External EMI effects on a CMOS circuit in a cavity with an aperture

This paper explores the disruption of a simple CMOS circuit in a rectangular cavity with a rectangular aperture. The CMOS circuit is fed by a microstrip line on the back face of the cavity opposite to the aperture. A cavity transfer function is determined that relates the E-field strength at the face of the cavity to a voltage at the input to the first gate of a 4-bit full adder circuit. Various waveshapes are analyzed using the cavity transfer function to get a modified wave at the input to the circuit and then determine the relative bit error rates of the various interference waveforms.