高頻快速電子遷移電晶體吉柏特混頻器及除頻器

Abstract

隨著無線通訊產業的快速成長，快速電子遷移電晶體（HEMT）依然是在微毫米波 及毫米波電路上所常用的技術。尤其是在很高頻的操作頻率下，不管在功率放大器或是 在低雜訊放大器上都有優於矽製程上的優點。為了高積體整合性，不管在混波器或是在 除頻器等等電路還是採用同一種製程HEMT 技術較為良好，以避免多晶片的互相連接 產生的損耗及減少外部晶片的匹配電路。然而我們使用矽製程常用的低頻吉伯特混波器 應用到HEMT 高頻設計，可以取代傳統的四分之一波長的匹配方式, 這樣一來就不用額 外設計放大器來補足傳統混波器的轉換損耗，且面積上也許還可以有效的縮小，而除頻 器也是採用此相同想法驗證建立，將來可以整合到毫米波頻帶的接收機。 我們利用高頻被動分波器和RC-CR 多重相位正交產生器來設計不同降頻轉換器或 是升頻的轉換器，其中包括基本，次諧波的水平式及堆疊式的吉伯特混波器架構。而在 除頻器則採用高速的再生除頻器。如果系統架構直接降頻的話會遇到雜訊的問題且降低 電路的特性,所以在本文也提到如何在電路上改善雜訊。

As the wireless communication system develops rapidly, high-electron mobility transistor technology is still used in the microwave and millimeter-wave regimes. The performances of HEMT-based low-noise amplifiers and power amplifiers are superior to those of silicon-based circuits at microwave and millimeter-wave regimes. Thus, HEMT-based LNAs and PAs are not yet replaceable for better performance especially at much higher frequencies. Connections between individual LNAs, PAs, and mixers using different technologies in a module suffer from large loss. It is preferable to implement the front-end circuits with the same process and on the same chip to reduce chip connections at high frequencies. Here, the HEMT technology is the best choice at high-frequency regimes. Many Gilbert complex mixers have been realized using CMOS and SiGe HBT technologies, mostly at low frequencies. Whereas the traditional microwave passive components based on quarter-wavelength design concepts are not compact and consume the real estate in the IC technology, analog circuit design concepts are adopted using HEMT technology in this project than implementing impedance matching design approaches. Furthermore, the frequency divider also uses this design concept to implement and verify. In the future, the HEMT Gilbert mixers and the HEMT analog frequency divider will be integrated in the millimeter-wave transceiver. Our research topic is that the high-frequency passive baluns and RC-CR polyphase quadrature generators are utilized to realize several typical HEMT Gilbert up- and down-converters, which are fundamental, leveled-LO and stacked-LO subharmonic Gilbert mixers. Furthermore, a high-speed regenerative frequency divider is adopted using HEMT technology. If a transceiver is designed with direct-conversion architecture, flicker noise needs to be concerned. The low frequency device flicker noise leaks directly through the down-converter to the IF baseband to degrade the direct conversion receiver. Therefore, the flicker noise reduction mixer circuit is also proposed in this project.