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Author

Xiaobang Shang

Other affiliations: University of Birmingham
Bio: Xiaobang Shang is an academic researcher from National Physical Laboratory. The author has contributed to research in topics: Waveguide filter & Band-pass filter. The author has an hindex of 17, co-authored 81 publications receiving 1019 citations. Previous affiliations of Xiaobang Shang include University of Birmingham.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, two W-band waveguide bandpass filters were fabricated using laser micromachining and 3-D printing techniques, one fabricated from a single metal workpiece and the other from polymer resin.
Abstract: This paper presents two W-band waveguide bandpass filters, one fabricated using laser micromachining and the other 3-D printing. Both filters are based on coupled resonators and are designed to have a Chebyshev response. The first filter is for laser micromachining and it is designed to have a compact structure allowing the whole filter to be made from a single metal workpiece. This eliminates the need to split the filter into several layers and therefore yields an enhanced performance in terms of low insertion loss and good durability. The second filter is produced from polymer resin using a stereolithography 3-D printing technique and the whole filter is plated with copper. To facilitate the plating process, the waveguide filter consists of slots on both the broadside and narrow side walls. Such slots also reduce the weight of the filter while still retaining the filter’s performance in terms of insertion loss. Both filters are fabricated and tested and have good agreement between measurements and simulations.

114 citations

Journal ArticleDOI
TL;DR: In this paper, a 5-band waveguide bandpass filter based on spherical resonators has been designed, and fabricated by 3-D printing, and a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection.
Abstract: A fifth order X-band waveguide bandpass filter, based on spherical resonators, has been designed, and fabricated by 3-D printing. In comparison with rectangular waveguide, spherical resonators have a higher unloaded quality factor, but at the same time suffer from closer higher order modes. In this letter, a special topology has been proposed to relieve the impact of the first three higher order modes in the resonator and ultimately to achieve a good out-of-band rejection. Stereolithography based 3-D printing is used to build the filter structure from polymer and a 25 $\mu{\rm m}$ thick copper layer is deposited to the filter. The measurement result of the filter has an excellent agreement with the simulations. The filter is also considerably lighter than a similar metal filter.

109 citations

Journal ArticleDOI
TL;DR: In this article, a two-layer SU8 photoresist micromachining technology was demonstrated in the WR-3 band (220-325 GHz) and three different waveguide circuits, namely, a straight-through waveguide, a bandpass filter and a dual-band filter, were demonstrated.
Abstract: This paper demonstrates a two-layer SU8 photoresist micromachining technology that has similar performance to conventionally machined metal. The technology is demonstrated in the WR-3 band (220-325 GHz). Three different WR-3 band circuits, namely a WR-3 band straight through waveguide, a bandpass filter and a dual-band filter are demonstrated. For the measurements, a conventionally precision machined metal block was used for the WR-3 band waveguide and the bandpass filter to achieve good calibration and accurate interconnection with standard waveguide flanges; whereas, for the dual-band filter, two back-to-back right-angle bends are added in order to achieve accurate, reliable waveguide interconnection without using the metal block. A measured average insertion loss of 0.03 dB/mm has been achieved for the 14.97 mm long straight through waveguide. This is comparable to the loss of around 0.02 dB/mm for a standard metal waveguide at this frequency. The fifth-order waveguide filter exhibits an 8% 3 dB bandwidth at a central frequency of around 300 GHz. The minimum passband insertion loss was measured to be around 1 dB and the return loss was better than 10 dB throughout the passband. The filter results showed a notable improvement over those obtained from the separate SU8 layer technique that was also used to make the same devices for comparison. To further demonstrate the advantages of the new two-layer SU8 micromachining technique, the dual-band filter included isolated regions in the waveguide channels that would have not been possible for micromachining using the previous separate single layer technique. The performance of the micromachined dual band filter was excellent in terms of very low insertion losses on both passbands.

