基于枝节加载谐振器的双频滤波功分器设计北大核心CSCD

无线通信系统中,滤波器用于滤除带外干扰信号,功分器用于实现将一路信号分成多路信号,二者广泛应用于射频/微波系统的接收之路前端。滤波功分器作为新型功能融合性器件,可以同时实现频率选择和功率分配的功能,并且能显著减小器件尺寸。本文对滤波功分器设计进行了研究,基于枝节加载谐振器设计了两款双频滤波功分器,滤波功分器采用了四个枝节加载谐振器以替代传统Wilkinson功分器的两段四分之一波长传输线,实现了双通带响应。引入了三个传输零点,两个通带内回波损耗都优于20dB,实际插入损耗小于1dB,隔离度优于10dB,仿真结果良好。     

一种基于LTCC的宽带一分三滤波功分器

为实现射频系统中微波器件的宽带化、小型化,设计了一款具有滤波性能的功分器。该滤波功分器创新性地将带通滤波器与一分三功分器级联在一个封装器件中,大大减小了体积且解决了阻抗不匹配问题。其中带通滤波器采用四级半集总结构,加入耦合电容版提高滤波性能,一分三功分器采用LC集总结构,实现了小型化。利用ADS软件进行二维仿真,利用HFSS软件进行三维模型的仿真。本文设计的一分三滤波功分器尺寸仅为3 mm×5.6 mm×1.5 mm,工作频带为1.8～2.2 GHz。仿真后的结果为:插入损耗小于7 dB,回波损耗优于19 dB,隔离度优于17 dB,所设计的滤波功分器满足性能要求,且具有小型化高性能的应用优势。     

一种宽带一分四Wilkinson功分器的设计与实现

对传统微带功分器的设计方式进行改进,利用薄膜芯片电阻代替传统电阻,工作至Ka波段也可保证较好的隔离度性能。利用薄膜芯片电阻制作了一款宽带一分四Wilkinson功分器,采用两级一分二功分器来实现一分四,每一级一分二功分器采用2节的Wilkinson功分器来实现。同时为了降低功分器的各端口在高频段下的回波损耗,功分器的各端口采用了空气腔的补偿方式。测试结果显示,在工作频段19~31 GHz内,功分器的各端口输出驻波小于1.6,输入驻波小于1.6,插入损耗小于10 dB,相邻端口之间的隔离度大于19 dB。     

基于电磁带隙结构的四路双频带滤波功分器

针对无线通信系统对微波器件多频段、多通道的应用需求，基于电磁带隙结构，提出了一款四路应用的小型双频滤波功分器。该滤波功分器由八对电磁带隙(Electromagnetic Bandgap, EBG)谐振器、隔离电阻以及隔离网络构成，同时实现功率分配和频率选择的功能。由于引入外部集总电容器，通过改变电容值可以独立控制每个通带的工作频率。其次，磁场主要集中于谐振器的谐振金属柱周围，减小了通带间的信号干扰，从而实现较好的通带间隔离。此外，采用奇偶模分析和耦合矩阵综合方法设计了该功分器的双通带响应。最后为验证设计的有效性，加工制作了一款四路双频带滤波功分器，两个通带中心频率分别工作于2.18 GHz和3.23 GHz,最小插入损耗分别为1.44 dB和2.63 dB。实测结果与仿真结果基本吻合。     

从S波段到毫米波段的可重构功分器设计研究

为满足毫米波可重构通信系统需要,文中设计了毫米波可重构威尔金森功分器. 首先在S波段设计了基于PIN二极管的可重构功分器电路和原型;然后在此基础上把原理外推到K/Ka频段,通过参数提取方法重点研究PIN二极管寄生参数的影响及其最佳匹配方式;最后设计了K/Ka频段的可重构功分器原型,并进行了仿真和测试. 实测结果表明,K/Ka频段可重构功分器在工作带宽内,双路导通模式下端口1到传输端口（端口2和端口3）的插入损耗小于4.92 dB,传输端口之间的隔离度大于15.8 dB;单路导通模式下插入损耗小于1.65 dB,端口1和隔离端口之间的隔离度大于22.4 dB,实测结果与仿真结果基本一致. 使用场路联合仿真的方法基于PIN二极管设计可重构功分器,在K/Ka频段考虑寄生参数的影响,设计的可重构功分器模型准确、结构简单,适合可重构系统应用.     

