Coaxial antenna array for 915 MHz interstitial hyperthermia: design and modelization-power deposition and heating pattern-phased array

Abstract

ABSTRACT:

Characterization of Microwave's Antennas for Intracardiac Ablation Frequencies 915 and 2450 MHz

“…The figures obtained from the SAR measurements show similar results to those obtained from monopoly probes in [18,19], and those obtained for the helical antennas in [20]. We can better appreciate the results in Fig.11b and 12b.…”

Capacitive-Loaded Interstitial Antennas for Perfect Matching and Desirable SAR Distributions

“…That may be one of reasons of the deviations between measured and calculated ones. Except that point, the measured matching properties at 2.45 GHz agree well with the calculated ones, and 28.4 dB seems to be the best among this type of conventional interstitial antennas [6], [7]. The two antennas, ZMIA and OMIA are resonant at the 2.45 GHz but the resonant frequency in the TMIA occurs at 2.415 GHz.…”

“…To verify the technique, the ZMIA, OMIA, and TMIA have been designed, fabricated and measured for muscle phantom, and the measured results of ZMIA, OMIA, and TMIA show 28.4, 21.9, and 22.8 dB, respectively. One of them, 28.4 dB, may be regarded as the best among those reported [6], [7].…”

“…5(a). The and in (1) are dependent on the radius and if let the effective radius of OMIA at to , the input impedance at is given by (5) The is composed of and , and finally results in (6) As expressed in (3)-(6), each input impedance consists of a characteristic impedance , a propagation constant , a length of transmission-line section and a termination load impedance . If a function expressing the input impedance is defined as , the input impedance of interstitial antennas with arbitrary number of MCLs may be derived in sequence as follows: (7) where is the number of MCL, is an input impedance at , and at 2.45 GHz.…”

“…For the determination of in Fig. 5(b), and are unknown variables in (4)-(6), which must ultimately be solved for the in (6). Varying the and at the same time in (6), the minimum reflection coefficient may be found out.…”