毫米波频段宽带CMOS片上巴伦的分析与建模

详细讨论了基于CMOS工艺宽带片上巴伦的实现.首先分析了应当采用的结构及参数化版图.然后给出了一个宽带集总元件等效电路模型,该模型考虑了各种必须考虑的物理效应.通过采用物理公式与优化拟合相结合的方法提取了模型参数,以保证模型在很宽频带范围内具有较高精度.最后,采用台湾半导体制造有限公司(TSMC)提供的0.13μm混合信号/射频CMOS工艺实际制作了两个具有不同几何参数的巴伦,并使用Agilent E8363B矢量网络分析仪测量了S参数.测量结果表明在高达毫米波频段范围内,模型仿真结果与测试结果符合得很好.     

基于三导体耦合线的毫米波Marchand balun建模与设计（英文）

提出了一种基于三导体耦合线结构的毫米波Marchand巴伦的新型宽带模型.基于c模和π模理论,对三导体耦合线进行了分析并采用传输线和理想变压器对其建立了模型.通过电磁场仿真提取了模型参数并使用该耦合线模型建立了Marchand巴伦的模型.基于该模型,使用GaAs工艺设计了一种毫米波Marchand巴伦并进行了流片制造,所设计的巴伦工作在15~55 GHz频率范围,测试结果表明该巴伦具有较好的幅值和相位平衡度,同时验证了模型的准确性.     

基于三导体耦合线的毫米波Marchand balun建模与设计

本文提出了一种基于三导体耦合线结构的毫米波Marchand巴伦的新型宽带模型。基于c模和π模理论,对三导体耦合线进行了分析并采用传输线和理想变压器对其建立了模型。通过电磁场仿真提取了模型参数并使用该耦合线模型建立了Marchand巴伦的模型。基于该模型,本文使用GaAs工艺设计了一种毫米波Marchand巴伦并进行了流片制造,所设计的巴伦工作在15GHz~55GHz频率范围,测试结果表明该巴伦具有较好的幅值和相位平衡度,同时验证了模型的准确性。     

一种宽带UHF印刷偶极子天线的设计

设计制作了一种宽带UHF印刷偶极子天线.为了使天线在UHF的低频段获得宽带特性,采用了改进的Marchand巴伦馈电.该巴伦在传统的结构上,通过在接地板上开槽以改变耦合微带线与接地板之间的电容值,从而调整巴伦的奇偶模阻抗,以提高偶模阻抗与奇模阻抗的比值,实现带宽的拓展.仿真表明天线在530 ～ 790MHz范围内,回波损耗低于-10dB,相对带宽可达40％.加工制作了天线,实测结果与仿真数据吻合良好.这类天线在微波低频段具有特别的实用意义.     

基于双导体耦合线Marchand 巴伦的 快速建模与设计*

针对Marchand 巴伦模型参数提取效率低,耗时长的问题,本文提出了一种快速提取Marchand 巴伦模型参数的 方法。传统的耦合线建模过程中,当耦合线的物理尺寸,如长度、宽度、间距发生变化,需要重新进行电磁场仿真,占据大量的 计算机资源和仿真时间。本文首先基于c、π 模表征的耦合线分布模型构建了Marchand 巴伦模型,通过对耦合线全波电磁场 仿真获得的模型参数提取结果进行数据分析和拟合,找出耦合线物理尺寸和模型参数之间的关系,建立对应方程,避免在巴伦 设计优化过程中反复进行电磁场仿真,达到快速设计Marchand 巴伦的目的。使用该方法基于PCB 板设计了中心频率为 2.4 GHz 的巴伦进行验证,测试结果表明该方法提取的模型参数具有较好的精度,能够满足巴伦的快速设计需求。     

50GHz宽带采样电路的SPICE仿真建模

本文首先提出了一个在NTN(Nose-to-Nose)校准中实际应用的50GHz宽带采样电路的SPICE默认仿真模型;然后通过设计采样电路的模型参数,使仿真的NTN冲击响应与实际测量重构的50GHz宽带采样示波器冲击相应波形基本相似.当仿真结果和测量结果近似时,可以通过仿真试验估计出采样电路对相位误差的影响,这和实际的物理采样电路对相位误差的影响是相同的,而该误差的影响却无法用实际测量实验确定;最后研究其收敛特性从而确定正确的仿真条件,目的是确保在较宽的元件参数取值范围内,该SPICE仿真模型对参数研究具有足够的鲁棒性.     

