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A technique of high computational efficiency for EMC diagnostics of complex co-located set of radio systems is presented. The technique is based on the following: the use of worst-case models of electromagnetic spurious couplings between antennas (in order to eliminate the second-type errors in detection of dangerous couplings), iterative refinement of these models for the potentially dangerous couplings in the process of solving an EMC problem, and the extra efficient discrete technique for nonlinear behavior simulation of radio receiver operation in complex electromagnetic environment.

Technique and results of testing of general-purpose electronic, radio communication, and industrial equipment for susceptibility to powerful ultra-wideband electromagnetic (EM) pulses is presented. An example of the implementation of the developed technique is given using equipment that provides exposure in form of series of electromagnetic pulses with amplitude of up to 50 kV /m, duration of 220–250 ps, and rise time of 120–150 ps. A pulse repetition rate is from 100 Hz to 1 kHz and duration of pulse train is from 0.1 to 300 s. The test results confirm the significant effect of EM pulses impact on the performance of the set of tested radioelectronic products of general purpose for pulse amplitudes of 1… 50 kV/ m.

An improved computationally efficient technique for EMC diagnostics of radio equipment of complex on-board radio-electronic systems is presented. The first improvement is based on the use of worst-case and conditionally worst-case mathematical models to describe unwanted electromagnetic (EM) interactions between transmitters and receivers of the system, which allows to detect all potentially dangerous interactions rapidly and avoid second-type errors when assessing the danger of these interactions. The second improvement concerns the iterative refinement of worst-case and conditionally worst-case models of potentially dangerous interactions (including models of transmitter radiation spectra, receivers susceptibility characteristics, amplitude-frequency characteristics of decoupling antenna filters and EM spurious couplings between antennas of on-board system) by the use of both numerical simulation methods and measurements to improve the accuracy of EMC diagnostics. The third improvement is associated with the use of an extremely effective technique of discrete nonlinear behavior simulation of radio receivers’ operation in a severe EM environment formed by a set of powerful EM radiations from radio transmitters of the analyzed on-board system and a variety of external EM fields generated by various radio systems of different services.

A wide set of shielding materials is used for protection of electronic systems and their critical components against the impact of Ultra Wideband Electromagnetic Pulses (UWB EMP). Widely known protection solutions are materials with polymer metalized films, the needle-punched and felt fabrics with conductive fillers, materials with ferromagnetic fillers, fabrics impregnated by electrolyte solutions such as regular water, NaCl and CaCl 2 water solutions. In this paper, a technique for express in-situ measurement of UWB EMP shielding effectiveness of composite materials is developed. The shielding effectiveness of materials with complex structure is tested in framework of the developed technique by the use of Test System providing the generation of EMP with duration of 242±24 ps (at half of maximum) and rise time of 139±14 ps. The obtained value of shielding effectiveness for the EMP with the noted parameters is 15.5 dB for four layers of the needle-punched material with carbon additives impregnated by electrolyte solution, 13.9 dB for the two layers of felt fabric material with a layer of polymer metalized film, and about 12.5 dB for material with the metalized films.

The analysis of EMC between medical short range devices of body area network system, capsule endoscopy system, active implant system and wireless equipment of mobile stations of cellular communications (LTE and 5G), RLAN equipment, NB IoT sensors operating inside a hospital building is performed. The integrated interference margin is used as a criterion of EMC. Results of the analysis show the following: 1) the equipment of wireless systems can create the interference to all considered types of medical short range devices (as well as medical short range devices can create the interference to receivers of the wireless systems) in case of allocation of emitters and receptors inside the same room or in neighboring rooms; 2) in order to ensure EMC of considered systems, it is advised to set more stringent requirements on characteristics of susceptibility of the medical equipment to radiofrequency electromagnetic fields created by wireless equipment of 4G/5G networks as well as on spurious emissions of transmitters of wireless systems. The results can be used in diagnostics of intersystem EMC in order to ensure safety of use of mobile wireless telecommunication equipment regarding medical vital devices in conditions of mass distribution of 4G/5G wireless information services in hospitals.

A wideband worst case model to account for the diffraction of a plane electromagnetic (EM) wave by a system hull made of a conductive material is developed. The model can be used for estimating the amplitudes of electric and magnetic fields in places of antenna mounting on the hull of an airborne vehicle (aircraft, helicopter, etc.). The model is based on consideration of the fields radiated by electric dipole in a low-frequency range and on the Fresnel approach to analysis of the diffraction in resonance- and high-frequency ranges. The use of analytical methods provides the high computational efficiency of the model. The developed model is validated by comparison of calculation results obtained by the model with results of numerical simulation performed in framework of FDTD and MOM (the ratio of the wavelength to the obstacle dimension is varied from 100 to 0.5).

