Tuning an electrically small on-the-move HF half-loop antenna

In this contribution, the implementation of a purely capacitive low loss high-power tuner for an electrically small vehicular HF half-loop antenna with NVIS capabilities is discussed. A quantitative comparison in terms of efficiency and tuning range of two minimum-component-count capacitive tuners is presented. Practical implementation of a tuner demonstrator is described. Measurements with the half-loop antenna mounted on a vehicle platform mock-up demonstrate an input matching better than 14 dB at two frequencies used for antenna testing.