【摘要】：混頻器作為毫米波收發(fā)系統(tǒng)中的關(guān)鍵器件,其工作的帶寬、變頻損耗等都對整個系統(tǒng)的性能有著非常重要的影響。對于拓展接收機的工作頻帶而言,研制具有較寬射頻工作帶寬的混頻器就具有非常重要的研究意義。同時,相較于基波混頻器而言,諧波混頻器因其本振端的工作頻率只為射頻工作頻率的二分之一、三分之一、四分之一等,對于本振源的研制來說降低了要求。在這種情況下,寬帶分諧波混頻器將是重要的研究方向。本文設(shè)計的W波段寬帶分諧波混頻器采用了反向并聯(lián)結(jié)構(gòu),通過金屬化過孔接地的方式將UMS公司的肖特基勢壘二極管DBES105a反向并聯(lián)于微帶傳輸線。通過波導(dǎo)到微帶的過渡結(jié)構(gòu)使射頻和本振信號饋入至微帶,再通過微帶加載至反向并聯(lián)二極管對上。本振信號通過射頻端的波導(dǎo)截止特性實現(xiàn)隔離;而射頻信號對于本振端而言,則通過CMRC結(jié)構(gòu)的低通濾波器實現(xiàn)射頻信號與本振端口的隔離。射頻信號通過波導(dǎo)至微帶的過渡之后,通過微帶的扇形匹配枝節(jié)實現(xiàn)射頻端與二極管的匹配。本振端與二極管對的匹配則由CMRC低通濾波器及其相移網(wǎng)絡(luò)實現(xiàn)。經(jīng)過混頻得到的中頻信號再通過包含扇形枝節(jié)的低通濾波器傳輸至K接頭輸出。對于二極管對而言,在分析比較傳統(tǒng)的二極管建模設(shè)計方法的基礎(chǔ)上,通過分析肖特基二極管的結(jié)構(gòu),在HFSS中建立了DBES105a的簡化三維模型。管芯用準線性等效的方式,通過對比測試與模型的仿真曲線提取了針對于射頻信號和本振信號而言不同的兩組二極管參數(shù)。再針對兩組不同參數(shù)通過反復(fù)迭代的方式,設(shè)計射頻端和本振端的匹配。通過HFSS軟件的仿真優(yōu)化,實現(xiàn)了射頻端在75~110GHz波段全頻段內(nèi)回波損耗大于10dB,本振端在40~50GHz內(nèi)回波損耗大于10dB的目標。為了測試需要,采用CHX2193、AMMC5040、M4AE1317以及TGA4522芯片,設(shè)計完成了U波段八倍頻器的研制并進行了相應(yīng)測試。最后針對研制的混頻器進行測試,在本振頻率為46.25GHz時,輸入功率為9dBm時,射頻信號在75~108GHz內(nèi)變頻損耗小于15dB,其中在88~102GHz內(nèi)變頻損耗小于11dB。
[Abstract]:As a key device in millimeter-wave transceiver system, mixer has a very important influence on the performance of the whole system, such as bandwidth and frequency conversion loss. It is of great significance to develop a mixer with wide RF bandwidth for expanding the operating band of the receiver. At the same time, compared with the fundamental mixer, the harmonic mixer reduces the requirement for the development of the local oscillator because the operating frequency of the local oscillator is only 1/2, 1/3, 1/4 of the RF operating frequency. In this case, broadband subharmonic mixer will be an important research direction. The W band broadband subharmonic mixer designed in this paper adopts the reverse parallel structure. The Schottky barrier diode (DBES105a) of UMS company is inversely parallel to the microstrip transmission line by metallizing through the hole. The RF and local oscillator signals are fed into the microstrip through the transition structure from the waveguide to the microstrip, and then loaded into the reverse parallel diode pair through the microstrip. The local oscillator signal is isolated by the waveguide cutoff characteristic of the radio frequency terminal, and the radio frequency signal is isolated from the local oscillator port by the low pass filter of the CMRC structure. After the transition from the waveguide to the microstrip, the RF signal is matched with the diode by the sector matching branch of the microstrip. The matching between local oscillator and diode pair is realized by CMRC low pass filter and its phase shifting network. The intermediate frequency signal obtained by mixing is then transmitted to the K-joint output through a low-pass filter containing sector branches. For diode pairs, based on the analysis and comparison of traditional diode modeling and design methods, the simplified three-dimensional model of DBES105a is established in HFSS by analyzing the structure of Schottky diode. By using quasilinear equivalent method, two sets of diode parameters for RF signal and local oscillator signal are extracted by comparing the test results with the simulation curves of the model. Then the matching between the RF and the local oscillator is designed for the two groups of different parameters by iterative method. Through the simulation optimization of HFSS software, the echo loss of RF terminal in 75~110GHz band is greater than 10 dB, and the return loss of local oscillator end in 40~50GHz is greater than that of 10dB. In order to meet the test requirements, the U-band octave frequency multiplier is designed and tested using CHX2193,AMMC5040,M4AE1317 and TGA4522 chips. Finally, when the local oscillator frequency is 46.25GHz and the input power is 9dBm, the frequency conversion loss of RF signal in 75~108GHz is less than 15 dB, and the frequency conversion loss in 88~102GHz is less than 11 dB.
【學(xué)位授予單位】：電子科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN773
，

本文編號：2341218