A Multiple Frequency Spectrum Impedance Matching Method of Nonlinear Geological Surveying Electromagnetic Method for Power Amplifier Capacity Utilization Enhancement

This article proposes a multiple frequency spectrum impedance matching method to extend the applying environment of the impedance matching technology from linear sinusoidal voltage to nonlinear voltage in the electromagnetic method (EM) of geological survey. First, the impedance characteristics of the transmitter, antenna, and load are analyzed to prepare for impedance matching. Second, based on the effect analysis of different impedance matching connection methods, a nonlinear multiple frequency spectrum impedancematching topology (NMIM) is proposed for nonlinear power amplifiers. Third, the optimized parameters design methods of the proposed topology and its load recognition-based control strategy are proposed for good nonlinear matching performance. At last, the dynamic hardware experiments validate the effectiveness of the proposed matching method and its control strategy. The results show that the proposed NMIM can match the impedance of the antenna and load dynamically to increase the amplifier emission current amplitude by over 21% and power capacity utilization rate by over 37% on average, which is at least 12% better than the results of the previous impedancematchingmethod.