ANTENNA SYSTEM FOR SMALL SIZED RADIO EQUIPMENT

摘要

PURPOSE:To reduce the deterioration in the antenna gain when the antenna is tilted with respect to a direction of a magnetic field by improving the antenna gain with a limited length of a loop. CONSTITUTION:A loop antenna is made up of an upper plate 1, a bottom plate 2 and a connection plate 6, and a feeding part 4 of the upper plate l and a feeding part 5 of the bottom plate 2 are connected respectively to a reception input circuit of a printed circuit board 3. Then a capacitive reactance element 7 is connected to a side a-d to which the feeding section 4 is connected and to a side e-h to which the feeding section 5 is connected, and a ratio of the capacitance of the capacitive reactance element 7 to the capacitance of the tuning capacitor at the reception input circuit side mounted on the printed circuit board 3 is set to a proper value.