Ming Wah R. Ng

Nonlinear system and subsystem modeling in time domain

Nonlinear models of microwave subsystems are identified from time domain measurements. Scattering functions in the form of nonlinear time domain functions are used to derive a system identification model instead of an equivalent circuit. The advantage being the simplicity of the measurement and the developed models and the speed and accuracy of the simulation of the entire system.

Time domain measurement and identification of microwave systems

Models of non-linear subsystems are idenfied from time domain measurements. Each subsystem is identitied separately and then the overall system is analysed using the identified models. The models are not based on equivalent circuits and this offers flexibiliy and saving in the amount of data stored for each model. The method also offer considerable saving in simulation time.

TLM analysis of microstrip patch antenna on ferrite substrate

A new TLM(SCN) algorithm has been developed for the simulation of microstrip antenna on magnetized ferrite substrate. The anisotropic permeability tensor of ferrite is modelled by state equations derived from the Polder tensor. Simulation results agree with measurement.

TLM Simulation of Ferrite Media

A new TLM(SCN) algorithm has been developed for the simulation of ferrite media. The permeability tensor of ferrite is modelled by state equations derived from the Polder tensor. A microstrip on ferrite medium has been simulated using the modified algorithm and results compared with measurement. The simulated gyromagnetic resonance of ferrite agrees with measurement.

Non-linear system and subsystem modelling in the time domain

This work describes how non-linear subsystems can be modelled from time domain measurements. The advantage being the simplicity of the measurement and the developed models and the speed of the simulation of the entire system.

Time domain modelling of microwave systems and subsystems

A new method of modelling non-linear microwave system and subsystem is presented. Non-linear models of the subsystem are identified and then combined to solve the entire system. Throughout the procedure time domain modelling and simulation is used but frequency domain characteristics can also be obtained. Models of non-linear subsystems are identified from time domain measurement which require less measurement time compared to frequency domain measurement. Black box models are used instead of equivalent circuits. The identified models are time domain transfer functions and this offers flexibility and saving in the amount of data stored for each model.

Non-linear time domain modelling of oscillators

This paper describes non-linear modelling of oscillators from time domain measurement. Non-linear time domain transfer functions are used to model both the generation of the oscillator output voltage wave and the reflection coefficient. The model can be combined with other subsystem models to perform complete system simulation. Overall non-linear system simulation in the time domain is computational efficient.

Time domain identification of non-linear systems

A new method of non-linear system design, and non-linear subsystem modelling is presented. The method is based on identifying a non-linear model for each subsystem and combining the individual models to solve the entire system. Time domain modelling and simulation is used throughout the procedure but frequency domain characteristics are also available. Modelling of non-linear subsystem is achieved by time domain measurement which offers considerable saving in measurement time. The identified models are not based on equivalent circuits and this offers flexibility and saving in the amount of data stored for each model.

Modelling of microwave circuits by system identification methods

Microwave circuits containing lumped as well as distributed sub-circuits are investigated by a method combining circuit simulation with system identification models. The signal transmission behaviour of the distributed sub-circuits is computed in the time domain using the transmission line matrix (TLM) method. Applying system identification methods to the TLM results compact circuit models are generated. By this way efficient circuit simulation is achieved.

Modelling and analysis of non-linear and dispersive microwave systems in the time domain

A new method of non-linear system design, and non-linear subsystem modelling is presented. The method is based on deriving the non-linear state equations for each subsystem and combining the individual state equations to solve the entire system. Time domain modelling and simulation is used throughout the procedure but frequency-domain characteristics are also available. Modelling of non-linear subsystems is achieved by a single shot measurement which offers considerable saving in measurement time. The derived models are not based on equivalent circuits and this offers flexibility and saving in the amount of data stored for each model.