% Encoding: UTF-8
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@inproceedings{faucris.238481116,
abstract = {In this work, an additively manufactured 3 dB hybrid coupler for the
D-Band frequency range is presented. The plastic body is printed from
UV-curable polymer resin with a conventional desktop DLP printer and
subsequently functionalized by an electroless silver plating process.
The slotted waveguide approach is used, in order to improve the metal
coating and enable the implementation of complex waveguide structures.
Measured isolation and matching range at -15 dB while the asymmetry in
magnitude between coupling and through port remains below 0.8 dB over
the frequency range from 115 to 154 GHz, yielding an operational
relative bandwidth of almost 28 % and hence, suggesting general
feasibility for directional coupling applications. Measured phase
differences deviate from the desired 90° by 40° to 50° which is related
to the overall tolerances with respect to absolute geometrical
dimensions of conventional desktop DLP printers and required post
processin},
author = {Lomakin, Konstantin and Klein, Laura and Sippel, Mark and Helmreich, Klaus and Gold, Gerald},
booktitle = {2020 50th European Microwave Conference (EuMC)},
date = {2021-01-12/2021-01-14},
doi = {10.23919/EuMC48046.2021.9337997},
faupublication = {yes},
isbn = {978-2-87487-059-0},
month = {Jan},
peerreviewed = {Yes},
title = {{3D}-{Printed} 3 {dB} {Hybrid} {Coupler} for {D}-{Band} {Applications}},
venue = {Utrecht},
year = {2021}
}
@inproceedings{faucris.234127013,
abstract = {This paper focuses on the latest aerosol based printing system in conjunction with a newly developed manufacturing method. The presented novel method is successfully demonstrated on a Bowtie Filter in comparison to the same pho-tolithographically produced structure.
In this work, an
additively manufactured 3dB hybrid coupler is presented. While the geometrical
structure is generated by an SLA printer from UV curable photopolymer resin as
one single part, conductive coating is provided by an electroless silverplating
process. The utilized slotted waveguide approach improves the solvent flow
during metal plating and therefore enables the fabrication of complex waveguide
struc- tures. Measured imbalance between the through and coupling port stays
below 1.5dB over the entire E-Band, while the respective phase difference
ranges only between 87◦ and 91◦ degrees
despite the challenges of additive manufacturing in such frequency
regions},
author = {Lomakin, Konstantin and Klein, Laura and Ringel, Lorenz and Ringel, Johannes and Sippel, Mark and Helmreich, Klaus and Gold, Gerald},
doi = {10.1109/LMWC.2019.2931458},
faupublication = {yes},
journal = {IEEE Microwave and Wireless Components Letters},
pages = {580-582},
peerreviewed = {Yes},
title = {{3D} {Printed} {E}-{Band} {Hybrid} {Coupler}},
volume = {29},
year = {2019}
}
@inproceedings{faucris.200709328,
author = {Lomakin, Konstantin and Pavlenko, Tatiana and Sippel, Mark and Gold, Gerald and Weidner, T and Helmreich, Klaus and Ankenbrand, Markus and Franke, Jörg},
booktitle = {European Conference on Antennas and Propagation (EUCAP)},
doi = {10.1049/cp.2018.1034},
faupublication = {yes},
peerreviewed = {unknown},
title = {{3D} {Printed} {Helix} {Antenna}},
venue = {London, GB},
year = {2018}
}
@inproceedings{faucris.238480092,
abstract = {In this work, an additively manufactured helix antenna for a center frequency of f
c
= 77 GHz is presented. A novel feed concept is proposed including a
transition from the helix coil to an E-band waveguide, which allows for
tuning of antenna matching. Measurements suggest a -15dB-bandwidth of B
15
dB
=8 GHz and -10dB-bandwidth of B
10
dB
=16 GHz respectively with a fractional -10dB-bandwidth of 20 %. An axial
ratio below AR<; 5 dB is achieved within the entire B-10 dB and even
AR<; 3 dB within B-15 dB in main lobe direction. The realized
antenna gain ranges at G
LP
≈11 dBi in linear polarization component yielding a circular polarization gain of G
CP
≈12 to 13 dBi. Hence, measurements suggest general feasibility of the
proposed helix antenna for mmWave applications despite the relatively
high structure complexity due to the miniaturized dimensions at the
aimed frequencie},
author = {Lomakin, Konstantin and Sippel, Mark and Ullmann, Ingrid and Helmreich, Klaus and Gold, Gerald},
booktitle = {2020 14th European Conference on Antennas and Propagation (EuCAP)},
date = {2020-03-15/2020-03-20},
doi = {10.23919/EuCAP48036.2020.9135996},
faupublication = {yes},
isbn = {978-88-31299-00-8},
peerreviewed = {Yes},
title = {{3D} {Printed} {Helix} {Antenna} for 77 {GHz}},
