| 1. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
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Gap waveguide components for millimeter-wave systems. Couplers, filters, antennas, MMIC packaging
- 2012
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Ingår i: IEEE Antennas and Propagation Society, AP-S International Symposium (Digest). - 1522-3965. - 9784885522703 ; , s. 243-246
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Konferensbidrag (refereegranskat)abstract
- Design of passive components (couplers, filters and antennas) and MMIC packaging validation intended for RF front ends for microwave links at 38 GHz using gap waveguide technology have been shown. The use of this technology allows all-in-one integration of receiver, transmitter, and diplexer including the antenna into one mechanical unit. These initial designs and studies have been made at the microwave band for validation and measurement purposes, and for comparison with existing technology. They represent the first step towards the application of gap waveguides to millimeter-wave systems, where gap waveguides could have a large potential.
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| 2. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
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Ka-Band Gap Waveguide Coupled-Resonator Filter for Radio Link Diplexer Application
- 2013
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Ingår i: IEEE Transactions on Components, Packaging and Manufacturing Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-3985 .- 2156-3950. ; 3:5, s. 870-879
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Tidskriftsartikel (refereegranskat)abstract
- Gap waveguide technology represents an interesting alternative as low-loss, cost-effective, and high-performance transmission line and package of microwave and millimeter-wave systems. A Ka-band coupled-resonator filter for a radio link diplexer, which requires high selectivity to isolate transmit and receiving channels, is proposed and realized using gap waveguide technology. The band-pass filter, which has a central frequency of 37.37 GHz and a pass bandwidth of 560 MHz, is fabricated between two parallel metal plates, leaving an air gap between them. After milling one of the plates, silver-plating is applied on them. Measurements show a minimum in-band insertion loss of 1 dB and agree quite well with simulations.
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| 3. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
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Ka-band gap waveguide coupled-resonator filter for radio link diplexers
- 2012
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Ingår i: XXVII Simposium Nacional de la Unión Científica Internacional de Radio, URSI 2012 (Spanish URSI), Elche, Spain, 12-14 September 2012.
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Konferensbidrag (refereegranskat)abstract
- Gap waveguide technology represents an interesting alternative as low-loss, cost-effective and high-performance transmission line and package of microwave and millimeter-wave systems. A Ka-band coupled-resonator filter for a radio link diplexer, which requires high selectivity to isolate transmit and receiving channels, is proposed and realized using gap waveguide technology. The band-pass filter, which has a central frequency of 37.37 GHz and a pass bandwidth of 560 MHz, is fabricated between two metal parallel plates leaving an air gap between them. Measurements show a minimum in-band insertion loss of 1 dB and agree quite well with simulations.
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| 4. |
- Alfonso Alos, Esperanza, 1979, et al.
(författare)
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Parabolic cylindrical reflector antenna at 60 GHz with line feed in gap waveguide technology
- 2013
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Ingår i: 7th European Conference on Antennas and Propagation, EuCAP 2013, Gothenburg, Sweden, 8-12 April 2013. - 2164-3342. - 9781467321877 ; , s. 319-323
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Konferensbidrag (refereegranskat)abstract
- A parabolic cylindrical reflector antenna is proposed in this paper for wireless multi-gigabit communications at 60 GHz. The line feed is realized by a power distribution in parallel plate waveguide (PPW). Inside the PPW waveguide there are metal pin rows forming the contours of an H-plane horn structure in front of a parabolic reflector, where we see possible mechanical advantages in not requiring metal contact of the pins to more than one metal plate. They will still work as a total reflecting wall by making use of the same stopband features as in gap waveguide technology. The result is a low loss, low cost and very versatile 60 GHz antenna with high gain. The electrical design for maximum aperture efficiency and minimum loss is explained.
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| 5. |
- Farjana, Sadia, 1983, et al.
