A Multiwalled Carbon Nanotube-Printed Resistive Vee Dipole Antenna Sensor for Short-Pulse Ground-Penetrating Radar

A carbon nanotube (CNT)-printed resistive vee dipole (RVD) antenna is designed, fabricated, and measured for use as a short-pulse ground-penetrating radar (GPR) sensor. For such applications, the antenna arms need to be resistively loaded for radiating and sensing nondispersive pulses. Compared to conventional subtractive process and subsequent surface-mount techniques utilized based on printed circuit boards (PCBs), printed electronics is an additive process that ensures the mechanical stability of the antenna and remarkably reduces the time, cost and waste for fabrication. For the resistive loading based on printing technology, CNTs are used as the resistive printing material in this research. In the proposed CNT-printed RVD, the antenna arm is divided equally into eight segments for discrete loading, where each segment contains both conductor and resistor areas for printing silver paste and CNT inks, respectively. To use the CNT inks, a multi-walled CNT (MWCNT) is synthesized by a catalyst chemical vapor deposition (CCVD), and the chemical properties of the synthesized powders are measured. During fabrication, the area for the silver ink is first printed using a screen-printing process, whereas the printing of the MWCNT is subsequently performed using a spray deposition technique. The structural properties of the printed inks are investigated using scanning electron microscopy (SEM). Finally, the performance of the CNT-printed RVD is validated through antenna measurements and a series of experiments. Because the fabricated antenna shows excellent performance for pulse radiation and sensing, the proposed realization method may be regarded as a promising replacement for existing processes based on PCBs.