Tetsuo Obunai

Nonreciprocal Propagation Characteristics of 526 GHz Submillimeter-Wave in Transversely Magnetized Two-Layer Parallel-Plate Waveguide Containing p-InSb Slab

The magnetic field dependence of 526 GHz submillimeter-wave propagation in two-layer waveguides containing p-type InSb slabs was studied in detail while varying the ambient temperature, and the results were compared with theoretical predictions. It was shown that, at the liquid nitrogen temperature, the submillimeter-wave propagation loss is very small, typically 0.3 dB/mm, and that fabrication of a submillimeter-wave image guide employing a p-InSb slab may be possible. At the dry ice temperature, slow surface wave resonance was clearly observed and a nonreciprocity of at least 15 dB was obtained with an insertion loss of 5 dB. These results indicate that the construction of nonreciprocal devices in submillimeter-wave monolithic integrated circuits may be possible. It is also suggested that this nonreciprocal wave propagation can be controlled by injecting plasma in the InSb slab.

Possibility of Submillimeter Slow Surface Wave Resonance in a Two-Layer Parallel-Plate Waveguide Containing n-Type or p-Type InSb Slab

The magnetic field dependence of submillimeter wave propagation in a two-layer parallel-plate waveguide containing n-type or p-type InSb slab has been experimentally studied at 526 GHz and 671 GHz. In each case, a resonant peak appeared on the transmission corresponding to the theoretically predicted slow surface wave resonance. Particularly with n-InSb, nonreciprocity of at least 20 dB was experimentally observed for transmission at the applied magnetic field of 0.2 T.

Wave Propagation Characteristics of a 70 GHz Imageguide Consisting of a Transversely Magnetized p-InSb Slab with Light Irradiation

Wave propagation characteristics of a 70 GHz imageguide consisting of a transversely magnetized p-InSb slab have been studied experimentally at 77 K. The results indicate the possibility of using p-InSb as a component of dielectric waveguides. It is also shown that the propagation characteristics of this imageguide can be controlled by light irradiation.

Nonreciprocal propagation characteristics of 671 GHz submillimeter wave in image guide consisting of transversely magnetized p-InSb slab

The temperature and magnetic field dependences of 671 GHz submillimeter-wave propagation characteristics in a transversely magnetized image guide consisting of a p-InSb slab have been studied experimentally and theoretically. The result of the theoretical analysis indicates that the propagation loss of this image guide is as small as about 0.116 dB/mm at liquid-nitrogen temperature. As the sample temperature increases to 240 K, a surface wave resonance occurs and a nonreciprocity of more than 20 dB appears in the transmission in an applied magnetic field B of 0.45 T. Experimentally observed results are in good quantitative agreement with theoretical predictions. These findings indicate the possibility of fabricating nonreciprocal devices embedded in a submillimeter-wave image guide consisting of a p-InSb slab. It is also shown that the attenuation of and nonreciprocity in the wave propagation in this image guide can be controlled by injecting plasma into the p-InSb slab.

Nonreciprocal Propagation Characteristics of 2.5 THz Submillimeter Wave in Two-Layer Parallel-Plate Waveguide Containing n-InSb Slab at Room Temperature

The temperature and magnetic field dependences of 2.5 THz submillimeter-wave propagation characteristics in a transversely magnetized two-layer parallel-plate waveguide containing an n-type InSb slab have been studied theoretically and experimentally at room temperature. The results show the formation of a resonant peak in the experimental transmission, which corresponds to the theoretically predicted slow surface wave resonance. Particularly at 295 K, a nonreciprocity of more than 20 dB is observed in the experimental transmission at the applied magnetic field of 0.5 T. The results also indicate the possibility of applying our waveguide configuration to terahertz-wave nonreciprocal devices operating at room temperature.

Seventy GHz slow surface wave propagation in a waveguide containing transversely magnetized p-type and n-type InSb slabs

Wave propagation characteristics in a 70 GHz waveguide containing transversely magnetized p-type and n-type InSb slabs have been studied experimentally. Surface wave resonance occurs in this configuration. It is also shown that the magnetic field required for slow surface wave resonance is greatly reduced by the addition of the p-layer.