This paper studies the performance of frequency agile radar (FAR) under the effect of chirp jamming technique. Also, the improvement in the barrage jammer range when using the chirp jamming technique is studied. The considered radar is assumed to be a search radar, and the jammer is stand off jammer. A simple simulation model is used to generate the jamming signal in both time and frequency domain. This model is applied to simulate both chirp jamming and barrage jamming signals. The effect of the proposed chirp jamming on the detecting range of FAR is studied. Moreover, the comparison between the effect of barrage jamming and chirp jamming techniques on the jammer effective range and on the FAR detection range is studied.