A wideband worst case model for estimation of electric and magnetic shielding effectiveness of an enclosure (e.g., an aircraft fuselage, ship hull, or vehicle cabin) divided into compartments by partitions is developed. The model makes it possible to estimate the spatial distribution of electric and magnetic fields in the compartments separated from each other by metallic walls with irregularities (apertures, slots, joints, etc.). The model is based on a combination of analytical solutions describing the penetration of radiation through a wall and the distribution of fields inside cavities. The combination is performed in the framework of the perturbation theory and technique of the multilayer structure calculation. The developed model is validated by comparison of results obtained by the model with known experimental results and with results of numerical simulation in the frequency range from 10 MHz to 3 GHz (that corresponds to the range of wavelengths from very large to quite small as compared with dimensions of the compartments used for the validation).

A behavioral model for analysis of intermodulation interference that may arise in a radio receiver operating in complicated electromagnetic environment is developed. The model makes it possible to predict the levels of unequal-power multi-signal intermodulation interference (generated by involving the receiver input signals and the local oscillator signal, including its main tone and harmonics) on the basis of information about the levels of receiver susceptibility to mixer-generated spurious responses and to two-signal intermodulation of different kinds and orders. The model combines the worst case nature of intermodulation level prediction (which is a distinctive feature of conventional methods for analysis of intermodulation) with the high speed of computations (which is implemented by the use of the discrete nonlinear analysis technology). The experimental analysis of intermodulation interference in the AOR AR5000 receiver is performed in order to validate the developed model; the measurements were implemented with the use of the double-frequency test technique, which makes it possible to detect all kinds of two-signal intermodulation interference arising in a receiver.

An experimental validation of the linearity of transfer characteristics for elements of the shielding-type protection of an onboard system against high-power electromagnetic fields is carried out by considering the examples of a metal mesh and a braid of a coaxial cable. The validation technique is based on a comparison of the protection element’s amplitude-frequency characteristics obtained at different levels of the electromagnetic test disturbance. The validation is performed for ultra-wideband pulsed disturbance with amplitude up to 50 kV/m, pulse duration of 230 ps, and pulse rise time of 140 ps. The results of the experiments confirmed the applicability of the linear model to the description of the protective properties of shielding elements in the specified range of levels of external disturbance. This fact substantiates the possibility of using the protection element’s frequency characteristics measured at low levels of test disturbance to describe the operation of this element in case of protection against disturbances with amplitudes up to 50 kV/m.

The technique for EMC computer diagnostics of ship radio equipment is presented. This technique is based on preliminary detection and identification of all potentially dangerous on-board electromagnetic spurious couplings between antennas with the use of the broadband analytical worst-case model developed within the framework of IEMCAP program, and further corrected EMC diagnostics with the use of the adjusted worst-case models for the elements of potentially dangerous interference propagation paths identified before (adjusted numerical models of frequency characteristics of spurious couplings, numerical or analytical models of emission spectra and susceptibility characteristics of the equipment), and discrete nonlinear EMC analysis with the use of high-order front-end nonlinearity models and frequency selectivity models of radio receivers (these models are obtained on the basis of the results of double-frequency testing of the receivers). High computational efficiency are the main advantages of the technique; that is demonstrated by the example of EMC diagnostics of ship on-board system containing a set of HF, VHF, UHF and SHF radio equipment operating in severe external electromagnetic environment.

The technology for step-by-step computer diagnostics of EMC of radio equipment contained in a complex on-board system is developed. At the first stage, all potentially dangerous paths of interference propagation are identified with the use of the broadband analytical worst-case model developed within IEMCAP program; the model allows to calculate spurious couplings between antennas of radio equipment. At the second stage, refined worst-case models for the elements of potentially-dangerous interference propagation paths identified before (i.e., numerical models of frequency characteristics of spurious couplings, numerical or analytical models of emission spectra and susceptibility characteristics of the equipment) are developed; then EMC diagnostics is performed on the basis of the refined models. The final stage of the diagnostics is discrete nonlinear analysis of EMC, which is made with the help of the high order nonlinearity models and radio receivers' selectivity models; these models are obtained on the basis of the results of double-frequency testing of the receivers. The use of the developed technology makes it possible to achieve high computational efficiency of EMC diagnostics; this is demonstrated by way of the example of EMC diagnostics for on-board system containing a set of HF, VHF, and UHF radio stations installed on the small-sized mobile object.

