3.1~10.6 GHz超寬頻接收機前端電路之研究

Study on 3.1~ 10.6 GHz Ultra-Wideband Receiver Front End

曾卿銘(Ching-Ming Tseng)

指導教授 ： 邱煥凱

國立中央大學/資訊電機學院/電機工程學系/碩士(2006年)

摘要

由於無線通訊及傳輸的便利，無線系統的應用已經普遍且深入我們的生活領域。隨著越來越多的無線傳輸應用，現今對大量資料傳輸系統的需求已經變的更加迫切，因此，我們需要更高的資料傳輸速率系統規範。超寬頻系統具備3.1 GHz到10.6 GHz，共計7.5 GHz的頻寬系統應用規範。
本論文主要研究內容為3.1-10.6 GHz超寬頻接收機前端電路，電路皆以台積電0.18微米互補式金氧半導體製程研製，其中包含超寬頻低雜訊放大器(ultra-wideband low noise amplifier)、超寬頻混頻器(ultra-wideband mixer)。
超寬頻低雜訊放大器使用電阻性電感電容合成電路作寬頻阻抗匹配，並同時達到增益與雜訊匹配，經由實作驗證後，與理論推導相同。另一個變壓器回授式寬頻低雜訊放大器藉由增加變壓器圈數可達到低功率消耗與高增益特性，且由實作驗證後，與理論推導相同。超寬頻混頻器使用電阻性電感電容合成電路作寬頻阻抗匹配，經由實作驗證後，與理論推導相同。
超寬頻接收機前端電路量測結果，超寬頻混頻器RF與IF返回損耗在2.5 - 10.6 GHz均小於10 dB以下。IF降頻頻率為10 MHz，RF頻率較LO頻率高，LO功率為-3 dBm時最有效率，混頻器最大轉頻增益為10.4 dB，3-dB頻寬是0.3 ~ 10.9 GHz。IF頻率3-dB操作頻寬為10 MHz - 250 MHz。混頻器增益壓縮點(1-dB compression point)及三階截斷點(IIP3)，頻率由2 GHz - 10 GHz，增益壓縮點在-14 dBm以上，IIP3在-2.5 dBm以上。RF-LO、LO-IF及RF-IF隔離度，頻率由2 GHz - 12 GHz各個埠的隔離度均在-27 dB以上。
源極退化式超寬頻低雜訊放大器的輸入返回損耗在0.1 - 20 GHz均小於10 dB，最大增益約為10.8 dB，小於± 0.5 dB的平坦度頻寬為3.1 - 10.6 GHz，3-dB頻寬由1.6 - 13.2 GHz，雜訊指數3.4 - 5.7 dB，IIP3及P1dB最小值分別在-4 dBm及-14 dBm以上。變壓器回授式寬頻低雜訊放大器的輸入返回損耗在3.1 - 9.1 GHz均小於-10 dB，但3.3 - 6.6 GHz的返迴損耗小於-10 dB，直流消耗功率6.4 mW。最大增益約為11.19 dB， 3-dB頻寬由3 - 9.1 GHz，雜訊指數2.99 - 4.77 dB，輸入頻率7 GHz的IIP3及P1dB分別在-5 dBm及-6 dBm以上。

關鍵字

超寬頻系統 ； 寬頻低雜訊放大器 ； 寬頻混頻器 ； 變壓器

並列摘要

Since the convenience of wireless communication, the wireless applications are popular and go deep into our life. As more and more applications trend to wireless, the data rate of the systems nowadays become not allowable. Thus, new high-data-rate standards are required. One of the conspicuous, high-data-rate standards is the Ultra-Wideband (UWB) with a total bandwidth of 7.5 GHz from 3.1 GHz to 10.6 GHz.
Ultra-wideband low noise amplifier use lossy LC ladder to wideband impedance match, and the broadband gain and noise match are simultaneously achieved. The implantation of the proposed UWB LNA shows the same performance with the simulation results. The second circuit, a transformer feedback wideband low noise amplifier use transformer to achieve low power consumption and high gain performance. The implantation of the proposed UWB transformer feedback low noise amplifier shows the same performance with the simulation results.
The main research in this thesis is 3.1 ~ 10.6 GHz Ultra-wideband receiver front end. The front end includes ultra-wideband low noise amplifier and ultra-wideband mixer. The circuits in this thesis are implemented in tsmc 0.18 μm CMOS process.
The measurement results of ultra-wideband reveiver fornt ends are as follows: for UWB mixer, the obtained return loss of RF and IF ports are both better than 10 dB. Low side local oscillator (LO) frequency is selected and inter-mediate frequency (IF) is chosen as 10 MHz. the optimized LO driver is -3 dBm. The conversion gain of mixer is 10.4 dB, with its RF 3-dB bandwidth from 0.3 GHz to 10.9 GHz. The IF 3-dB bandwidth is measured from 10 MHz to 250 MHz. The 1-dB compression point and IIP3 are better than -14 dBm and -2.5 dBm across the RF frequency from 2 to 10 GHz. The port to port isolations of RF-LO, LO-IF and RF-IF are better than -27 dB from 2 GHz to 12 GHz.
For the lossy LC ladder source inductor degeneration low noise amplifier, the obtained return loss is better than 10 dB from 0.1 to 20 GHz, a 10.8 dB maximum with the ± 0.5 dB flatness is achieved across 3.1 to 10.6 GHz. The 3-dB bandwidth is from 1.6 to 13.2 GHz. The noise figure is achieved between 3.4 to 5.7 dB across UWB frequency range. The measurement results of IIP3 and P1dB are better than -4 dBm and -14 dBm, respectively. For the transformer feedback wideband low noise amplifier, the measured input return loss is better than 10 dB from 3.1 to 9.1 GHz under the excellent dc power consumption of 6.4 mW. A 11.19 dB maximum gain is achieved with 3-dB bandwidth from 3 to 9.1 GHz. The noise figure is between 2.99 to 4.77 dB across the whole band. The measurement results of IIP3 and P1dB are better than -5 dBm and -6 dBm, respectively.

並列關鍵字

UWB ； transformer ； Wideband mixer ； Wideband low noise amplifier

參考文獻

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