Design of the Compact Dual-Band Bandpass Filter With High Isolation for GPS/WLAN Applications

In this letter, a novel compact dual-band bandpass filter (BPF) is designed to achieve the characteristic of low insertion loss and high isolation for global position system (GPS)/wireless local area network (WLAN) applications. This BPF is implemented by properly selecting the impedance ratio (R) and physical length ratio $(alpha)$ of the asymmetric stepped-impedance resonator (SIR) with one step discontinuity. The coupling coefficient between the coupled asymmetric SIRs is calculated by using full-wave simulator IE3D. The proposed filter has very good measured characteristics including a low insertion loss of 1.1 dB for both passbands, a high isolation insertion loss of 55 dB between the two passbands and a wide stopband rejection of 38 dB from 2.7 to 5.3 GHz. Good agreement with responses of electromagnetic (EM) simulation and measurement is compared.      

超低压CMOS混频器比较设计及特性分析

讨论并设计了基于PMOS衬底驱动技术和CMOS准浮栅技术的两种超低压CMOS混频器电路,并对混频器的特性进行了比较分析。在电源电压为O．8V,本征频率和射频频率分别是20MHz、100MHz和1GHz、2,4GHz的输入正弦信号时,衬底驱动混频器的转换增益为-17.95dB和-8．5dB,三阶输入截止点的值为33.2dB和28．4dB;在0．6V的单电源电压下,输入正弦信号分别为频率为20MHz、100MHz和1GHz、2．4GHz时,准浮栅混频器的转换增益为-14．23dB和-21．8dB,三阶输入截止点的值为35．9dB和34．6dB。仿真结果比较显示,衬底驱动混频器具有更高的转换增益,而准浮栅混频器具有更好的频域特性和低压特性。而且它们在频率较低时的性能更好。     

802.11b无线LAN功率放大器设计

随着无线局域网(WLAN)在办公室、家庭和公共场所（如：机场、宾馆、会议中心等)的广泛应用，同时．在基于802.11b无线通信网络标准元器件的支持下．这种网络正逐步成为企业通信的酋选择方案、IEEE802.11b为手提电脑或其它手持终端提供了一条接入网络资源的便利途径，从而增强了现有无线装置的功能，新一代WLAN无线收发装置将安装在与高密度     

Ka波段高效紧凑型功率放大器设计

提出了一种基于波导四路功分/合成器和波导—微带探针过度相结合的空间功率合成方案。使用波导定向耦合器实现双层两路合成器的紧凑连接,提高合成通道间的隔离度,减小合成链路间的耦合干扰。采用四只GaAs MMIC功放芯片,制作出高效率毫米波放大模块,在34GHz～36GHz频率范围内实现连续波15W饱和功率输出,合成效率高于95%,功率附加效率大于20%,在Ka波段实现了高效功率合成和大功率输出。     

Design of the Compact Parallel Coupled Wideband Bandpass Filter With Very High Selectivity and Wide Stopband

In this letter, a compact and high performance parallel coupled line wideband bandpass filter (PCL-WBF) with open stubs is designed and implemented on the commercial substrate, RT/Duroid 5880. The PCL-WBF is composed of a one-stage coupled line and two open stubs connected near the input/output ports. The design procedure and limit are discussed in detail. The designed filter was fabricated and measured, showing good characteristics of wide stopband and very high passband selectivity. Measured results also have a good agreement with the simulated results.     

6 ~ 18GHz 小型化低噪声放大器的设计

选用FUJITSU公司的GaAs HEMT管芯FHX13X,采用负反馈技术设计制作了一个小型化宽频带超低噪声放大器。利用ADS软件进行设计、优化和仿真,采用电阻负反馈改善电路频响特性,实现较好的输入输出匹配特性,同时引入电抗元件补偿管芯高频增益的下降,实现较好的动态特性。采用三级放大的电路结构形式实现了工作频率在6GHz～18GHz内,增益大于30dB,噪声系数小于1.5dB,1dB压缩点输出功率大于10dBm,带内平坦度为±2.0dB,输入输出驻波比<2。放大器的外形尺寸仅为10.9mm×9.8mm×2.7mm。     

