Effects of back gate bias on radio-frequency performance in partially depleted silicon-on-inslator nMOSFETs

The effects of back gate bias(BGEs) on radio-frequency(RF) performances in PD SOI n MOSFETs are presented in this paper. Floating body(FB) device, T-gate body-contact(TB) device, and tunnel diode body-contact(TDBC) device, of which the supply voltages are all 1.2 V, are compared under different back gate biases by different figures of merit, such as cut-off frequency( fT), maximum frequency of oscillation( fmax), etc. Because of the lack of a back gate conducting channel, the drain conductance(gd) of TDBC transistor shows a smaller degradation than those of the others, and the trans-conductance(gm) of TDBC is almost independent of back gate bias. The values of fT of TDBC are also kept nearly constant under different back gate biases. However, RF performances of FB and TB each show a significant degradation when the back gate bias is larger than ～ 20 V. The results indicate that TDBC structures could effectively improve the back gate bias in RF performance.

A Low-Voltage,Low-Power CMOS High Dynamic Range dB-Linear VGA for Super Heterodyne Receivers

This paper presents a low-voltage low-power variable gain amplifier,which is applied in the automatic gain control loop of a super heterodyne receiver. Six stages are cascaded to provide an 81dB digitally controlled gain range in a 3dB step. The gain step error is less than 0.5dB. It operates at an intermediate frequency of 300kHz, and the power consumption is 1.35mW from a 1.8V supply. The prototype chip is implemented in a TSMC＇s 0.18μm 1P6M CMOS process and occupies approximately 0.24mm^2 . It is very suitable for portable wire- less communication systems. The measurement results agree well with the system requirements.

An Implementation of a CMOS Down-Conversion Mixer for GSM1900 Receivers

A 1.9GHz down-conversion CMOS mixer with a novel folded Gilbert cell,intended for use in GSM1900 （PCS1900） low-IF receivers,is fabricated in a RF 0.18μm CMOS process. The prototype demonstrates good performance at an intermediate frequency of 100kHz. It achieves a conversion gain of 6dB, SSB noise figure of 18. 5dB （1MHz IF） ,and IIP3 11.5dBm while consuming a 7mA current from a 3.3V power supply.

Ultra-wide dual-band Rydberg atomic receiver based on space division multiplexing radio-frequency chip modules

Detecting microwave signals over a wide frequency range is endowed with numerous advantages as it enables simultaneous transmission of a large amount of information and access to more spectrum resources.This capability is crucial for applications such as microwave communication,remote sensing and radar.However,conventional microwave receiving systems are limited by amplifiers and band-pass filters that can only operate efficiently in a specific frequency range.Typically,these systems can only process signals within a three-fold frequency range,which limits the data transfer bandwidth of the microwave communication systems.Developing novel atom-integrated microwave sensors,for example,radio-frequency(RF)chip–coupled Rydberg atomic receiver,provides opportunities for a large working bandwidth of microwave sensing at the atomic level.In the current work,an ultrawide dual-band RF sensing scheme was demonstrated by spacedivision multiplexing two RF-chip-integrated atomic receiver modules.The system can simultaneously receive dual-band microwave signals that span a frequency range exceeding 6 octaves(300 MHz and 24 GHz).This work paves the way for multi-band microwave reception applications within an ultra-wide range by RF-chip-integrated Rydberg atomic sensor.

A HIGH SENSITIVITY AND WIDE DYNAMIC RANGE ZERO-IF RF RECEIVER FOR COGNITIVE RADIO APPLICATION

This paper presents an RF receiver of zero-Intermediate Frequency(IF) architecture for Cognitive Radio(CR) communication systems.Zero-IF architecture reduce the image reject filter and IF filter,so it is excellent in low cost,compact volume,and low power dissipation.The receiver employs three digital attenuator and a high gain,high linearity low noise amplifier to achieve wide dynamic range of 70 dB and high receiving sensitivity of-81 dBm.A fully balanced I/Q demodulator and a differential Local Oscillator(LO) chips are used to minimize the negative effects caused by second-order distortion and LO leakage.In order to select an 8 MHz-channel from 14 continuous ones located in UHF band(694-806 MHz) accurately,approach of channel selectivity circuits is proposed.The RF receiver has been designed,fabricated,and test.The measured result shows that the noise figure is 3.4 dB,and the error vector magnitude is 7.5% when the input power is-81 dBm.

Rydberg electromagnetically induced transparency and Autler–Townes splitting in a weak radio-frequency electric field

We utilize an electromagnetically induced transparency(EIT) of a three-level cascade system involving Rydberg state in a room-temperature cell, formed with a cesium 6 S_(1/2)–6 P_(3/2)–66 S_(1/2) scheme, to investigate the Autler–Townes(AT)splitting resulting from a 15.21-GHz radio-frequency(RF) field that couples the |66 S_(1/2) → |65 P_(1/2) Rydberg transition.The radio-frequency electric field induced AT splitting, γAT, is defined as the peak-to-peak distance of an EIT-AT spectrum.The dependence of AT splitting γAT on the probe and coupling Rabi frequency, ?_p and ?_c, is investigated. It is found that the EIT-AT splitting strongly depends on the EIT linewidth that is related to the probe and coupling Rabi frequency in a weak RF-field regime. Using a narrow linewidth EIT spectrum would decrease the uncertainty of the RF field measurements.This work provides new experimental evidence for the theoretical framework in [J. Appl. Phys. 121, 233106(2017)].