Wideband worst-case model for estimation of effectiveness of electric and magnetic fields shielding by a metallic enclosure is developed. The model is intended to take into account a contribution of EMI gaskets that are mounted in gaps, joins between metal skin plates, and other apertures presented in a system (e.g., aircraft, ship, vehicle) body. The model is based on the generalization of the analytical model of electromagnetic field shielding by a metallic enclosure with combined walls (containing apertures of various shapes); this provides a high computational efficiency in the wide frequency band. Influence of the gasket structure and geometry on the shielding effectiveness is analyzed for the following high-usage gasket types: stamped or formed solid metal gaskets, gaskets in form of metal spring fingers, and knitted wire mesh. Validation of the developed model is carried out by comparison of results obtained in framework of the model with results of numerical simulations. For the validation, the ratios of the wavelength to the maximum dimension of the aperture with gasket are taken in the range from 1 to 1000.

A defected microstrip structure (DMS) method is used for crosstalk reduction between parallel coupled pair transmission lines (CPTLs). To reduce the couplings from the adjacent transmission line, a new DMS is designed and etched on one of the transmission line. Additionally, equivalent circuit model is also studied to provide an effective analysis method for analyzing the crosstalk of DMS-CPTLs by considering the S-parameters, namely, S11, S12, S13 and S14. The proposed designs are verified by using HFSS based on FEM and the equivalent circuit is studied by using ADS. The results show that the far-end crosstalk and near-end crosstalk are reduced by about 30dB and the equivalent circuit simulation agrees well with the HFSS simulation.

Co-site interference is becoming an increasingly significant issue in electronic vehicular systems. Communication system designers are facing challenges due to the ever increasing demand for higher performance systems on one hand, and the need for multi-channels communication in congested electromagnetic environments on the other. Solutions to mitigate the electromagnetic interference in sophisticated system are therefore crucial to enable reliable satellite communications and VHF communications. In this paper, a procedure of interference diagnosing is introduced, and an approach for the mitigation of the interference from Satellite Communication (SatCom) on-the-move system to co-site VHF system is proposed, where a simulation is performed to verify the interference mode and to optimize the suppressing process. In the final test, the result shows that the suppression method of controlling the interference propagation paths is effective.

In this paper, a defected microstrip structure (DMS) is proposed and put on the transmission line to reduce the mutual coupling between closely spaced patch antenna and microstrip line. The equivalent circuit model of the considered structure with loading DMS are presented and extracted. The lumped elements of the equivalent circuit model are obtained from the antenna and DMS equivalent circuits by including the coupling between the patch antenna and the 50-Ω transmission line. The proposed structure is simulated by HFSS and the extracted circuit is verified by using ADS simulation. The accuracy of the circuit model agrees well with the full wave, which help to verify its effectiveness.

A worst-case model of spurious resonances which can occur in electromagnetic system consisting of an antenna, cable and transmitter output filter (or receiver input filter) is proposed. These resonances may cause significant increase in power of spurious emissions for transmitting equipment and the decrease in out-of-band radiated susceptibility levels for receiving equipment. Three amplitude-frequency characteristics (AFCs) are the initial data for the model synthesis: AFC of the cable attenuation, AFC of the transmitter output port impedance (or AFC of the receiver input port impedance), and AFC of the antenna input impedance. It is assumed in the model that the cable length and phases of the impedances are unknown, therefore, at each frequency, the maximum possible increase in power of spurious emissions or the decrease in radiated susceptibility levels is estimated. Validation of the developed model is performed by numerical computation of an equivalent circuit containing a circuit-level model of the transmitter output filter, two-port network described by scattering matrix of the cable and one-port network characterized by the antenna input impedance. Measured AFC of the input impedance for antenna S65-8262-2, calculated AFC of the attenuation in radio-frequency cable RG58, and parameters of the transmitter output filter (pass band, attenuations in pass band and stop band, shape factor) are used as initial data for the validation. As a result of the numerical modeling, the influence of the cable is estimated: the AFC maximum for ratio of spurious emission power accepted by the antenna to the power of this emission accepted by the 50 ohm load is 7.7 dB; the AFC maximum for ratio of spurious emission powers accepted by the antenna using 2 m cable and without the cable is 29 dB. The validation demonstrates the worst-case behavior of the developed model.

