Sensitivity Analysis for Active Matched Antennas With Non-Foster Elements

Abstract

Abstract-During the last years many researchers have been working on the active matching or on non-Foster matching networks for one-and two-port electrically small antennas (ESAs). A new parameter on the sensitivity of the two-port electrically small antenna when loaded with a non-Foster network is presented. This sensitivity analysis will allow us to choose what kind of antennas can be properly matched with non-Foster networks and their position in order to optimize the performance of the design. Then, a typical high Q two-port antenna will be harder to match over a broad bandwidth, since |s 21 1 is very small and only agrees with |sn| over very small frequency bands, yielding very large sensitivity values. However, for these two-port antennas, if high levels of coupling can be engineered for a high Q multiple-port antenna, the return and insertion losses can be similar over larger bandwidths and, hence, the sensitivity can be kept low over larger bandwidths, enabling broader impedance matched bandwidths to be achieved, even for highly resonant antennas.

Design considerations in an active matched semiloop array with non-foster networks

“…Two-element array loaded with a non-Foster network A multiport antenna approach is used to deduce the analytical impedance, Z^,, that have to be implemented well with an ideal non-Foster MN well with a transistorized circuit for broadband impedance matching. As a previous work in [7], the authors found the most suitable location for an active MN in a single semiloop. Such location is the opposite side from the input port.…”

Stability Analysis and Design of Negative Impedance Converters: Application to Circuit and Small Antennas

“…The active matching antenna method, proposed in [29], can be applied in this case, to calculate an analytical impedance (Z MN ) to b) The S 11 parameter at the input port for both cases: the unloaded and the active loaded monopole with the MOSFET-based NIC.…”

Non-Foster Matching Circuit Design via Tunable Inductor for VLF Receive Loop Antennas

“…Earlier researchers mainly concentrated studies on the high frequency (HF) band [6][7][8][9][10]. Different NFCs, including CMOS based NFC [11], diode based NFC [12], and amplifier based NFC [13] have been matched to various types of antennas, including the monopole antenna [14], loop antenna [15], Egyptian axe dipole antenna [16], microstrip leaky-wave antenna [17], and parasitic array [18], with mostly favorable results.…”