微带巴伦设计

根据微带耦合线的准TEM模参数 ,推导出相同耦合线Marchand巴伦须满足的导纳方程 ,讨论了改善巴伦性能的方法———电容补偿法。ADS仿真结果表明 :采用最佳条件选取的耦合线 ,巴伦的反射系数接近最小 ,传递系数接近最大 ;采取电容补偿后 ,可进一步改善巴伦的性能。最后给出宽边耦合线巴伦的实验结果。结果表明 :可用上述导纳方程设计巴伦耦合线的参数。     

小型化三耦合线Marchand巴伦的等效模型分析与验证

为了实现三耦合线Marchand巴伦的快速设计,缩小巴伦的尺寸,提出了一种简化的三耦合线Marchand 巴伦等效模型及小型化设计方法。该等效模型将复杂的三耦合线的S参数散射矩阵的计算问题简化为对两个并联的平行耦合线的S参数散射矩阵的计算。为了验证该模型和设计方法的有效性,采用0.1 μm 砷化镓pHEMT (pseudomorphic High Electron Mobility Transistor)工艺制作了一款75~110 GHz的单平衡混频芯片,最终应用于单平衡混频器的巴伦耦合线长度被缩减为中心频率1/4波长的44%。良好的混频器性能和紧凑的芯片面积证明了所提三耦合线巴伦的等效模型和设计方法能够为单片集成微波电路芯片的设计提供指导作用。     

Systematic design of 7‐to‐40‐GHz on‐chip mixer based on optimal impedance deviation coefficient

In this article, a 7‐GHz to 40‐GHz ultra‐wideband passive double‐balanced mixer MMIC using compact wideband Marchand balun (CWMB) is presented. The CWMB is analyzed and designed by introducing a novel optimal impedance deviation coefficient. A trade‐off between the needed bandwidth and the acceptable insertion loss in an ultra‐wideband passive‐doubly‐balanced mixer design can be made through introducing the optimal impedance deviation coefficient. Finally, to verify the proposed methodology, a compact wideband passive double‐balanced mixer monolithic microwave integrated circuit (MMIC) was designed and fabricated using a standard gallium arsenide (GaAs) pHEMT technology according to the process characteristics. Experimental results show that an ultra‐wideband mixer MMIC is realized from 7 GHz to 40 GHz (140% fractional bandwidth) with a measured conversion loss between 9.5 dB~12.5 dB (in‐band fluctuation less than 3 dB) and a LO‐to‐RF isolation larger than 34 dB. The measurement results are in good agreement with the simulation results.     

基于LTCC技术的C频段星载接收机混频器

利用低温共烧陶瓷(LowTemperature Co-fired Ceramic,简称LTCC)技术,设计制作了一种可应用于C频段星载接收机的双平衡混频器。该混频器将射频和本振巴伦等无源器件集成在多层LTCC基板内,实现了电路的小型化、高集成度和高可靠性。测试表明,当射频输入为5.925～6.425GHz、本振频率为2.225GHz、中频输出频率为3.7～4.2GHz时,混频器的变频损耗≤9.3dB,P1dB为5.7dBm,本振到射频和本振到中频的隔离度分别为39.44dB和35.58dB。混频器的尺寸为40×22×1.92mm3。     

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。     

一种平面宽带Marchand Balun的新型模型

本文提出了一种新的Marchand Balun 模型。通过对构成Balun基本单元的λ/4耦合线进行奇、偶模分析,获得了耦合线的基本等效表达式。基于所提出的5阶集总元件等效电路,耦合线的自感、互感系数和电容均能根据奇偶模特性阻抗计算得到,从而可以较为方便的得到Balun的模型参数。为对模型进行验证,本文基于GaAs工艺设计了一个单片宽带Marchand Balun,并使用三维电磁场工具对其进行了仿真验证,最后通过流片测试对模型进行了实验验证。电磁场仿真与实验结果与所提的模型仿真结果相一致,应用该模型可以使对Marchan Balun的设计变得更为快速和便捷,并且适用于较宽的频带范围。     

A millimeter-wave monolithic doubly balanced diode mixer

A broadband miniature doubly balanced diode mixer chip fabricated by Win's 0.15μm pHEMT technology is presented. In order to save chip area, a four-fold modified Marchand balun is used. A coupled line U section improves the port to port isolation and provides the IF-output port. The mixer achieves a low conversion loss of 5.5 to 10.7 dB and high isolation of more than 26 dB over a 26-40 GHz RF/LO bandwidth and a DC-14 GHz IF bandwidth. The mixer's chip size is around 0.96 mm~2.     

Improved planar Marchand balun using a patterned ground plane

In this article, a novel planar Marchand balun using a patterned ground plane is presented. This new design has a slot under the coupled lines cut on the ground plane so that the even‐mode impedance can be increased substantially. Meanwhile, we propose that two additional separated rectangular conductors be placed under the coupled lines in order to act as two capacitors, so that the odd‐mode impedance will be decreased. The design theory and procedure for optimizing the Marchand balun are presented. As an example, one Marchand balun on a double‐sided PCB is designed, simulated, fabricated, and measured. The measured return loss is found to be better than ?10 dB over the frequency band from 1.2 to 3.3 GHz, or around 100% bandwidth. The measured amplitude and phase imbalance between the two balanced output ports are within 1 dB and 4°, respectively, over the operating frequency band. © 2005 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2005.     

A novel model for a planar wideband Marchand balun

A new lumped element model for conventional Marchand baluns is presented.Analyzed by the evenand odd-mode method,the equivalent equations are derived forλ/4 coupled lines.Based on the proposed 5th-order lumped equivalent circuit forλ/4 coupled lines,the self-inductance,mutual inductive coupling and the capacitance can be calculated according to the even- and odd-mode characteristic impedance,therefore,the model parameters of the balun can be easily gained from the derived equations.To verify the model,a GaAs monolithic wideband Marchand balun was implemented and tested.The EM simulation and experimental results show a good agreement with the model simulation.This model is available in a wide frequency range and makes the design procedure of the Marchand balun faster and easier.     

双频带巴伦馈电的宽带双频印刷偶极子设计

研究一种巴伦馈电双频印刷偶极子天线。为了使印刷偶极子天线工作在WLAN 频段,H 形状的缝隙开在偶极子两个臂上。优化无巴伦馈电的辐射单元,使得天线在回波损耗小于-10 dB 的情况下工作在2.4 GHz (2180-2750 MHz)和5.2 GHz (5040-5480 MHz)。为了展宽带宽,本文设计了一种改进的Marchand 巴伦,它能提供两个谐振点以增加阻抗带宽。通过优化辐射单元和双频带巴伦,设计了工作在2150-2750 MHz 和5050-6230 MHz 的印刷偶极子天线。设计公式在文章中已经给出,计算和测试结果吻合得很好。