高线性宽带非对称SPDT射频开关设计

发布时间：2018-06-15 13:28

本文选题：高线性 + 非对称　；参考：《浙江大学》2017年硕士论文

【摘要】：射频微波行业突飞猛进,促进手机终端、智能控制系统、通信市场的快速发展,使得人们越来越依赖性能优良的收发系统,对高集成度、高性能和低成本射频前端的需求愈发迫切。本设计中的射频微波开关是射频前端的关键元件,其电路性能将直接影响射频系统性能。设计针对收发系统的导通关断需求的单刀双掷开关进行研究,首先探讨了射频开关芯片市场的需求现状,针对几款常见芯片进行参数对比综合评价,进而提出设计目标。然后讨论目前业内常用工艺,对比得出用于专门设计开关芯片的0.5μm栅宽砷化镓基赝配异质结高速电子迁移率晶管(GaAs pHEMT)工艺的优势。此工艺能较好实现射频前端集成模块中的功率放大器、开关、低噪放等元件的设计,性能参数优良。可以满足高集成度的需求,功耗低且成本可控。文中针对发射支路与接收支路性能要求不同,创新设计非对称结构的开关拓扑;利用场效应管的堆叠理论、对于开关管芯的多栅理论、开关控制的基本原理等在保证插入损耗以及隔离度的情况下着重提高其线性度。通过优化接地电容增大开关的使用带宽、提高谐波抑制能力。同时考虑减小键合线引入的电感影响等。为了进一步提高功率处理能力,针对性设计大小合适的前馈电容。然后利用ADS软件进行原理图与整体版图设计、仿真,将插入损耗、反射损耗、隔离度等小信号性能参数与线性度包括谐波抑制比和输入三阶交调截点等进行综合分析,取性能折衷最优,完成版图设计。最后完成流片、封装,芯片大小为3*3 mm2。采用射频微波试验台对开关芯片进行实测,测试结果表明,本设计开关芯片工作带宽为10MHz-2.6GHz,插入损耗(IL)小于0.6dB,隔离度(ISO)大于26dB,发射支路功率处理能力可达42dBm(70dBc),接收支路为35dBm(68dBc),符合应用需求。
[Abstract]:The rapid development of RF and microwave industry promotes the rapid development of mobile terminal, intelligent control system and communication market, which makes people rely more and more on the excellent transceiver system and high integration. The demand for high performance and low-cost RF front-end is becoming more and more urgent. The RF microwave switch in this design is the key component of the RF front end, and its circuit performance will directly affect the RF system performance. A single-pole double-throw switch is designed for the on-off requirement of transceiver system. Firstly, the market demand of RF switch is discussed, and the parameters of several common chips are compared and evaluated, and then the design goal is put forward. Then the current common technology is discussed, and the advantages of the 0.5 渭 m gate width GaAs pHEMT-based pseudo-heterojunction GaAs pHEMTs process for designing switch chips are compared. This process can realize the design of power amplifier, switch, low noise amplifier and so on in RF front-end integrated module, and the performance parameters are good. It can meet the needs of high integration, low power consumption and controllable cost. In this paper, the switching topology of asymmetric structure is innovatively designed according to the different performance requirements of the transmitting branch and the receiving branch, and the multi-gate theory of the switch core is applied to the stack theory of FET. The basic principle of switch control is to improve the linearity of insertion loss and isolation. By optimizing the grounding capacitance, the bandwidth of the switch is increased, and the harmonic suppression ability is improved. At the same time, the influence of inductance induced by bonding line is also considered. In order to improve power processing capability, feed forward capacitors of appropriate size are designed. Then, the small signal performance parameters such as insertion loss, reflection loss, isolation and linearity, such as harmonic suppression ratio and input third-order intersecting cut-off point, are analyzed synthetically by using ads software to design schematic diagram and overall layout, simulation, etc. The performance tradeoff is obtained and the layout design is completed. The chip size is 3 3 mm 2 mm. The RF microwave test rig is used to test the switch chip. The test results show that, The operating bandwidth of the switch chip is 10MHz ~ 2.6GHz, the insertion loss is less than 0.6dB, the isolating degree is more than 26dB, the power processing capacity of the transmission branch is up to 42dBm ~ (-1) and the power processing capacity of the transmission branch is up to 70dB ~ (cc), and the receiving branch is 35dBm ~ (6) dB ~ (cc), which meets the requirement of application.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM564

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