Investigation of radiation source using disc-cone antenna with optical/electrical converter operating from 1 to 10 GHz

The recent progress of radio wave communication and high-speed electrical equipment has brought the need for radiation sources operating at more than 1 GHz to evaluate EMC test facilities and shielding characteristics. This paper proposes a radiation source using a disc-cone antenna with an O/E converter. A wire grid model construction based on a triangle was studied to maintain the wire density constantly, and a laser diode with an electroabsorption (EA) device was used as the E/O converter. The radiation source was constructed, and the characteristics were measured in an anechoic chamber from 0.3 to 10 GHz. The investigation indicated that the calculation accuracy was improved to employ the wire grid model based on a triangle, and the deviation between the calculated value and the measured value is within ±3 dB from 1 to 10 GHz. This also indicated that the deviation of the gain is within ±5 dB from 1 to 10 GHz and the maximum radiated field is more than 0.1 V/m at a distance of 1 m. Using the radiation source, the shielding effect of the PC case was investigated. The results indicated that the shielding effect decreased in proportion with the increase in frequency, and a careful design is important for maintaining the shielding effect in this frequency range.