directional / omnidirectional dual band antenna.

摘要

An antenna system comprising: an antenna element dual-band (108, 200) for operation in a higher frequency and a lower frequency, wherein the antenna element dual-band (108, 200) is a dipole antenna; and a second antenna element (132, 134, 136), wherein, in response to an electrical current having a higher frequency and a lower frequency, the antenna system radiates a diagram directional antenna at the upper frequency and with an omnidirectional antenna at the lower frequency, characterized in that the antenna element dual-band (108, 200) comprises: a center dipole; two chokes (110) electrically connected to a first end of the center dipole and two chokes (110) electrically connected to a second end of the center dipole; wherein the two chokes (110) electrically connected to the first end of the center dipole and the two chokes (110) electrically connected to the second end of the center dipole shorten an electrical length of the antenna element dual-band (108, 200) at a higher frequency, and wherein the center dipole radiates at the upper frequency in response to an applied current at the upper frequency and radiating the central dipole and the chokes (110) to a lower frequency in response to an applied current frequency lower.