| 1. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
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Design and Validation of Microstrip Gap Waveguides and Their Transitions to Rectangular Waveguide, for Millimeter-Wave Applications
- 2015
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 63:12, s. 4035-4050
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Tidskriftsartikel (refereegranskat)abstract
- The paper describes the design methodology, experimentalvalidation and practical considerations of two millimeterwave wideband vertical transitions from two gap waveguide versions (inverted microstrip gap waveguide, and microstrip packaged by using gap waveguide) to standard WR-15 rectangular waveguide. The experimental results show S11 smaller than -10 dB over relative bandwidths larger than 25% and 26.6% when Rogers RO3003 and RO4003 materials are used respectively. The vertical transition from standard microstrip line packaged by a lid of pins to WR-15, shows measured return loss better than 15 dB over 13.8% relative bandwidth. The new transitions can be used as interfaces between gap waveguide feed-networks for 60 GHz antenna systems, testing equipment (like Vector Network Analyzers) and components with WR-15 ports, such as transmitting/receiving amplifiers. Moreover, the paper documents the losses of different gap waveguide prototypes compared to unpackaged microstrip line and Substrate Integrated Waveguide (SIW). This investigation shows that in V-band the lowest losses are achieved with inverted microstrip gap waveguide.
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| 2. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of a Butler Matrix at 60GHz in Inverted Microstrip Gap Waveguide Technology
- 2015
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Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 1522-3965. ; , s. 2125-2126
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Konferensbidrag (refereegranskat)abstract
- A four-port Butler matrix is designed at 60GHz in the new gap waveguide technology, inverted microstrip type. The simplicity of doing this circuit in a printed technology and the low loss characteristic makes this design very promising. All the different components of the matrix have been designed and optimized and the complete matrix is currently under optimization.
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| 3. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of a coplanar waveguide-to-ridge gap waveguide transition via capacitive coupling
- 2012
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Ingår i: Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012. Prague, 26-30 March 2012. - 9781457709180 ; , s. 3524-3528
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Konferensbidrag (refereegranskat)abstract
- A transition from Coplanar Waveguide (CPW) via capacitive coupling in order to provide feeding to the so-called Ridge Gap Waveguide (RGW) has been investigated. The main objective of this work is to find a way to facilitate integration of active electronics with the gap waveguide structure and also to do measurements of the components made in gap waveguide technology working around 100 GHz. The transition design and simulation of S parameters for the designed topology is presented.
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| 4. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of a transition from WR-15 to microstrip packaged by gap waveguide technology
- 2015
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Ingår i: ISAP 2014 - 2014 International Symposium on Antennas and Propagation, Conference Proceedings, Taiwan, 2-5 December 2014. - 9789869147408 ; , s. 235-236
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Konferensbidrag (refereegranskat)abstract
- The gap waveguide technology is an advantageous way of packaging passive microstrip components. This work presents a wideband transition from a standard microstrip line packaged by using a bed of nails, to a rectangular waveguide operating in V band. The transition is designed by means of a T-shaped patch that couples the fields into a rectangular waveguide extending vertically from the microstrip circuit. The simulated results show more than 28.5% bandwidth with S11 lower than -10 dB. This transition is intended to be used as a WR-15 port of a planar array antenna for 60 GHz applications, where the array elements are fed by microstrip distribution networks packaged by gap waveguide technology. Thereby, radiation is avoided from the distribution network itself.
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| 5. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Design of F-Band Transition From Microstrip to Ridge Gap Waveguide Including Monte Carlo Assembly Tolerance Analysis
- 2016
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - : Institute of Electrical and Electronics Engineers (IEEE). - 0018-9480 .- 1557-9670. ; 64:4, s. 1245-1254
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Tidskriftsartikel (refereegranskat)abstract
- This paper describes the design and realization of a transition from a microstrip line to a ridge gap waveguide operating between 95 and 115 GHz. The study includes simulations, measurements, and a Monte Carlo analysis of the assembly tolerances. The purpose of this tolerance study is to identify the most critical misalignments that affect the circuit performance and to provide guidelines about the assembly tolerance requirements for the proposed transition design.
