Ferrite Phase Shifters Research Articles

Ku-band 300 kW high power ferrite phase shifter.

Phase shifter (PS) is a key component of a phased array antenna (PAA) system, which controls the microwave phase and realizes the antenna beam forming and scanning. A ferrite PS (FPS) is a current-controlled PS that uses the ferrite's gyromagnetic properties to realize phase shifting. It has the advantages of short phase switching time, low microwave loss, and high reliability and, therefore, has been widely used in low-power PAA systems. However, the power handling capability of the traditional Ku-band FPS is only a few kW, prohibiting FPS from being used in high-power microwave (HPM) PAA systems. Spurred by this concern, this paper proposes a new dual-toroid FPS structure with an external magnetic excitation. By optimizing the PS configuration, improving the integration process, and enhancing the performance of ferrite materials, a single FPS in the Ku band has reached the power handling capability of more than 300 kW with an insertion loss of less than -1.2 dB, the phase shift range of 0°-360°, the width less than 11.5mm, and the ability of a one-dimensional array. The FPS has the potential to be used in the PAA of an HPM system, laying a foundation for the research of the HPM PAA system.

Resilience-oriented approach of dynamic production and maintenance scheduling optimisation considering operational uncertainty

ABSTRACT One of the main challenges in operating multistate manufacturing systems (MMSs) is maintaining stable and robust production against various disruptions. Therefore, an urgent need exists for an operation and maintenance (O&M) method that optimises MMS resilience, i.e. the capability of withstanding or recover from disruptions of various sources. Consequently, this study proposes an integrated resilience-oriented production and maintenance scheduling approach for MMSs. This approach enhances MMS resilience by reinforcing its adaptivity to the variation in production requirements. Based on a conceptual investigation of operational uncertainty and its mechanism of disruption, this study devotes to (i) formulating a performance loss-based resilience measurement with consideration of operational uncertainties and (ii) proposing a reinforcement learning-based approach to schedule MMS operation and maintenance activities for MMS components of different performance states. An industrial case study of a ferrite phase shifter manufacturing system is subsequently conducted to validate the proposed approach. Results demonstrate the effectiveness of the proposed approach in the resilience optimisation of MMSs.

Microstrip‐line‐based K‐band isolator and Ku‐band phase shifter with barium hexa ferrite disc

AbstractThis article deals with the operational behavior of barium hexaferrite (BHF) disc when incorporated in microwave substrates for wireless applications. A microstrip line printed on a Rogers substrate (35 mm × 35 mm × 1.6 mm) has been used in the design to observe the effect of BHF material. A BHF circular‐shaped disc of radius 4.5 mm and thickness 1 mm is inserted in the middle of the microstrip line. The ferrite is biased using miniature lightweight neodymium magnets stacked one over the other to obtain desired magnetic field strength. The proposed microstrip line inserted with a BHF disc exhibits wide band isolation properties in the K‐band (15–21 GHz) with an average isolation of 20 dB and peak isolation of 51 dB centered at 18.5 GHz. It is observed that the same circuit is behaving as a phase shifter showing a 45° ± 3° phase shift in the band ranging from 12 to 14 GHz. The proposed compact microstrip‐line circuit can be used as both ferrite phase shifter and isolator in consecutive bands (Ku‐ and K‐bands) with ease of integration and biasing.

Inkjet-Printed Ferrite Substrate-Based Vialess Waveguide Phase Shifter

Magnetically controlled waveguide-based phase shifters are desirable for their high performance, but are bulky and heavy, thus cannot be easily integrated with printed circuit board (PCB) based circuits. To tackle this, substrate-integrated waveguide (SIW) technology has been utilized, which brings the waveguide to a standard PCB, but requires large numbers of vias as well as multiple cavities in the substrate for ferrite slab placement. This implementation technique involves complex fabrication and yields a relatively low figure of merit (FoM). To alleviate this, we present the first completely vialess ferrite substrate-based waveguide phase shifter realized through low-cost inkjet printing technique. All the four sides of a yttrium iron garnet (YIG) substrate have been metalized through inkjet printing, allowing the fabrication of a conventional rectangular waveguide on a standard magnetic substrate. The prototype has been tested in symmetric as well as antisymmetric modes of biasing and peak FoMs of 160°/dB at 7.22 GHz and 332°/dB at 7.46 GHz have been measured, which are higher than those of the previously reported designs. This all-around inkjet printing approach can open the door to low-cost, integrable magnetic phase shifters with excellent RF performances.

