An Antenna-Theory Method for Modeling High-Frequency RF Coils: A Segmented Birdcage Example

Figure 3

(a) Schematics of a shielded single-segmented birdcage model and a representative current distribution on an axial conductor. A model with 10 conductors is shown. The length 𝑙 satisfies 𝑙=(𝑛+1/2)𝜆 where 𝑛 is an even integer and 𝜆 is the wavelength of the source current. A representative current distribution on a 2.5𝜆-long center-fed dipole antenna is also shown. (b) Schematics of a shielded multisegmented birdcage model and a representative current distribution on an axial conductor consisting with five half-wavelength-long center-fed dipole antennas.

(a)

(b)