具有谐波抑制的小型化混合环耦合器设计

提出一种具有谐波抑制的小型化混合环耦合器。采用T型结构代替7λ/6混合环中的每一段λ/6传输线,以显著减小混合环的尺寸;并且通过T型结构中的并联开路枝节引入带外传输零点,实现针对三次谐波的抑制作用。为验证理论的正确性,设计了一个中心工作频率为1 GHz的小型化混合环,并给出电磁仿真和实物测试结果。测试结果表明,所设计的混合环在保持3 dB耦合器工作特性的同时,在三次谐波附近插入衰减大于30 dB,实现了良好的谐波抑制功能。此外,该混合环的尺寸仅为传统混合环耦合器的34.2%,具有广阔的应用前景。     

一种小型化混合环及基于它的混频器设计

提出一种小型化混合环,它只有0.9倍中心频率导引波长,相比经典1.5波长混合环,电路面积有所减少。介绍了混合环的理论推导,并对比经典1.5波长混合环与0.9波长混合环的仿真结果,得到比较理想的结果。同时以0.9波长混合环为基础构建单平衡二极管混频器,在频段内变频损耗小于6dB,射频与本振端口隔离大于20dB,证明了其在实际电路中的使用价值。     

一种大功率宽带混合环及其功率容量分析

为了提高宽频带混合环的功率容量，本文采用了具有强耦合结构的重叠平行短路耦合线节作倒相器，并阐述了这种倒相器的设计方法，分析了它的功率容量。最后我们在400-450MHZ频段上设计制作了这种高功率宽带混合环，并对其进行了测试。     

S波段微波上变频器的设计

本文简要叙述了上变频器的工作原理,并详细介绍了一种采用3dB混合环电路的S波段微波上变频器的具体设计过程。     

五臂混合环的分析改进和具有三种分配比的功率分配器的设计

本文用等效电路法对五臂混合环进行了分析,并得出两种改进方案。改进后的方案,既能使中心臂同环完全匹配,同第二对侧臂理想隔离,也能使第一对侧臂同环完全匹配,并彼此理想隔离。本文还提出用五臂混合环设计具有三种分配比的功率分配器的方法,给出了分析和计算公式。理论分析和实验结果基本一致。     

微带式混合环特性的分析和双环微波门电路的研究

本文回顾了微波逻辑电路的研究现状。计算了微带式混合环的特性;并在这基础上发展了一种双混合环调相式逻辑电路,它可用作与门,或门和多数逻辑电路。文中写出了理论分析和实验证明。     

微带混合环定向耦合器计算机辅助设计

本文介绍了用奇偶模和场匹配法分析微带混合环定向耦合器特性的方法,并编制了软件对微带混合环定向耦合器S参数进行优化。利用编制的优化软件设计了一个3公分微带定向耦合器和5.9GHz功分器,测试结果和计算结果吻合得相当好。     

六端对分支线微带混合环

本文论述一种六端对分支线微带混合环。采用偶型及奇型的分析方法导出了六端对分支线混合环的设计计算公式,并通过实验获得在C波段频率上,三路等功率分配时插入损耗≤0.6db,输入端驻波系数≤1.15,不平衡度≤0.2db,三路彼比隔离>20db。此种混合环是专为某应答机模拟源的功率相加器而研制的,实现了在C波段上三路频率相近的信号相加,从同一端口输出。在电路结构上它不需要垂直过渡接头,宜于平面化,容易制作,体积小,因而它比一般的混合型三路等功率分配器优越。     

一种小型混合环及其在单平衡混频器中的应用

一种小型混合环及其在单平衡混频器中的应用ＭｉｃｒｏｗａｖｅａｎｄＯｐｔｉｃａｌＴｅｃｈｎｏｌｏｇｙｌ。ｅｔｔｅｒｓ，１９９４年第１６期报导了已研制成一种新型小巧的１８０ｏ混合环。它的周长仅为一个波长，与以往的一个半波长混合环不同。该文推导了这种环路的...     