A worst-case wideband model for estimation of effectiveness of electric and magnetic field shielding by a rectangular metallic enclosure, the walls of which can contain rectangular or circular apertures, is developed. The model is based on a combination of analytical solutions of the following two problems: transmission of electromagnetic radiation through the aperture and propagation of the radiation in lossy waveguides. The analytical solutions ensure high computational efficiency of the model in a wide frequency range. The developed model makes it possible to estimate the effectiveness of external field shielding by a metallic board-system hull (the hull of a car, aircraft, ship, etc.) the internal compartments of which can be approximated by a rectangular waveguide. In order to do this, it is necessary to define the amplitude-frequency characteristic (AFC) for the loaded Q-factor of the compartment under consideration. Such AFC takes into account the presence of objects inside the compartment as well as the field absorption in the compartment walls, and it can be calculated (analytically or numerically) or measured. The developed model is validated by comparison of calculation results obtained by the model with known experimental results and with results of numerical simulation (ratios of the wavelength to the maximum dimension of the enclosure from 0.1 to 1000 are examined). Examples of modeling of the shielding enclosures containing the apertures of various sizes and shapes (circular, rectangular with different ratios of the sides) are considered; the number of apertures is varied from 1 (window) to 1000 (mesh).

Results of discrete nonlinear behavior simulation of aircraft wireless systems' operation in complicated electromagnetic environment (EME) created by electromagnetic radiations of wireless systems allocated on the earth's surface and in different surrounding airborne vehicles are presented. The simulation is performed with the use of technique of virtual testing area; this technique is based on implementation of geoinformation technologies for analysis of different scenarios of influence of unwanted signals on wireless systems of aircraft flying at low and medium altitudes. Results of simulation prove the presence of real danger of intermodulation interference in onboard VHF/UHF radio receivers of piloted aircraft in case of complicated EME at small and medium altitudes if unmanned aerial vehicles approach to the aircraft at distances which are acceptable from the viewpoint of air traffic control regulations.

Techniques for experimental evaluation of the amplitude-frequency characteristic of a radio receiver input filter on basis of the measured frequency characteristic of the receiver susceptibility to two-signal (or three-signal) third-order intermodulation are developed: the known technique based on the fitting of parameters of the filter's theoretical model is generalized to deal with a switchable input filter having a high shape factor of the amplitude-frequency characteristic; two new techniques which do not require solving the optimization problem are proposed. The developed techniques are validated experimentally by examination of two radio-receiving paths with different types of the preselection filter: with narrow-band tunable filter and with wide-band switchable filter. The techniques are useful for synthesis of a receiver's behavioral model (describing the intermodulation and other nonlinear effects) on basis of experimental data.

This research was supported in part by the EU Horizon 2020 project H2020-MSCA-RISE-2014-644076 CoExAN and EU FP7 projects, FP7-PEOPLE-2012-IRSES-316432 QOCaN and FP7-PEOPLE-2013-IRSES-612285 CANTOR. Discussions of the basic ideas underlying this work with Dr S Starobinets and Dr D Mogilevtsev are acknowledged.

We show that the electromagnetic coupling at the nanoscale may be accompanied by another coupling mechanism, related to quantum entanglement. Consequently, a combined "electromagnetic-quantum" coupling is created, which stipulates long-distance and long-living interactions in electric circuits. Manifestation of this effect in electromagnetic compatibility (EMC) is discussed. An efficient theoretical framework for EMC analysis in nanoelectronics is developed based on the generalized theory of electric circuits. It is shown that the action of quantum entanglement is equivalent to an addition of the supplementary elements in electric circuit with the effective admittances defined as general susceptibilities that can be calculated using the Kubo-technique.

A technique of two-phase EMC diagnostics of complex ground-based radio systems with the use of worst-case models of electromagnetic spurious couplings between antennas is introduced. At the first phase, the ultra wideband analytical model of antenna coupling developed in the framework of IEMCAP program is used, and the ensemble of potentially dangerous spurious couplings is found. For these couplings, the improved numerical worst-case models for the reduced frequency bands, as well as for given types, orientations, and relative positions of the antennas are developed at the second phase of EMC diagnostics. Each of these improved models is obtained by finding the envelope of results of multiple (based on variations of model parameter values) FDTD modeling of the corresponding coupling. The example of application of the introduced technique for diagnostics of intrasystem EMC of an operating radio-TV complex is provided: the computer model of its radio mast is developed, and the two-phase EMC diagnostics of this complex (which contains radio equipment of more than 20 systems of radio-TV broadcasting, fixed and mobile radio communication, radio navigation, and other services) is performed. The obtained results have confirmed the efficiency of the presented technique for the analysis of intrasystem EMC due to significant improvement in estimation of potentially dangerous spurious couplings between antennas at the second phase of EMC diagnostics (by 5…20 dB in comparison with analytical model of IEMCAP) with acceptable computational burden.

