Receiving or transmitting antenna esp. for car radio - has prim. winding of coupling transformer inserted into loop formed by windings on rectangular ferrite bars

摘要

A ferrite core composed of four straight bars (31-34) of square or rectangular cross-section carries windings (31a-34a) which extend over most of the length of each bar but leave both ends free. Adjacent bars are arranged at 90 deg. so that the core constitutes a hollow square, with the coupling transformer (41) in a copper casing (42) at its centre. The depth of penetration of the transformer core (41c) into its two windings is adjusted for tuning of the antenna to a chosen frequency. The ferrite bars are bonded together at their gaps (35-38) by cyanolite-based adhesive, and their windings (31a-34a) are connected in series to form a closed loop. USE/ADVANTAGE - Also for radiotelephony or TV reception of transmission, increased efficiency and performance are obtd. without undue directivity.