Improved Avalanche Triode First-Order Gauss Pulse Miniature Circuit Board Design for Biomedical Imaging

In recent years, ultra-wideband microwave medical imaging technology has gradually emerged with its advantages of low radiation and non-invasive. The current imaging equipment, however, is bulky, and the design requirements for ultra-wideband pulses in RF systems are exceedingly demanding. This manuscript delineates the development of a 35×35×1.6 mm^3 first-order Gaussian pulse generator tailored for ultra-wideband applications. The architecture of the circuit encompasses a crystal oscillator module, an amplification stage, a differential component, and a triggering mechanism. By optimizing the circuit topology using avalanche transistors and adjusting the component parameters, a first-order Gaussian pulse was successfully produced on an FR-4 substrate, exhibiting a pulse duration of 1.5 ns, a peak-to-peak amplitude of 14 V, and a half-peak full-width of 0.5 ns. Experimental results validate the pulse generator's compliance with the necessary ultra-wideband characteristics.