Showing papers by "Yi Wang published in 2014"
TL;DR: In this article, the authors presented several freestanding bandpass mesh filters fabricated using an SU-8-based micromachining technique, where the important geometric feature of the filters, which SU8 is able to increase, is the thickness of the cross-shaped micromACHined slots.
Abstract: This paper presents several freestanding bandpass mesh filters fabricated using an SU-8-based micromachining technique. The important geometric feature of the filters, which SU8 is able to increase, is the thickness of the cross-shaped micromachined slots. This is five times its width. This thickness offers an extra degree of control over the resonance characteristics. The large thickness not only strengthens the structures, but also enhances the resonance quality factor ( Q-factor). A 0.3-mm-thick, single-layer, mesh filter resonant at 300 GHz has been designed and fabricated and its performance verified. The measured Q-factor is 16.3 and the insertion loss is 0.98 dB. Two multi-layer filter structures have also been demonstrated. The first one is a stacked structure of two single mesh filters producing a double thickness, which achieved a further increased Q-factor of 27. This is over six times higher than a thin mesh filter. The second multilayer filter is an electromagnetically coupled structure forming a two-pole filter. The coupling characteristics are discussed based on experimental and simulation results. These thick mesh filters can potentially be used for sensing and material characterization at millimeter-wave and terahertz frequencies.
41 citations
Proceedings Article•
10 Nov 2014TL;DR: In this paper, a traveling wave slotted waveguide antenna array based on micromachined layers operated in the WR-03 frequency band (220-325 GHz) is demonstrated.
Abstract: A design of travelling wave slotted waveguide antenna array based on micromachined layers operated in the WR-03 frequency band (220-325 GHz) is demonstrated in this paper. The antenna structure remains simple and is designed to be fabricated by using thick SU-8 photoresist technology. Instead of a matched load or a back-short at the termination of the waveguide, a novel H-plane bend followed by a radiating slot is integrated in order to minimise the power reflected to the input port and achieve the travelling wave operation. It also enables broadening of the bandwidth, and keeps the high gain value of the antenna. The 8-slot linear array antenna has shown a simulated gain of 13.5 dBi in the E-plane at 300 GHz, and 30% fractional bandwidth from 240 GHz to 325 GHz. The main beam scans in the H-plane, from -25° to -6°over the bandwidth. The scanning feature is attractive for radar applications.
6 citations
08 Dec 2014
TL;DR: In this paper, a double-feed patch antenna and a quadrature hybrid coupler were used to achieve circular polarisation and isolate the reflected signal from the incident, which showed a good agreement in terms of scattering parameters and radiation patterns.
Abstract: This paper presents a circularly polarised antenna for determining the speed of blood-flow, using Doppler effects at microwave frequencies. The structure consists of a double-feed patch antenna and a quadrature hybrid coupler in order to achieve circular polarisation and to isolate the reflected signal from the incident. The design was simulated and then fabricated. Both results were compared which showed a good agreement in terms of scattering parameters and radiation patterns.