A computationally effective wideband worst-case model of spurious coupling between monopoles placed at line of sight of each other is proposed. The model is constructed by combining analytic solutions of the problem for low-frequency and high-frequency bands by means of weight function determined empirically. The low-frequency solution is used at frequencies below the main resonance frequency of the longer monopole, and it is based on induced emf method. This solution takes into account the mismatch of antennas with a source and a load, and it is validated in three-decade frequency range. The high-frequency solution is based on the equation for free-space transmission of radio waves. The model can be used in the framework of express analysis of EMC to calculate mutual influence of monopoles installed on the fuselage of an aircraft. Validation of the proposed model and determination of its applicability region are performed by comparing results computed by the model with results of numerical modeling by the method of moments (MoM) for the following values of parameters: ratio of the fuselage diameter to the antenna length is varied from 1.75 to 12.5, ratio of a distance between the antennas to the antenna length is varied from 1.00 to 12.5. For additional validation, the comparison of results computed by the proposed model with results of numerical modeling by the finite element method (FEM) for two blade antennas AT-1076 installed at KC-135B airplane is performed.

In this paper, we developed an analytical model that makes it possible to estimate the response (i.e., the voltage or current at the output) of a dipole antenna to arbitrary-shaped electromagnetic pulse if the minimum information about the antenna is available (it is enough to know the following parameters of the antenna: working frequency range, gain, and wave impedance of the radiofrequency port). The developed model is validated by comparing the computed responses of VHF- and UHF-band dipole antennas to wideband electromagnetic pulses with the measurement results published in the literature. The validation demonstrates that the model estimates the values of the most important antenna-response parameters (total energy, amplitude, and voltage rate), which define the requirements to the radio-equipment terminal protection devices, with reasonable accuracy. The possibilities of increasing the response estimation accuracy by numerical modeling of the antenna are investigated (MoM and FDTD methods are involved).

A worst-case computationally-effective model for analysis of coupling between on-board antennas mounted on the conducting hull of a system (aircraft, ship, car, etc.) is proposed. Consideration of electromagnetic wave diffraction by the arbitrary-shaped hull is based on combining of the model for calculation of shading by convex surfaces of rotation bodies (cylinder, cone) and the wedge diffraction model obtained in the framework of the Uniform Theory of Diffraction (UTD). The proposed model of antenna coupling is validated by comparison with results of experiments and numerical simulation (by FDTD and GTD-PO methods) in a wide range of parameter values: cases of monopole and dipole antenna mounting in various points of the aircraft hull with several mutual orientations are considered, the frequency is varied from 50 MHz to 7 GHz, the ratio of wavelength to diffraction-path length is varied from 0.001 to 1.

A technique for detection of reverse intermodulation components (which are generated if an external interfering signal received by the transmitting antenna influences on the output stages of the transmitter) by measuring the interference frequency response of the transmitter output spectrum and visualizing that response as a double-frequency diagram is developed. A technique for automated recognition (identification) of the reverse intermodulation types and orders on the basis of the double-frequency diagram is proposed. Both techniques are validated by the experiments. Amplitude responses for reverse intermodulation components of various types and orders are measured.

A technique for calculation of currents in transmission lines in a wide frequency range is proposed. The technique is based on a generalization of the lumped-circuit calculation methods to the case of long transmission lines by the introduction of refinement functions. A worst-case model for the amplitude-frequency characteristics of currents in the transmission line is developed on the basis of the proposed technique. The model is intended for diagnostics (express analysis) of electromagnetic compatibility in complexes of radio and electronic equipment. Worst-case nature of the model is provided by construction of the envelope of the current's maxima (observed at resonances) for the high-frequency band. The validity of the model is checked by comparison with the results of numerical simulation of single wire above ground plane, twowire, coaxial, and triaxial transmission lines in a wide range of parameter values: the frequency is varied from 10 kHz to 8 GHz, the length of the line is from 20 cm to 5 m, height of the line above the ground surface is from 2 mm to 100 mm, the ratio of the load capacitance (inductance) to the line capacitance (inductance) is from 10−40 to 104. Straight and piecewise-straight lines (both parallel and non-parallel to the ground plane) are considered during the validation.

