RETRACTABLE SLANT MONOPOLES ANTENNA FOR UHF-VHF BANDS WITH NARROW BANDS TUNING SWITCHES

摘要

A user deployable slant monopole antenna element (16) with multiple tuning stages (20, 30) comprising each an RF switch for a tuning inductor. This achieves good performance across both the 170-225 MHz and 470-850 MHz band widths. The slant monopole antenna responds to both V and H polarizations, in addition to providing both spatial and radiation pattern diversity in a multi-path environment. Through this design, a low profile antenna can be provided that is 'electrically small' (i.e. below about 650Mhz) yet provides good performance with a minimum gain of approximately -6dBi.