On The Move (OTM) High Frequency (HF) Communications Capability for the EFV

The EFV is a strong asset in the arsenal of the US Marines. One of the targeted efforts of the Marines is to improve the HF communications capability of the vehicle by upgrading the current fixed-base whip antenna to an antenna that supports a Near Vertical Incident Signal (NVIS) mode of operation. Point-to-point terrestrial communications at the HF Band (2-30 MHz) provides flexibility in link range unavailable at other bands. In order to support a NVIS mode, the peak-of-beam of the antenna must point towards zenith within approximately 10„a so that the transmitted signal reflects from one of several layers of the ionosphere. FIRST RF proposes two possible design solutions. The first approach utilizes a pair of configurable vertical monopoles. The second approach is a loop antenna. Omni-directional coverage On the Move (OTM) is achieved.