venue = {Copenhagen, Denkmark},
year = {2020}
}
@article{faucris.305313262,
abstract = {Nowadays, additive manufacturing provides far-reaching possibilities for use in radio frequency components. In addition to almost unlimited freedom of design as compared to conventional manufacturing, the absence of further assembly steps is a key aspect of 3D printing. In this paper, a 3D printed monolithic antenna for millimeter wave-sensing applications is presented with a full hemispherical coverage. The antenna is designed as an ensemble of a waveguide horn antenna and a differentially fed dipole antenna. The slotted waveguide approach was utilized to improve the manufacturing quality on the waveguide inside. The influence of two optimized antenna elements, a metal plane, and a cut-out window, on the beam pattern is comprehensively investigated. A huge half power beam width of 142° in both directions, elevation and azimuth, is presented at 79 GHz and a boresight gain of 4.7 dBi was measured. The beam pattern in the frequency range from 76 to 81 GHz is studied in greater detail, where a half power beam width of at least 112° is achieved. Due to the −10 dB matching capability bandwidth of over 28 GHz, the antenna is also suitable for extremely broadband applications with a −5 dB angular width of better than 100°. Furthermore, the system design describes how to integrate the antenna into hybrid circuit designs and the manufacturing tolerances are examined. The antenna offers attractive possibilities for millimeter wave-sensing applications in the area of assisted living and industrial monitoring, especially whenever blind spots have to be avoided.
c
= 77 GHz is presented. A novel feed concept is proposed including a
transition from the helix coil to an E-band waveguide, which allows for
tuning of antenna matching. Measurements suggest a -15dB-bandwidth of B
15
dB
=8 GHz and -10dB-bandwidth of B
10
dB
=16 GHz respectively with a fractional -10dB-bandwidth of 20 %. An axial
ratio below AR<; 5 dB is achieved within the entire B-10 dB and even
AR<; 3 dB within B-15 dB in main lobe direction. The realized
antenna gain ranges at G
LP
≈11 dBi in linear polarization component yielding a circular polarization gain of G
CP
≈12 to 13 dBi. Hence, measurements suggest general feasibility of the
proposed helix antenna for mmWave applications despite the relatively
high structure complexity due to the miniaturized dimensions at the
aimed frequencie},
author = {Lomakin, Konstantin and Sippel, Mark and Helmreich, Klaus and Gold, Gerald},
booktitle = {2021 15th European Conference on Antennas and Propagation (EuCAP)},
date = {2021-03-22/2021-03-26},
doi = {10.23919/EuCAP51087.2021.9410911},
faupublication = {yes},
peerreviewed = {Yes},
title = {{3D} {Printed} {Slotted} {Waveguide} {Array} {Antenna} for {D}-{Band} {Applications}},
venue = {Düsseldorf},
year = {2021}
}
@inproceedings{faucris.276799133,
abstract = {A novel approach of a differential microstrip line to a rectangular
waveguide realized by an alternative manu-facturing method, based on
additive manufacturing, is presented. In comparison with conventional
machining, this approach offers an improved behavior regarding weight,
costs and uncomplicated alignment with simultaneous high manufacturing
accuracy. The transition is designed for applications in the frequency
range of 70 - 90 GHz in particular for automotive radar at 77 GHz but
yet can easily be adapted for other frequencies. Measurements are
carried out stating a return loss of /S11/2 < -24 dB and an insertion
loss /S21/2 better than -1.3 dB at 77 GHz for the transition. To
demonstrate excellent suitability for hybrid circuits an analysis of
manufacturing tolerances and resulting degradation on the performance of
the transition have been conducted. The measurements of this analysis
prove a high reproducibility and robustness of the promising technology
even for precision demanding mmW application},
address = {Ulm},
author = {Engel, Lukas and Lomakin, Konstantin and Gold, Gerald and Pfahler, Tim and Schür, Jan and Vossiek, Martin},
booktitle = {Published in: 2022 14th German Microwave Conference (GeMiC)},
date = {2022-05-16/2022-05-18},
faupublication = {yes},
isbn = {978-3-9820397-2-5},
peerreviewed = {unknown},
title = {{3D} {Printed} {Waveguide} {Transition} for 77 {GHz} {Radar} {Applications}},
venue = {Ulm, Germany},
year = {2022}
}
@article{faucris.272614287,
abstract = {In this work, a combined frontend of horn and slotted waveguide array
antenna serving as feeding subsystem is presented. This setup allows to