宽带微带线3dB混合环设计

本文给出了宽带微带线3dB混合环电路中移相网络的新的结构和一种简便的设计方法。电路在40％的带宽内,电性能指标良好,电路能承受较大的功率,而且电路的制造工艺简单。     

功率合成电路在氮化镓放大器中的应用

针对氮化镓大功率放大器,由于传统1/4λ枝节线的电桥互耦造成放大器的直流自激和低频自激,在传统1/4λ传输枝节的Wilkinson电桥的基础上,结合氮化镓器件尺寸,设计出以3/4λ传输枝节的Wilkinson电桥为功率分配器/合成器。其输出端口尺寸为27.2mm。在8GHz～9GHz内,插入损耗<1dB,输出端口隔离度>14dB,端口回波损耗>9dB。利用实验室自制的SiC材料衬底的2.5mm栅宽GaN HEMT器件为放大单元,设计完成了两路合成放大器,在8GHz连续波条件下,放大器饱和输出功率为41.46dBm,合成效率为82.3%。通过分析发现,放大器合成效率的下降主要是由每路放大单元特性不一致和功率合成网络损耗所造成的。     

一种小型化电调正交耦合器

该文提出了一种3dB正交电调耦合器。该耦合器基于传输线变换技术进行设计,利用变容二极管调节3dB正交耦合器的中心频率,实现了从1.8~2.8GHz的中心频率调节范围,在可调范围内实现S11优于-15dB,S31大于-4.4dB,直通和耦合端的相位差为90±5°。该耦合器具有结构紧凑,偏置电路简单的优点。     

Size-reduction and band-broadening design technique of uniplanarhybrid ring coupler using phase inverter for M(H)MIC's

The hybrid coupler is one of the most fundamental building blocks in microwave and millimeter-wave systems. Ring topology can be often found in the hybrid microwave integrated-circuit design of narrow and broad-band integrated couplers and mixers. In this paper, we propose a new design theory using a phase inverter for systematic size reduction and band broadening of a uniplanar hybrid ring coupler. The features and design criteria of broad-band reverse-phase hybrid ring couplers are presented. Effective bandwidth of a new reverse-phase hybrid ring coupler can be increased by 28% with a return loss of 20 dB. In addition, we present a class of uniplanar phase inverters and discuss their technical aspects. Experimental results show that the bandwidth of the proposed phase inverter is greater than 1.9 octaves with insertion loss below 1 dB and phase shift error of less than ±20°. Measurements confirm that the new uniplanar hybrid ring coupler provides attractive features. Its isolation is better than 20 dB over a 1.8-octave bandwidth attributed to the phase inverter providing almost a frequency-independent phase shift     

Effect of wall thickness on broadband design of a Ka-band TE21-mode coupler

Commonly, the classical formulas for designing TE₂₁-mode coupler are suitable for the operating frequency under Ka-band by virtue of ignoring wall thickness. However, in real application of TE₂₁-mode coupler design beyond Ka-band, the new formulas need to consider the effect of wall thickness. Herein, we demonstrate a design measure of a TE₂₁-mode coupler beyond Ka-band via computer simulation, giving attention to wall thickness. The experimental results show that a measure of linear second weighted sum for coupling hole size could improve coupler performance. Amazingly, such coupler shows 10% bandwidth with less than 0.5 ​dB coupling loss and more than 40 ​dB isolation is possible.     

