短波宽带高功率传输线变压器设计

针对高功率短波通信系统中天线与馈线之间的宽带阻抗匹配及平衡转换问题,对于传输线变压器的设计进行了理论分析,重点分析了高功率应用时,如何正确选择磁芯材料技术参数从而确保特定传输线变压器指标的实现。根据理论分析结果,设计并制作了一只传输线变压器,在2～30MHz的带宽内,驻波系数小于1.4,应用于1.6kW高功率短波通信系统中得到了满意的结果。     

不对称传输线理论分析及实验研究

该文在假设双线传输线两线上电流大小相等、方向相反的条件下,运用双线传输线理论思想,推得不对称(电流)双线均匀传输线的电压、电流关系。由此,文中给出了一种分析双线传输线变压器的实用、有效的方法,且理论结果与实测结果具有较好的一致性。     

宽带高效片上传输线变压器的设计

采用集成电路工艺设计了两款Ruthroff型传输线变压器,其相应的阻抗比分别为1∶4和1∶9。基于TSMC 180nm CMOS工艺参数,传输线变压器采用ADS Momentum软件进行电磁仿真。结果表明:1∶4传输线变压器的1 d B带宽为6.3 GHz,插入损耗为0.56 d B;1∶9传输线变压器的1 d B带宽为7 GHz,插入损耗为0.55 d B,可以应用于宽带功率放大器的设计,实现负载阻抗的转换。     

非均匀有耗传输线ABCD参量的求解

传输线理论是射频与微波电路的重要基础理论,而其中ABCD参量特别适用于分析级联网络的传输性能.本文针对非均匀有耗传输线的ABCD参量求解问题,建立传输线的数学模型,给出了三种解法,即级联法、微分方程法和积分方程法,并对三种方法的准确性和效率进行了讨论.     

一种大功率宽频带低损耗定向耦合器的设计与实现

根据传输线变压器串并联同时耦合的原理,设计了一种13dB铁氧体定向耦合器,该定向耦合器是用漆包线绕在射频铁氧体磁芯上做成.具有尺寸小、结构简单和频带宽等优点,工作范围在100～400MHz.对其参数进行了理论计算和测量,满足设计要求.经过实际应用,验正了设计方法的可行性.     

射频电路中平面螺旋电感的计算

介绍了单晶集成电感、单晶传输线变压器以及将其作为balun的运用方案.对射频电路中平面螺旋电感的分布参数模型进行了分析,进而讨论了平直导体的电感值的理论计算方法,然后以此为基础,以两圈的长方形、一圈的平面螺旋线圈电感和正方形平面螺旋电感为例计算了其电感值.     

2～30MHz功率放大器设计

根据宽带功率放大器的设计原理，采用传输线变压器宽带匹配技术，用MOSFET晶体管VRF141，设计了一种推挽宽带功率放大器。通过测试，得到较为理想的结果。     

30～150MHz宽带双定向耦合器设计

介绍了基于三线变压器魔T的双定向耦合器工作原理,分析了串联耦合信号与并联耦合信号通过魔T进行同相和反相合成的机理,应用电报方程分析它的阻抗变换特性,得到扭绞三线传输线变压器魔丁的最佳传输条件。设计了一种耦舍度为30dB的宽带双定向耦合器,并对其参数进行了理论分析和测量,满足设计要求,为充带双定向耦合器的设计和优化提供了理论基础。     

宽带射频信号背板实现的可行性分析

通过仿真分析和试验测试方法评估了通过板级传输方式替代射频电缆实现射频信号传输的可行性,对宽带射频信号纳入微波多层板进行传输的关键技术进行了分析,包括大尺寸、高机械强度背板的微波基材的选择,射频连接器的选择,复杂电磁环境下的路间隔离度,传输链路阻抗平滑和连续,长距离射频传输线的插入损耗,以及宽带范围内如何消除平面层自激等...     

CMOS射频功率放大器中的变压器合成技术

设计了一种可在CMOS射频功率放大器中用于功率合成的宽带变压器。通过对变压器的并联和串联两种功率合成形式进行分析与比较,指出了匝数比、功率单元数目以及寄生电阻对变压器功率合成性能的影响;提出了一种片上变压器的设计方法,即采用多层金属叠层并联以及将功放单元内置于变压器线圈中的方式,解决了在CMOS工艺中设计变压器时面临的寄生电阻过大及有效耦合长度不足等困难。设计的变压器在2～3 GHz频段内的损耗小于1.35 dB,其功率合成效率高达76%以上,适合多模多频段射频前端的应用。     

225MHz～512MHz宽带功放设计与仿真

根据宽带功放的设计原理,采用平衡式结构,负反馈技术,稳定化技术,传输线变压器以及微带混合匹配电路设计出了一款宽带功率放大器。用ADS对其进行优化仿真,通过分析仿真结果,可以看出在225 MHz～512 MHz频段内,放大器功率增益可达到23 dB,增益平坦度小于1.1 dB,理想情况下输入输出驻波比达到1∶1,并具有良好的稳定性。     

Broadband phase switches for radio-frequency and microwave interferometry

Two wideband phase switches have been built for radio and microwave interferometry. In one, the directions of current flow in a balanced transmission line are reversed periodically. The line is coupled into the interferometer via broadband baluns. The second device switches between the E plane outputs of a magic T.     