RF CMOS工艺片上MOM电容的宽频带建模与验证

提出了一种新的基于RF CMOS技术的金属-氧化物-金属(MOM)电容宽频带建模方法。为了提高模型精度、扩展有效频带,模型在构造时加入了测试焊盘和输入/输出互连线的等效电路。测试结构是基于自身物理结构进行架构的,充分考虑了其在高频时引入的各种寄生效应。互连线模型考虑了高频时的趋肤效应。通过解析提取的方法,在低频时提取测试结构引入的容性和阻性寄生参数。采用物理公式计算互连线的等效电感和电阻以及高频下互连线产生的趋肤效应参数初值。对于模型拓扑结构和参数提取方法,采用40 nm RF CMOS工艺上设计所得连带测试结构MOM电容数据进行验证。在0.25～110 GHz的频率范围内,可得测试和仿真的S参数精确吻合。     

一种用于表征亚阈值电流镜电路中CMOS工艺波动的统计学方法

提出了一种新的表征亚阈值电路镜电路中CMOS工艺波动的方法.与现有的统计学方法相比,该方法在理论上和计算复杂度上相对简洁,但对亚阈值电流镜电路中的CMOS工艺波动做出了准确的评估.此模型利用统计学的概念将依赖于IC工艺的物理参数抽象为具有确定均值和方差的随机变量,并进一步将所有随机因素累加为离散鞅.在SMIC 0.18μm CMOS 1P6M混合信号工艺下,利用工作在100pA～1μA范围内、增益为100的亚阈值电流镜电路对此方法的正确性进行了实验验证.该理论成功地预测了～10%的实测芯片间工艺波动,并且给出了～1mV的片上阈值电压标准偏差,此结果与SMIC提供的没计参数吻合.该理论给出的概率分布与实测结果的偏差小于8%.同时,还针对高工艺稳定性的亚阈值模拟电路设计方法进行了相关的讨论.     

一种用于表征亚阈值电流镜电路中CMOS工艺波动的统计学方法

提出了一种新的表征亚阈值电路镜电路中CMOS工艺波动的方法.与现有的统计学方法相比,该方法在理论上和计算复杂度上相对简洁,但对亚阈值电流镜电路中的CMOS工艺波动做出了准确的评估.此模型利用统计学的概念将依赖于IC工艺的物理参数抽象为具有确定均值和方差的随机变量,并进一步将所有随机因素累加为离散鞅.在SMIC 0.18μm CMOS 1P6M混合信号工艺下,利用工作在100pA～1μA范围内、增益为100的亚阈值电流镜电路对此方法的正确性进行了实验验证.该理论成功地预测了～10%的实测芯片间工艺波动,并且给出了～1mV的片上阈值电压标准偏差,此结果与SMIC提供的没计参数吻合.该理论给出的概率分布与实测结果的偏差小于8%.同时,还针对高工艺稳定性的亚阈值模拟电路设计方法进行了相关的讨论.     

高耦合系数层叠结构片上变压器的频率无关等效电路

针对高耦合系数层叠结构的片上变压器提出了一个新型2-Ⅱ集总元件等效电路模型.主要基于解析公式提取了该模型的元件参数.由于该模型中伞部元件取值均与工作频率无关,因此该模型完全可以用于射频集成电路设计中的时域瞬态仿真及噪声分析.为了验证该模型的精度,采用台湾半导体制造有限公司(TSMC)提供的0.13μm混合信号/射频CMOS工艺实际制作了一个高耦合系数层叠结构片上变压器,并使用Agilent E8363B矢量网络分析仪测量了其S参数.测量结果表明该模型在高于两倍自谐振频率范围内均能够与测试结果很好地符合.     

