Design and characterization of a miniature varactor tuned ferrite rod antenna for 4 to 24MHz

This paper presents an electrically small ferrite rod receive antenna which is electronically tunable over the majority of the HF band. The tunability allows the antenna to operate when detuned by nearby conductive objects. The small size makes the antenna particularly suitable for applications where larger antennas cannot easily be accommodated. This paper addresses the issues affecting the size of the antenna and its construction. A method of measuring the gain of the antenna is presented and the performance is compared to that of a full size half wave dipole.