109 citations

Journal ArticleDOI
TL;DR: In this article, a 3D printed fourth-order cavity bandpass filter (BPF) with a 3% fractional bandwidth is presented, which was designed using two high- $Q$ spherical dual-mode cavity resonators and fabricated using a stereolithography-based 3D printing technique.
Abstract: A 3-D printed fourth-order cavity bandpass filter (BPF) centered at 10 GHz and with a 3% fractional bandwidth is presented in this letter. The BPF was designed using two high- $Q$ spherical dual-mode cavity resonators, and was fabricated using a stereolithography-based 3-D printing technique. Compared to dual-mode filters constructed by square or cylindrical resonators, the use of spherical resonator gives a wider spurious-free region. In order to fully exhibit the light weight advantage of additive manufacturing, the redundant material outside of the filter was removed. In addition, rectangular apertures were added through the cavities and waveguide walls without interrupting the surface current distributions, which further yields reduced filter weight as well as easier electroplating. Measured results of the BPF exhibit an excellent agreement with simulations.

91 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented two novel multiplexer topologies based on all-resonator structures, which remove the need for conventional transmission-line-based splitting networks.
Abstract: This paper presents two novel multiplexer topologies based on all-resonator structures. Such all-resonator structures remove the need for conventional transmission-line-based splitting networks. The first topology is a diplexer with transmission zeros in the guard band, shared by both channels. These transmission zeros are generated by introducing a cross coupling in a quadruplet in resonators common to both channels. A twelfth-order diplexer with a pair of transmission zeros is presented here as an example. The second topology is a multiplexer with a bifurcate structure that limits the connections to any resonator to three or less, regardless of the number of output channels. A sixteenth-order four-channel multiplexer is presented as an example. Both topologies have been demonstrated at X-band using waveguide technology. Good agreements between measurements and simulations have been achieved.

86 citations


Cited by
More filters
01 Jan 2017
TL;DR: The 2017 roadmap of terahertz frequency electromagnetic radiation (100 GHz-30 THz) as mentioned in this paper provides a snapshot of the present state of THz science and technology in 2017, and provides an opinion on the challenges and opportunities that the future holds.
Abstract: Science and technologies based on terahertz frequency electromagnetic radiation (100 GHz–30 THz) have developed rapidly over the last 30 years. For most of the 20th Century, terahertz radiation, then referred to as sub-millimeter wave or far-infrared radiation, was mainly utilized by astronomers and some spectroscopists. Following the development of laser based terahertz time-domain spectroscopy in the 1980s and 1990s the field of THz science and technology expanded rapidly, to the extent that it now touches many areas from fundamental science to 'real world' applications. For example THz radiation is being used to optimize materials for new solar cells, and may also be a key technology for the next generation of airport security scanners. While the field was emerging it was possible to keep track of all new developments, however now the field has grown so much that it is increasingly difficult to follow the diverse range of new discoveries and applications that are appearing. At this point in time, when the field of THz science and technology is moving from an emerging to a more established and interdisciplinary field, it is apt to present a roadmap to help identify the breadth and future directions of the field. The aim of this roadmap is to present a snapshot of the present state of THz science and technology in 2017, and provide an opinion on the challenges and opportunities that the future holds. To be able to achieve this aim, we have invited a group of international experts to write 18 sections that cover most of the key areas of THz science and technology. We hope that The 2017 Roadmap on THz science and technology will prove to be a useful resource by providing a wide ranging introduction to the capabilities of THz radiation for those outside or just entering the field as well as providing perspective and breadth for those who are well established. We also feel that this review should serve as a useful guide for government and funding agencies.

690 citations

Journal ArticleDOI
TL;DR: In this article, a novel kind of patch antenna with high-selectivity filtering responses and high-gain radiation performance is presented, which is mainly composed of a driven patch and a stacked patch, with its entire height being ${0.09\lambda }$.
Abstract: This paper presents a novel kind of patch antenna with high-selectivity filtering responses and high-gain radiation performance. The proposed antenna is mainly composed of a driven patch and a stacked patch, with its entire height being ${0.09\lambda }$ . Three shorting pins and a U-slot are embedded in the driven patch to enhance out-of-band suppression levels and skirt selectivity near the lower band-edge, whereas the stacked patch provides a sharp roll-off rate at the upper band-edge and also an enhanced gain. Without using extra filtering circuits, the proposed antenna exhibits a quasi-elliptic boresight gain response with three radiation nulls. For demonstration, an antenna is implemented covering the LTE band (2.3–2.7 GHz). The antenna achieves an average gain of 9.7 dBi within passband, and out-of-band suppression levels of more than 21 dB.

