A microwave chaotic Cascodeoscillator which can be used as wideband chaotic signal generator is presented. The chaotic oscillation circuit is designed using microwave transistor BFG520. A source follower is added between the oscillation circuit and output port for isolation and to reduce the load influence. The PSpice simulation results based on GummelPoon model of BFG520 proves that the novel circuit has a chaotic performance in a large range of parametric variation. Numerical and experimental results show that: compared to traditional chaotic oscillator, the Lyapunov dimension of the novel circuit is improved 20% and up to 2.5, the fundamental frequency of the measured spectra is improved 33% and up to 1.41 GHz.