Analysis and Design of a Novel Dual-Band Array Antenna With a Low Profile for 2400/5800-MHz WLAN Systems

A novel dual-band array antenna and its associated feed networks for 2400/5800-MHz wireless local area networks (WLAN) is proposed. The nested dual-band array is composed of a 2400-MHz band array formed by 16 (4$,times,$4) parallel-fed rectangular patches and a 5800-MHz band array formed by 64 (8 $,times,$8) hybrid-fed double-sided printed dipoles. The measured and simulated results are presented and analyzed. The relative impedance bandwidths and the peak gains of the 2400-MHz band and 5800-MHz band arrays reach 8%, 13% $({rm VSWR}<1.5)$, 24 dBi and 18 dBi respectively. The dual-band array has regular radiation patterns, high polarization purity and antenna efficiency, and it is suitable for integration with other microwave circuits and can be applied in other dual-band system by scaling its size. The design consideration for side lobe level (SLL) suppression by amplitude weighting combining the quarter-wavelength transformer and a small adjustment in the antenna geometry is discussed as well.      

Dual-Band Compact DRA With Circular and Monopole-Like Linear Polarizations as a Concept for GPS and WLAN Applications

The concept of achieving a dual-band antenna with two different radiation patterns using a single cylindrical dielectric resonator is presented. Both simulated and experimental measured results are conducted to prove the validity of the proposed concept. A broadside circularly-polarized pattern with 7% bandwidth and a vertically polarized omnidirectional pattern with 17.3% bandwidth are obtained, simultaneously. The minimum measured axial ratio is found to be 1.3 dB. The front-to-back ratio is measured to be 15 dB. A design suitable for both Global Positioning System and wireless local area network applications is proposed.     

Design and Analysis of a Compact UWB-MIMO Antenna with Improved Isolation for UWB/WLAN Applications

Near field communication, development in radio frequency detection has put its foot in today’s life of individuals through sophisticated mobile phones. NFC technology has become very popular due to its transparent and simple integration with a number of applications such as health care, consumer electronics, public transport payment methods, etc. A few new approaches have been attempted to make NFC progressively competent in routine day-to-day applications. This paper discusses the latest development in the use of NFC’s in a few implementations and the potential outcomes of the hustle-free implementation of these applications. A systematic analysis of recent research deployment in different areas of use has been clarified and explored.

     

Design and Analysis for a 60-GHz Low-Noise Amplifier With RF ESD Protection

An RF electrostatic discharge (ESD) protection for millimeter-wave (MMW) regime applied to a 60-GHz low-noise amplifier (LNA) in mixed-signal and RF purpose 0.13-$mu{hbox{m}}$ CMOS technology is demonstrated in this paper. The measured results show that this chip achieves a small signal gain of 20.4 dB and a noise figure (NF) of 8.7 dB at 60 GHz with 65-mW dc power consumption. Without ESD protection, the LNA exhibits a gain of 20.2 dB and an NF of 7.2 dB at 60 GHz. This ESD protection using an impedance isolation method to minimize the RF performance degradation sustains 6.5-kV voltage level of the human body model on the diode and 1.5 kV on the core circuit, which is much higher than that without ESD protection ( $≪$350 V). To our knowledge, this is the first CMOS LNA with RF ESD protection in the MMW regime and has the highest operation frequency reported to date.      

TFT-LCD驱动芯片内置电源电路IP核设计

设计了一种采用0.25μm CMOS低压/中压/高压混合电压工艺的TFT-LCD驱动芯片内置电源电路IP核.该IP模块包括低压降线性稳压电路、电荷泵升压/反压电路、VCOM驱动电路和VGOFF驱动电路等,能够提供驱动芯片的系统工作电压和TFT-LCD的驱动电压.所产生的电压值可实现编程控制,具有启动时间快、工作稳定和较低的温度系数等特点.仿真与测试结果表明,在上电200ms后能够生成稳定、正确的输出电压.电源电路模块的总静态功耗小于2mW.     