330 citations

Journal ArticleDOI
TL;DR: In this paper, 3D printed air-filled metal-pipe rectangular waveguides (MPRWGs) and 3D printing for microwave and millimeter-wave applications are investigated in detail.
Abstract: This paper first reviews manufacturing technologies for realizing air-filled metal-pipe rectangular waveguides (MPRWGs) and 3-D printing for microwave and millimeter-wave applications. Then, 3-D printed MPRWGs are investigated in detail. Two very different 3-D printing technologies have been considered: low-cost lower-resolution fused deposition modeling for microwave applications and higher-cost high-resolution stereolithography for millimeter-wave applications. Measurements against traceable standards in MPRWGs were performed by the U.K.’s National Physical Laboratory. It was found that the performance of the 3-D printed MPRWGs were comparable with those of standard waveguides. For example, across X-band (8–12 GHz), the dissipative attenuation ranges between 0.2 and 0.6 dB/m, with a worst case return loss of 32 dB; at W-band (75–110 GHz), the dissipative attenuation was 11 dB/m at the band edges, with a worst case return loss of 19 dB. Finally, a high-performance W-band sixth-order inductive iris bandpass filter, having a center frequency of 107.2 GHz and a 6.8-GHz bandwidth, was demonstrated. The measured insertion loss of the complete structure (filter, feed sections, and flanges) was only 0.95 dB at center frequency, giving an unloaded quality factor of 152—clearly demonstrating the potential of this low-cost manufacturing technology, offering the advantages of lightweight rapid prototyping/manufacturing and relatively very low cost when compared with traditional (micro)machining.

263 citations

Journal ArticleDOI
TL;DR: In this article, a review of the additive manufacturing of structural materials is presented, including multi-material additive manufacturing (MMa-AM), multi-modulus AM (MMo-AM) and multi-scale AM (MSc-AM).
Abstract: Additive manufacturing (AM), also known as three-dimensional (3D) printing, has boomed over the last 30 years, and its use has accelerated during the last 5 years AM is a materials-oriented manufacturing technology, and printing resolution versus printing scalability/speed trade-off exists among various types of materials, including polymers, metals, ceramics, glasses, and composite materials Four-dimensional (4D) printing, together with versatile transformation systems, drives researchers to achieve and utilize high dimensional AM Multiple perspectives of the AM of structural materials have been raised and illustrated in this review, including multi-material AM (MMa-AM), multi-modulus AM (MMo-AM), multi-scale AM (MSc-AM), multi-system AM (MSy-AM), multi-dimensional AM (MD-AM), and multi-function AM (MF-AM) The rapid and tremendous development of AM materials and methods offers great potential for structural applications, such as in the aerospace field, the biomedical field, electronic devices, nuclear industry, flexible and wearable devices, soft sensors, actuators, and robotics, jewelry and art decorations, land transportation, underwater devices, and porous structures

194 citations

Journal ArticleDOI
17 Nov 2017-Sensors
TL;DR: An overview of smart tactile sensing systems, with a focus on signal processing technologies used to interpret the measured information from tactile sensors and/or sensors for other sensory modalities.
Abstract: During the last decades, smart tactile sensing systems based on different sensing techniques have been developed due to their high potential in industry and biomedical engineering. However, smart tactile sensing technologies and systems are still in their infancy, as many technological and system issues remain unresolved and require strong interdisciplinary efforts to address them. This paper provides an overview of smart tactile sensing systems, with a focus on signal processing technologies used to interpret the measured information from tactile sensors and/or sensors for other sensory modalities. The tactile sensing transduction and principles, fabrication and structures are also discussed with their merits and demerits. Finally, the challenges that tactile sensing technology needs to overcome are highlighted.

179 citations