| 1. |
- Algaba Brazalez, Astrid, 1983, et al.
(författare)
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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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| 2. |
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| 3. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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AMC pin waveguide flange for screw redundant millimeter and submillimeter measurements
- 2016
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Ingår i: 87th ARFTG Microwave Measurement Conference: Measurements for Emerging Communications Technologies, ARFTG 2016. - 9781509013081 ; , s. 7501946-
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Konferensbidrag (refereegranskat)abstract
- Measurements with waveguide flanges at frequencies above 100GHz have a considerable issue with leakage due to problems with achieving good electrical contact between the opposite flanges. The higher the frequency, the higher is the requirement for full contact. However, by using an artificial magnetic conducting (AMC) flange on one side of the interface, full electric contact is not needed between the two joining flanges. The AMC is realized as a pin-surface, and the leakage is stopped by a parallel-plate stopband like in gap waveguides. This paper describes how these AMC pin waveguide flanges can be used for screw redundant measurements.
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| 4. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Design of micromachined ridge gap waveguides for millimeter-wave applications
- 2011
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Ingår i: Procedia Eng.. - : Elsevier BV. ; 25, s. 519-522
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Konferensbidrag (refereegranskat)abstract
- The ridge gap waveguide is a new transmission line for millimeter-wave applications. Traditionally, rectangular waveguides are used for those applications due to their low loss. However their fabrication requires precision machining, very good electrical contact and alignment between two joining mechanical parts. Ridge gap waveguides can obtain similar performance without requiring conductive sidewalls and this provides more freedom during the fabrication and assembly process as the structure is no longer sensitive to small gaps between the side walls and the upper lid. The ridge gap waveguide has already been validated for 10-20 GHz using conventional fabrication methods. The ridge gap waveguide prototypes presented in this paper are designed to work in the frequency region between 210 and 340 GHz, and fabricated using MEMS technology. MEMS technology provides fabrication precision of the structures and thus opens the path for high-frequency components.
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| 5. |
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| 6. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Micromachined Ridge Gap Waveguide and Resonator for Millimeter-Wave Applications
- 2012
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Ingår i: Sensors and Actuators, A: Physical. - : Elsevier BV. - 0924-4247 .- 1873-3069. ; 186, s. 264-269
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Tidskriftsartikel (refereegranskat)abstract
- The ridge gap waveguide is a fundamentally new high-frequency waveguide. It does not need any electrical contact between the split blocks which gives it an advantage compared to the rectangular waveguide which is the standard today. These waveguides are conventionally fabricated by milling, although above 100 GHz milling is not adequate anymore. MEMS technology on the other hand, can offer high-precision fabrication and thus opens the path for new types of high-frequency components. In this paper both a ridge gap waveguide and a ridge gap resonator have been fabricated for the frequencies 220–325 GHz using MEMS technology. Support packages have been designed to enable device measurements. Simulations show that the reflection coefficient for the ridge gap waveguide is below −15 dB between 240 and 340 GHz. Two resonance peaks were measured at the frequencies 234 GHz and 284 GHz for the ridge gap resonator with unloaded Q-values of 336 and 527 respectively. Both the waveguide and resonator have the potential to obtain similar performances as the rectangular waveguide without strict requirement on electrical contact, allowing simplified fabrication and assembly technique.
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| 7. |
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| 8. |
- Rahiminejad, Sofia, 1987, et al.
(författare)
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Polymer Gap Adapter for Contactless, Robust, and Fast Measurements at 220-325 GHz
- 2016
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Ingår i: Journal of Microelectromechanical Systems. - : Institute of Electrical and Electronics Engineers (IEEE). - 1057-7157 .- 1941-0158. ; 25:1, s. 160-169
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Tidskriftsartikel (refereegranskat)abstract
- Radiation leakages are a considerable problem when measuring waveguide structures at high frequencies. In order to maintain good electrical contact, flanges need to be tightly and evenly screwed to the device under test. This can be a time-consuming operation, especially with repeated measurements. We present a metamaterial-based adapter, which prohibits leakage even in the presence of gaps at the interconnects. This so-called gap adapter has been fabricated from a metallized polymer (SU8). The reflection coefficient is below -20 dB throughout the band for a 50-mu m gap on both sides of the gap adapter. In comparison, a conventional waveguide with a 50-mu m gap on both sides has a reflection coefficient of -10 dB. The gap adapter can be used to perform fast measurements, since the normal flange screws are redundant. We compare the SU8 gap adapter with a Si version and to a smooth metal waveguide reference disc. The SU8 gap adapter performed better than the Si version and much better than the waveguide disc in all test cases. SU8 gap adapters were used to measure on a waveguide component. The SU8 gap adapters with 50-mu m gaps performed comparable with the waveguide component with the flange screws carefully tightened. The polymer also makes the gap adapter mechanically robust and easy to mass fabricate. [2015-0113]
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| 9. |
- Uz Zaman, Ashraf, 1975, et al.
(författare)
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Increasing parallel plate stop-band in gap waveguides using inverted pyramid-shaped nails for slot array application above 60GHz
- 2011
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Ingår i: Proceedings of the 5th European Conference on Antennas and Propagation, EUCAP 2011. Rome, 11-15 April 2011. - 9788882020743 ; , s. 2254-2257
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Konferensbidrag (refereegranskat)abstract
- This paper presents a proposal for a slot array antenna for frequencies above 60 GHz. Also, The array is using the new air gap waveguide as a feeding structure. Here we present a new structure for the parallel plate stop-band based on replacing the uniform cross sectional nails with inverted pyramidal shaped pins. This new type of pin is more suitable for micromachining and manufacturing of gap waveguides above 60 GHz. The wider parallel-plate bandwidth achieved with this new type of pins makes it suitable for integration of very wideband active MMIC circuit with gap waveguide without package resonance problem. Once the RF circuitry is integrated with gap waveguide, the slot arrays can be easily built by having slots on the top metal wall of the gap waveguide thus enabling low cost integrated antenna solution at frequencies above 60GHz.
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| 10. |
- Uz Zaman, Ashraf, 1975, et al.
(författare)
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Millimeter Wave E-Plane Transition From Waveguide to Microstrip Line With Large Substrate Size Related to MMIC Integration
- 2016
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Ingår i: IEEE Microwave and Wireless Components Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 1558-1764 .- 1531-1309. ; 26:7, s. 481-483
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Tidskriftsartikel (refereegranskat)abstract
- This letter demonstrates a packaging concept where a waveguide-to-microstrip transition can be assimilated on a mm-wave MMIC of an arbitrary size and thus avoid the use of bond wires at the high frequency ports of the MMIC circuit. The advantage of the proposed concept is that-it does not require an extra substrate with sub-critical dimensions for the waveguide-to-microstrip transition. The transition can be integrated onto the MMIC, and thus the MMIC can be coupled directly to the waveguide. A Perfect Magnetic Conductor (PMC) surface is used to suppress the unwanted waveguide mode coupling to the oversized circuit cavity. The measured back-to-back transition works over the frequency band 66-98 GHz (relative BW of 38%) with minimum return loss of 12.7 dB. The total insertion loss of the manufactured prototype is found to be 3.26 dB, which also includes a 14.8 mm long microstrip line on an Alumina substrate. The losses in a single transition vary between 0.25 and 0.42 dB.
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