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| 6. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
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Design of Millimeter-Wave Wideband Gap Waveguide Transitions Considering Integration into the Antenna System
- 2015
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Ingår i: 9th European Conference on Antennas and Propagation, EuCAP 2015, Lisbon, Portugal, 13-17 May 2015. - 9788890701856
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Konferensbidrag (refereegranskat)abstract
- Two wideband vertical transitions from inverted microstrip gap waveguide to rectangular waveguide (WR-15) for 60 GHz antenna array applications are proposed. Thesetransitions are aimed to interconnect the WR-15 with the gap waveguide feed-network employed to provide feeding to the radiating elements of slot/horn antenna arrays. The wideband field transformation is achieved without the need of adding a quarter-wavelength cavity backshort on a metal block placed over the transition. First, we replace this backshort by creating a cavity in the radiating layer when this is made in Substrate Integrated Waveguide (SIW) technology, and thereafter we use an air-filled pin cavity in the radiating layer. The simulated Sparametersshow that the presented transitions cover the unlicensed 60 GHz band (57-64 GHz) with good margins.
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| 7. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Evaluation of losses of the ridge gap waveguide at 100 GHz
- 2013
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Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 1522-3965. - 9781467353175 ; , s. 1456-1457
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Konferensbidrag (refereegranskat)abstract
- An evaluation of losses of the Ridge Gap Waveguide (r-GAP) at 100 GHz has been developed in terms of Quality Factor. For this aim, an r-GAP resonator has been designed, simulated and measured. The feeding to the circuit is provided via a transition from Micostrip-to-Ridge Gap Waveguide based in electromagnetic coupling in order to ensure compatibility with the available probe stations.
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| 8. |
- Algaba Brazalez, Astrid, 1983
(författare)
-
Gap waveguide for packaging microstrip filters & investigation of transitions from planar technologies to ridge gap waveguide
- 2013
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Gap waveguide technology has proved to constitute an effective alternative for the design of microwave passive components, due to its advantages with respect to traditional planar technologies and standard waveguides. There is no requirement for conductive contact between the two different metal pieces making up a gap waveguide prototype, since one of these pieces makes use of a textured surface that eliminates any possible leakage of the field through the gap to the surface of the other metal piece above it. The textured surface provides together with the opposite surface a cutoff of parallel-plate modes, so cavity modes are suppressed for any extent of the gap between the two surfaces. It is also less lossy than microstrip and coplanar waveguide, because there is no need to use dielectric in the design of gap waveguide components. The packaging of electronic circuits has become a critical factor, and it is important to study the effects on the performance when packaged. The first part of this thesis is focused on the study of packaging using gap waveguide technology, as a promising packaging method of microstrip passive devices such as filters. The gap waveguide packaging is in this thesis realized by using a lid of nails. Planar technologies, such as microstrip lines, are open structures that need to be electrically shielded and physically protected. One of the main drawbacks of the traditional packaging in metal boxes with a smooth metal lid, is the appearance of cavity resonances when two of the dimensions of the box are larger than half wavelength. It is possible to dampen these resonances by attaching absorbers to the lid of the metal cavity. The problem with this is the uncertainties in locating the absorbers in the package, and the additional losses introduced by the absorbing material. The present thesis investigates a microstrip coupled line filter by employing different types of packaging, including gap waveguide technology in Ku-band. Numerical results are also presented for the ideal case of using a Perfect Magnetic Conductor (PMC) as a lid. There is a stronger potential for advantages of the gap waveguides at higher frequencies, approaching and including the THz range. Therefore, the second part of this report deals with gap waveguide components that have been numerically analyzed at 100 GHz. At these frequencies, there is in particular a need for appropriate transitions that can ensure compatibility between the gap waveguide circuits and existing vector network analyzer ports and probe stations. For this reason, we have designed a transition from coplanar waveguide to ridge gap waveguide and another transition from microstrip to ridge gap waveguide. The integration of active components (MMIC) into the gap waveguides is challenging and can only be achieved with good transitions.
