Signal and Noise Analysis of Small Antennas Terminated with High-Impedance Amplifiers

We consider the noise performance of an active antenna with high impedance amplifier as a receiver front end for an electrically small antenna. In comparison to standard impedance matching techniques, the resulting output signal to noise ratio may be suboptimal, but the bandwidth is much broader than can be achieved when a small antenna with high Q-factor is matched to a standard microwave amplifier. High impedance amplifiers with carefully designed noise parameters allow fundamental power matching bandwidth limits for small antennas to be bypassed, thereby enabling small, ultra-wideband receivers for size-constrained wireless device applications. The goal is to determine how the noise parameters of the amplifier could be adjusted to minimize noise and maximize bandwidth.