毫米波上变频器及其本振倍频链

【作者】 徐荧；

【导师】 徐军；

【作者基本信息】 电子科技大学 ， 无线电物理， 2006， 硕士

【摘要】 在微波、毫米波系统中,性能优越的上变频组件对系统性能起着关键性的作用。本文对毫米波上变频器及其本振倍频链的理论和设计进行了研究。本文的主要工作是应用户要求制作一具有三发射通道的上变频系统,可以将C波段的微波信号上变频到Ka波段的毫米波信号。系统的本振输入基频由一相位噪声非常好的低频率晶振提供,经过512次的倍频放大至Ka波段。本系统作为实验室中引信的发射源,由于目标反射信号具有时变的多维性,反射信号变得极为复杂,在信号处理时,不仅信号幅值、频率有决定意义而且相位关系也很有决定意义。因此,本系统对单路发射以及三路发射通道之间的相位一致性都有指标要求。由于作为本振基频的晶振信号相位噪声优至-150dBc@10KHz,在减少设计难度的基础上,我们舍弃了本振源采用锁相合成的形式,而采取了两次两次向上倍频的方案,中间加入窄带滤波器滤除谐波,并通过加入隔离器降低放大器之间的窜绕。根据本振倍频系统的频率高低将整个倍频链系统划分为分为两条16×16的倍频链并用独立的腔体分开安装。另外,考虑到在Ka频段进行三路功分很难保证三路本振信号等副等相,我们采取了在Ku波段进行三功分,然后三路各自进行倍频至Ka波段的方案。测试结果表明,该组件具有很好的线性度、动态范围、隔离度、幅度一致性指标,而且具有功耗小,稳定度高等优点。在单路发射通道上,群时延达到了2ns,优于国内很多产品。三路通道之间的相位一致性由于测试方法的误差以及隔离度指标的牵引作用,我们不能调试达到非常好的在相位一致性指标,再下一轮的工作中必须提高滤波器对本振信号的抑制度,改进相位测试方法以达到指标要求。更多还原

【Abstract】 In the Microwave and Milli-wave system,the performance of the up-mixers play a key role in the whole system.This dissetation make a research in the theoretics and design of the Milli-wave up-mixers and the LO Multipliers.The major job is manufactured a transmitter,which has three upmixer channels.Its function is to up convert the signals from C-band to Ka-band.The input local oscillator is provided by a low frequency crystal oscillator which has a good performance of phase noise,through 512 times multiply to Ka band.This sysetem is used in the laboratory as transmitter source of the fuze,for the multidimensional objects in practise ,which lead to the complexity of the reflect signal ,so the amplitude,frequency and the phase of the transmit signals both have a key role in dealing with the reflection signals.Therefore,this system requires for both the coherence of the single channel’s amplitude ,phase and multi channels.Because the phase noise of the input crystal oscillator is excellent to 150dBc@10KHz,we don’t adopt the PLL method to yield the LO souce,but multiply the input signal.For to discard the harmonious frequencies yield by the multiplier,we have connected narrow-band filter between the circuit,and connected the isolator to reduce the interferes bring by the feedback signal of the amplifier.According to the frequency of the LO system,we aparted the whole LO system to two subsystems, and fixed in the different capsules. In addition,considering the coherence of the LO signal,we divided it at the Ku-band but not the Ka-band,then multiply to the Ka-band separately.The results of the test demonstrated that the system has a good performance in the linearity, dynamic scope,isolation,coherence of the amplitude.The group delay of the upmixers is 2ns,which is better than other domestic manufactures.Because the inconsistency between the isolation and the phase coherence,and the error of the test method,we haven’t gotten the good performance of the phase coherence.The next work is improving the restrain of the filter to the LO signal and the phase test methods.更多还原