implement an amplitude taper in one plane while using the horn aperture
to shape the far field radiation characteristics in the perpendicular
plane independently and tailored to the individual demand of the
application. Moreover, the feeding system is implemented as a loop
resulting in a standing wave distribution for a wide frequency range in
order to increase the antenna bandwidth. Two specimens with different
horn apertures are additively manufactured in slotted waveguide
technology from UV curable photopolymer resin using a digital light
processing 3D printer and subsequently metal coated by electroless
silver plating. A relatively large bandwidth of B-10dB=7.2 GHz and a
B-15dB of 4.9 GHz is achieved in measurements indicating a relative
bandwidth of 9% and 6% respectively. Antenna Gain is characterized as
17.5 and 20.17 dBi in measurements while maintaining a sidelobe level of
20-22.5 dB at 77 GHz and exhibiting a radiation efficiency of 78.9 and
79.4%. The proposed antenna architecture provides a flexible approach
for beam shaping in applications where azimuth and elevation planes
exhibit different or contrary requirements, e.g. broad vs. narrow field
of view - especially suitable for automotive MIMO-radar sensor},
author = {Lomakin, Konstantin and Alhasson, Saif and Gold, Gerald},
doi = {10.1109/ACCESS.2022.3162830},
faupublication = {yes},
journal = {IEEE Access},
peerreviewed = {Yes},
title = {{Additively} {Manufactured} {Amplitude} {Tapered} {Slotted} {Waveguide} {Array} {Antenna} with {Horn} {Aperture} for {77GHz}},
year = {2022}
}
@inproceedings{faucris.315899675,
abstract = {In this work an additively manufactured waveguide antenna array for
automotive radar applications is presented. The antenna is based on a
slotted single ridged waveguide design with four radiating elements in
the elevation plane. This allows for a λ
0
/2 spacing at 76 to 77 GHz, which is desirable to minimise azimutal
angular ambiguities in automotive radar applications. The influence of
adjacent surfaces close to the radiating slots in the azimutal field of
view (FoV) is evaluated based on simulations and measured prototypes,
especially demonstrating its role when extending the FoV towards ±70°.
Furthermore, the impact on mutual coupling with neighboring antenna
elements and the interaction of several channels with the arrays’ cover
are evaluated based on a 4x4 channel array prototype, which is also
manufactured and measured. The entire antenna arrays are manufactured
monolithically with a photopolymer based 3D-printing process and
subsequently electroplated in cooperation with Golden Devices Gmb},
author = {Kleinlein, Micha and Lomakin, Konstantin and Rösner, Felix and Hofmann, Andreas and Sippel, Mark and Gold, Gerald},
booktitle = {2023 IEEE Conference on Antenna Measurements and Applications (CAMA)},
date = {2023-11-15/2023-11-17},
doi = {10.1109/CAMA57522.2023.10352716},
faupublication = {yes},
isbn = {979-8-3503-2304-7},
keywords = {Antenna measurements
,
Slot antennas
,
Surface waves
,
Three-dimensional printing
,
Radar antennas
,
Loss measurement
,
Radar applications},
peerreviewed = {Yes},
title = {{Additively} manufactured antennas based on slotted ridged waveguides for 77 {GHz} {MIMO} radar applications},
url = {https://ieeexplore.ieee.org/document/10352716},
venue = {Genoa, Italy},
year = {2023}
}
@inproceedings{faucris.269631698,
author = {Hofmann, Andreas and Lomakin, Konstantin and Sippel, Mark and Gold, Gerald},
booktitle = {German Microwave Conference},
faupublication = {yes},
peerreviewed = {unknown},
title = {{Additively} {Manufactured} {Broadwall} {Waveguide} {Couplers} for {V}-{Band} {Applications}},
venue = {Ulm},
year = {2022}
}
@inproceedings{faucris.291815289,
abstract = {
In this work, an additively manufactured endfire bifilar helix antenna with a center frequency of fc = 66 GHz employing a novel transition from bifilar helix to E-band waveguide is presented. This novel transition enables a higher bandwidth of the antenna and also tuning of the antenna matching. Mea- surements suggest a -20 dB-bandwidth of B20dB ≈ 5.2 GHz and -15 dB-bandwidth of B15dB = 16 GHz respectively. An axial ratio below AR<3.15dB is achieved over the entire E-Band and even AR < 2 dB within B20dB in main lobe direction. The realized linear polarization gain ranges at Glp 11 dBi with a circular polarization gain of Gcp 12 to 13dBi was measured. Hence, measurements suggest general feasibility of the proposed bifilar helix antenna for mmWave applications due to the small form factor of the antenna and the circular polarization. Those applications in future could be satellite systems or future 6G infrastructures.
