We have developed a new muscle-equivalent phantom which is composed of water, polyethylene powder, NaCl, agar and so on. This phantom can maintain its shape by itself and it is easy to make and handle. The complex permittivity of the phantom is very similar to that of the actual muscle tissue at UHF. The specific heat and thermal conductivity are suitable for the thermographic method.

The interstitial hyperthermia is an invasive heating method applied by inserting the applicator into the human body. We have been studying on coaxial-slot antennas for interstitial microwave hyperthermia. The characteristics of the square antenna array were theoretically examined. Firstly, the basic structure of the antenna, and a simplified analysis model taking account of the effect of the boundary surface were explained. Then analysis was performed by using the moment method. Finally, the calculated results were discussed. The catheter thickness has much effect on the characteristics and must be considered both in designing and in using the antenna. When the array spacing was increased, the effective heating area became larger and more uniform. As the insertion depth was increased, the effective heating area was also enlarged.

Results obtained from a study on junction properties of n-CdS/p-InP heterodiodes which were prepared as solar cells by the close-spaced technique are described. The junction properties were examined by means of injection electroluminescence. It has been shown that these diodes have very low interface state density at least in deep levels even for an as-grown sample from the fact that only an electroluminescence due to the band-to-band transitions was observed at room temperature. At liquid nitrogen temperature, however, luminescence spectra originated from both band-to-band and free-to-bound transitions were observed. The energy difference between the two spectral peaks was found to be 67 meV, which corresponds to the activation energy of typical acceptors in InP. The internal electroluminescent quantum efficiency was 12.8% at 77 K.

This paper describes that the dielectric characteristics of a catheter around the interstitial antenna have an effect on the wavelength for current, and this effect results in the variation of the SAR (Specific Absorption Rate) distribution around the antenna. A theoretical study of SAR distribution ground a coaxial-slot antenna is performed. Analytical technique used is the moment method. Result and discussion on the effect of material and thickness of the catheter are presented. The wavelength for the current shortens with increasing dielectric constant or decreasing thickness of the catheter. Due to this variation of the wavelength for current, the SAR distributions take various shapes.