具有良好選擇度的寬頻吸收式帶止濾波器;Wideband Absorptive Bandstop Filters with Good Selectivity

NCUIR > College of Electrical Engineering & Computer Science > Graduate Institute of Electrical Engineering > Electronic Thesis & Dissertation > Item 987654321/73028

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/73028

Title:	具有良好選擇度的寬頻吸收式帶止濾波器;Wideband Absorptive Bandstop Filters with Good Selectivity
Authors:	簡世桓;Chien, Shih-Huan
Contributors:	電機工程學系
Keywords:	寬頻
Date:	2017-01-20
Issue Date:	2017-05-05 17:39:25 (UTC+8)
Publisher:	國立中央大學
Abstract:	本論文提出一種新型寬頻吸收式帶止濾波器，可達到比既有相關研究增加數倍的止帶頻寬，同時具有高頻率選擇度及良好通帶特性。本研究於傳統寬頻帶止濾波器之共振器中放入適當電阻，成功地消耗掉止帶訊號，達到吸收止帶之功能，並提供一套完整的設計流程。為了驗證所提出之設計流程，本研究於印刷電路板實現一吸收式帶止濾波器，其中心頻率為2 GHz，比例頻寬為50%，漣波常數為0.1005 (即為0.044 dB等漣波響應)。於中心頻率2 GHz實測之衰減量為60.7 dB，30-dB止帶頻寬為23.5%，形狀因子 (Shape factor = RBW3-dB /RBW30-dB) 為2.1，>95%功率損耗頻寬為35.6%，以及在8 GHz之前的最大反射係數為-11.2 dB，具有良好吸收式止帶特性。又為拓展此寬頻吸收式帶止濾波器可實現之規格範圍，本研究亦提出兩種修正電路設計，並實作比例頻寬由30%至70%的吸收式帶止濾波器，其30-dB止帶頻寬為11.9%至42%，止帶內反射損耗均優於10 dB，超過90%的止帶內訊號皆能夠有效地消耗掉。本論文所提出之新型寬頻吸收式帶止濾波器具有高設計彈性，止帶頻寬以及止帶頻率選擇度均可依所需規格設計，並提出一套簡潔的設計流程，只需依據系統規格得到設計參數後，即可快速地設計寬頻吸收式帶止濾波器，將可應用於吸收非線性主動元件的諧波輸出，從而提升系統效能。;This study presents a new type of wideband absorptive bandstop filter (ABSF) design whose stopband bandwidth is several times wider than those in the other related previous works. In addition, high frequency selectivity and good passband response are achieved. The proposed wideband ABSF is based on adding one additional resistor to a conventional wideband bandstop filter to absorb the input power. A complete design procedure is proposed to realize the circuit design under given specifications. To validate the proposed design method, a proposed wideband ABSF with a center frequency of 2 GHz, a fractional bandwidth (FBW) of 50% and a Chebyshev response with a ripple constant ɛ = 0.1005 is implemented on a printed circuit board. The measured stopband rejection is 60.7 dB at 2 GHz. The measured 30-dB rejection bandwidth is 23.5% and the shape factor, i.e., RBW3-dB /RBW30-dB is 2.1. The measured bandwidth for better than 95% power dissipation is 35.6%. In addition, the measured input reflection coefficient is better than 11.2 dB from dc to 8 GHz and good stopband performance is achieved. This study also presents two modified design methods for expanding the realizable range on stopband bandwidth and filter order of the proposed wideband ABSF. Wideband ABSFs with FBWs ranging from 30% to 70% are implemented, and the corresponding measured 30-dB rejection band-width ranges from 11.9% to 42%. The measured input return losses are all better than 10 dB. Larger than 90% of the input power within the stopband can be successfully dissi-pated. The proposed ABSF features a complete design procedure with high design flexi-bility. The stopband bandwidth and frequency selectivity can all be designed according to the desired specifications. They can be applied to the harmonic suppression of nonlinear active devices to improve the system performance.
Appears in Collections:	[電機工程研究所] 博碩士論文

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