一种Q波段多孔耦合型定向耦合器

论述了一种宽带多孔耦合型定向耦合器,工作频段中心频率为40 GHz,相对带宽50%,拟用于射电望远镜Q波段接收机系统。该定向耦合器为一款结构紧凑的器件,采用对称的等间距多孔耦合形式,将主通道圆波导TE11模式信号耦合到耦合通道的矩形波导中,实现了小于-20 dB 耦合特性。为了对设计进行验证,对该定向耦合器进行了加工和测试。测试结果表明,在30~50 GHz 工作频段内,主通道反射系数小于-24.2 dB,且全频段内的端口耦合度保持在-20~-21 dB 之间。仿真与测试结果具有较高的吻合度,进一步证实了该设计可用于射电天文望远镜的Q波段接收机系统。     

A Novel Terahertz Rat-Race Hybrid Coupler Based on PPDW

A novel rat-race hybrid coupler based on parallel-plate dielectric waveguide (PPDW) is proposed. PPDW has been proposed as a basic terahertz transmission line for its remarkable simple structure and comparatively low attenuation at terahertz frequency band. It can be applied to design many terahertz components. In this paper, a (3 N + 3/2) × lambda circumference PPDW rat-race hybrid coupler operating at quasi-TE₁₀ mode is studied. The investigation results show that, at 0.34 THz, the transmission losses of the two split output ports are both equals −3.2 dB; the return loss at its input port is below −20 dB; the insertion loss at each split transmission port is less than 0.2 dB; and the two isolated ports show good isolation of above 20 dB. Therefore, it will have wide potential applications at terahertz frequency band.     

基于3 dB 定向耦合器的0.14 THz 功率分配器设计方法

介绍了一种基于3 dB 定向耦合器的0.14 THz 功率分配器设计方法。由于太赫兹频段的器件尺寸越来越小型化、微型化,特别是对于功率分配器中的核心结构,造成精密机械加工方式难以实现。典型的波导3 dB 定向耦合器结构是90电桥结构,其耦合缝隙之间的间距仅有不到0.5 mm,这样的尺寸是机加时产生的应力难以承受的。通过分析波导定向耦合器支路间的相位关系得出:如果耦合缝隙的间距增加到半波长的整数倍,支路间的相位差仍为90,但这样变化的结果是带宽的降低。通过耦合缝隙间距的适度增加,降低了机加的难度,工作相对带宽降到10%。经仿真分析,结果得到了验证。加工的样品测试结果表明,在0.133 ~0.147 THz 的频率范围内,插入损耗小于1 dB,回波损耗小于-20 dB。     

Miniaturized microstrip branch-line coupler with good harmonic suppression performance

This paper presents a miniaturized microstrip branch-line coupler with good harmonic suppression performance. The proposed coupler consists of four branch-line sections, each of which is loaded by open-circuit stubs both at the center and the two ends. This type of loading can realize size reduction and harmonic suppression. As an example, a proposed branch-line coupler operating at 1.0 GHz is designed, fabricated and measured. The results show that the proposed branch-line coupler occupies 67% size of a conventional one and has better than 20 dB suppression from 1.9 to 5.8 GHz. Furthermore, the high slop of the transition band ensures good selectivity of the coupler.     

Novel Rat-race Hybrid Coupler for RF Front-end Module

In this paper, a novel compact rat-race hybrid coupler incorporating an improved beeline compact microstrip resonant cell(IB-CMRC) is presented firstly. The size of the coupler is reduced by 46.5% than conventional one due to IB-CMRC’s excellent slow-wave effect. The novel coupler possesses strong ability of high-order harmonic suppression (above 30 dB) in addition. The measured insertion loss is comparable to that of a conventional microstrip hybrid coupler. Great potential applications of this IB-CMRC can be explored in MICs and MMICs to reduce the circuits size, suppress harmonics and improve the overall performance of the RF front-end module.     

一种超宽带宽边耦合微带定向耦合器

提出了一种新颖的超宽带宽边耦合微带定向耦合器,相比窄边耦合结构,宽边耦合增加了耦合面积,可实现宽频的3 dB紧耦合.同时,为进一步拓展耦合器工作带宽,该文采用渐变耦合结构替代传统的矩形耦合结构.通过HFSS仿真验证,此定向耦合器在2～6 GHz频带内插入损耗小于0.9dB,输入端口回波损耗大于20 dB,端口隔离度大于21 dB.