The present invention relates to a broadband I-shaped monopolization oscillator. It contains first oscillator, second oscillator, feeder apparatus, parallel double plate and double wire between double arm of each oscillator, wherein feeder apparatus including power feed piece and additional concentric line, double wire between double arm of each oscillator extented to parallel double plate, respectively to form first balancer and second balancer for countervailing component reactance of two oscillators, feeding point of said feeder apparatus set on central position of parallel double plate wire, power feed piece set on a parallel edge, inside and outside conductor of concentric line respectively connected on power feed piece and another parallel edge of parallel double plate wire. The present invention realizes broadband function under metallic reflection plate size unchanged condition with high front-to-back ratio radiation performance. |