Research on COB De-embedding in Scattering Parameter Measurement

The popular radio frequency (RF) chip on board (COB) test has gradually taken the place of on-wafer test due to the high efficiency and high power. This paper presents the extended Open-Short-Load (OSL) that is one-port calibration method to verify the error model de-embedding in S parameter measurement. Three-level cascade structure on COBs system error model is proposed and analyzed. Four kinds of calibration plane solutions for de-embedding are verified. At last, on-board calibration (CAL) kits solution is established to decrease the system error to the least value. The maximum error shift can be controlled less than 0.1 dB comparing with the on-wafer test results. In general, the practical application results prove that this method is reasonable and effective and easy to be mastered.     

用高速光器件分析仪测试高增益CATV光站

介绍了使用安捷伦50Ω高速光器件分析仪测试75Ω高增益CATV接收光站的原理和方法。着重解决了测试过程中遇到的测试设备与被测产品阻抗不匹配问题和被测产品增益过高问题。对于阻抗不匹配问题,采用光器件分析仪的去嵌入功能实现50Ω和75Ω间的匹配;对于增益过高问题,采用降低光器件分析仪的光调制度方法来降低光站增益。从实验结果分析,两种解决方法完全可行,并且不会引入测试误差。     

An accurate and simplified small signal parameter extraction method for GaN HEMT

In this paper, development of a small signal model for 2 × 200 μm GaN HEMT based on the conventional 20-element model is presented. The proposed model presents a direct parameter extraction algorithm, instead of the hybrid optimization approach, that provides simplification, accuracy, and less computational complexity. The extrinsic elements are extracted using a modified cold pinch-off condition while discarding the unwanted forward biasing of the gate. The negative drain to source capacitance C_ds is also observed in the ohmic region (for smaller V_DS). An excellent agreement found between the measured and modeled data for a wide range of frequencies and bias values shows the effectiveness of the proposed approach. The proposed modeling technique is validated with a good agreement between the achieved bias dependency of intrinsic parameter values and the respective theoretical parameter values.     

微波射频差分探针去嵌入理论研究

为了获得被测件(DUT)准确的散射参数(S参数),研究了用于差分网络的去嵌入理论。在经典的差分探针结构的基础上,提出了一种可以抑制差分测试中共模信号影响的新型差分探针模型,即信号-信号探针(SS探针)。并完成了直通-反射-传输线(TRL)校准件和DUT的设计,推导了差分网络的多模去嵌入理论,编写算法并利用测试数据进行计算,仿真与测试结果表明在0~8 GHz的频率范围内,去嵌入后的散射参数的幅度、相位与仿真结果一致性较好。     

锗硅器件高频噪声的去嵌算法研究

提出了一种"开路-直通"的级联结构的二端口网络的晶体管高频噪声去嵌结构以及与此相关的基于噪声相关性矩阵的去嵌方法。和传统的需要配备两个"直通"结构的方法相比较,该结构及方法在版图配合的基础上,只需要使用一个"开路"结构和一个"直通"结构,而且多个不同尺寸的被测试器件结构可以共用一个直通去嵌测试结构进行测试及去嵌,结果显示,使用该方法测试及去嵌后的精度几乎不受影响。该方法的意义在于能极大地减少硅片上直通去嵌测试结构的数量从而节省硅片面积;同时,又减少了测试时间、提高了测试效率,极大地降低了成本。     

混合平衡-非平衡射频探针的在片测试方法

随着对微波单片集成电路(MMIC)愈发严苛的尺寸限制和集成度要求,越来越多的MMIC芯片如限幅器、射频开关等同时具有平衡和非平衡的不同测试焊盘结构,需采用平衡-非平衡混合射频探针进行在片测试,而基于单一平衡或非平衡结构的直通在片校准件无法同时满足混合射频探针的阻抗匹配要求,导致校准精度大幅下降,无法用于MMIC在片测试.为此,本文对采用传统SOLR校准方式的平衡-非平衡混合射频探针测试的校准误差进行了评估计算,并结合带误差修正的OSL二阶去嵌技术和级联矩阵变换技术,提出一种基于平衡-非平衡混合射频探针的MMIC在片测试方法,同时搭建了以矢量网络分析仪、SG与GSG射频探针、微波探针台等组成的在片测试系统来验证方案可行性.通过矢量修正和级联矩阵去嵌,将校准参考平面精确平移至探针尖端面,有效地保证了测试精度,并且结合C#面向对象语言为该测试方案构建了自动测试系统,实现了仪器控制、数据采集、结果修正、数据分析等全自动操作,避免了人为干预的影响,解决了晶圆级测试面临的效率问题.     

一种测量差分片上螺旋电感类器件的简便方法

This paper proposes a simple method of measuring differentially-excited on-wafer RF CMOS spiral inductor-like components.This method requires only two common ‘G-S-G＇ probes and an ordinary two-port VNA.Using a network instead of a detailed equivalent circuit, this method completes the de-embedding with only one ‘Through＇ dummy, and thus the measurements are greatly simplified.By designing the ports ‘Open＇ or ‘Shortcircuited＇ deliberately, a multi-port transformer can be transformed into three two-port networks with different terminators.Then, couplings between the two coils can be solved, and the differentially-excited scattering parameters（S-parameters） can be constructed.Also, a group of differential inductors and transformers were designed and measured, and then comparisons between simulated and measured electromagnetic results are performed to verify this method.     

开口同轴探头去嵌入技术的研究

开口同轴探头测量技术,由于可实现非破坏性测试,一直是众多科学家及工程技术人员关注的焦点。但对于同轴探头的误差分析,研究不够深入。相位补偿技术是最常用的同轴探头去嵌入技术,该技术假设同轴探头是理想器件,忽略了同轴探头加工精度带来的误差。为此,提出了一种更为精确的去嵌入技术,即基于传输线模型的开口同轴探头去嵌入技术,通过实测得到表征同轴探头误差的校准参量,从而量化同轴探头的误差模型,以去除在测量中同轴探头带来的误差。介绍了该技术的基本原理,并与相位补偿技术进行了对比,最终通过实测验证了该技术是有效可行的。     

一种单端谐振器去夹具测试方法

介绍了一种单端谐振器去夹具测试的方法。该方法是将夹具误差等效成3项系统误差,利用矢量网络分析仪对夹具的短路、开路和负载状态进行直接测量求得这3项误差,然后通过公式转换得到被测件去除夹具影响后真实的S参数。通过编写优化程序拟合器件的导纳曲线,从而可准确计算出谐振器各等效电路元件值以及品质因数(Q)值。实验证明,该方法准确有效,适用于声表面波单端谐振器和声表面横波单端谐振器。     

A simple method of measuring differentially-excited on-wafer spiral inductor-like components

mea-sured, and then comparisons between simulated and measured electromagnetic results are performed to verify this method.