INCREASING CHARACTERISTICS OF BSNR 9С32 DURING IMPLEMENTATION IN ITS ANTENNA SYSTEM OF THE ELEMENTS ON A MODERN ELEMENT BASE

The military conflicts of the last decade are characterized by the wide use of air assets including small - sized and (or) unmanned ones by the warring parties. In modern conditions one of the effective measures to combat them is to increase the accuracy of coordinate information provided to combat (or fire) means. Increasing the accuracy of coordinate information determines: the possibility of non-searching detection and (or) capture of aerial targets by fire means, increasing the survivability of air defense systems due to the reduction of working time (including the time for "radiation") and rapid change of their positions after completing the assigned task.
 The modern development of science and technology makes it possible to create effective means of air defense to combat existing and promising means of air attack but their development and commissioning requires large costs. In this regard, the issue of improving the characteristics of existing complexes without significant capital investments is gaining relevance.
 One of the important characteristics of the detection means and tracking of a multi-channel air assets anti- aircraft missile complex is the resolution and accuracy of measuring the angular coordinates of objects. This is due to the fact that modern air defence anti-aircraft missile complex uses information about the angular velocities of the missile-target line and the missile velocity vector when aiming anti-aircraft guided missiles using the proportional approximation method. Therefore, the accuracy of their measurement depends on the features of the missile’s flight trajectory when firing at the target and as a result the probability of its damage. The resolution and accuracy of angular coordinate measurement depends significantly on the characteristics of the antenna system.
 It is proposed to use their analogues on a modern element base instead of standard multi-channel missile guidance station 9C32 antenna elements in the work . Estimates of the characteristics of the phased antenna array when introducing promising pass-through ferrite phase shifters (in particular the increase in the accuracy of measuring angular coordinates and the range of aerial targets detection) were obtained using mathematical modeling and calculation methods. Obtained ratios allow for an appropriate assessment.
 The obtained results can be used in the development of proposals for the introduction of modern antenna elements (ferrite phase shifters) into the antenna systems of multi-channel radio equipment of anti-aircraft missile systems.The last decade is characterized by a number of military conflicts, in most episodes of which the achievement of the goal (reconnaissance and (or) defeat of certain targets) by the warring parties is mostly achieved through the use of aircraft, including small and (or) unmanned. The main difference is to obtain the desired results without a direct collision with the enemy ground component of troops (forces).
 Most of the recommended measures to combat aircraft in modern conditions can be reduced to: the rational construction of battle order (using the air defense separation), the widespread use of covert communications, radio reconnaissance and electronic warfare, the creation of erroneous and camouflage combat (reserve) air defence means positions, automation of transmission and processing of information about the air situation with the use of modern technologies and increase the accuracy of coordinate information provided to combat (or fire) means.
 Improving the accuracy of coordinate information causes: the possibility of searchless detection and (or) capture of air targets by fire, increasing the survivability of air defense systems by reducing working hours (including time for “radiation”) and rapid change of their positions after the task. Modern algorithms for processing coordinate information provided by air defense systems take into account the errors of primary coordinates measurement by radio engineering, the delay time of information in communication channels and its possible distortion. At the same time, they do not explicitly take into account the influence of topographic errors and orientation errors of radio equipment.
 In the work with the use of mathematical modelling methods, an assessment of the characteristics of the phased antenna array was carried out with the introduction of a promising pass-through ferrite phase shifter (in particular, an increase in the accuracy of measuring angular coordinates and the range of detection of aerial targets). The obtained ratios allow to make an appropriate assessment.
 The obtained results can be used when introducing modern ferrite phase shifters to the antenna system of the multi-channel missile guidance station 9С32.

Verification of Phase Shifter Measurements of a Reflective Array Antenna

Introduction. Large-size phased antenna arrays (PAA) frequently incorporate optical excitation schemes, whose main elements include the feed and the reflective aperture. In turn, the reflective aperture consists of several tens of thousands of radiators and phase shifters. Major distortions of the radiation pattern in reflective arrays occur due to phase errors, leading to a decrease in the gain and an increase in the side lobes of the radiation pattern. In the millimeter wavelength range, ferrite phase shifters can have an initial phase from 0 to 360 °, thus requiring measurements of the array elements following their assembly.Aim. To develop a method for evaluating errors in measurements of the parameters of phase shifters incorporated in an antenna array by comparing theoretical and experimental data.Materials and methods. A convenient method for determining the parameters of phase shifters is probing, in which a movable probe is connected in series with each array element. In cases where a PAA element represents a single structure consisting of a ferrite segment and a dielectric radiator, measurements are carried out using a probe in the form of a segment of a round waveguide moving towards the radiator. In order to evaluate the measurement error of such a scheme, a mechanically controlled reference phase shifter was used.Results. Measurement errors for the probe structure used were calculated based on the assumption of the phase error arising from the vector addition of the controlled and uncontrolled reflected signals at the input of the PAA element, in the section of the reference plane at the input of the probe. In addition, the S-parameters of the superposition section were calculated. The extrema of the error function were used to determine the maximum errors in measuring the phase and amplitude.Conclusion. The performed analysis confirmed the validity of the proposed method for measuring the parameters of phase shifters using a waveguide probe. The measurement error of the PAA elements according to the proposed scheme was found to be about 3 o, which is commensurate with that of recording devices.