This paper presents an additively manufactured helix antenna for X-Band applications with a center frequency of 10GHz. A comparison between stereolithography and selective laser sintering processes is made. The proposed antenna concept includes a transition from the helix coil to an X-band waveguide, which allows for matching of the antenna to the waveguide. In our measurements, the proposed antennas featured a -10dB-bandwidth of 2.8GHz and a -20dB-bandwidth of 0.28GHz respectively. The suggested manufacturing and design process is, therefore, a major step towards enabling complex antenna geometries.
An
existing analytical transmission line model to describe propagation
properties of coplanar waveguides including dispersion and radiation
effects was extended to take into account surface roughness of conductor
traces. The influence of parasitics is successively included in
the simulation and compared to measurements. The device under
test (DUT) was fabricated on an Al2O3 wafer. A metal and ceramic
chuck was utilized during measurements up to 120 GHz. The extended
model is then capable of precisely predicting propagation properties in a
wide frequency range and can now be used for calibration purposes like the
development of uncertainty budget},
author = {Gold, Gerald and Lomakin, Konstantin and Helmreich, Klaus and Arz, Uwe},
doi = {10.5194/ars-17-51-2019},
faupublication = {yes},
journal = {Advances in Radio Science},
peerreviewed = {Yes},
title = {{High}-{Frequency} {Modeling} of {Coplanar} {Waveguides} {Including} {Surface} {Roughness}},
year = {2019}
}
@inproceedings{faucris.200709620,
author = {Lomakin, Konstantin and Pavlenko, Tatiana and Sippel, Mark and Gold, Gerald and Helmreich, Klaus and Ankenbrand, Markus and Urban, N and Franke, A},
booktitle = {European Conference on Antennas and Propagation (EUCAP)},
doi = {10.1049/cp.2018.1235},
faupublication = {yes},
peerreviewed = {unknown},
title = {{Impact} of {Surface} {Roughness} on {3D} printed {SLS} {Horn} {Antennas}},
year = {2018}
}
@inproceedings{faucris.200709862,
abstract = {This work presents an additively manufactured termination circuit in
terms of a microstrip transmission line with gradually varying
conductivity applicable up to 67 GHz with an absolute reflection
coefficient of less than −10 dB — and even less than −15 dB above 12
GHz. Different load conditions and manufacturing approaches are
discussed and a time domain analysis supporting the design is presente},
author = {Lomakin, Konstantin and Sippel, Mark and Gold, Gerald and Fröhlich, Jan and Helmreich, Klaus and Ankenbrand, Markus and Franke, Jörg},
booktitle = {German Microwave Conference},
doi = {10.23919/gemic.2018.8335109},
faupublication = {yes},
peerreviewed = {unknown},
title = {{Low} reflective aerosol {Jet} printed broadband matched load up to 67 {GHz}},
year = {2018}
}
@inproceedings{faucris.317591484,
abstract = {In this work, an additively manufactured MIMO radar antenna setup is
presented based on stereolithography 3D-printing of photopolymer resin
and subsequent electroplating. The 8 antennas are based on slotted
waveguide array design, each with 20 radiating elements along the
elevation plane and are combined with an additional horn aperture on top
of the radiating elements. The array incorporates two types of antennas
which differ within the horn aperture yielding one type with wide
azimuthal field of view and the other with a narrow field of
view.Moreover, the antenna elements are conformally placed on a bent
surface, consequently, directing the maximum gain into different
directions.The entire array is manufactured as one monolithic part
without the need of tedious assembly steps and thus, enhancing the
feasibility towards serial productio},
author = {Lomakin, Konstantin and Alhasson, Saif and Hofmann, Andreas and Sippel, Mark and Gold, Gerald},