(författare)
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Multilayer Dry Film Photoresist Fabrication of a Robust >100 GHz Gap Waveguide Slot Array Antenna
- 2023
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Ingår i: IEEE Access. - 2169-3536 .- 2169-3536. ; 11, s. 43630-43638
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Tidskriftsartikel (refereegranskat)abstract
- This article presents the first use of a multilayer dry film photoresist to fabricate a slot array antenna by micromachining. The proposed fabrication process demonstrates a straightforward and fast method of realizing antenna structures and delicate features with very high accuracy above 100 GHz. The slot array antenna design is based on gap waveguide technology. The designed antenna consists of two layers: a slot layer and a feed layer with a transition to measuring waveguide. The antenna contains structures that require a multiple level dry film fabrication process with thicknesses ranging from 80 μm to 400 μm with ± 10 μm tolerance. The fabricated antenna shows good accuracy. To make the fabricated antenna layers conductive, the fabricated polymer antenna was coated with Ti and Au. The input reflection coefficient was measured to be below – 11 dB over a 10% bandwidth from 136-148 GHz, and the antenna gain was measured to be 11.4 dBi at 142 GHz, both of which are in fair agreement with simulations. A thermal cycling test has been conducted on the fabricated antenna and the results show insignificant degradation at least up to 300 cycles in the temperature range –50 °C to 135 °C which is the typical temperature gradient range for many practical outdoor wireless applications.
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| 6. |
- Kildal, Per-Simon, 1951, et al.
(författare)
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Design and experimental verification of ridge gap waveguides in bed of nails for parallel plate mode suppression
- 2011
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Ingår i: IET Microwaves, Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725 .- 1751-8733. ; 5:3, s. 262-270
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Tidskriftsartikel (refereegranskat)abstract
- This study describes the design and experimental verification of the ridge gap waveguide, appearing in the gap between parallel metal plates. One of the plates has a texture in the form of a wave-guiding metal ridge surrounded by metal posts. The latter posts, referred to as a pin surface or bed of nails, are designed to give a stopband for the normal parallel-plate modes between 10 and 23 GHz. The hardware demonstrator includes two 90 bends and two capacitive coupled coaxial transitions enabling measurements with a vector network analyser (VNA). The measured results verify the large bandwidth and low losses of the quasi-transverse electromagnetic (TEM) mode propagating along the guiding ridge, and that 90 bends can be designed in the same way as for microstrip lines. The demonstrator is designed for use around 15 GHz. Still, the ridge gap waveguide is more advantageous for frequencies above 30 GHz, because it can be realised entirely from metal using milling or moulding, and there are no requirements for conducting joints between the two plates that otherwise is a problem when realising conventional hollow waveguides.
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| 7. |
- Raza Zaidi, Syed Hasan, 1977, et al.
(författare)
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Microstrip-Ridge Gap Waveguide – Study of Losses, Bends and Transition to WR-15
- 2014
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Ingår i: IEEE Transactions on Microwave Theory and Techniques. - 0018-9480 .- 1557-9670. ; 62:9, s. 1943 - 1952
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents the design of microstrip-ridge gap waveguide using via-holes in printed circuit boards, a solution for high-frequency circuits. The study includes how to define the numerical ports, pin sensitivity, losses, and also a comparison with performance of normal microstrip lines and inverted microstrip lines. The results are produced using commercially available electromagnetic simulators. A WR-15 to microstrip-ridge gap waveguide transition was also designed. The results are verified with measurements on microstrip-ridge gap waveguides with WR15 transitions at both ends.
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| 8. |
- Raza Zaidi, Syed Hasan, 1977, et al.
(författare)
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Resemblance Between Gap Waveguides and Hollow Waveguides
- 2013
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Ingår i: IET Microwaves, Antennas and Propagation. - : Institution of Engineering and Technology (IET). - 1751-8725 .- 1751-8733. ; 7:15, s. 1221-1227
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Tidskriftsartikel (refereegranskat)abstract
- There is a lack of suitable numerical ports for the gap waveguides. This study studies the resemblance between the ridge/groove gap waveguide and the conventional hollow ridge/rectangular waveguide, respectively, by using numerical analysis. The dispersion diagrams and characteristic impedances are compared and found to be similar within the stopband of the parallel-plate modes. Therefore conventional hollow waveguides can be used as ports in numerical analysis of gap waveguides. In addition, this means that the geometry of circuit components in hollow ridge/rectangular waveguides can be used as a good starting point when designing ridge/groove gap waveguide components.
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| 9. |
- Razavi, S. A., et al.
