This paper presents a design of a transmitter pulse generator UWB (Ultra-Wideband) in standard 180nm MOSIS/CMOS technology. We proposed a 5th derivative Gaussian Pulse Generator using a compact Phase Detector (PD) that was designed with dynamic n-blocks and n-latches, and using a delay circuit of a modified pseudo-nMOS inverter architecture. The whole circuit has been simulated using LTSpice and the results had demonstrated the circuit capability to operate as a pulse generator; it generates pulses with proportional width range of the delay circuit. The like-Gaussian impulse achieves a very short pulse width of 51ps, and the output impulse achieves a signal width of 187ps signal width and amplitude of 156mV peak-to-peak. The generated pulse shape is similar to the 5th derivative. The complete design occupies a small area of 53.4 × 43.6μm2 (excluding the PAD's) and a power consumption of 14.2mW at input frequency of 100MHz@ 2V power supply voltage.