Analytical and numerical techniques for analyzing an electrically short dipole with a nonlinear load

Abstract

An electrically short dipole with a nonlinear dipole load is analyzed theoretically using both analytical and numerical techniques. The analytical solution is given in terms of the Anger function of i morder and imaginary argument and is derived from the nonlinear differential equation for the "Ikvenin's equivalent circuit of a dipole with a diode. The numerical technique is to solve the nodal equation using a timestepping finite difference equation method. The nonlinear resistance of the diode is treated using the Newton-Raphson iteration technique. A comparison between the a n a l y t i c a l and numerical solutions is given. KANDA: YZINGAN ELECTRICALLY SHORT DIPOLE

The Effect of Diode Response of Electromagnetic Field Probes for the Measurements of Complex Signals

“…Kanda [12] analyzed the response of a diode detector using the equivalent circuit model for the probe as shown in Fig. 2.…”

“…Several recent studies have reported errors when measuring pulse-based RF signals as well as digitally modulated signals (e.g., IEEE 802.11b, IEEE 802.16e, WCDMA) using wideband electric-field probes typically employed in electromagnetic compatibility measurements and electromagnetic exposure assessments [7]- [11]. Kanda [12] performed analytical and numerical analysis of an electrically short dipole loaded with a diode detector in the presence of an incident CW signal. He derived the closed-form expressions for the response of the diode detector as a function of the incident signal showing the transition from square-law detection region to linear detection region.…”

“…The analytical evaluation of diode detector response to CW signals [12] and the implementation of the numerical model are discussed. This numerical analysis is then extended to various communication signaling schemes.…”

Methodology for Standard Electromagnetic Field Measurements

“…20(b) can be simplified as shown in Fig. 20(c), since the loop capacitance and diode capacitance are much smaller than the external capacitors C, resonant frequency and Q of the simplified equivalent circuit are given by I fo 2 r'NC3 -(C3 R) (31) and Q 2= La R (32) where C3 is the net capacitance of the two capacitors Cl and C2 in series.…”

Analysis of Non-Linearly Loaded Antennas and Scatterers

“…At present there is considerable interest in developing efficient methods for the analysis of non-linearly loaded antennas.This problem is of importance since non-linear effects must be taken into account in systems of antennas which include semiconductor componentslintegrated circuits and voltage limiters with very strong incident fields such as those produced by lightning or by NEMP (Nuclear ElectroMagnetic Pulse) [1] .Moreover,some field measurement techniques such as the EDM (Energy Density Meter) now being deve loped at the National Bureau of Standards [2] make use of short dipoles loaded by a diode-.It must also be noted that some radar applications with co-o perative targets are based on the use of non-linearly loaded scatterers [3].…”