| 摘要 |
An E-field probe comprises one or more dipoles, each comprising plural, parallel, strings of discrete resistors mounted on a section of printed circuit board and connected electrically so that the parallel strings are twisted about each other for optimum orientation symmetry and minimum stray field pick-up. The values of the individual resistors are chosen so that the dipole is essentially a tapered resistance dipole, providing good performance over a very broad range of frequencies. A pair of diodes connected respectively in parallel strings of one arm of the dipole allows the feeder to be constituted by a pair of parallel series of resistors of comparatively high resistance value continuing from the outer end of the arm in which the diodes are situated. The dipole is effectively "end fed" rather then center fed, and pattern distortion and axial asymmetry are minimized. |
