| 1. |
|
|
| 2. |
- Baghchehsaraei, Zargham, et al.
(författare)
-
MEMS 30μm-thick W-band waveguide switch
- 2012
-
Ingår i: European Microwave Week 2012. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 1055-1058, s. 675-678, s. 1055-1058
-
Konferensbidrag (refereegranskat)abstract
- This paper presents for the first time a novel concept of a MEMS waveguide switch based on a reconfigurable surface, whose working principle is to short-circuit or to allow for free propagation of the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. This transmissive surface is only 30μm thick and consists of up to 1260 reconfiguring cantilevers in the waveguide cross-section, which are moved simultaneously by integrated MEMS comb-drive actuators. For the first fabrication run, the yield of these reconfigurable elements on the chips was 80-86%, which still was good enough for resulting in a measured insertion loss in the open state of better than 1dB and an isolation of better than 20dB for the best designs, very wideband from 62 to 75GHz. For 100% fabrication yield, HFSS simulations predict that an insertion loss in the open state of better than 0.1dB and an isolation of better than 30dB in the closed state are possible for designs with 800 and more contact points for this novel waveguide switch concept.
|
|
| 3. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
A CPW Probe to Rectangular Waveguide Transition for On-wafer Micromachined Waveguide Characterization
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- A new transition from coplanar waveguide probe to micromachined rectangular waveguide for on-wafer device characterization is presented in this article. The transition is fabricated in the same double H-plane split silicon micromachined waveguide technology as the devices under test, requiring no additional post-processing or assembly steps. We outline the design and fabrication process of the transition for the frequency band of 220 – 330 GHz. A coplanar waveguide structure acts as the probing interface, with an E-field probe protruding in the waveguide cavity exciting the fundamental waveguide mode. Guard structures around the E-field probe increase the aspect ratio during deep reactive ion etching and secure its geometry. A full equivalent circuit model is provided by analyzing its working principle. RF characterization of fabricated devices is performed for both single-ended and back-to-back configurations. Measured S-parameters of the single-ended transition are obtained by applying a two-tiered calibration and are analyzed using the equivalent circuit model. The insertion loss of the single-ended transition lies between 0.3 dB and 1.5 dB over the whole band, with the return loss in excess of 8 dB. In addition to previously reported characterization of a range of devices under test the viability of the transition for on-wafer device calibration is demonstrated by characterizing a straight waveguide line, achieving an insertion loss per unit length of 0.02 – 0.08 dB/mm in the frequency band of 220 – 330 GHz.
|
|
| 4. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
A CPW Probe to Rectangular Waveguide Transition for On-Wafer Micromachined Waveguide Characterization
- 2024
-
Ingår i: IEEE Transactions on Terahertz Science and Technology. - : Institute of Electrical and Electronics Engineers (IEEE). - 2156-342X .- 2156-3446. ; 14:1, s. 98-108
-
Tidskriftsartikel (refereegranskat)abstract
- A new transition from coplanar waveguide probe to micromachined rectangular waveguide for on-wafer device characterization is presented in this article. The transition is fabricated in the same double H-plane split silicon micromachined waveguide technology as the devices under test, requiring no additional post-processing or assembly steps. We outline the design and fabrication process of the transition for the frequency band of 220–330 GHz. A coplanar waveguide structure acts as the probing interface, with an E-field probe protruding in the waveguide cavity exciting the fundamental waveguide mode. Guard structures around the E-field probe increase the aspect ratio during deep reactive ion etching and secure its geometry. A full equivalent circuit model is provided by analyzing its working principle. RF characterization of fabricated devices is performed for both single-ended and back-to-back configurations. Measured S-parameters of the single-ended transition are obtained by applying a two-tiered calibration and are analyzed using the equivalent circuit model. The insertion loss of the single-ended transition lies between 0.3 dB and 1.5 dB over the whole band, with the return loss in excess of 8 dB. In addition to previously reported characterization of a range of devices under test the viability of the transition for on-wafer device calibration is demonstrated by characterizing a straight waveguide line, achieving an insertion loss per unit length of 0.02–0.08 dB/mm in the frequency band of 220–330 GHz.
|
|
| 5. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
A Very Low Loss 220–325 GHz Silicon Micromachined Waveguide Technology
- 2018
-
Ingår i: IEEE Transactions on Terahertz Science and Technology. - : IEEE. - 2156-342X .- 2156-3446. ; 8:2, s. 248-250
-
Tidskriftsartikel (refereegranskat)abstract
- This letter reports for the first time on a very low loss silicon micromachined waveguide technology, implemented for the frequency band of 220–325 GHz. The waveguide is realized by utilizing a double H-plane split in a three-wafer stack. This ensures very low surface roughness, in particular on the top and bottom surfaces of the waveguide, without the use of any surface roughness reduction processing steps. This is superior to previous micromachined waveguide concepts, including E-plane and single H-plane split waveguides. The measured average surface roughness is 2.14 nm for the top/bottom of the waveguide, and 163.13 nm for the waveguide sidewalls. The measured insertion loss per unit length is 0.02–0.07 dB/mm for 220–325 GHz, with a gold layer thickness of 1 μm on the top/bottom and 0.3 μm on the sidewalls. This represents, in this frequency band, the lowest loss for any silicon micromachined waveguide published to date and is of the same order as the best metal waveguides.