Reggia – Spencer type high-speed ferrite phase shifters for modern phased array antennas

Reggia – Spencer type high-speed ferrite phase shifters for modern phased array antennas

Development of small-sized phased antenna arrays on ferrite phase shifters for unmanned aerial vehicles

In this paper, an approach to the development of small-sized phased antenna arrays on ferrite phase shifters is considered. The paper presents examples of predicting the radiation characteristics of phased antenna arrays and processing their measured characteristics using mathematical models. On the basis of a phased array antenna for an unmanned aerial vehicle, the influence of the design features of such an antenna on its radiation characteristics is shown. The radiation characteristics of a phased array antenna for an unmanned aerial vehicle developed at V. V. Tikhomirov Scientific Research Institute of Instrument Design are presented.

Effect of peak power enhancement of ferrite phase shifter from full-height to increased-height rectangular waveguide.

In order to enhance the high-power performance of the ferrite phase shifter (PS), a method of increasing waveguide height is proposed and experimentally demonstrated. Dual-toroid geometry is utilized as a high-power structure. Two configurations of X-band PSs with full-height (FH) and increased-height (IH) waveguides are designed and fabricated while keeping other parameters consistent. Comparative analysis based on simulation and high-power experiments is conducted. The simulation results agree well with experiments. Compared with the FHPS, the IHPS can enhance the peak-power-capacity from 90 kW to 140 kW while maintaining almost the same insertion loss of 0.5 dB with a slight increase in differential phase shift from 360° to 380°.

Analysis of a fast-acting waveguide ferrite phase shifter with longitudinal magnetization phasing structure

The electrodynamic analysis and calculation of the phasing structure of a waveguide ferrite Faraday phase shifter with longitudinal magnetization of a ferrite rod with a square cross-section are performed. In the strict electrodynamic formulation, the Galerkin method solves the key problem for the design of the phase shifter: the problem of eigenwaves finding with a second-order differential magnetic operator in the projection procedure for a rectangular waveguide with a transversely inhomogeneous ferrite-dielectric filling under longitudinal magnetization. The problem is reduced to solving the complete eigenvalue problem of a complex matrix. The computational algorithm, implemented as a computer program in DELPHI, gives in one procedure the numerical values of the coefficients of the decomposition of fields in the form of eigenvectors of the matrix, and the coefficients of wave propagation in the form of its eigenvalues. The results of calculations of the phasing structure activity for two particular cases of its implementation are presented: on the basis of a ferrite rod both with a conductive coating and without a coating, it is shown that in the second case the activity of the phase shifter is 1.5 times higher. For the real parameters of the ferrite medium, the length of the phasing structure is calculated depending on the transverse dimensions of the ferrite rod and the square waveguide, which ensures the creation of a 360° controlled phase shift.

Design of integrated Ka-band reflective phased array antenna element

The results of a constructively simple high-tech small-sized integrated element of the Ka-band electric beam scanning reflective phased array antenna (PAA) development are shown. Beam scanning sector of the phased array antenna is up to 60 by both coordinates. The PAA element is based on the Faraday type waveguide ferrite phase shifter, which works on the circular polarized electromagnetic waves. More than 30000 PAA elements has been produced, 100% control and statistical data processing of their main characteristics has been carried out. Graph for initial phases and steepness of linearized phase characteristics, medium and maximum losses of PAA elements are performed. Average value of the average deviation for parameters which is important for PAA and the beam control system design have been determined. The developed element can be used in PAA which have different sizes, forms and sectors of electrical beam scanning. Small deviations in the characteristics of PAA elements from the linearized characteristics indicate the high quality of the production and their identity, which makes it possible to create PAA without taking into account the real individual parameters of mass-produced PAA elements.

