Device for Coupling Electromagnetic Radiation from a Source into a Microwave Chamber

1 . A device for coupling electromagnetic radiation from a source into a microwave chamber, the device comprising a waveguide configured to be attached to a window of a said microwave chamber, and further comprising a shield operable to cover an outer part of the window so as to prevent electromagnetic radiation passing through said outer part, the shield defining an opening configured to expose an inner part of the window in such a manner as to allow electromagnetic radiation to pass through said inner part from said waveguide, the opening having a cross-sectional area substantially equal to a cross-sectional area of the waveguide.

2 . A device according to claim 1 , wherein the shield comprises a first substantially circular flat aluminum plate operable to be attached to the window on a side facing inside the said microwave chamber.

3 . A device according to claim 2 , wherein the shield further comprises a second substantially circular flat aluminum plate operable to be attached to the window on a side facing outside the said microwave chamber, said second plate having a thickness greater than said first plate.

4 . A device according to claim 3 , wherein said second plate comprises a circumferential sealing means configured to provide a vacuum seal when the device is attached to the window.

5 . A device according to any one of claims 1 to 4 , wherein the opening is arranged substantially centrally in the shield.