|
|
| 6. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
Integrated Micromachined Waveguide Absorbers at 220 – 325 GHz
- 2017
-
Ingår i: Proceedings of the 47th European Microwave Conference, Nuremberg, October 8-13, 2017. - 9782874870477 ; , s. 695-698
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the characterization of integrated micromachined waveguide absorbers in the frequency band of 220 to 325 GHz. Tapered absorber wedges were cut out of four different commercially available semi-rigid absorber ma terials and inserted in a backshorted micromachined waveguide cavity for characterization. The absorption properties of these materials are only specified at 10 GHz, and their absorption behavior above 100 GHz was so far unknown. To study the effect of the geometry of the absorber wedges, the return loss of different absorber lengths and tapering angles was investigated. The results show that longer and sharper sloped wedges from the material specified with the lowest dielectric constant, but not the highest specified absorption, are superior over other geometries and absorber materials. The best results were achieved for 5 mm long absorbers with a tapering angle of 23° in the material RS-4200 from the supplier Resin Systems, having a return loss of better than 13 dB over the whole frequency range of 220 to 325 GHz. These absorber wedges are intended to be used as matched loads in micromachined waveguide circuits. To the best of our knowledge, this is the first publication characterizing such micromachined waveguide absorbers.
|
|
| 7. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
Integrating InP MMICs and Silicon Micromachined Waveguides for sub-THz Systems
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220–330 GHz in a back-to-back configuration. Measured insertion loss is 3–6 dB at 250–300 GHz, and return loss is in excess of 5 dB.
|
|
| 8. |
- Beuerle, Bernhard, et al.
(författare)
-
Integrating InP MMICs and Silicon Micromachined Waveguides for Sub-THz Systems
- 2023
-
Ingår i: IEEE Electron Device Letters. - : Institute of Electrical and Electronics Engineers (IEEE). - 0741-3106 .- 1558-0563. ; 44:10, s. 1800-1803
-
Tidskriftsartikel (refereegranskat)abstract
- A novel co-designed transition from InP monolithic microwave integrated circuits to silicon micromachined waveguides is presented. The transition couples a microstrip line to a substrate waveguide sitting on top of a vertical waveguide. The silicon part of the transition consists of a top and a bottom chip, fabricated in a very low-loss silicon micromachined waveguide technology using silicon on insulator wafers. The transition has been designed, fabricated and characterized for 220 GHz to 330 GHz in a back-to-back configuration. Measured insertion loss is 3 dB to 6 dB at 250 GHz to 300 GHz , and return loss is in excess of 5 dB.
|
|
| 9. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
Low-Loss Silicon Micromachined Waveguides Above 100 GHz Utilising Multiple H-plane Splits
- 2018
-
Ingår i: Proceedings of the 48th European Microwave Conference, Madrid, October 1-3, 2018. - : Institute of Electrical and Electronics Engineers (IEEE). - 9782874870514 ; , s. 1041-1044
-
Konferensbidrag (refereegranskat)abstract
- For sub-millimeter and millimeter wave applications rectangular waveguides are an ideal transmission medium. Compared to conventional, metal-milled rectangular waveguides, silicon micromachined waveguides offer a number of advantages. In this paper we present a low-loss silicon micromachined waveguide technology based on a double H-plane split for the frequency bands of 110 – 170 GHz and 220 – 330 GHz. For the upper band a reduced height waveguide is presented, which achieves a loss per unit length of 0.02 – 0.10 dB/mm. This technology has been further adapted to implement a full height waveguide for the lower frequency band of 110 – 170 GHz. The full height waveguide takes advantage of the benefits of the double H-plane split technique to overcome the challenges of fabricating micromachined waveguides at lower frequencies. With measured insertion loss of 0.007 – 0.013 dB/mm, averaging 0.009 dB/mm over the whole band, this technology offers the lowest insertion loss of any D-band waveguide to date. The unloaded Q factor of the D-band waveguide technology is estimated to be in excess of 1600, while a value of 750 has been measured for the reduced height upper band waveguide.
|
|
| 10. |
- Beuerle, Bernhard, 1983-, et al.
(författare)
-
Micromachined Waveguides with Integrated Silicon Absorbers and Attenuators at 220–325 GHz
- 2018
-
Ingår i: IEEE MTT-S International Microwave Symposium, IEEE conference proceedings, 2018. - : IEEE.
-
Konferensbidrag (refereegranskat)abstract
- This paper reports for the first time on micromachined waveguides with integrated micromachined silicon absorbers. In contrast to epoxy-based microwave absorbers, micromachined lossy silicon absorbers are fully compatible with high temperature fabrication and assembly processes for micromachined waveguides. Furthermore, micromachining enables the fabrication of exact, near ideal taper tips for the silicon absorbers, whereas the tip of epoxy-based absorbers cannot be shaped accurately and reproducibly for small waveguides. Silicon of different conductivity is a very well understood and characterized dielectric material, in contrast to conventional absorber materials which are not specified above 60 GHz. Micromachined silicon waveguides with integrated absorbers and attenuators were designed, fabricated and characterized in the frequency band of 220 – 325 GHz. The return and insertion loss for various taper-geometry variations of double-tip tapered absorbers and attenuators was studied. The average return loss for the best investigated device is 19 dB over the whole band. The insertion loss of the two-port attenuators is 16 – 33 dB for different designs and shows an excellent agreement to the simulated results. The best measured devices of the one-port absorbers exhibit an average and worst-case return loss of 22 dB and 14 dB, respectively, over the whole band. The return loss is not characterized by a good simulation-measurement match, which is most likely attributed to placement tolerances of the absorbers in the waveguide cavities affecting the return but not the insertion loss.
|
|
