亚毫米波高次谐波混频检测远红外激光

用光学和微波技术设计了一种交叉波导结构的肖特基势垒二极管(S.B.D.)亚毫米波高次谐波混频器,成功地应用于远红外激光检测及其谱线频率的精密测量,并获得满意的结果。     

基于肖特基二极管的670 GHz四次谐波混频器设计

常温固态太赫兹谐波混频器是太赫兹系统应用中的关键器件。介绍了一款基于肖特基二极管的670 GHz四次谐波混频器的仿真与设计。在高频结构仿真软件(HFSS)中对准垂直结构肖特基势垒变阻二极管进行三维结构建模,采用基于谐波平衡算法的整体综合仿真方法对混频器进行仿真和优化。结果表明：在功率为10 mW的167 GHz本振信号驱动下,混频器单边带变频损耗在637~697 GHz射频频率范围内小于13.8 dB,3 dB变频损耗带宽为60 GHz;最优单边带变频损耗在679 GHz为10.6 dB。     

3mm波段四次谐波混频器阵的研究

采用微带结构研制出3毫米波段8路四次谐波混频器阵。该混频器核心器件采用型号为MS8251的GaAs梁式引线肖特基势垒二极管对。设计了一种便于组阵结构的四次谐波混频器,把混频器分解为反向二极管对模块和双工器模块。反向二极管对模块和双工器模块电路分别设计和安装在厚度为0.127mm和0.254mm的RT/Duriod 5880基片上。实测混频器的最低变频损耗为17dB。     

基于肖特基二极管的四次谐波混频器

针对冰云探测设备的预研,详细介绍了一款基于肖特基二极管的低变频损耗670 GHz四次谐波混频器.为了提升混频效率,采用两级紧凑微带共振单元（CMRC）本振低通滤波器来抑制射频信号、本振三次谐波及二次谐波混频产物.由于本振频率仅为射频频率的四分之一,大大降低了本振链路的复杂度和成本.测试结果表明,在640~700 GHz频带内单边带变频损耗为16.7~22.1 dB,在665 GHz最优单边带变频损耗为16.8 dB.     

利用三次谐波的射频放大电路

文章简要介绍利用三次谐波的射频放大电路提高电子管屏极效率的原理以及改进后的电路。     

基于T形阳极GaAs肖特基二极管薄膜集成电路工艺的664 GHz次谐波混频器

报道了用于冰云探测的基于0.5 μm T形阳极砷化镓肖特基二极管薄膜集成电路工艺664 GHz次谐波混频器。为降低器件寄生参数,提升太赫兹频段电路性能,设计并分析了了T形阳极GaAs SBD器件结构,开发了厚度仅5 μm的薄膜电路工艺。混频器芯片组装成664 GHz接收模块,经测试室温下664 GHz最小双边带变频损耗达到 9.9 dB。     

220GHz 次谐波混频器设计

本文介绍了一种基于平面肖特基势垒二极管的220GHz 次谐波混频器的设计。该混频器采用Teratech 公司的反 向并联二极管对,安装在0.05mm 厚的石英基片悬置微带上。采用HFSS 和ADS 联合仿真,使得混频器在射频频率为 215GHz~225GHz 范围内仿真所得变频损耗低于8dB,并在219GHz 时取得最佳变频损耗6.75dB。该混频器具有结构简单, 易于加工,变频损耗低的优点。     

330 GHz高性能二次谐波混频器设计

采用反向并联肖特基二极管对设计了一种330 GHz二次谐波混频器。混频器电路采用微带结构,使用波导-微带探针耦合的形式进行过渡;采用50 μm厚的石英作为基板,有效减小了电路体积;采用HFSS和ADS对电路进行仿真和谐波平衡仿真。仿真结果显示,混频器在310~350 GHz范围内的变频损耗优于9.5 dB,所需本振(LO)功率为3 dBm,有效降低了对本振的要求。     

四次谐波级联二阶非线性效应传输特性数值分析

得到四次谐波多级级联二阶非线性耦合方程的近似解析解.数值分析了各参数对基波非线性相移、二次谐波和四次谐波功率的影响.     