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| 9. |
- Algaba Brazalez, Astrid, 1983
(författare)
-
Gap Waveguide Technology- Electromagnetic Packaging and Transitions
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The scarcity of available frequency bands for new wireless communication systems, as well as the growing need for higher capacity, motivates the current interest in moving upwards in frequency. The millimeter wave frequencyrange is very attractive to allocate potential commercial opportunities such as short range wireless communications that allow high-speed data/video transmission, and automotive radars for both driver assistance and increasedsafety.The shift towards higher frequencies involves significant challenges. For instance, the mechanical tolerance requirements become much stricter, which provokes the need for high precision fabrication and assembly processes.Moreover, in order to achieve highly functional and densely packed electronic modules, new waveguide technologies that can meet the demands of high interconnectivity and ensure optimum electromagnetic packaging, need to be developed. The gap waveguide technology constitutes a new type of guiding structure that shows strong potential to become a suitable millimeter wave approach, and overcome the limitations of conventional planar transmissionlines and hollow waveguides.This thesis presents recent investigations on gap waveguide technology, concerning packaging aspects and design of millimeter wave transitions. The first part of the thesis deals with an investigation of the electromagnetic packagingcapabilities of the gap waveguide. This study addresses the performance of a Ku-band microstrip coupled line filter when it is packaged in different ways: unpackaged situation, and packaged by using a: i) metal cover, ii) metal cover with absorbing material (i.e. the conventional approach), iii) Perfect Magnetic Conductor (PMC), and iv) gap waveguide packaging realized by using a lid of nails. The obtained results show that the best filter performanceis achieved when the microstrip circuit is packaged with a PMC, and a lid of nails. The PMC packaging condition is an ideal situation and can only be simulated, but it is still of great interest since it enables us to reduce simulation time compared to other packaging approaches. Also, the PMCrepresents a good approximation of the practical lid of nails. The lid of nails solution has been properly validated by both simulations and measurements.The second part of the thesis focuses on the design of millimeter wave transitions between different types of gap waveguide and classical waveguide or transmission lines. In order to achieve high integration between passivecomponents, active components and antennas in a gap waveguide module, good compatibility between gap waveguides and other technologies is critical. One of the reasons is that for integrating gap waveguide circuits with MonolithicMicrowave Integrated Circuits (MMIC), we need to develop suitable interconnections to microstrip and coplanar waveguide since the MMICs are substrate based. On the other hand, the interfaces of millimeter wave measurement instruments are either standard coaxial connectors, coplanar waveguide probes or rectangular waveguides. The transitions are therefore necessary in order to enable measurements of gap waveguide prototypes at highfrequencies. We present two different F-band transition designs between ridge gap waveguide and coplanar waveguide/microstrip, and a V-band transition from inverted microstrip gap waveguide to rectangular waveguide. Duringthe experimental validation of these transitions, we have identified different mechanical limitations involved in the assembly process of the gap waveguide prototypes. The assembly has an impact on the gap waveguide performance,and we have analyzed methods to mitigate the effect on the measurements.
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| 10. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
-
Improved Microstrip Filters Using PMC Packaging by Lid of Nails
- 2012
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Ingår i: IEEE Transactions on Components, Packaging and Manufacturing Technology. - 2156-3985 .- 2156-3950. ; 2:7, s. 1075-1084
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Tidskriftsartikel (refereegranskat)abstract
- This paper shows that microstrip filters perform like textbook examples when packaged with perfect magnetic conductor (PMC). A PMC is made as a pin surface or lid of nails, and this is used to package a microstrip parallel coupled line bandpass filter. Our measurements confirm that parallel plate, cavity modes, and radiation are suppressed. This paper also includes a study of the reasons for a frequency shift between the ideal PMC packaged case and the realized case.
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