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

Table 1

Optimal current (a) amplitudes and (b) phases of the half-wavelength-long center-fed dipole antenna elements in the multisegmented birdcage model.

(a) Current amplitudes/A

Azimuthal angle of RF elements/degree	22.5	67.5	112.5	157.5	202.5	247.5	292.5	337.5
The rightmost (leftmost) section	10.95	7.45	3.47	12.38	10.95	7.45	3.47	12.38
The right (left) section	6.35	4.23	2.65	7.43	6.35	4.23	2.65	7.43
The middle section	4.02	2.88	2.26	5.32	4.02	2.88	2.26	5.32

(b) Current phases/degree

Azimuthal angle of RF elements/degree	22.5	67.5	112.5	157.5	202.5	247.5	292.5	337.5
The rightmost (leftmost) section	158.59	216.59	264.86	317.69	338.59	36.59	84.86	137.69
The right (left) section	283.06	335.27	23.05	90.43	103.06	155.27	203.05	270.43
The middle section	95.49	145.82	196.06	268.50	275.49	325.82	16.06	88.5005