booktitle = {2023 IEEE Conference on Antenna Measurements and Applications (CAMA)},
date = {2023-11-15/2023-11-17},
doi = {10.1109/CAMA57522.2023.10352679},
faupublication = {yes},
peerreviewed = {Yes},
publisher = {IEEE},
title = {{Monolithic} {Additively} {Manufactured} {Conformal} 4x4 {MIMO} {Radar} {Frontend} based on {Slotted} {Waveguide} {Array} {Antennas} for 77 {GHz} {Corner} {Radar}},
venue = {Genoa, Italy},
year = {2023}
}
@inproceedings{faucris.217487063,
abstract = {This work proposes an approach for
manufacturing of high precision ungrounded coplanar
waveguides as high speed interconnections for flexible and
wearable sensor as well as IoT systems. Characterization of
these printed transmission lines up to a frequency of 24 GHz
reveals an insertion loss of up to 8 dB/cm and therefore provides
practical advice towards realizable line lengths. Although
exhibiting approximately 4 times the attenuation as compared
to conventionally manufactured flexible PCB transmission lines,
the proposed approach allows for selectively realizing highly
precise structures where necessary. Moreover, it is applicable on
three-dimensional substrates, such as 3D-MIDs and therefore
addresses various future applications.
This work proposes a fabrication approach for 3D printed waveguide paths based on a combination of an optimized electroless silver plating process with a waveguide-specific design rule for general metal plating by introducing large scale non- radiating slots into the broad and narrow waveguide walls with a periodicity shorter than quarter of the guided wavelength. Experimental fabrication of straight sections of the proposed slotted waveguide with various gap dimensions yields an optimum gap size as result of a trade-off between silver plating quality and leakage losses through the sidewall gaps.
Moreover, a
successful practical application of the proposed approach is presented in terms
of a 3D printed multiple bend waveguide interconnect in three different space
dimensions which imposes a complex task for conventional manufacturing tech- niques
due to the need of multiple cutting planes for split block assembly. The
proposed approach benefits of low cost, moderate handling effort and
independence of the concrete geometry to manufacture making it therefore
especially interesting for distri- bution and feeding networks in the context
of rapid prototyping, automotive and space related applications},
author = {Lomakin, Konstantin and Herold, Sophie and Ringel, Lorenz and Ringel, Johannes and Simon, D. and Sippel, Mark and Sion, A. and Vossiek, Martin and Helmreich, Klaus and Gold, Gerald},
doi = {10.1109/TCPMT.2019.2927671},
faupublication = {yes},
journal = {IEEE Transactions on Components, Packaging and Manufacturing Technology},
pages = {2476-2481},
peerreviewed = {Yes},
title = {{SLA} {Printed} {3D} {Waveguide} {Paths} for {E}-{Band} using {Electroless} {Silver} {Plating}},
volume = {9},
year = {2019}
}
@inproceedings{faucris.314526356,
abstract = {The continuous improvement of additive stereo-lithographic manufacturing (SLA) allows to fabricate filigree sub-Terahertz antennas. This paper presents the first 3D-printed bifilar WR6 helix antenna, which depends on recent developments of printed transition from waveguides to bifilar helices. The measurements of the circularly polarized antenna indicate a −15 dB bandwidth of B15 dB = 10GHz. The axial ratio AR is within B15 dB <3.5dB in the main lobe direction. The achieved linear polarization gain is Glp 14dBi with a circular polarization gain of Gcp 11 to 12 dBi. Due to its small form factor and circular polarization the proposed bifilar helical antenna is suitable for applications in the 120 GHz ISM band, i.e. polarimetric imaging and decomposition as well as broadband communication, e.g. 6G applications.