應用於數位電視選台器中線性寬頻混波器之設計

Abstract

本論文以TSMC 1P5M25 0.25 UM製程實現數位電視諧調器之寬頻高線性之升頻混波器與具鏡像抑制之降頻混波器電路。 第一升頻混波器為了達高線性度之要求，將原本Gilbert Cell Mixer之電流源移除，並於RF埠之源極加上電阻，它的輸出三階交叉點OIP3（Output Third Intercept Point）可達61.577 dBmv，它的功率增益為6 dB，功率消耗為22.5625 mW。至於鏡像抑制混波電路，採用Hartley的架構，包含了降頻混波器、具有正交輸出的震盪器等，其正交電路以Polyphase Filter實現，最後輸出中頻在43.75MHz，在製程偏移之下其鏡像抑制比仍然能達到系統之要求31 dB。總結此升降頻混波器，輸入頻率為50〜860MHz，輸出中頻為43.75 MHz，功率增益為86.9221 mW，OIP3為62.7145 dBmv。

A wideband linear up-down converter mixer for digital TV Tuner is studied by using TSMC 1P5M25 0.25 UM process. The current sourse of the Gilbert Cell Mixer is removed and the degenerated resistance is used to achieve the high linearity of the upconvertion mixer. The power gain of the upconversion mixer is 6 dB, the OIP3（Output Third Intercept Point） is 61.577 dBmv, and the power consumption is 32.5625mW. As for the image rejection mixer, it consists of downconversion mixer , voltage-controlled oscillator , polyphase filter, and the Hartley architecture is employed to realize image rejection. The ratio of image rejection is at least 31 dB in spite of the process variation. In summary, the bandwidth of this up-down converter mixer is 50〜860MH, the output IF frequency is 43.75 MHz, the power consumption is 86.9221 mW, the OIP3 is 62.7145 dBmv.