Broadband impedance compensation for ground penetration radar antenna using genetic algorithms

For ground penetration radar (GPR), a broadband antenna is important for system performance. However, in low operating frequency ranges, impedance matching conditions can be satisfied but at the cost of lower antenna gain. Impedance compensation seems to be an efficient way for fulfilling both the antenna gain and impedance matching requirements. A genetic algorithm (GA) is introduced to design the broadband impedance compensation network in which there is no need for any equivalent circuit nor an analytical function for the antenna and network. The experimental data of the broadband ground radar antenna is processed directly to synthesize the compensation network. Complex conjugate matching conditions, provided by the compensation network on the antenna input port to allow an overall return loss of -10 dB across the frequency band, are design specifications for the GA.