一种微带线高隔离度功分器的设计

在功分器设计中,随着频率的升高,输出端口的隔离度会变差,使系统性能下降。应某课题的需求,利用微 带传输线的特性,仿真设计了一种具有高隔离度的Ku 频段威尔金森功分器,设计原理是通过在输出臂适当增加微带线, 同时引入隔离电阻实现输出端口匹配。将此功分器应用到阵列天线的馈电系统,子天线间端口隔离度变大,仿真结果 能达到-40dB,能够满足应用需求,提升了阵列天线系统的性能。     

小型双频Wilkinson功分器的设计与制作

为了简化双频Wilkinson功分器的总体结构,并减小功分器的整体尺寸,在对奇模-偶模理论深入研究的基础上,利用传输线的双频阻抗变换特性,并在输入端口并联开路微带线,设计出了一个尺寸小,工作在900和2 450 MHz两个RFID频段的功分器。对功分器进行ADS仿真与实际测试,测试结果显示:当其在两个中心频率点时,传输损耗分别为3.20和3.23 dB,隔离度小于-28 dB,各个端口的回波损耗小于-30 dB,测试与仿真结果吻合良好。同时,该实测结果也显示出了功分器在两个RFID频率上具有良好的性能指标,验证了设计方案是可行的,也保证了能够很好地应用于双频RFID系统中。     

一种新型双频Wilkinson功分器的设计

为了实现功分器工作在任意两个频率的目的,设计了一种新型功分器.基于奇偶模分析方法,利用微波网络理论推导了电路参数的设计公式,通过求解相应的非线性方程组获取了具体电路参数.制作了一个工作频率为1GHz和2.6 GHz的双频Wilkinson功分器.实物测试结果表明,该功分器在两个中心频率的传输衰减小于3.3dB,端口回波损耗大于21 dB,端口隔离度大于28 dB,在中心频率100 MHz的通带范围内都具有良好性能,验证了设计方法的可靠性.     

小型化和差功分器的设计

提出了一种小型化微带环形耦合器,利用该耦合器和威尔金森功分器设计并制作了一个和差功分器。测试结果表明,在1 030~1 060 MHz内,该功分器插损小于1.2 dB,输入端回波损耗大于14 dB,输出端隔离度大于20 dB。该和差功分器在保证了器件各端口的相位关系的前提下,其尺寸可减小30%,具有插损小、隔离度大、结构简单、成本低的优点。     

改进K型单刀四掷射频MEMS开关

针对射频器件小型化以及5G通信发展的需求，设计了一款射频微机电系统（RF-MEMS）单刀四掷开关。该开关由一个改进型K型功分器和六个单刀单掷开关级联构成，并基于硅基MEMS工艺进行制造。其中，改进型K型功分器由多个Y型功分器串并联构成。改进的开关各端口具有插入损耗小和隔离度高的特点。最终流片的测试结果显示：该单刀四掷MEMS开关的插入损耗优于2.8 dB，隔离度优于29 dB。     

基于谐振器慢波传输线的小型化宽阻带谐波抑制功分器

该文提出一种基于谐振器慢波传输线的小型化宽阻带谐波抑制功分器,该谐振器慢波传输线由矩形谐振器、T型谐振器和蛇形线构成,来取代功分器中的1/4波长传统微带传输线。所设计制作的功分器,其尺寸仅为传统微带功分器的37.4%。实验结果表明,该功分器回波损耗大于10 dB的带宽范围为0.1～1.19 GHz,在2.2～11.05 GHz频率范围内衰减大于20 dB,具有较宽的阻带从而具有抑制谐波效果。仿真和测试结果较为吻合,验证了所提设计方法的有效性。     

Compact and Harmonic Suppression Wilkinson Power Divider With Short Circuit Anti-Coupled Line

A compact Wilkinson power divider using a short circuit anti-coupled line for harmonic suppression is presented in this letter. The structure consists of a pair of anti-coupled line short circuited by a capacitive load realized by a low impedance line. It can offer three finite attenuation poles in the stopband, while arbitrary phase shift can be obtained in the passband. Design procedures have been clearly presented. A 1.8-GHz power divider is designed, fabricated and measured for demonstration. It agreed well with the simulated results. The circuit area of the proposed divider is only 40% of that of the conventional one. Furthermore, the proposed divider has spurious pass-band suppression as high as 20dB.     

Compact Bandpass Filter with high selectivity and wide stopband using Slotted Stepped-Impedance Resonator

In this paper, a Slotted Stepped-Impedance Resonator (SSIR) is proposed. Due to the slots in the low-impedance section of the conventional SIR, the new resonator has a lower fundamental resonance f0 and can provide a potential finite transmission zero fz close to f0. Based on the proposed SSIR, a fourth-order Chebychev BandPass Filter (BPF) is designed at f0=1 GHz. The measured results show that a better than –65 dB rejection is achieved on both the lower and the upper stopband. Moreover, the new filter has a wide –30 dB rejection upper stopband from 1.13f0 to 6.52f0. The fab-ricated filter exhibits a size of The new filter has a planar topology and is easily integrated with modern portable communication systems.     

