• 作者： 翁金輅; 陳文祥
• 作者服務機構： 國立中山大學電機工程學系
• 中文摘要： 在螺旋天線的繞線導體內側加上一接地金屬片，中間加上一介質，可在天線上形成分佈電容。此時，螺旋天線將具有傳輸線之基本特性，而具有一特性阻抗。此一特性阻抗可被調整至與外接傳輸線之特性阻抗相等。此種天線應用在軸向指向性電波輻射的設計及製造，以及其電波輻射特性之實驗結果，將在本文中提出。
• 英文摘要： An internally matched helical antenna radiating in the axial mode is reported. The coil section of ahelical antenna is transformed into a slow wave section having a transmission line structure by placing aground copper sheet on the inner side of the coil and inserting a dielectric sheet between the coil and thecopper sheet to form a distributed capacitance along the antenna. By carefully selecting the coil inductanceand the distributed capacitance, we can cause the antenna to be radiated in the axial mode and to beinternally matched to the transmission line feeding it. No external matching circuits need to be considered.Moreover, this internally matched helical antenna in the axial mode has the advantage of much smallersize as compared with the ordinary helical beam antenna. Details of the construction and experimentalresults of VSWR characteristics and radiation properties are presented.
• 中文關鍵字： helica; beam antenna; transmission line structure
• 英文關鍵字： --