10.5061/DRYAD.31ZCRJDH6
Isakov, Dmitry
0000-0002-3913-8096
University of Oxford
Wu, Yingwei
.
Allen, Ben
.
Stevens, Chris
.
Grant, Patrick
.
Gibbons, Greg
.
Data from: Evaluation of the Laguerre-Gaussian mode purity produced by
3D-printed microwave spiral phase plates
Dryad
dataset
2020
Orbital angular momentum
3D printing
Wireless communication
Spiral phase plate
Additive manufacturing
Engineering and Physical Sciences Research Council
https://ror.org/0439y7842
EP/P005578/1
2020-07-31T00:00:00Z
2020-07-31T00:00:00Z
en
https://doi.org/10.1098/rsos.200493
50765430 bytes
4
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Computer-aided design software and additive manufacturing provide
flexibility in the direct fabrication of multi-material devices. This
design and fabrication versatility has been investigated for the
manufacture of dielectric spiral phase plates (SPP) to generate
electromagnetic waves with helical wave-fronts. Three types of SPPs
designed to produce an orbital angular momentum (OAM) mode number l=|1|
were additively manufactured using multi-material extrusion and multijet
fabrication methods. The phase mode and mode characteristics of
transformed helical microwaves as a function of the SPP geometrical
features was investigated experimentally in the 12 to 18 GHz frequency
range, providing high purity at characteristic frequencies. The SPPs were
further combined with an additively manufactured dielectric lens that
provided a marked improvement in OAM mode purity. Finally, multiplexing
and de-multiplexing of two OAM modes were demonstrated successfully using
the optimum SPP geometry and design.
Two oppositely directed horns were fed by commercial Ku-band SMA coax via
waveguide adaptors (Flann Microwave) connected to a vector network
analyzer (Rhode&Schwarz ZNB20) for excitation and response
measurement in the frequency range 12 to 18 GHz. A computer-controlled X-Y
gantry system was used to move the receiver horn in a pre-programmed
pattern to map complex scattering parameters in the plane perpendicular to
the beam direction, positioned at approximately 35 wavelengths from the
stationary source horn. The raw experimental data presents the table of
the view (x, y, S21(12.0GHz), S21(12.5GHz), S21(13.0GHz), … S21(17.5GHz),
S21(18.0GHz) ) where x and y are the scans coordinate and S21(F) is the
complex transmission parameter measured in this coordinate point at the
frequency F (in the range 12–18 GHz with 0.5 GHz step). The data has
simple naming such TypeSPP.txt (for the type of the SPP please refer the
manuscript). The *.mat files contain the centre position of the S21 phase
for corresponding SPP and need to be used in the SPP_Mode_Ratio.m script
accordingly. Files organised as follows: // main code // | -
SPP_Mode_Ratio.m // Raw data // | - GRINSPP.txt | -
GRINSPP_lens.txt | - SmoothSPP.txt | - SmoothSPP_lens.txt | - StepSPP.txt
| - StepSPP_lens.txt | - MPlex_Mode2.txt // modulation l=2 | -
DeMPlex_Mode0.txt // demodulation l=0 // minimum amplitude table // | -
T_GRIN.mat | - T_Smooth.mat | - T_Step.mat | - T_Mod.mat | - T_DeMod.mat
The graphical representation of the data can be done using Matlab
script.