This paper proposes a transient-optimized radio frequency power amplifier (RFPA) system that incorporates a nonlinear correction methodology in conjunction with a high-speed gate voltage control circuit, aiming to address the stringent dynamic requirements of high-speed pulsed RF applications. To enable a comprehensive characterization of system dynamics, a novel analytical technique for calculating transient response time is introduced, facilitating accurate assessment and optimization of both switching behavior and phase response. The proposed architecture demonstrates significant improvements in response speed and low-frequency stability, effectively overcoming limitations observed in conventional RFPA designs. The system was successfully implemented in an 8 kW RFPA operating at 210.78 MHz, a frequency commonly utilized in magnetic resonance imaging (MRI) systems. Under the optimized configuration, the gate voltage turn-on time was reduced from 2 μs to 154 ns, and the turn-off time from 2 μs to 50 ns. Furthermore, the phase linearization response time was reduced from 180.1 μs to 41.96 ns, while the average response time of the linearization system, as evaluated using the proposed method, was 63.1 ns. These enhancements contribute to the precise generation of high-speed, high-fidelity RF hard pulses, thereby supporting improved performance in advanced MRI applications.