Abstract: An electrolytic corrosion prevention structure at a flange connection part in which the occurrence of an electrolytic corrosion is suppressed without increasing the number of the airtight and/or watertight parts and that can be easily processed is provided. a pair of pipe members 21 and 22, which has flanges 21a and 22a at the end of pipes and which has a groove surrounding the end of the pipe formed between the flanges 21a and 22a by jointing the flanges 21a and 22a; an annular seal member 23 which places in an outer circumference of the joint part of the flanges 21 a and 22a in the groove: and an interposition member 24 which places in an outer circumference of the seal member 23; wherein the electric potential difference which occurs when either material of the pair of pipe members 21 and 22 and the material of the interposition member 24 are contacted, smaller than the electric potential difference when the materials of the pair of pipe member 21 and 22 are contact with each other.

Abstract: A waveguide circuit is provided, in which fixing a metal cover to a waveguide body with screws can prevent radiowave leakage suitably without any application of the conductive adhesive, solder and braze as a material for the radiowave leakage prevention. A metal plate is provided at the end of an aperture of a waveguide body in a radiowave traveling direction and overlaps with the end of a metal cover.

Abstract: A division type waveguide circuit is provided, in which fixing a metal cover to a waveguide body with screws can prevent radiowave leak suitably without any application of the conductive adhesive, solder and braze as a material for the radiowave leak prevention. A radiowave leak preventing plate 8 is provided at the end of an opening area 3 of a waveguide body 2 in a radiowave traveling direction and overlaps with the end of a metal cover 4.

Abstract: An electrolytic corrosion prevention structure at a flange connection part in which the occurrence of an electrolytic corrosion is suppressed without increasing the number of the airtight and/or watertight parts and that can be easily processed is provided. a pair of pipe members 21 and 22, which has flanges 21a and 22a at the end of pipes and which has a groove surrounding the end of the pipe formed between the flanges 21a and 22a by jointing the flanges 21a and 22a; an annular seal member 23 which places in an outer circumference of the joint part of the flanges21 a and 22a in the groove: and an interposition member 24 which places in an outer circumference of the seal member23; wherein the electric potential difference which occurs when either material of the pair of pipe members 21 and 22 and the material of the interposition member 24 are contacted, smaller than the electric potential difference when the materials of the pair of pipe member 21 and 22 are contact with each other.

Abstract: An apparatus adapted for easily performing polarization switching is disclosed. Within a second waveguide connected to a first waveguide, there is embedded a polarization transformation circuit in the state rotated relative to the second waveguide at an angle set, based on a reflection characteristic indicating a characteristic of a reflection coefficient with respect to a polarization frequency.

Abstract: An apparatus adapted for easily performing polarization switching is disclosed. Within a second waveguide connected to a first waveguide, there is embedded a polarization transformation circuit in the state rotated relative to the second waveguide at an angle set, based on a reflection characteristic indicating a characteristic of a reflection coefficient with respect to a polarization frequency.