广电城域网络面临的发展趋势和挑战

随着宽带中国的逐步演进,广电运营即将面对视频和宽带业务带来的带宽提速压力,高清视频点播导致宽带流量承爆炸式增长,网络IP化趋势加速变革（例如终端IP化,业务IP化,传输IP化）,新业务飞速增长也迫使长期存在的传统业务例如广播视频、固定语音、传统专线等受到挑战。     

A fully integrated 10-Gb/s tapped delay Hilbert transformer for optical single sideband

A 10-Gb/s SiGe HBT tapped delay Hilbert transformer (HT) integrated circuit (IC) is described. The four tap filter uses an integrated LC transmission line with a total delay of 180ps, and the HT has a nominal group delay of 120ps. The circuit is fabricated in a 47-GHz f/sub T/ SiGe HBT process and consumes 112mW from a -3.3-V supply. Measured s-parameters and time domain waveforms are shown to agree with theory. Measurements of a 10-Gb/s optical single sideband system indicate that 7dB of broadband sideband suppression is obtainable using the IC.     

Vertical microstrip transition for multilayer microwave circuits with decoupled passive and active layers

A novel broadband (including dc) microstrip-to-microstrip vertical transition for multilayer microwave circuits is proposed. This transition solves the problem of the discontinuity typically appearing in via hole transitions between two microstrip transmission lines in different layers. An analogy existing between this transition and a rectangular coaxial line is discussed. A parametric study alongside with the experimental results of the transition are presented. Reduction of local oscillator to radio frequency leakage in a mixer with this transition is demonstrated.     

Basic RF Characteristics of the Microstrip Line Employing Periodically Perforated Ground Metal and Its Application to Highly Miniaturized On-Chip Passive Components on GaAs MMIC

In this study, highly miniaturized on-chip impedance transformers employing periodically perforated ground metal (PPGM) were developed for application to broadband low-impedance matching. In order to realize a broadband operation by using an equal ripple transfer characteristic over a passband, a three-section transformer was designed by mapping its reflection coefficient to the Chebyshev function. The three-section transformer showed a good RF performance over a broadband (1.5–13 GHz) including ultra-wideband. The size of the three-section transformer was 0.129$hboxmm^2$, which is 2.3% of the size of the transformer fabricated by a conventional microstrip line. Using the PPGM structure, a highly miniaturized on-chip Wilkinson power divider with a low port impedance of 13$Omega $was also developed, and its size is 0.11$hboxmm^2$, which is 6% of the size of the one fabricated by the conventional microstrip line. In addition, in this study, the PPGM structure was theoretically characterized using a conventional capacitive loaded periodic structure. Using the theoretical analysis, basic characteristics of the transmission line with PPGM were also investigated in order to evaluate its suitability for application to a development of miniaturized on-chip passive components. According to the results, it was found that the PPGM structure is a promising candidate for application to a development of miniaturized on-chip components on monolithic microwave integrated circuits.     

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.     

Miniaturised broadband on-chip transformer employing PPGM on MMIC for application to low impedance transformation

Using a microstrip line employing periodically perforated ground metal (PPGM) on a GaAs monolithic microwave integrated circuit (MMIC), a highly miniaturised and broadband impedance transformer was developed for application to low impedance matching in broadband. Its size was 0.132 mm/sup 2/ on GaAs substrate, which was 2.3% of the one fabricated by a conventional microstrip line. The transformer showed good RF performance over a broadband including ultra-wideband. This is the first report of an on-chip broadband impedance transformer fabricated on MMIC.     

传输线在宽带匹配中的应用

提出了一种宽带匹配网络设计的新思路。文中以任意输入阻抗的匹配为分析模型,详细分析了传输线在宽带匹配中的各种应用,并从宏观角度定性分析了传输线在阻抗匹配中的应用原理。在此基础上分析设计了一副工作在30～88 MHz频段、电压驻波比小于3．0的实用单极子天线,其实测结果良好地满足了要求。