Abstract
The problem of the lower bound on the radiation Q
for an arbitrarily shaped finite size antenna of non-zero volume is
formulated in terms of equivalent electric and magnetic currents
densities distributed on a closed surface coinciding with antenna
exterior surface. When these equivalent currents radiate in free
space, the magnetic current augments the electric current, so that
the fields interior to the surface vanish. In contrast to approaches
based solely on electric currents, the proposed technique ensures
no stored energy interior to the antenna exterior surface, and
thus, allows the fundamental lower bound on Q to be determined.
To facilitate the computation of the bound, new expressions for
the stored energy, radiated power, and Q of coupled electric and
magnetic source currents in free space are derived
Original language | English |
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Journal | IEEE Transactions on Antennas and Propagation |
Volume | 64 |
Issue number | 1 |
Pages (from-to) | 146-154 |
ISSN | 0018-926X |
DOIs | |
Publication status | Published - 2016 |
Keywords
- Electrically small antennas
- Frequency bandwidth, magnetic currents
- Physical bounds
- Poynting’s theorem
- Quality factor
- Q factor
- Radiation
- Reactive energy
- Stored energy