| 1. |
- Hassan, Emadeldeen, et al.
(författare)
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Design of Planar Microstrip-to-Waveguide Transitions Using Topology Optimization
- 2019
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Ingår i: 2019 IEEE Radio and Wireless Symposium (RWS), Orlando, USA, January 20-23, 2019. - : IEEE. ; , s. -3
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Konferensbidrag (refereegranskat)abstract
- This paper presents a topology optimization approach to design planar transitions between a microstrip line (MSL) and a rectangular waveguide (RWG) in the K-band. The transition comprises two sub-transitions: one from the MSL to a substrate integrated waveguide (SIW) and the second from the SIW to the RWG. Both are on the same substrate and can be manufactured with a standard printed circuit board process. This leads to a very costeffective solution compared with other approaches. A WR-42 waveguide can easily be surface mounted to the transitions using a standard flange. The transitions have been fabricated, and their measured performance shows good agreement with the simulations. The MSL-SIW transition has a broadband behavior and the SIW-RWG transition still reaches a relative bandwidth of 10%.
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| 2. |
- Hassan, Emadeldeen, et al.
(författare)
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Multilayer Topology Optimization of Wideband SIW-to-Waveguide Transitions
- 2020
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Ingår i: IEEE transactions on microwave theory and techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 68:4, s. 1326-1339
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Tidskriftsartikel (refereegranskat)abstract
- This article utilizes a topology optimization approach to design planar multilayer transitions between substrate integrated waveguides (SIWs) and rectangular waveguides (RWGs). The optimization problem is formulated based on the modal field analyses and Maxwell's equations in the time domain solved by the finite-difference time-domain (FDTD) method. We present a time-domain boundary condition based on the Klein–Gordon equation to split traveling waves at homogeneous waveguide ports. We employ the boundary condition to compute portal quantities and to devise an adjoint-field system that enabled an efficient computation of the objective function gradient. We solve design problems that include more than 105 000 design variables by using less than 400 solutions of Maxwell's equations. Moreover, a new formulation that effectively combats the development of in-band resonances in the design is presented. The transition configuration allows the direct mount of conventional RWG sections on the circuit board and aims to cover the entire K-band. The guiding structure of the optimized transition requires blind vias, which is realized by a simple and cost-efficient technique. In addition, the transition is optimized for three different setups that can be used to provide different field polarizations. The proposed transitions show less than 1-dB insertion loss and around 15-dB return loss over the frequency interval 18–28 GHz. Several prototypes are fabricated with an excellent match between the simulation and measurement results.
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| 3. |
- Heining, Simon, et al.
(författare)
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An Ultra Broadband Multi-Tone Six-Port Radar for Distance Measurements in K-Band Waveguides
- 2020
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Ingår i: Proceedings of the 2020 IEEE Radio and Wireless Symposium (RWS). - : IEEE. - 9781728111209 ; , s. 279-282
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Konferensbidrag (refereegranskat)abstract
- Continuous wave (CW) radars show an excellent performance in high precision distance measurements. However, when it comes to absolute distances, the ambiguity of these systems is a notable issue. To extend the unambigous range beyond λ/2, dual tone systems have been presented using two spaced CW measurements. In this paper, a broadband multi-tone radar operating in the K-band using six-port technology is presented. By using more than two frequencies, the unambigous range can be further enlarged. The radar system presented in this paper is able to perform 5-FSK measurements within a bandwidth of 5.5GHz delivering an update rate of 25Hz and a precision of 37.96µm.
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