To provide a loop antenna system that can match its impedance with impedance of a feeder or the like so as to enhance the power efficiency.
This loop antenna system 1 has a double loop structure where an outer conductive loop 3 and an inner conductive loop 4 are concentrically formed on a printed circuit board 2. The outer conductive loop 3 is connected to one end of the feeder 6 at a feeding point 5 and a power supply section 7 is connected to the other end of the feeder 6. Each conductive loop has a capacitive component (capacitive reactance), an inductive component (inductive reactance) and a resistive component and the diameter of each conductive loop and the inner diameter or the like of conductive wires forming the loops are selected so as to have a resonance frequency and the impedance depending on the frequency of a radio wave to be sent/received and the characteristic impedance or the like of the feeder.
SUMIYOSHI TATSUHIRO
OKANO YOSHINOBU
SUMIYOSHI TATSUHIRO
OKANO YOSHINOBU