(författare)
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2×2-slot Element for 60GHz Planar Array Antenna Realized on Two Doubled-sided PCBs Using SIW Cavity and EBG-type Soft Surface fed by Microstrip-Ridge Gap Waveguide
- 2014
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 62:9, s. 4564 - 4573
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Tidskriftsartikel (refereegranskat)abstract
- A wideband 2x2-slot element for a 60-GHz antenna array is designed by making use of two double-sided printed circuit boards (PCBs). The upper PCB contains the four radiating cavity-backed slots, where the cavity is formed in substrate-integrated waveguide (SIW) using metalized via holes. The SIW cavity is excited by a coupling slot. The excitation slot is fed by a microstrip-ridge gap waveguide formed in the air gap between the upper and lower PCBs. The lower PCB contains the microstrip line, being short-circuited to the ground plane of the lower PCB with via holes, and with additional metalized via holes alongside the microstrip line to form a stopband for parallel-platemodes in the air gap. The designed element can be used in large arrays with distribution networks realized in such microstrip-ridge gap waveguide technology. Therefore, the present paper describes a generic study in an infinite array environment, and performance is measured in terms of the active reflection coefficient S11 and the power lost in grating lobes. The study shows that the radiation characteristics of the array antenna is considerably improved by using a soft surface EBG-type SIW corrugation between each 2x2-slot element in E-plane to reduce the mutual coupling. The study is verified by measurements on a 4x4 element array surrounded by dummy elements and including a transition to rectangular waveguide WR15.
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| 10. |
- Razavi, Seyed Ali, et al.
(författare)
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Design of 60GHz Planar Array Antennas Using PCB-based Microstrip-Ridge Gap Waveguide and SIW
- 2014
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Ingår i: 8th European Conference on Antennas and Propagation, EuCAP 2014, The Hague, The Netherlands 6-11 April 2014. - 2164-3342. - 9788890701849 ; , s. 1825-1828
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Konferensbidrag (refereegranskat)abstract
- A wideband 2×2-slot element for a 60 GHz antenna array is designed by making use of two double-sided printed circuit boards (PCBs). The upper PCB contains the four radiating cavity-backed slots backed by a substrate-integrated waveguide (SIW) cavity. The SIW cavity is excited by a coupling slot fed by a microstrip-ridge gap waveguide formed in the air gap between the upper and lower PCBs. The designed 2×2-slot element is considered in an infinite array environment. A sample 32×32 slot array aperture is simulated using infinite array approach and the relative bandwidth of 16% over 57-66GHz frequency range with the directivity of more than 38 dBi over the operating bandwidth is obtained. The simulations are verified by measurements on a smaller 4×4 slot array surrounded by dummy elements.
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| 11. |
- Wang, Enlin, 1998, et al.
(författare)
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A 50 dBi E-Band Dual-reflector Antenna for 5G Backhauling with Auto-beam-tracking Function
- 2024
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Ingår i: IEEE Transactions on Antennas and Propagation. - 0018-926X .- 1558-2221. ; 72:6, s. 4874-4887
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Tidskriftsartikel (refereegranskat)abstract
- An ultra-high-gain E-band dual-reflector antenna for 5G backhaul with beam tracking function is proposed in this paper. Beam tracking is achieved by defocussing the feed away from the focus point of the sub-reflector, while keeping the interface with the transmit-receive unit stationary by applying a movable gap-waveguide configuration. The antenna has been prototyped and measured. The measured reflection coefficients remain below –10 dB for both horizontal and vertical polarizations over 71 – 86 GHz, almost independent from the offset positions of the feed. The measured radiation patterns agree well with the simulated ones, with a peak gain of about 50 dBi in the band and less than 1 dB gain drop for beam steering within ±2°. Finally, a low-cost and environmentally friendly mechanical tracking system is proposed, prototyped, and tested. Measurements have verified that the tracking system functions well for slow sways.
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| 12. |
- Wang, Enlin, 1998, et al.
(författare)
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Antenna and Mechanical Co-Design for Auto-Beam-Tracking in Backhaul Systems
- 2024
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Ingår i: 18th European Conference on Antennas and Propagation, EuCAP 2024.
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Konferensbidrag (refereegranskat)abstract
- This paper addresses the electrical-mechanical co-design challenges of beam alignment in ultra-high-gain antennas due to mast sway by adopting a defocusing strategy for the reflector antenna feed in order to meet the requirements of 5G mmWave backhaul communication systems. Three automatic beam tracking methods have been investigated and evaluated: a sensor-motor-based control method, a gear-driven compensation method by using a secondary mast as a reference, and a gravity-driven pendulum method that leverages gravitational force as the reference. Detailed description of the integrated design approach combining both antenna design and mechanical structure is given in the paper, providing potential platform for further improved system developments.
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