此論文包含兩種縮小化寬頻天線的設計,一種為由摺疊式雙迂迴線與尾端加了金屬片的單極天線所組合而成的小型寬頻天線,天線的大小為0.1λx 0.1λx0.098λ當它的中心頻率為1.495GHz,實驗結果確定了此天線具有10.8% 的操作頻寬當滿足反射係數( |S11| )在-10dB 以下,此天線在操作頻寬內所量測到的輻射效率皆超過65%;另一種為由摺疊式圈型天線與尾端加了金屬片的單極天線所組合而成的小型寬頻天線,天線的大小為0.08λx 0.1λx 0.1λ當他的中心頻率為1.5GHz,實驗結果確定了此天線具有11.2% 的操作頻寬當滿足反射係數( |S11| )在-10dB 以下,此天線在操作頻寬內所量測到的輻射效率皆超過67%。此兩種縮小化寬頻天線在水平面上皆具有全向性的垂直極化輻射場型。
This thesis is about two kinds of small broadband antenna designs. One is a small broadband antenna composed of a dual-meander folded loop and a disk-loaded monopole. Its size is 0.1λ × 0.1λ × 0.098λ at the center frequency of 1.495 GHz. Measurement results confirm a fractional bandwidth of 10.8 % with the voltage standing-wave ratio (VSWR) less than 2. The measured radiation efficiency exceeds 65 % over the whole band. Another small broadband antenna is designed and measured as titled of a small broadband folded-loop antenna with a disk-loaded monopole. Its size is 0.08λ×0.1λ ×0.1λ at the center frequency of 1.5 GHz. The measured fractional bandwidth is 11.2 % with the voltage standing-wave ratio (VSWR) less than 2. The measured radiation efficiency exceeds 67 % over the whole band. Both of these two small broadband antennas have omni-directional radiation patterns of vertical polarization in the horizontal plane.