基于肖特基二极管的宽带低本振功率太赫兹四次谐波混频器

介绍了基于反向并联肖特基二极管的宽带低驱动功率太赫兹四次谐波混频器。详细地分析了二极管寄生参量与混频器性能间的关系。为了降低四次谐波混频器的最佳本振功率,对肖特基二极管的主要参数进行了优化。实际测试结果显示,在 7 mW 的最佳本振功率驱动下,该四次谐波混频器在 340 - 490 GHz的宽带内,变频损耗在 14.2 - 20 dB 之间。同时,该频段内的混频器噪声温度为 4020 ~ 17100 K。     

基于平面肖特基二极管的毫米波固定调节式谐波混频器

基于GaAs肖特基势垒二极管,研制出了两个不同波段的谐波混频器。在场仿真软件中,二极管的非线性结采用lumped端口来模拟,通过场分析方法分析二极管各端口的阻抗。谐波混频电路被分成不同部分来单独优化设计,基于优化设计的各独立电路,建立谐波混频器的整体场仿真模型,通过提取相应的S参数文件分析混频器的变频损耗。150GHz 谐波混频器测得最低变频损耗10.7dB,在135-165GHz变频损耗典型值为12.5dB。180GHz 谐波混频器测得最低变频损耗5.8dB,在165-200GHz变频损耗典型值为13.5dB,在210-240GHz变频损耗典型值为11.5dB。     

A novel general approach for the optimum design of microwave andmillimeter wave subharmonic mixers

The design of subharmonic mixers is complicated and involves separation of signals and application of correct loading at the important idler frequencies. In this paper we present a novel general approach, which enables the designer to establish the optimum loading conditions for the different signals to get low conversion loss and good matching simultaneously. The method is demonstrated by a design example using a 30 GHz X2 subharmonic mixer. In this example it is shown that a nonoptimal design can yield conversion loss of up to 13.5 db, while an optimal design yields a conversion loss of 3.6 db     

Ka波段对极鳍线混频器和检波器设计

This paper mainly discusses the analysis and design of a finline single-ended mixer and detector. In the circuit, for the purpose of eliminating high-order resonant modes and improving transition loss, metallic via holes are implemented along the mounting edge of the substrate embedded in the split-block of the WG-finline-microstrip transition. Meanwhile, a Ka band slow-wave and bandstop filter, which represents a reactive termination, is designed for the utilization of idle frequencies and operation frequencies energy. Full-wave analysis is carded out to optimize the input matching network of the mixer and the detector circuit using lumped elements to model the nonlinear diode. The exported S-matrix of the optimized circuit is used for conversion loss and voltage sensitivity analysis. The lowest measured conversion loss is 3.52 dB at 32.2 GHz; the conversion loss is flat and less than 5.68 dB in the frequency band of 29-34 GHz. The highest measured zero-bias voltage sensitivity is 1450 mV/mW at 38.6 GHz, and the sensitivity is better than 1000 mV/mW in the frequency band of 38-40 GHz.     

Design of Ka-band antipodal finline mixer and detector

This paper mainly discusses the analysis and design of a finline single-ended mixer and detector. In the circuit, for the purpose of eliminating high-order resonant modes and improving transition loss, metallic via holes are implemented along the mounting edge of the substrate embedded in the split-block of the WG-finline-microstrip transition. Meanwhile, a Ka band slow-wave and bandstop filter, which represents a reactive termination, is designed for the utilization of idle frequencies and operation frequencies energy. Full-wave analysis is carried out to optimize the input matching network of the mixer and the detector circuit using lumped elements to model the nonlinear diode. The exported S-matrix of the optimized circuit is used for conversion loss and voltage sensitivity analysis.The lowest measured conversion loss is 3.52 dB at 32.2 GHz; the conversion loss is flat and less than 5.68 dB in the frequency band of 29-34 GHz. The highest measured zero-bias voltage sensitivity is 1450 mV/mW at 38.6 GHz,and the sensitivity is better than 1000 mV/mW in the frequency band of 38-40 GHz.     

