ANTENNA FEEDING CIRCUIT

摘要

An antenna feeding circuit needing no balanced-to-unbalanced transformer and having a simple structure. A microstrip line comprises a pair of strip conductors (5a, 5b) provided on the outer surface of a tube (1) and an internal conductor (6) provided on the internal surface of the tube (1). A 180 DEG distributing circuit (2) outputs electric powers the phases of which are different by 180 DEG to the strip conductors (5a, 5b) to cancel the unwanted currents produced by connection of a balanced-to-unbalanced line. Since the internal conductor (6) is provided over the whole inner surface of the tube (1), the unwanted currents induced in the internal surface of the internal conductor (6) cancel each other.