Patent ID: 6639559
Filing Date: 2003-10-28
Classification: H01Q

Abstract:
An antenna element comprising:a dielectric substrate, a radiation electrode of an electric conductor formed mainly on a surface of the dielectric substrate, the radiation electrode having a first and a second halves, the first and the second halves being substantially symmetric in form to one another with respect to a center of the radiation electrode, and radiating with the same direction of main polarization of radiation emitted from the radiation electrode, the first half having a first open end at its outer end, another end at a distance of a quarter radiation wavelength along the radiation electrode from the first open end, and a first connection terminal between the first open end and the other end of the first half, the second half having a second open end at its outer end and a second connection terminal at a distance of a quarter radiation wavelength along the radiation electrode from the second open end, the second connection terminal being at a distance from the first connection terminal on the radiation electrode, a power supply conductor formed on the dielectric substrate and connected to the first connection terminal at one end of the power supply conductor and having at the other end of the power supply conductor a terminal for connecting to a high frequency signal source, and a ground conductor formed on the dielectric substrate and connected to the second connection terminal at one end of the ground conductor and having at the other end of the ground conductor a terminal for connecting to a ground, wherein a total conductor length of a portion of the first half between the first open end and the first connection terminal, and the power supply conductor is so different from a total conductor length of a portion of the second half, between the second open end and the second connection terminal, and the ground conductor that the total impedance of the power supply conductor and the portion of the first half between the first open end of the first half and the terminal of the power supply conductor at the other end for connecting to a high frequency signal source and the internal impedance of the high frequency signal source substantially match, in total impedance, the ground conductor and the portion of the second half between the second open end of the second half and the terminal of the ground conductor at the other end for connecting to a ground.