Papers by Keyword: Compact

Abstract: In this paper, a W-band dual-mode substrate integrated cavity fourth-order band-pass filter is presented, which utilizes LTCC technology. The filter is composed of two dual-mode resonators which are constructed by rows of via arrays in the substrate layer. Two coupling vias near particular diagonal corners are set to perturb the two degenerate modes in each cavity and thus to generate an intra-cavity coupling. The filter exhibits 3dB bandwidth about 2.4GHz, return loss better than 19dB and out of band rejection better than 30dB. The filter occupies the area of 3.752mm4.064mm (including the two feeding lines) in the LTCC substrate.

Abstract: In this paper, a novel coplanar waveguide (CPW)-fed and miniaturized slot antenna for triple-frequency operation is proposed and investigated, which is printed on a small 20mm×20mm FR4 substrate with thickness of 1.0 mm and relative permittivity of 4.3. Through loading different slits, three perfect operating bands of 2.4GHz-2.45GHz, 3.25GHz-4.15GHz and 5.05GHz-6.25GHz are achieved respectively, when return loss is less than-10dB. Experimental results show that the antenna gives monopole-like radiation patterns and good antenna gains over the operating bands. Such antennas is suitable for WLAN 2.4/5.2/5.8 GHz and WiMAX 3.5/5.5 GHz applications.

Abstract: In this paper, a compact differential dual-frequency antenna based on metamaterial is presented. To realize the dual-frequency operation of the left-handed and zeroth-order resonant modes, a ring slot and two diagonal slots are embedded in the radiating patch, and via holes are employed to connect the patch and the ground plane. In order to improve the impedance matching of the antenna, four corners are truncated in the ground plane. The proposed antenna has a compact size of 40 mm × 40 mm, which equals to 0.25 λ₁ × 0.25 λ₁ (λ₁, the guided wavelength at f₁). The simulated results show that the proposed antenna can operate at 0.89 and 1.79 GHz bands. Meanwhile, good radiation performances are achieved.

Abstract: In this paper, an Ultra-wide-band (UWB) filter based on composite right/left handed transmission line (CRLH TL) is presented. The structure of the proposed band-pass filter is quite simple, of which the size is 0.5cm×1.5cm. Left-handed capacitor is obtained by couple of microstrip lines, and Left-handed inductance is obtained by the grounded stub. The simulated results indicate that the pass band of UWB filter is 3.4-11GHz, the insertion loss is less than 1 dB and the return loss is smaller than -12.5dB. The performance of UWB filter could meet the requirement of UWB communication systems.

Abstract: This paper reviews principle and characteristics of the tennis serving machine and the tennis picking machine on the market. According to the actual situation, it intends to design a new type of tennis equipment for the tennis practitioners, which is named intelligent tennis vehicle. This machine consists of ball-storage mechanism, supply mechanism, serving mechanism, picking mechanism, frame and control circuit. This machine uses storage battery for the power supply, and it uses MCU (micro controller unit) as the controller, controlling all kinds of the mechanisms. It can help people to practice tennis, and pick up the large number of scattered tennis balls conveniently. This machine can meet the needs of different requirements, so that practitioners can better improve the tennis technology in order to achieve the purpose of fitness and training.

Abstract: Yamabe flow, curvature, tensor, compact. Abstract. This paper focuses a compact Riemannian manifold Mn evolving under the Yamabe flow and proves that if the Ricci curvature is uniformly bounded under the flow for all times that t from 0 to T and the injectivity radius is bounded below at each time slice, then the curvature tensor is uniformly bounded.

Abstract: This paper propose a new design of dual-band GPS microstrip antenna by spreading out the patches on the ground plane. With two independent patches, the antenna operates at two frequencies, which are available in different GPS systems. When patches are spread on the ground plane, the beam of radiation pattern shifts away and axial ratio degrades. In this design, two patches are printed on two independent substrates with a compact design, and positions of two antennas are optimized. Finally, above problems are solved with a conductive vaulted base. The design procedure is discussed, and optimized results are presented.

Abstract: Only by making intensive use of land to achieve highly compact, can a city achieve functional concentration and optimization to promote the urban sustainable development. To exploit urban underground space, the irreversibility of development should be considered and the guide rules and genre analysis of urban underground space development should be made with the emphasis on exploiting earth-covered construction, underground public buildings and underground complex.

Abstract: The corrosion behavior of lanthanum hexaboride (LaB6) in the environment containing H2S and CO2 was studied. The results show that the corrosion of LaB6 was severe when the environmental temperature and the partial pressure of H2S were high, and the corrosion would preferentially happen at the central part of the sample due to the lower compact of this part.

Abstract: Most of the ion implanter is large scale, high acceleration voltage and expensive. For research and development, such a huge implanter is not required. Our motivation is to make desktop type ion implanter for SiC device. We report the fabrication of a compact 100 kV ion implanter. In order to miniaturize the equipment, an ion source, an accelerator tube and a main chamber were vertically arranged. We implanted Argon (Ar) and Nitrogen (N) ions to 6H-SiC substrate and the implanted 6H-SiC substrates were characterized by Fourier Transform Infrared Spectrometer (FTIR), Rutherford Backscattering Spectrometry (RBS) and Secondary Ion Mass Spectrometry (SIMS). In this report, concept of desktop ion implanter, evaluation of implanted substrate and its device application are presented. In order to characterize capability, with using the newly made compact ion implanter, it was possible to make implantation on SiC to get amorphous layer suitable for deices.