# Physical Limitations of Omni‐Directional Antennas

@article{Chu1948PhysicalLO, title={Physical Limitations of Omni‐Directional Antennas}, author={Lan Jen Chu}, journal={Journal of Applied Physics}, year={1948}, volume={19}, pages={1163-1175} }

The physical limitations of omni‐directional antennas are considered. With the use of the spherical wave functions to describe the field, the directivity gain G and the Q of an unspecified antenna are calculated under idealized conditions. To obtain the optimum performance, three criteria are used, (1) maximum gain for a given complexity of the antenna structure, (2) minimum Q, (3) maximum ratio of G/Q. It is found that an antenna of which the maximum dimension is 2a has the potentiality of a…

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