Design of the 3.7 GHz, 500 kW CW circulator for the LHCD system of the SST-1 tokamak

Circulators are used in high power microwave systems to protect the vacuum source against reflection. The Lower Hybrid Current Drive (LHCD) system of SST-1 tokamak commissioned at IPR, Gandhinagar in India comprises of four high power circulators to protect klystrons (supplying 500kW CW each at 3.7GHz) which power the system. This paper presents the design of a Differential Phase Shift Circulator (DPSC) capable of handling 500kW CW power at 3.7GHz so that four circulators can be used to protect the four available klystrons. As the DPSC is composed by three main components, viz., magic tee, ferrite phase shifter and 3dB hybrid coupler, the designing of each of the proposed components is described. The design of these components is carried out factoring various multiphysics aspects of RF, heating due to high CW power and magnetic field requirement of the ferrite phase shifter. The primary objective of this paper is to present the complete RF, magnetic and thermal design of a high CW power circulator. All the simulations have been carried out in COMSOL Multiphysics. The designed circulator exhibits an insertion loss of 0.13dB with a worst case VSWR of 1.08:1. The total length of the circulator is 3m.

A novel high power X-band ferrite phase shifter.

A novel high power X-band ferrite phase shifter (PS) employing the structure of several waveguides connected in parallel is proposed. Each of the waveguides is a phase shift unit utilizing a dual-toroid structure. First, the phase shift unit is designed, manufactured, and tested. The results indicate that the power capacity reaches 115 kW. At this power, the maximum magnetic field strength of ferrite is 7.9 kA/m, beyond which the nonlinear effect of ferrite will occur. On this basis, the PS that consists of four units connected in parallel is designed. According to the threshold of ferrite, the power capacity of the PS can theoretically reach 430 kW. Limited by the maximum output power of the microwave source, the preliminary high-power test results demonstrate that the PS can operate properly at 270 kW. The PS exhibits an insertion loss of 0.82 dB and a maximum differential phase shift of approximately 300° at 9.3 GHz. The return loss of the PS is more than 16 dB from 9.0 to 9.5 GHz.

Characterization of LTCC-Based Ferrite Tape in ${X}$ -band and Its Application to Electrically Tunable Phase Shifter and Notch Filter

In this paper, low temperature cofired ceramic compatible ferrite tape (ESL 40011) is characterized in ${X}$ -band to study the properties of the tape in the demagnetized state. Data obtained are used to design an electrically tunable ferrite phase shifter and a tunable notch filter. These components are made electrically tunable by winding the bias coils around the ferrite substrate. They operate in the partially magnetized state at the magnetic fields $^{{\mathbf {3}}}$ including the bias circuitry and the test fixture. For a biased current of 700 mA, the measured differential phase shift of 215° having a figure of merit of 48°/dB is achieved at 10.6 GHz. Tunable reflection-type notch filter is designed using the same method of biasing. Center frequency of the notch is observed at 12.35 GHz. A tunability of 3.5% is achieved by varying the bias current from 50 to 450 mA. Simulation of the structures in a 3-D electromagnetic simulator shows good agreement with the measured results. High power measurements carried out up to a 2 W of input power show good stability in the performance of these components.

Modeling non-saturated ferrite-based devices: Application to twin toroid ferrite phase shifters

This article describes a new set of tools developed to improve the conception and modeling of non-saturated ferrite-based devices such as twin toroid phase shifters. These new simulation tools benefit from a generalized permeability tensor model able to describe the permeability tensor of a ferrite sample whatever its magnetization state. This model is coupled to a homemade 3D multi-scale magnetostatic analysis program, which describes the evolution of the magnetization through the definition of a hysteresis loop in every mesh cell. These computed spectra are then integrated into 3D electromagnetic simulation software that retains the spatial variations of the ferrite properties by using freshly developed macro programming functions. This new approach allows the designers to accurately model complex ferrite devices such as twin toroid phase shifters. In particular, we demonstrated a good agreement between simulated and measured phase shifts as a function of applied current values with a predicted maximum phase shift of 0.96 times the measured value.

Research on a Defects Detection Method in the Ferrite Phase Shifter Cementing Process Based on a Multi-Sensor Prognostic and Health Management (PHM) System.