Preparation and Characterization of Transparent Conductive Zinc Doped Tin Oxide Thin Films Prepared by Radio-frequency Magnetron Sputtering

High transparent and conductive thin films of zinc doped tin oxide （ZTO） were deposited on quartz substrates by the radio-frequency （RF） magnetron sputtering using a 12 wt% ZnO doped with 88 wt% SnO2 ceramic target.The effect of substrate temperature on the structural,electrical and optical performances of ZTO films has been studied.X-ray diffraction （XRD） results show that ZTO films possess tetragonal rutile structure with the preferred orientation of （101）.The surface morphology and roughness of the films was investigated by the atomic force microscope （AFM）.The electrical characteristic （including carrier concentration,Hall mobility and resistivity） and optical transmittance were studied by the Hall tester and UV- VIS,respectively.The highest carrier concentration of -1.144×1020 cm-3 and the Hall mobility of 7.018 cm2（V ·sec）-1 for the film with an average transmittance of about 80.0% in the visible region and the lowest resistivity of 1.116×10-2 Ω·cm were obtained when the ZTO films deposited at 250 oC.

Aerodynamic actuation characteristics of radio-frequency discharge plasma and control of supersonic flow

In this paper, aerodynamic actuation characteristics of radio-frequency(RF) discharge plasma are studied and a method is proposed for shock wave control based on RF discharge. Under the static condition, a RF diffuse glow discharge can be observed; under the supersonic inflow, the plasma is blown downstream but remains continuous and stable.Time-resolved schlieren is used for flow field visualization. It is found that RF discharge not only leads to continuous energy deposition on the electrode surface but also induces a compression wave. Under the supersonic inflow condition, a weak oblique shock wave is induced by discharge. Experimental results of the shock wave control indicate that the applied actuation can disperse the bottom structure of the ramp-induced oblique shock wave, which is also observed in the extracted shock wave structure after image processing. More importantly, this control effect can be maintained steadily due to the continuous high-frequency(MHz) discharge. Finally, correlations for schlieren images and numerical simulations are employed to further explore the flow control mechanism. It is observed that the vortex in the boundary layer increases after the application of actuation, meaning that the boundary layer in the downstream of the actuation position is thickened. This is equivalent to covering a layer of low-density smooth wall around the compression corner and on the ramp surface, thereby weakening the compressibility at the compression corner. Our results demonstrate the ability of RF plasma aerodynamic actuation to control the supersonic airflow.

Influence of Discharge Parameters on Tuned Substrate Self-Bias in an Radio-Frequency Inductively Coupled Plasma

The tuned substrate self-bias in an rf inductively coupled plasma source is controlled by means of varying the impedance of an external LC network inserted between the substrate and the ground. The influencing parameters such as the substrate axial position, different coupling coils and inserted resistance are experimentally studied. To get a better understanding of the experimental results, the axial distributions of the plasma density, electron temperature and plasma potential are measured with an rf compensated Langmuir probe; the coil rf peak-to-peak voltage is measured with a high voltage probe. As in the case of changing discharge power, it is found that continuity, instability and bi-stability of the tuned substrate bias can be obtained by means of changing the substrate axial position in the plasma source or the inserted resistance. Additionally, continuity can not transit directly into bi-stability, but evolves via instability. The inductance of the coupling coil has a substantial effect on the magnitude and the property of the tuned substrate bias.

Direct RF Sampling GNSS Receiver Design and Jitter Analysis

This paper describes the design of a flexible Direct RF Sampling based GNSS receiver as well as its use for the verification of jitter effects on various performance metrics. The proposed architecture allows the sampling and the real-time digital signal processing of real GNSS signals. The analysis of the measurements obtained from this system validates theoretical formulations from which the sampling jitter limit is established in order not to impact the GNSS signal’s detection.

基于信噪比和噪声功率密度测量的射频接收通道状态检测方法

针对传统射频接收通道中靠近天线射频前端的故障检测代价大,检测颗粒度受限等问题,提出了一种基于噪声功率密度测量的射频接收通道状态检测方法。利用噪声系数与增益的级联迭代关联特性,实现对射频接收通道中各单元故障的准确定位。对技术原理进行了理论推导,并构建测试系统验证了方法的可行性与有效性。与传统方法相比,该方法可减少自检电路设计复杂度,减少链路上各个单元自检成本,并可消除自检盲区,实现对故障单元的准确定位。

无线接收机RF前端研究

移动通信的迅速发展 ,对无线接收机提出了严格的要求 ,即低功耗 ,高可靠性 ,低价格 ,以及更小的尺寸 .接收机射频前端的设计是实现这一目标的关键 .本文从无线接收机前端的拓扑结构、电路技术。

