Transmission characteristics of CPW bends having various curvatures and a fixed bend angle were measured. It was found that the transmission level shows dips at some particular frequencies, and that the dips are less pronounced as the radius of curvature becomes larger.

This paper presents a method of analyzing the electromagnetic field inside an equipment housing. The electromagnetic field is assumed to be coming from outside and coupled into the housing through an aperture on the housing surface. The analysis is based on the transmission-line modeling method. Results of the analysis show a good agreement with the results of measurement. Also, it is found that the coupling through the aperture shows peaks at some frequencies that depend almost only on the structure of the housing and aperture and, therefore, can be estimated at the time of equipment design.

A new sealing structure for helical heater terminal used in a combination microwave oven is suggested, and its sealing characteristics are investigated. The new structure is simply a conductor tube coaxially covering the heater at the input terminal. With an optimally-designed structure of this type, the transmission coefficient of the heater can be reduced to -41.6 dB at 2450 MHz. When installed in a test set which is running with an output of 500 W at 2450 MHz, the microwave power leaking out from the heater terminal is found to be less than 0.2 mW/cm2.