Mateusz Mazur

PROPAGATION IN A FERRITE CIRCULAR WAVEGUIDE MAGNETIZED THROUGH A ROTARY FOUR-POLE MAGNETIC FIELD

The coupled mode approach is applied to the ferrite circular waveguide magnetized through a rotary four-pole transverse bias magnetic fields. The plausible mathematical model of the ferrite waves propagation in the guide is developed which includes gyromagnetic interaction of two orthogonal TE11 isotropic modes. The importance of the birefringence effect in determining of phase shift and polarization phenomena are thereby demonstrated. As a result basic design consideration of the circular polarizer applied as a “half-wave plate” in rotary-field phase shifter are provided. 2 Mazur, Sȩdek, and Mazur

Ferrite coupled lines junction and its nonreciprocal devices

The properties of axially magnetized ferrite coupled microstrip line junctions are investigated numerically, and good agreement with the previously published experimental results are obtained. The novel configurations of the circulator and novel quasicyclic devices comprising the FCL (ferrite coupled microstrip line) section are proposed, and their overall scattering is calculated and discussed.

Development of ferrite coupled lines gyrator

New gyrators based on a ferrite coupled line section (FCL) are developed and investigated. The scattering parameters are calculated for microstrip and slot-line configurations providing the practical information for design of these components. As an example, an isolator using the microstrip gyrator is designed and its scattering characteristics are calculated and discussed.

Effect of time varying measurement conditions on antenna pattern in near field measurement and its correction procedure

Authors present the procedure of taking into account the changes of electrical parameters of setup due to the time drift of temperature during the procedure of near field measurement. It is proposed to make additional measurements in determined positions of probe are next used the results to introduce corrections terms in measured data. Such approach was verified practically in experimental near field measurement system.

Capabilities of a bistatic receivers' network using hyperbolic positioning method

In this paper capabilities of target detection and tracking of bistatic receivers network cooperating with ATC radar are presented. Simulations are performed for different scenarios. A novel approach based on a modified hyperbolic approximation of target position is proposed that allow to improve the accuracy of radar measurements. The method appears efficient with three or more measurements available.

Experimental Investigations of Ferrite Phase Shifter Magnetized with Rotary Four-Pole Magnetic Fields

The practical ferrite rotary field phase changer is designed and fabricated for low frequency by using a composite ferrite dielectric rod that allows to reduce diameter of a circular waveguide of phase shift section. Experimental results at 1.3 GHz agree well with ones predicted theoretically confirming the developed design procedure.

Propagation in a ferrite cylindrical waveguide magnetized by a two four-pole magnetic fields

The normal modes of a transversely magnetized ferrite cylindrical waveguide are found using a coupled mode approach. The bias yoke generates an electrically rotatable four-pole transverse magnetic field in the ferrite producing birefringence phase shift. The changes of polarization state of the electromagnetic wave at the output of the guide sections of different lengths are investigated and applied to develop a rotatable half-plate section useful for phase shifter design.

Extraction of antenna pattern from near field antenna measurements distorted by undesired emission

In this paper authors present experimental correction of antenna pattern obtained from near field measurements when they are distorted by determined electromagnetic emission. Such situation may be met e.g. when feeding or supply subsystem interacts with antenna radiation pattern due to self-emission. Presented results of experiments show effectiveness of extraction of antenna pattern utilizing near field antenna measurements.

The isolator tuning using sequential method with applied Artificial Neural Network

This paper presents the approach and results of utilizing sequential method, reported recently, with applied Artificial Neural Network (ANN) in postproduction ferrite isolator tuning. For isolator with R tuning elements, based on physically measured scattering characteristics, ANNs are used as a multidimensional approximators realizing inverse models for all R sub-devices. The sub-isolators (sub-devices) are obtained by successive detuning and removing tuning screws. For each subisolator, the input and output vectors are defined as physical scattering characteristics and the corresponding positions of the tuning element, detuned, in controlled way. Throughout the tuning process, these inverse models are used for calculating the tuning element increments needed for adjusting the tuning element in the proper position. Earlier that method was successfully used in filter tuning process so it encourage authors to adopt and verify that method in other microwave devices tuning. The obtained and presented results of our investigations prove that mentioned above method may be successfully used for other devices and systems that require tuning.

Ridged Horn Antenna for Ground Penetrating Radar

In this paper dielectric filling is presented as a simple way of adapting ridged horn antenna for ground penetrating radar (GPR). The requirements for GPR antenna were described to justify the choice of dielectric ridged horn as a simple handheld device aimed to landmines finding. An attempt of detection of the buried metal plate is also shown.