This article is focused on analytical solution of the target position computing in passive systems using the Time Difference Of Arrival (TDOA) method where the altitude (or Height) above the see is known (TDOAH). Passive surveillance systems using TDOA may be divided into 2-D three positional and 3-D four positional where analytical solution are known. Despite this fact the most task solved in practice is TDOAH in both cases especially for long range electronic intelligence (ELINT) where the target height measuring by 3-D TDOA is inaccurate. This task may be solved with using of iterative method but using of analytic method gives direct solution, the number of solutions and all possible solutions. Direct solution is free of errors given by iterations and possible divergences. Analytic solution gives better conditions for position error estimation and singularity analysis. In this paper is TDOAH method derived and presented on example.

This article describes the effect of high-power electromagnetic environments (HPEMs) on the operation of all basic elements of electrical power networks. Frequency bands are defined for the HPEM environments. Attention is focused particularly on directed energy weapons (DEWs) and intentional electromagnetic interference (IEMI). A classification of DEW and IEMI generators in terms of E-field level and target distance from the DEW or IEMI generator antenna aperture is also described. The main focus of this article is on the design and testing of a low-tech DEW generator used to determine the electromagnetic immunity of standard electronic circuits. In addition, verification of electromagnetic immunity for a simple electronic circuit without adequate protection against the E-field is also explained. The outcome of this article is the determination of the E-field limits for fault-free operation, for malfunctioning states of the tested circuits and for irreversible destruction of the circuits. The measured E-field was compared to basic microwave radiation theory and to simulation results in COMSOL Multiphysics software (COMSOL, Inc. 100 District Avenue Burlington, MA 01803 USA).

This paper presents the application of a phase shifter with a ferrite Y-circulator in band S. Global literature addresses primarily the basic types of power waveguide phase shifters, however, there has been minimal literature on a phase shifter that uses a ferrite circulator for phase shifting. The paper describes theoretical and practical results where a ferrite circulator is used to shift the phase. A power phase shifter utilizing a ferrite circulator could be used in power applications where high demands are placed on the phase shift accuracy with minimal power losses. The phase shift is handled by a tunable waveguide short circuit that is connected to the port 2 of the ferrite circulator. By changing the waveguide length, the phase is changed. The measured results are compared with theoretical calculations and evaluated. The proposed phase shifter utilizing the ferrite circulator has its advantages in its simple design, in the accuracy of the phase adjustment and in the speed of the tuning. Another great advantage is its quite low cost due to its simple design.

The paper describes the device based on a dual microwave pulse generator that can be used for verifying and setting the standards suitable for measuring and mapping a high-frequency electromagnetic field at great power.