高频RFID读写器射频模拟前端的实现

射频识别(RFID)系统主要由RFID读写器和RFID电子标签两部分组成。给出了高频(13.56MHz)RFID系统中读写器射频模拟前端的电路设计,符合ISO/IEC14443typeA/typeB,ISO/IEC15693和ISO/IEC18000-3中任一个标准的读写器芯片设计均可采用,设计工艺采用了中芯国际0.35μm2P3M混合CMOS技术,并给出了Cadence环境下的仿真结果。

机载超短波接收机射频前端系统级设计与仿真

针对某型号超短波接收机研制需求,使用ADS(Advanced Design System)软件对该超短波接收机射频前端进行设计与仿真。通过分析接收机的性能需求,结合接收机主要工作原理和技术指标选取二次变频超外差接收机结构做为实现方案,根据设计方案在ADS中建立了射频前端的系统级仿真模型,并对射频前端的噪声系数、灵敏度、增益和互调失真等多个关键指标进行了设计分析和仿真计算,结果表明该射频前端各项指标满足设计要求。

一种高性能DAB接收终端RF模块设计

依据欧洲电信标准协会(ETSI)提出的ETSI EN 300 401标准,设计了一种高性能DAB接收终端RF接收模块的设计方法,实现了DAB信号稳定同步和接收,达到了高灵敏度和低功耗,在移动速度达到200 km/h时能够稳定接收。该设计方法已经用于批量生产的DAB接收终端中。

基于Web和nRF24L01的远程数据接收器设计

基于S3C2440-Linux嵌入式平台和nRF24L01射频模块,介绍了一种远程数据接收器的设计。该数据接收器利用SQLite3存储nRF24L01射频模块接收来自数据采集节点的数据,用户通过浏览器访问接收器上的BOA服务器进行数据管理。在CGI程序设计中采用Posix消息队列给数据接收器的射频接收单元传递命令,利用多线程的方式对接收到的数据进行处理。这种将传感器采集到的数据通过2.45 GHz无线射频模块发送到数据接收器的方式非常适合用于远程环境监测、旅游管理等场合。

基于StarRFT500的DMB数字广播接收机的设计

通过分析基于StarRFT500为核心芯片的数字广播接收机的硬件结构,介绍了各个硬件组成模块的功能,着重论述了基于StarRFT500芯片RF模块的设计。该接收机具有低成本,灵敏度高的优点,适合产业化推广。

5G终端抗自干扰射频接收前端设计

以发射机非线性为主的自干扰普遍恶化5G终端接收机性能。为此,设计了一款抗自干扰射频接收前端。从典型架构和设计要求入手,提出抗自干扰因素分解法,通过实际场景的指标分解,分别讨论隔离度和线性度等因素,利用理论分析及公式推导给出了设计要求与射频接收前端各指标之间的关系,从而提供了在已知设计要求条件下的产品设计准则。经产品投产和实物测试,测试结果与设计要求吻合,验证了该套设计方法的有效性。与国际通用标准相比,该产品的抗自干扰能力提升15 dB以上。

噪声系数最小1.6 dB有高带外抑制的5~6 GHz射频接收前端芯片

为了满足射频通信前端接收部分对高线性与带外信号抑制能力的要求,基于130 nm绝缘体上硅工艺设计并实现工作在5~6 GHz的射频接收前端芯片.该前端芯片由带有旁路和带外抑制功能的低噪声放大器(LNA)、射频开关和带隙基准偏置电路等组成.基于共源共栅结构的LNA,在输入匹配中使用LC陷波实现带外抑制;在偏置电路中,使用带隙基准电流源对LNA的偏置进行温度补偿,屏蔽电源纹波影响.对该前端芯片进行流片加工并测试,结果表明,当工作频率为5~6 GHz时,芯片的接收增益为13.4~14.0 dB,输入与输出反射系数均小于-10 dB,频带内的最小噪声系数为1.6 dB,在工作频率内1 dB压缩点的输入功率大于-4 dBm,输入三阶交调点大于+7 dBm.低噪声放大器在整个工作频段内无条件稳定,在2 V供电电压下电路的直流功耗为30 mW,芯片面积为0.56 mm2.

一种基于CMOS的宽带抗阻塞射频接收机设计

针对在多频段、多模式无线通信应用中传统射频接收机频段单一、集成度低的问题,基于N通道滤波技术与接收机集成化技术,提出一种基于互补金属氧化物半导体(CMOS)的宽带抗阻塞射频接收机。该接收机集成N通道混频器与基带滤波器,在65 nm CMOS工艺下进行版图测试。仿真实验结果表明,该接收机在5 MHz的基带带宽外提供超过60 dB的带外阻塞抑制,频率调谐范围0.25~2.5 GHz;前置内嵌巴伦的低噪声放大器,使接收机转换增益达到46 dB,同时降低整体噪声系数至3.1~4 dB;实现了24.5 dBm的带外三阶交调截取点(IIP3),功耗为26 mW。