THE RESONANT CIRCULAR ARRAY OF ELECTRICALLY SHORT ELEMENTS

Different resonant distributions of current in circular arrays with N=60, 72, and 90 elements are investigated theoretically with the method of symmetrical components and a two-term representation of current in each element. The arrays studied have only one driven element. The remarkable results - which are displayed in a sequence of graphs - indicate that the relative currents in the elements can be distributed in triplets, triplets alternating with singlets, two independent sets of singlets, or one set of singlets. The driving-point impedance of this last distribution is a pure resistance, the Q of the 90-element array is over 30 000, and the half-power beamwidth of each of the 90 sharp peaks in the power pattern is 2°.