The analytical model for radiation of a rectilinear uniform transmission line placed above a conducting screen is proposed. The model is intended for diagnostics (express analysis) of unintentional interference in large complexes of radio and electronic equipment. The model makes it possible to compute the envelopes of the amplitude-frequency characteristics for electric and magnetic fields in any spatial point above the screen. Single wire above ground plane, coaxial and triaxial lines with various grounding configurations are considered. The model is based on replacement of the complicated transmission line by an equivalent (in terms of the radiated field) single wire over ground plane. Correctness of the proposed model was verified by comparison with numerical simulation results in the frequency band from 10 kHz to 2 GHz for lines of length from 5 cm to 10 m with various load and source impedances, the line height above the ground plane was varied from the radius of the line to 5 m, the observation point position was up to 5 m away from the center of the line in arbitrary direction.

A computationally-effective model for radiation of a rectilinear twisted pair placed above a conducting screen is proposed. The model is intended for diagnostics (express analysis) of unintentional interference in large complexes of radio and electronic equipment and makes it possible to compute the worst-case amplitude-frequency characteristics for electric and magnetic fields. The model was validated by comparison with numerical simulation results in the frequency band from 10 MHz to 1.2 GHz (for balanced feed and load) and from 300 kHz to 1.2 GHz (for unbalanced terminations), the observation point was located above the screen from 4 cm to 2 m away from the center of the twisted pair in arbitrary direction.

The concept of electromagnetic crosstalk in nano-circuits via quantum entanglement between the elements is considered. Manifestation of this effect in electromagnetic compatibility (EMC) and a solution for for its suppression are discussed.

A worst-case model of the plane wave diffraction by the rectangular or circular aperture is proposed. The model is intended for EMC analysis in a frequency range from 1 Hz to 40 GHz, and it is based on combining the analytic solutions of the diffraction problem for low-frequency, resonance, and high-frequency ranges. The combining is carried out by the use of matching functions which define a contribution of each analytic solution. The correctness of the proposed model was checked by comparison with numerical solutions of the diffraction problem in a wide range of the parameters' values: ratio of the wavelength to the maximal dimension (diagonal or diameter) of the aperture is from 0.05 to 300; ratio of rectangular aperture sides is from 1 to 100; ratio of the distance (from the aperture center to the observation point located behind the screen at arbitrary position) to the maximal dimension of the aperture is from 0 to 1000.

The worst-case model of a wire radiation field intended for the analysis of spurious couplings in complexes of radio and electronic equipment has been developed. The model is based on dividing the wire into straight-line segments and considering forward and backward current waves in each segment. The solution for each current wave is interpreted as interference of fields radiated by equivalent point sources, and the envelope of the amplitude-frequency characteristic is found in the area of resonances. The correctness of the model is checked in a wide range of problem parameters values: the length of the wire ranges from 0.1 m to 10 m, the height of the wire above the ground plane ranges from 0.1 mm to 1 m, and the observation point position is up to 10 m away from the center of the wire in arbitrary direction.

A worst-case approach to development of nonlinear models for RF front-ends and components is proposed. This approach makes it possible to avoid the omission of nonlinear interference in process of the computer simulation, which is very important for EMC analysis. Based on the proposed approach, we developed a technique for synthesis of the models intended for the use in framework of the discrete nonlinear analysis technology. For validation of the developed technique, nonlinear behavioral model of a microwave amplifier was synthesized.

Features and limitations of the radio receiver's front-end nonlinearity characterization technique based on measurements of spurious-free dynamic ranges for intermodulation of different orders are investigated. The technique is familiarly illustrated by the case study (a high-quality radiomonitoring receiver is used as an example): the dynamic ranges for intermodulation of all detected orders (up to 81st) are measured by the instrumentality of the automated double-frequency test system, models of the receiver's front-end nonlinearity are then extracted from the measurement results and validated by experiment.

Capabilities of the nonlinearity-filter (Hammerstein) cascade for amplitude demodulator simulation at the system level are described. This behavioral model is then validated for the diode envelope demodulator notwithstanding that the model structure is not compliant with the physical description of the demodulator.

It is suggested to use the method of signal-to-interference ratio (SIR) estimation by the minimum of interference power in combination with the technique of discrete nonlinear analysis of radio receivers. The method of the interference power minimum is compared to the SIR estimation methods being used in the framework of the discrete nonlinear analysis (method of two iterations and frequency selection method) in terms of applicability and computational efficiency.