The cementing manufacturing process of ferrite phase shifters has the defect that cementing strength is insufficient and fractures always appear. A detection method of these defects was studied utilizing the multi-sensors Prognostic and Health Management (PHM) theory. Aiming at these process defects, the reasons that lead to defects are analyzed in this paper. In the meanwhile, the key process parameters were determined and Differential Scanning Calorimetry (DSC) tests during the cure process of resin cementing were carried out. At the same time, in order to get data on changing cementing strength, multiple-group cementing process tests of different key process parameters were designed and conducted. A relational model of cementing strength and cure temperature, time and pressure was established, by combining data of DSC and process tests as well as based on the Avrami formula. Through sensitivity analysis for three process parameters, the on-line detection decision criterion and the process parameters which have obvious impact on cementing strength were determined. A PHM system with multiple temperature and pressure sensors was established on this basis, and then, on-line detection, diagnosis and control for ferrite phase shifter cementing process defects were realized. It was verified by subsequent process that the on-line detection system improved the reliability of the ferrite phase shifter cementing process and reduced the incidence of insufficient cementing strength defects.

Virtual Prototyping and Development of Rotary Field Ferrite Phase Shifter

<p>Review of the virtual prototyping and physical development of the rotary field ferrite phase shifter is presented. A description of the basic principle of operation of the rotary field ferrite phase shifter has been given along with the key aspects about the design and virtual prototyping of various parts of the phase shifter viz ferrite rod, yoke, polarisers and matching section using HFSS and 3-D Maxwell softwares. Calibrated simulation performance of the phase shifters is presented and it shows good agreement with physical measurement results. Three prototypes and one hundred production capable phase shifter modules were fabricated, functionally tested and RF characterised. This is an indigenous development of the physical prototypes of rotary field class of ferrite phase shifters of C-band. This class of ferrite phase shifters finds application in phased array radars, such as battery level radar and weapon locating radar, because of its high phase accuracy and high power handling capability.</p><p> </p>

LABVIEW BASED RF CHARACTERIZATION AND TESTING OF DUAL MODE PHASE SHIFTER

R.F. characterization of C-band dual mode ferrite phase shifter cannot be done manually due to enormous and huge amount of data. So this paper provides the solution in term of automated procedure for testing of C-band DMPS in LabVIEW(Laboratory Virtual Instrument Engineering Workbench) software. Dual mode phase shifter is currently being used in phased array Radar and WLR (Weapon Locating Radar). The DMPS is in production to realize the exorbitant demand of these radars. The desirable characteristic of phase shifter for phased array radar as differential phase shift, insertion loss, return loss, Hi-low phase difference, insertion phase, Rx-Tx phase can be measured with high accuracy. The output can be presented in any desirable form such as concluded summary form, graphical form and in excel sheet for future reference purposes.

A Partially Magnetized Ferrite LTCC-Based SIW Phase Shifter for Phased Array Applications

The theory and design of a half-mode substrate-integrated waveguide ferrite low-temperature cofired ceramic-based phase shifter are presented in this paper. Unlike typical ferrite-based designs, the biasing is done through embedded windings in a multi-layer substrate that not only obviates the requirement of bulky electromagnets, but also prevents loss of bias fields at the air-to-ferrite interface. The phase shifter is operated in the partially magnetized state of ferrite substrate. Through the combined effect of embedded windings, half-mode waveguide operation, and partially magnetized state, the required bias fields have been reduced by 90% as compared with conventional ferrite-based designs employing electromagnets. A complete analytical model, backed up by electromagnetic simulations and measured results from a prototype, is presented in this paper. The fabricated prototype demonstrates a phase shift of 83.2° at a center frequency of 13.1 GHz and a figure of merit of 83.2°/dB. As a proof-of-concept, the proposed phase shifter design is monolithically integrated with a two-element antenna array to demonstrate a measured beam steering of 30°. The phase shifter design is highly efficient in terms of required bias fields, and it has a small form factor and can be easily integrated with other electronic components and systems.

Microrectangular-coaxial phase shifter for microwave devices

This article reports the simulated performance of rectangular coaxial ferrite phase shifter at Ka-band. The proposed technique exploits rectangular coaxial waveguide with a symmetrically placed inner signal conductor inside an outer conductor connected to the ground. Strontium ferrite-SU8 composite is used as an anisotropic material of choice in the modeled design. Two model phase shifting structures were designed for reciprocal and nonreciprocal applications using High Frequency Structure Simulator, HFSS. The reciprocal model produced a tunable phase shift of almost across 0 to 400 kA/m applied field and at 1800 Gauss. The predicted simulated performance of the nonreciprocal phase shifter was from a reference phase of at 0 A/m at the same saturation magnetization. A return loss better than 20 dB and an insertion loss less than 1.5 dB were predicted for the two models. © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:502–509, 2015.