340GHz 四次谐波混频器的研制

太赫兹波是电磁波谱中最后一个未被全面研究开发的频率窗口,它的开发和利用具有重大的科学价值。介绍了一种太赫兹频段内340GHz基于肖特基势垒二极管的四次谐波混频器设计。应用高频场仿真软件(HFSS)以及谐波平衡仿真软件(ADS),对反向并联二极管对进行3D建模及阻抗频率特性分析,并在此基础上对混频器进行优化。最后,对该混频器进行加工和测试,结果表明,在327~343GHz频带范围内,变频损耗小于15dB,最优值为12.7dB。     

X波段低变频损耗混频器设计

采用商用肖特基势垒二极管HSMS-2822,研制了低变频损耗、高隔离度X波段单平衡混频器。为实现所需要的混频带宽,本振信号和射频信号采用三分支定向耦合器耦合输入,仿真研究表明其能有效地改善工作频率带宽,提高本振端口与射频端口间的隔离度。通过设计合理的空闲频率回收电路,回收利用空闲频率能量,能有效地降低混频器变频损耗,提高本振信号、射频信号及空闲频率信号到中频端口的隔离度。在10.6GHz,测得最小变频损耗5.67dB;在10～11.5GHz,混频器变频损耗为6.4±0.7dB,变频损耗平坦度好,RF-IF隔离度优于27dB,LO-IF隔离度高于24dB,LO-RF隔离度优于14dB。     

A seamless context-aware architecture for fourth generation wireless networks

The integration of a multitude of wireless networks is expected to lead to the emergence of the fourth generation (4G) of wireless technologies. Under the motivation of increasing the levels of user satisfaction while maintaining seamless connectivity and a satisfactory level of QoS, we design a novel cross-layer architecture that provides context-awareness, smart handoff and mobility control in heterogeneous wireless IP networks. We develop a Transport and Application Layer Architecture for vertical Mobility with Context-awareness (Tramcar). Tramcar presents a new approach to vertical handoff decisions, which is not exclusively based on network characteristics but also on higher level parameters which fall in the application and transport layers. Tramcar is tailored for a variety of different network technologies with different characteristics and has the ability of adapting to changing environment conditions and unpredictable background traffic. Furthermore, Tramcar allows users to identify and prioritize their preferences. Tramcar is a smart and practical system, which is more capable of dealing with 4G challenges. Simulation results demonstrate that Tramcar increases user satisfaction levels and network throughput under rough network conditions and reduces overall handoff latencies.     

一种用于高速QPSK解调的四次方环载波恢复电路

为解决高速QPSK信号全数字解调的技术瓶颈问题,采用模拟方案,研制了一种四次方环载波恢复电路,重点介绍了应用混频器上变频特性的宽带平方电路以及锁相环(PLL)载波提取电路的设计过程.测试结果表明,该载波恢复电路可以完成载频为720 MHz、码速率100 Mbit/s～1 Gbit/s范围的QPSK信号同步载波恢复,解决了高速信号相干解调中载波同步的关键技术问题.     

A novel interface circuit for triboelectric nanogenerator

For most triboelectric nanogenerators (TENGs), the electric output should be a short AC pulse, which has the common characteristic of high voltage but low current. Thus it is necessary to convert the AC to DC and store the electric energy before driving conventional electronics. The traditional AC voltage regulator circuit which commonly consists of transformer, rectifier bridge, filter capacitor, and voltage regulator diode is not suitable for the TENG because the transformer''s consumption of power is appreciable if the TENG output is small. This article describes an innovative design of an interface circuit for a triboelectric nanogenerator that is transformerless and easily integrated. The circuit consists of large-capacity electrolytic capacitors that can realize to intermittently charge lithium-ion batteries and the control section contains the charging chip, the rectifying circuit, a comparator chip and switch chip. More important, the whole interface circuit is completely self-powered and self-controlled. Meanwhile, the chip is widely used in the circuit, so it is convenient to integrate into PCB. In short, this work presents a novel interface circuit for TENGs and makes progress to the practical application and industrialization of nanogenerators.