Pulse modulated power supply for the Microwave oscillator

We present the design of a cheap and easy to build pulse generator, which is both reliable and robust enough for everyday use within the Microwave laboratory (as a power supply for the continuous-wave 1 GHz oscillator). The design goals for the pulse generator are: voltage amplitude of V_max = 24 V, output current of at least I =100 mA, fundamental frequency of f =1 kHz, and a 50 % duty cycle. The essence of the generator is its simplicity, where an IC NE555 is used to drive a power transistor output, thus providing high current for a relatively low impedance load. The generator is designed and simulated using Orcad pSpice. Rigorous testing and measurements, performed on a fabricated prototype, show excellent agreements with the design goals and with the computer aided simulated results.