Papers by Keyword: RF

Abstract: This paper presents results from metal contact processing experiments towards the implementation of durable 500 °C high-frequency 4H-SiC bipolar junction transistors (BJTs). Specifically, p-type ohmic contacts have been demonstrated on a 0.25 μm-thick p-type homoepitaxial layer of doping 8 × 10¹⁸ ± 4 × 10¹⁸ cm^-3. Finally, preliminary current-voltage characteristics of fabricated BJTs are presented.

Abstract: Wide bandgap semiconductors, such as 4H SiC, are suitable for power regulating devices, due to compatibility with conventional process integration, high breakdown voltage and thermal conductivity [1]. For RF applications, in order to achieve better switching speed, high cut off frequency, and low series resistance (Rdson), it is essential to choose the right gate metals [2]. Engineering of the gate metals not only improves the critical device parameters by adjustment of the metal workfunction, but also affects how the high aspect ratio trenches are filled for a next generation SIT device configuration [3] - [5].

Abstract: The application of embedded speech recognition technology in the smart home is researched, combining of the Internet of Things, the voice control system for smart home has been designed. The core processor chooses the high-performance Cortex-M4 MCU STM32F407VGT6 produced by STMicroelectronics. The system contains a hardware unit based on LD3320 for speaker-independent speech recognition. RF wireless communication uses ultra-low power chip CC1101 and GSM employ SIM900A. Real-time operating system FreeRTOS is used for multitask scheduling and the operation of household devices. The practical application verifies that this voice control system practicably can identify voice commands quickly and accurately, complete the control actions primely, has a wide application prospect.

Abstract: Because of difficulty in deep ion implantation, the recessed gate structure has been favored in SiC SIT. In order to improve the frequency, it is a good method to decrease the gate length by eliminating the side wall ion implantation affection. We developed normally-on RF 4H-SiC SIT with high small signal gain. The effect of forming the side wall protection between the source mesa and the gate area was simulated

Abstract: This thesis takes AIO (All-In-One) type of RF-EAS systems as the object, to study how to improve its anti-interference performance. Interference noise in the article is divided into two types, which are steady noise and transient noise. According to the characteristics of different interference noises, their impacts on all aspects of the system are fully analyzed, and then, we give a series of targeted hardware and software measures. Finally in this paper, the adaptability of the system is studied, and we presented a feasible way to improve the anti-interference ability and stability of the system.

Abstract: Wireless sensor network (WSN) is the network which is composed of a large number of intelligent sensor nodes, it has the ability of self-organizing network routing, therefore, it has been widely used. Building wireless sensor networks is the key to WSN nodes. This paper introduces the basic structure of wireless sensor network node based on ARM, and it delivers a detailed analysis on the operating features and the CC2480 hardware interface of the ZigBee processor, what’s more, it specifically talks about the implementation of the Wince driver of WSN nodes.

Abstract: Currently, micro-power wireless communication technology used in power user electrical energy data acquire system have some problems such as transport distance, power, data rate, antenna length, interaction (standard), deployment environment, stray radiation and so on. This paper proposed a micro-power wireless communication module which meets the State Grid Corporation of China Enterprise Standard Q/GDW 1374.3-2013 was designed by the author,and the key technology and major problems were researched and analyzed.

Abstract: This paper an analysis of the present teaching of electric control system of the office building,the use of RF wireless communication technology combined with single chip microcomputer, using infrared technology, through the central control room for the entire teaching office lights and other electrical equipment for centralized, reasonable control; to ensure the stability of the system.

Abstract: The design and analysis of Ku-band ladder-type filters based on film bulk acoustic wave resonator (FBAR) is presented. The proposed FBAR filter has an insertion loss of-3dB, out-of-band rejection of-12dB, centre frequency of 15.5GHz with 3dB bandwidth of 1.0GHz. Based on the characteristics of the FBAR filter, the expected characteristics of FBAR resonators are determined by using the Butterworth Van Dyke (BVD) equivalent circuit.

Abstract: In this paper, the general theory and polarization property of RB in single mode fiber is discussed. According to the theoretical analysis results, the bidirectional carrying system with a polarization rotating device for analog radio frequency (RF) signal is set up. The relationship of the system CRN and the different polarization state by the polarization rotating device is studied. The results show that the RB light polarization state of backward fiber end can keep to perpendicular to that of forward light when backward lights polarization is orthogonal forward lights polarization. So utilizing orthogonal polarization method for decreasing CRN can be carried on. The system performance is analyzed by simulation. The simulation results show that CRN of the bidirectional communication system on a single mode fiber can be inhibited by using the method and RB light can decrease by an order of magnitude.