| 摘要 |
A low-pass filter 17 is provided for a heater supply of a magnetron 11 for filtering stray radiation 23 emitted by the magnetron from being emitted by the heater supply means is arranged for attachment to an exterior face of a wall of an electrically conducting screened chamber 16 encasing the magnetron 11 and an associated isolation transformer 14 electrically connected to terminals 12 of the magnetron. An output connection 3, 4 of the filter 17 passes directly through an interface between the electrically conducting screened chamber 16 and the filter 17 to connect electrically, directly or indirectly, with the isolation transformer 14. There are therefore no electrical leads outside the screened chamber 16 electrically connecting the filter 17 to the isolation transformer 14. The filter is based upon a double-sided 1.0 mm thick FR4 board 175 with one side a ground plane 173 with all components surface mounted on the upper face opposed to the ground plane. A soldered case 174 bonded to the ground plane 173 provides full screening to the filter unit 17. |