An Ultra-Wideband High-Linearity CMOS Mixer With New Wideband Active Baluns

A 2-11-GHz high linearity CMOS down-conversion mixer with wideband active baluns using 0.18-mum CMOS technology is demonstrated in this paper. The mixer employs a folded cascode Gilbert cell topology and on-chip broadband active baluns. The folded cascode approach is adopted to increase the output swing, and the linearity is enhanced by a harmonic distortion canceling technique derived from the harmonic balance analysis. The proposed configuration shows the highest IIP₃ and IP_{1 dB}, and exhibits more compact size than most published studies. A broadband active balun is used to generate wideband differential signals, together with the derivation of a closed-form expression for the phase imbalance. This single-ended wideband mixer has the conversion gain of 6.9plusmn1.5 dB, input 1-dB compression point (IP_{1 dB}) of - 3.5 dBm, single-sideband noise figure of 15.5 dB, and third-order input intercept point (IIP₃) of 6.5 dBm under the power consumption of 25.7 mW from a 1.8-V power supply. The chip area is 0.85 x 0.57 mm².     

Low-Loss and Broadband Asymmetric Broadside-Coupled Balun for Mixer Design in 0.18-$mu{hbox {m}}$ CMOS Technology

This study presents an asymmetric broadside coupled balun with low-loss broadband characteristics for mixer designs. The correlation between balun impedance and a 3D multilayer CMOS structure are discussed and analyzed. Two asymmetric multilayer meander coupled lines are adopted to implement the baluns. Three balanced mixers that comprise three miniature asymmetric broadside coupled Marchand baluns are implemented to demonstrate the applicability to MOS technology. Both a single and dual balun occupy an area of only 0.06 mm². The balun achieves a measured bandwidth of over 120%, an insertion loss of better than 4.1 dB (3 dB for an ideal balun) at the center frequency, an amplitude imbalance of less than 1 dB, and a phase imbalance of less than 5deg from 10 to 60 GHz. The first demonstrated circuit is a Ku-band mixer, which is implemented with a miniaturized balun to reduce the chip area by 80%. This 17-GHz mixer yields a conversion loss of better than 6.8 dB with a chip size of 0.24 mm². The second circuit is a 15-60-GHz broadband single-balanced mixer, which achieves a conversion loss of better than 15 dB and occupies a chip area of 0.24 mm². A three-conductor miniaturized dual balun is then developed for use in the third mixer. This star mixer incorporates two miniature dual baluns to achieve a conversion loss of better than 15 dB from 27 to 54 GHz, and occupies a chip area of 0.34 mm².     

Novel miniaturised wideband baluns for MIC and MMIC applications

Very compact novel planar broadband baluns are described. Each balun consists of two Lange couplers. Less than 0.3 dB and 2.5 degrees for the amplitude and phase balances, respectively, have been measured over the 1.0-2.2 GHz bandwidth for a microstrip balun. As compared with other reported baluns, these baluns are simpler, more compact, easier to design, and fabricated on only one side of the substrate. They are thus very attractive for microwave integrated circuit (MIC) and monolithic microwave integrated circuit (MMIC) applications.<>     

Broadband monolithic passive baluns and monolithic double-balancedmixer

The design and fabrication of four broadband monolithic passive baluns including CPW Marchand, multilayer MS Marchand, planar-transformer and broadside-coupled line baluns are presented. Operational frequencies range from 1.5 GHz to 24 GHz. Maximum relative bandwidths in excess of 3:1 are achieved. Simulated performances using full wave electromagnetic analysis are shown to agree with the measured results. Two accurate equivalent circuit models constructed from either electromagnetic simulated or measured S-parameters are developed for the MS Marchand and transformer baluns making the optimization of baluns and circuit design using the baluns much more efficient. The design of monolithic double-balanced diode mixer using two planar-transformer baluns is also presented. Without DC bias, the mixer shows a minimum conversion loss of 6 dB with the RF at 5 GHz and a LO drive of 15 dBm at 4 GHz. The measured input IP₃ of this mixer is better than 15 dBm over the 4 to 5.75 GHz frequency band     

A 9-50-GHz Gilbert-cell down-conversion mixer in 0.13-/spl mu/m CMOS technology

A broadband microwave/millimeter-wave (MMW) Gilbert-cellmixer using standard 1P8M 0.13-/spl mu/m complementary metal oxide semiconductor (CMOS) technology is presented in this letter. Two radio frequency (RF) transformer baluns are used in RF-and local oscillator (LO)-ports to convert single-ended signals to differential signals. Thin film microstrip line is employed for the matching networks and transformer design. This mixer has a conversion gain of better than 5dB from 9 to 50GHz. Between 5 and 50GHz,the RF- and LO-to-intermediate frequency (IF) isolations are better than 40dB. The RF-to-LO and LO-to-RF isolations are all better than 20dB. To the authors' knowledge, this is the first CMOS Gilbert-cell mixer operating to MMW frequency to date.     

