Abstract: A rectangular wave for determining a range of a weight function is transformed to frequency domain by an FFT or the like, and after being multiplied by a window function (BlackmanHarris window function, for example) generated on a frequency axis by a multiplier, the frequency domain is transformed again to the time domain by an IFFT or the like thereby to generate a weight function.

Abstract: A secondary surveillance radar system for use in surveillance of an airspace, which reliably achieves surveillance of the airspace even when an aircraft including a mode S transponder and an aircraft including an ATCRBS transponder are both located in the airspace, wherein both of a time interval between time when transmission of an all-call interrogation signal specific for mode S is completed and time when the transmission of an all-call interrogation signal specific for mode A is started and a time interval between time when transmission of the all-call interrogation signal specific for mode S is completed and time when transmission of an all-call interrogation signal specific for mode C is started is varied in units of one all-call time period.

Abstract: A method of producing an SOI wafer comprises the steps of forming an ion-implanted layer by forming an oxide film on at least one silicon wafer between two silicon wafers and implanting hydrogen ions or rare gas ions into one silicon wafer, superposing the surface of the silicon wafer on which the ion-implanted layer is formed and the other silicon wafer, heating at a temperature between 300° C. and 900° C., and delaminating from the ion-implanted wafer, and performing a heat treatment of the delaminated wafer at a temperature between 1000° C. and 1300° C., wherein the wafer forming the ion-implanted layer has an interstitial oxygen concentration of 1×1018/cm3 (old ASTM) or higher, and the method further comprises a step to grow an epitaxial layer on the SOI layer formed in the previous step.