TFT-LCD驱动芯片内置电源电路IP核设计

设计了一种采用0.25μm CMOS低压/中压/高压混合电压工艺的TFT-LCD驱动芯片内置电源电路IP核.该IP模块包括低压降线性稳压电路、电荷泵升压/反压电路、VCOM驱动电路和VGOFF驱动电路等,能够提供驱动芯片的系统工作电压和TFT-LCD的驱动电压.所产生的电压值可实现编程控制,具有启动时间快、工作稳定和较低的温度系数等特点.仿真与测试结果表明,在上电200ms后能够生成稳定、正确的输出电压.电源电路模块的总静态功耗小于2mW.     

高保真电子管功放输出变压器的精确设计计算法

hi-end电子管功放音质优美绵厚,影响其音质的关键部件是输出变压器的电声性能,成为系统的喉舌。提出了一个新的方法,改变了以往粗略的估算法,使设计计算更合理﹑更科学﹑更实验化,成功解决了设计制造输出变压器的关键问题。     

一种用于WLAN的宽频带微带天线

采用双层结构拓展矩形微带天线带宽,利用有限积分法软件研究了寄生单元大小、以及两层贴片间的空气间隔对天线性能的影响。优化设计出的天线在电压驻波比(Voltage Standing Wave Ratio,VSWR)≤2的情况下,将原普通贴片天线4.5%的带宽提高到了23.6%,且增益在整个频带范围内达到6dB以上。该天线的工作频带完全覆盖无线局域网(Wireless Local Area Network,WLAN)的IEEE802.11a标准(5.15～5.825GHz)。实验测量结果与数值模拟结果相吻合。     

一种低电压CMOS折叠-共源共栅跨导运算放大器的设计

设计了一种全差分折叠-共源共栅跨导运算放大器,并将其应用于80 MHz开关电容带通Δ-Σ A/D转换器中.该跨导运算放大器采用0.35 μm CMOS N阱工艺实现,工作于2.5 V电源电压.模拟结果表明,该电路的动态范围为80 dB、直流增益63.4 dB、单位增益带宽424 MHz;在最大输出摆幅、建立精度为0.1%时,建立时间为7.5 ns,而功耗仅为7.5 mW.     

A Novel Design of Compact Dual-Band Bandpass Filter for Wireless Communication Systems

Wireless Personal Communications - In this paper, design, fabrication, and measurement of a new microstrip dual-band bandpass filter with compact size and high selectivity characteristics for...     

Built-In Self-Test Design for the 3D-Stacked Wide-I/O DRAM

Mobile Wide-I/O DRAMs are used in smartphones, tablets, handheld gaming consoles and other mobile devices. The main benefit of the Wide-I/O DRAM over its predecessors (such as LPDDRx DRAMs) is that it offers more bandwidth at lower power. In this paper, we propose a Wide-I/O DRAM built-in self-test design, named WIO-BIST including the local BIST (LO-BIST), global BIST (GL-BIST) and test interface structures, to support the fault detection in memory-die channels and TSVs. It should be noted that, a TSV test scheme is presented embedding the test procedure of TSVs into the memory-die channel test processes to significantly save the test time of TSVs. A logic die and 4 memory-dies stacking configuration is used to act as a dedicated circuit to demonstrate the feasibility of the proposed WIO-BIST design. Experimental results and comparisons show that the proposed WIO-BIST design has good performance in test time reduction with tiny extra area overhead penalty.     

一种基于WLAN零中频CMOS混频器的设计

本文提出了一种应用于无线局域网(WLAN)的2.4GHz的零中频下变频混频器的设计方案,采用中芯国际5层金属0.25μm的CMOS工艺制作完成。测试和仿真结果表明,该混频器增益为-1.2dB,IIP3为-11.1dB,其单边带噪声NF为7dB。文中对混频器的噪声进行了简单的分析,提出了一种解决直流溃通的方法。