Calculation for the pattern degradation of the parabolic reflector caused by both the surface roughness of the reflector and the structural misalignment

반사판의 표면거칠기와 구조의 오정렬에 의한 파라볼라 반사판 안테나 패턴 일그러짐 계산

For a parabolic reflector antenna, a simple method is presented for computing efficiently the average power pattern degradations caused by the surface roughness of the reflector and misalignments between the reflector and the feed. In this procedure, both nonuniform surface errors and nonuniform illuminations are employed. The assumptions to derive the expressions are that in each annular region of the antenna, the rms value of the surface roughness is known, and in a zone in a annular region, the phase error by misalignments is constant, and can be taken to its value at the center of the zone. Detailed parametric studies are performed with derived expressions to determine the effects of those errors and illumination tapers on parameters such as gain and sidelobe levels.