Abstract: An antenna and multi-antenna system are provided. Each antenna of the system is a mirror image and comprises first and second conductive elements each having a first end and a second end portion, the second end portions being capacitively coupled to each other. Each antenna can be operated as a lower-frequency folded dipole having a series capacitive gap which facilitates electrical lengthening of the antenna, or as a higher-frequency monopole antenna having a parasitic element which facilitates improved bandwidth. The antennas' feedpoints may be placed at opposite corners of a ground plane, and separated by a distance which is less than one quarter of an operating wavelength of the dipole but greater than one quarter of an operating wavelength of the monopole. Locating the feedpoints at the ground plane corners facilitates orthogonal polarization of the two antennas at least in dipole mode. The antennas thus provided exhibit good isolation.

Abstract: An antenna and multi-antenna system are provided. Each antenna of the system is a mirror image and comprises first and second conductive elements each having a first end and a second end portion, the second end portions being capacitively coupled to each other. Each antenna can be operated as a lower-frequency folded dipole having a series capacitive gap which facilitates electrical lengthening of the antenna, or as a higher-frequency monopole antenna having a parasitic element which facilitates improved bandwidth. The antennas' feedpoints may be placed at opposite corners of a ground plane, and separated by a distance which is less than one quarter of an operating wavelength of the dipole but greater than one quarter of an operating wavelength of the monopole. Locating the feedpoints at the ground plane corners facilitates orthogonal polarization of the two antennas at least in dipole mode. The antennas thus provided exhibit good isolation.