Abstract: There is provided a method for designing a corrugated Fermi antenna having a broad-band and circular directivity required for receiving an image by using a wave of millimeter order. As a first step, an inflection point of the Fermi-Dirac function as a taper function of the Fermi antenna is changed so as to set the beam width of plane H to a beam width having a target directivity. After the beam width of the plane H is set to the target value, the aperture width of the Fermi antenna is changed so as to set the beam width of the plane E to a beam width having a target directivity. Thus, by adjusting the beam width values of the planes H and E independently from each other and matching them with the target values, it is possible to design a Fermi-antenna having a broad-band and circular directivity in a short time.

Abstract: There is provided a method for designing a corrugated Fermi antenna having a broad-band and circular directivity required for receiving an image by using a wave of millimeter order. As a first step, an inflection point of the Fermi-Dirac function as a taper function of the Fermi antenna is changed so as to set the beam width of plane H to a beam width having a target directivity. After the beam width of the plane H is set to the target value, the aperture width of the Fermi antenna is changed so as to set the beam width of the plane E to a beam width having a target directivity. Thus, by adjusting the beam width values of the planes H and E independently from each other and matching them with the target values, it is possible to design a Fermi-antenna having a broad-band and circular directivity in a short time.

Abstract: Dielectric strips made of a dielectric material are placed between a pair of conductor plates located a specified distance apart. Cutouts are formed in the dielectric strips. The cutouts, a part of each dielectric strip is formed into an electrically asymmetric portion. When high-frequency power is supplied to the dielectric strips, the power is transmitted through an NRD waveguide composed of the dielectric strips and the pair of conductor plates, with the result that electromagnetic wave is radiated from the cutouts into the space between the conductor plates. This electromagnetic wave excites the radiation elements formed in the conductor plates, which then radiate electromagnetic waves.

Abstract: A radio frequency (RF) excited waveguide gas laser has a hollow wavegide defined by dielectric or lossy materials and metal electrodes coated by thin films with small absorptions so that the metal electrodes are separated from the filling gas and the waveguide loss is very low. With such thin films on the electrodes, a sealed-off, high-power, compact waveguide gas laser having an extended life is realized.

Abstract: A radio frequency (RF) excited waveguide gas laser has a hollow waveguide defined by dielectric or lossy materials and metal electrodes coated by thin films with small absorptions so that the metal electrodes are separated from the filling gas and the waveguide loss is very low. With such thin films on the electrodes, a sealed-off, high-power, compact waveguide gas laser having an extended life is realized.