低损耗高阻带抑制声表面波滤波器

为了提高雷达信号的接收灵敏度,提出一种低损耗高性能的单相单向换能器,其设计采用了电极宽度控制来实现。发射和接收叉指换能器分别选取适当的加权函数,能得到更低的旁瓣电平。设计制作了中心频率67 MHz,3 dB带宽1 MHz,单向性为21 dB,插损3.8 dB,阻带抑制大于45 dB的低损耗高阻带抑制声表面波滤波器。     

Power divider with microstrip electromagnetic bandgap element for miniaturisation and harmonic rejection

A novel technique for harmonic suppression and size reduction in planar Wilkinson power divider is presented. The proposed technique served by a microstrip electromagnetic bandgap element (MEBE) is used to reject the unwanted harmonics by employing its stopband effect and to reduce the length of microstrip by utilising its slow- wave effect. The whole size of the proposed divider has been reduced by 39% compared to the conventional power divider. Higher harmonics are effectively suppressed.     

Novel coplanar-waveguide bandpass filters using loaded air-bridge enhanced capacitors and broadside-coupled transition structures for wideband spurious suppression

Novel inline coplanar-waveguide (CPW) bandpass filters composed of quarter-wavelength stepped-impedance resonators are proposed, using loaded air-bridge enhanced capacitors and broadside-coupled microstrip-to-CPW transition structures for both wideband spurious suppression and size miniaturization. First, by suitably designing the loaded capacitor implemented by enhancing the air bridges printed over the CPW structure and the resonator parameters, the lower order spurious passbands of the proposed filter may effectively be suppressed. Next, by adopting the broadside-coupled microstrip-to-CPW transitions as the fed structures to provide required input and output coupling capacitances and high attenuation level in the upper stopband, the filter with suppressed higher order spurious responses may be achieved. In this study, two second- and fourth-order inline bandpass filters with wide rejection band are implemented and thoughtfully examined. Specifically, the proposed second-order filter has its stopband extended up to 13.3f/sub 0/, where f/sub 0/ stands for the passband center frequency, and the fourth-order filter even possesses better stopband up to 19.04f/sub 0/ with a satisfactory rejection greater than 30 dB.     

一种新型毫米波8路功分器/合成器的设计

设计了一种Q波段8路功分器/合成器。利用波导功分器及微带功分器混合设计,提出了波导-微带4路功分器与3 dB Wilkinson电桥一体化设计思想,设计出一种较高隔离度,结构紧凑的新型8路功率分配器/合成器。通过高频电磁仿真软件(HFSS)仿真设计,在42 GHz~47 GHz频带范围内,8路分配器输出端口反射损耗优于-19 dB;8路输出端口的幅度不平衡度小于0.25 dB,相位不平衡度小于0.5o,插损小于0.25 dB;4个输出口之间的隔离度大于9 dB,是一种较为理想的8路功率分配器/合成器,在实际小体积高合成效率要求的固态功率合成领域,以及具有小体积的多路信道实现中,具有较高的应用价值。     

A S-Bridged Inductive Electromagnetic Bandgap Power Plane for Suppression of Ground Bounce Noise

In this letter, a novel power plane using an inductive S-bridged electromagnetic bandgap (EBG) is proposed for ultra wideband suppression of the ground bounce noise. The S-shaped bridge detouring unit cells effectively increase the power plane inductance. -30 dB stopband is realized from 220 MHz to 7 GHz. The stopband lower limit (220 MHz) of the proposed EBG has been greatly reduced from that (550 MHz) of L-bridged EBG. It is expected that the number of local decoupling capacitors for the power plane integrity is reduced using the proposed S-bridged EBG without the self resonance effect.     

采用卷积神经网络的双频功分器优化设计

功率分配器(简称功分器)作为微波电路中常用的射频器件,是构建5G系统多输入多输出(MIMO)馈电网络的重要组成单元。为了对已有固定频率的功分器结构进行重新快速地优化设计,以适用于包括5G工作频段在内的任意实际所需的工作频段,该文以预先设计的一种双频功分器作为优化设计目标,提出了一种基于改进后的一维卷积神经网络的深度学习方案。预测功分器在其他任意双谐振频率处拥有良好性能的几何结构参数,运用自组织映射神经网络进行样本的选取,提高卷积神经网络的训练效率。预测出的功分器在电磁仿真软件中进行验证,仿真结果显示功分器在工作频率处的回波损耗高于20 dB,隔离度高于25 dB,插入损耗低于3.4 dB,工作带宽约为450~600 MHz,证明了利用神经网络实现多参数目标功分器的优化设计是一种快速有效的方法。     

A novel couple-type power divider with large-angle low-losscharacteristics

A novel large-angle low-loss direction-coupler type power divider with designed ratio between output waveguides is proposed. The radiation loss is greatly reduced by using a micro-prism at the bend corner to compensate the phase mismatch due to bending. A normalized transmitted power of the power divider with a bend angle of 10° simulated by the semivectorial beam propagation method is about 93%, which is much larger than those were reported for single-mode waveguides. Application of more micro-prisms is also shown. The calculated loss of a symmetric large-angle 3-dB directional coupler with eight micro-prisms is less than 0.953 dB