左手非线性传输线三倍频器设计

非线性传输线通常用来实现谐波产生和脉冲形成。利用左手非线性传输线的谐波产生特性,设计仿真了100MHz的三倍频器。该倍频器采用5级级联的“T”形非线性单元,不需要任何偏置电路。相比传统方法,该方法具有电路尺寸小、结构简单、调试容易、倍频效率高、相对带宽较宽等优点。     

Multi‐band pattern reconfigurable Yagi‐Uda antenna

In this study, novel designs of single‐band and tri‐band pattern reconfigurable antennas are proposed. The design of single‐band pattern reconfigurable antenna is accomplished by the use of varactor diodes with the parasitic elements placed on both sides of the driven conventional printed dipole antenna. By tuning the capacitance of varactor, the antenna operates in four different configurations of radiation pattern which include bi‐directional end‐fire, broadside, and uni‐directional end‐fire radiation patterns. The tri‐band pattern reconfigurable antenna design is achieved by the use of parasitic elements on both sides of a tri‐band driven dipole antenna. Dual‐band LC resonators are used as loading elements along the arms of printed dipole to get two lower order modes in addition to the reference dipole mode, resulting in a triband operation of the driven element. The electrical lengths of the parasitic elements with respect to the tri‐band driven element are controlled by suitably embedding varactor and PIN diodes with them. The proposed tri‐band antenna operates in ten different configurations of radiation patterns in the three operating bands. Fully functional prototypes of single‐band and tri‐band pattern reconfigurable antennas along with the DC bias networks have been fabricated to validate the results obtained in simulation.     

MPNIM结构光致变电容效应

本文报告了作者之一首先发现的MPNIM(金属-P型半导体-N型半月比-绝缘体-金属)结构的光致变电容效应。基于该效应已研制出新器件:半导体双向光控变容器.新器件的电容值与入射光强的关系,光谱响应特性,频率特性,C-V特性,温度特性已被研究.     

一种K波段GaAs MESFET压控振荡器的设计

利用微波晶体管的负阻特性,基于Agilent ADS软件,设计出一种K波段微带结构、变容管调谐的MESFET压控振荡器(VCO)。对VCO进行实测．结果表明,VCO的中心频率为20.56GHz,调频带宽大于100MHz,带内输出功率大于2mW,相位噪声大于-90dBc／Hz@100kHz,满足实际应用。     

砷化镓倍频变容管的研制

倍频变容管的特性直接影响变容管倍频器的性能。文中介绍倍频变容管的设计 ,并制作出了与设计结果基本一致的器件。获得了输入 8GHz、5 0 0 m W,输出 16 GHz,最高倍频效率大于5 0 %的二倍频测试结果 ,并给出了 8mm四倍频器的使用结果     

High Performance Millimeter‐Wave Image Reject Low‐Noise Amplifier Using Inter‐stage Tunable Resonators

A Q‐band pHEMT image‐rejection low‐noise amplifier (IR‐LNA) is presented using inter‐stage tunable resonators. The inter‐stage L‐C resonators can maximize an image rejection by functioning as inter‐stage matching circuits at an operating frequency (F_OP) and short circuits at an image frequency (F_IM). In addition, it also brings more wideband image rejection than conventional notch filters. Moreover, tunable varactors in L‐C resonators not only compensate for the mismatch of an image frequency induced by the process variation or model error but can also change the image frequency according to a required RF frequency. The implemented pHEMT IR‐LNA shows 54.3 dB maximum image rejection ratio (IRR). By changing the varactor bias, the image frequency shifts from 27 GHz to 37 GHz with over 40 dB IRR, a 19.1 dB to 17.6 dB peak gain, and 3.2 dB to 4.3 dB noise figure. To the best of the authors' knowledge, it shows the highest IRR and F_IM/F_OP of the reported millimeter/quasi‐millimeter wave IR‐LNAs.     

一种芯片集成Ku波段MESFET压控振荡器的设计

利用微波晶体管的负阻特性，基于Agilent ADS软件，设计出一种Ku波段微带结构、变容管调谐的MESFET压控振荡器（简称VCO）。对VCO进行实测，结果表明，VCO的中心频率为14.14GHz，调频带宽大于100MHz，带内输出功率大于2mW，满足实际应用。     

V波段变容管三倍频器

设计制作了一个从22.8GHz到68.4GHz的封装型变容管三倍频器,这是目前报导的用封装型变容管所达到的最高频率。该倍频器在结构上实现了空闲回路独立可调,从而提高了倍频效率。当频率为22.8GHz而输入功率为47mW时,最大三次谐波输出为4.9mW,最大倍频效率为10.4％,输出频率至少在2GHz的范围内倍频效率不低于7％。     

A 4.2-5 GHz,low phase noise LC-VCO with constant bandwidth and small tuning gain

As the tuning frequency of an integrated LC-voltage controlled oscillator （LC-VCO） increases, it is difficult to co-design the active negative resistance core and the varactor to achieve wideband frequency range, low phase noise, constant bandwidth and small tuning gain together. The presented VCO solves the problem by designing a set of changeable varactor units. The whole VCO was implemented in a 0.18μm CMOS process. The measured result shows -120 dBc/Hz phase noise at 1 MHz offset. The measured tuning range is from 4.2 to 5 GHz and the tuning gain is 8-10 MHz/V. The VCO draws 4 mA from a 1.5 V supply voltage.     

基于准MMIC技术的12~18GHz宽带VCO

提出了一种基于准MMIC技术的Ku波段宽带压控振荡器.该电路采用MMIC芯片和外加高Q值的超突变结变容管的方式,实现了覆盖整个Ku波段的超宽带的振荡信号输出.通过将MMIC技术与混合集成技术相结合的方法,大大降低了调试难度,更重要的是,克服了通用pHEMT MMIC工艺难于兼容高Q值的变容管对超宽带设计VCO的限制,在相位噪声和调谐频率线性度方面都有较大改善.该方法为微波、毫米波压控振荡器的设计提供了一个新的途径.