電源傳輸網路於射頻元件接收感度惡化之系統改善設計

Abstract

中文摘要 本論文在針對由電感性耦合主導之問題，提出兩種抑制方法。第一種由雜訊源端進行抑制。提出交錯式電源線結構以代替傳統電源線。相較於傳統的抑制方式，擁有不額外佔據空間等優勢，特別適合使用在尺寸小層數少之產品。且其在有地平面之封裝系統中，一次交錯式電源線即可達到20dB之隔離度改善度，最後以實驗驗證。在無地平面之封裝系統中，一次交錯式結構在板材較厚情形下可達到12dB之隔離度改善度，另外亦提出兩種二次交錯式電源線結構，分別在板厚較薄及板厚較厚情形可以得到良好性能表現。 第二種抑制方式透過對於受害者RF電路之直流供應端進行抑制，我們透過對T型電路之改進其規一化，可達到S21在2~6GHz擁有-20dB，且可單純不改變共振頻之情況之下，只透過電容值改變止帶之深度。最後經過和LNA共同模擬，對於雜訊源於電源供應端由Vn=1~1000nV之情況之下，吾人提出之濾波器基本上均能使NF壓制在3dB以下，比傳統的方法包含單純電感到EBG表現優越，達到尺寸小且抑制能力好的結果。

關鍵字：電磁能隙結構、接收感度惡化、電磁干擾、射頻干擾、交錯式電源線

ABSTRACT The goal of this thesis is to solve the crosstalk issue dominated by inductive coupling. Two methods are proposed. The first is to suppress the noise coupling through power lines from the source. An interleaved power line structure is proposed to replace the traditional power line. Compared with the traditional suppression methods, it does not need to occupy additional space and thus particularly suitable for products with small size, fewer layers and dense layouts. In packaging systems with a ground plane, the interleaved power line can achieve 20dB improvement in noise suppression, which is also verified by the experiment. In packaging systems without ground plane layer, the interleaved power line can provide up to 12 dB noise suppression improvement for thick layers. Two kinds of doubly interleaved power line structures are thus proposed to provide good suppression performance in both thicker and thinner substrates, respectively. The second method is to suppress the noise from DC supply end of the RF circuit on the victim side. A T-type filter circuit with small occupied space is proposed. The performance in suppressing S21 is -20dB at 2~6GHz. Design formula is also derived so that the insertion loss in the stopband can be designed by changing the capacitance value while keeping the resonance frequency fixed. Finally, after co-simulation with LNA, the noise from the power supply, with Vn = 1~1000nV, is considered and the proposed filter can successfully suppress NF of the LNA below 3dB. As compared with the conventional methods such as direct inductor and EBG, the proposed filter can yield better performance, including small size and good suppression ability. Index terms – electromagnetic band gap, RF de-sense, electromagnetic interference (EMI), radio-frequency interference (RFI), interleaved power line