A STUDY OF CIRCULAR ARRAYS -3- RADIATION PATTERNS AND CURRENT DISTRIBUTIONS,
Abstract
Measured radiation patterns and current distributions are compared with the results computed from quasi-zeroth-order theory for a single antenna and arrays of up to five antennas. Circular arrays with one driven element are shown to radiate very little power in the backward direction if the elements are located near the resonant spacings. Agreement between theory and experiment is somewhat poorer near these spacings. The endfire couplet consisting of two antennas separated by quarter wavelength with driving-point currents 90 degrees different in phase is shown to give the cardioidal pattern predicted by zeroth-order (sinusoidal) theory only when wavelength is not much greater than 0.2500. This pattern can be produced with other antenna lengths, but the required current ratios are very different from those given by zerothorder theory. Experimental results are correctly predicted by quasi-zeroth-order theory. When two antennas are fed with equal amplitudes but a 180 degree difference in phase, the power gain of the array is shown to increase and the beamwidths to decrease as the separation between the antennas is decreased. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1963
- Accession Number
- AD0428780
Entities
People
- Richard B. Mack
Organizations
- Harvard University