Modeling of monolithic RF spiral transmission-line balun

This paper presents models for monolithic RF spiral transmission-line baluns. The balun consists of a pair of spiral transformers fabricated on high-resistivity silicon. The lumped-element equivalent models are developed. The second-order or higher order models are synthesized from the first-order lumped model. All lumped parameters for the models are extracted from the real physical structures. Simulated behaviors from the second-order models are in good agreement with the measured results within 10% difference     

Broadband tapered microstrip leaky-wave antenna

This study proposes a novel scheme based on the characteristics of leaky-wave antennas for the empirical design of broadband tapered microstrip leaky-wave antennas. This scheme can explain and approximately model the radiation characteristics of a linearly tapered leaky-wave microstrip antenna. A broadband feeding structure that uses the balanced and the inverted balanced microstrip lines to form a pair of broadband baluns is also presented. The measured return loss of the inverted balanced microstrip lines has a VSWR/spl les/2 from dc to 18.6 GHz and that of the back-to-back feeding structures has a VSWR/spl les/2 from 2.2 to 18.6 GHz. This feeding structure can be used to feed a broadband planar leaky-wave antenna with a fixed mainbeam that uses the tapered microstrip structure. The measured bandwidth of the antenna for a VSWR/spl les/2 exceeds 2.3:1.     

Broadband Via-Free Microstrip Balun Using Metamaterial Transmission Lines

A novel metamaterial broadband microstrip balun design is proposed. The broadband balun consists of a pair of identical metamaterial transmission lines. In the odd mode, a virtual ground is formed between the symmetric plane. The odd mode is allowed while the even mode is rejected. No vias are required to realize the shunt inductors of the metamaterial lines, and no power divider is used. Baluns with good performance can be achieved. In this letter, two baluns are fabricated and measured. For the balun with seven units, the output amplitude difference is less than 0.7 dB, and the differential phase is 181deg plusmn 3deg from 1.6 to 3.6 GHz, while the input return loss is greater than 10 dB.     

片上螺旋变压器等效电路参数的直接提取

本文比较了四端口和两端口测试方式下变压器模型的差异。虽然两端口测试方式对变压器的测试和应用更为合适,但它将给模型参数的提取带来巨大困难。在这篇文章中,一种基于物理意义的等效电路模型和它相应的直接提取步骤被提出来用于片上变压器。基于两端口（而非四端口）测试方式,这种参数提取步骤能够提取器件的模型参数而不需要使用任何参数优化和拟合。在这个步骤中,一个新方法首次被提出用来提取阶梯电路的参数,而阶梯电路被广泛用于模拟各种无源器件中的趋肤效应。这样,这个方法便可以推广应用到其他无源器件的建模中,如片上传输线、电感、巴伦等。为了检验这种参数提取步骤的有效性和准确性,我们用90-nm 1P9M CMOS工艺制作了一个片上互绕型变压器。我们比较了模型仿真和实际测试在自感、品质因数、感性互感系数和阻性互感系数等方面的结果,在很宽的频带宽度内这两者吻合得很好。     

A physical-based analytical model for hot-carrier inducedsaturation current degradation of p-MOSFET's

The delay time of a CMOS inverter is directly related to the p-MOSFET saturation current. An accurate aging model for the saturation current is essential for the modeling of the CMOS inverter degradation. In this paper, we report that the saturation current degradation proceeds logarithmically in stress time. A physical analytical model, based on the pseudo-two-dimensional model, is derived for the first time to describe the saturation current degradation under various stress and measurement conditions. There are no empirical parameters in the model. Two physical parameters, the capture cross section and the density of states of electron traps, can be determined independently from the measured degradation characteristics. The simple expression is highly recommended for the modeling of the degradation of the digital CMOS circuits