The MicroDipole TM consists of two highly efficient mobile whips and a special mount. Mobile whips are used for several reasons. First, they are built to withstand high winds and severe weather. Also, they are very light in weight and they are readily available at reasonable cost. Most importantly, they are efficient.
All short antennas are compromises.
A designer can compromise performance or bandwidth or both. In the MicroDipole I have chosen to trade bandwidth for small size while maintaining good efficiency. To the contrary, it makes more sense, especially in limited space applications, to make the antenna as efficient as possible and accept a narrow bandwidth. Actually, bandwidth is severely limited only on 80 and 40 meters. On most other bands, all, or at least most of the band is available without retuning the antenna.