to the conventional 1-D/2-D counterparts, the use of circular arrays holds great promise to advance the overall steering performance by improving the FOV ideally up to 2π sr.…”

Section: Introductionmentioning

confidence: 99%

Circular Optical Phased Array with Large Steering Range and High Resolution

Benedikovič

Liu

Sánchez‐Postigo

et al. 2022

Sensors

View full text Add to dashboard Cite

Light detection and ranging systems based on optical phased arrays and integrated silicon photonics have sparked a surge of applications over the recent years. This includes applications in sensing, free-space communications, or autonomous vehicles, to name a few. Herein, we report a design of two-dimensional optical phased arrays, which are arranged in a grid of concentric rings. We numerically investigate two designs composed of 110 and 820 elements, respectively. Both single-wavelength (1550 nm) and broadband multi-wavelength (1535 nm to 1565 nm) operations are studied. The proposed phased arrays enable free-space beam steering, offering improved performance with narrow beam divergences of only 0.5° and 0.22° for the 110-element and 820-element arrays, respectively, with a main-to-sidelobe suppression ratio higher than 10 dB. The circular array topology also allows large element spacing far beyond the sub-wavelength-scaled limits that are present in one-dimensional linear or two-dimensional rectangular arrays. Under a single-wavelength operation, a solid-angle steering between 0.21π sr and 0.51π sr is obtained for 110- and 820-element arrays, respectively, while the beam steering spans the range of 0.24π sr and 0.57π sr for a multi-wavelength operation. This work opens new opportunities for future optical phased arrays in on-chip photonic applications, in which fast, high-resolution, and broadband beam steering is necessary.

show abstract

Revisiting the Appearance of Grating Lobes for Antennas With Circular Periodicity

Cited by 8 publications

References 12 publications

Array design using rotational symmetry for high performance optical phased arrays

Array design using rotational symmetry for high performance optical phased arrays

Circular Optical Phased Arrays with Radial Nano-Antennas

Circular Optical Phased Array with Large Steering Range and High Resolution

Contact Info

Product

Resources

About