Theoretical Considerations for Tuning of HF Arrays of Electrically Small Monopoles

A theoretical framework of an impedance tuner for phased arrays is presented. Specifically proposed is a closed-form, deterministic method for calculating the tuning network parameters and compensating the input excitation using only the scattering parameters of the array and tuners providing a perfect match at a tuned frequency. Furthermore, the treatment of negative input resistance at certain scan conditions due to the mutual coupling is discussed and a potential solution given that minimizes the impact to efficiency while still achieving a perfect system match. Results are presented using a simulated finite array of electrically small antennas for the high frequency band. While studied with a specific geometry, the method and findings can be extended to other phased arrays and impedance tuners of interest.