Ferrite Phase Shifters Research Articles

Study of Adhesive Curing Pressure in Process of Ferrite Phase Shifter

The adhesive cure reaction in manufacture of ferrite phase shifter is studied. Strength of epoxy adhesive joint has been tested in process experiments. Mathematical model is fitted to describe the relationship between the strength of adhesive joint and curing pressure, and an appropriate curing pressure is obtained through sensitivity analysis. The real-time control scheme of process parameters is carried out to improve the first pass rate, which is influenced by void defects in the adhesive layer.

Failure analysis of the adhesive joint of microwave ferrite phase shifter

Failure investigation is carried out on the adhesive joint of microwave ferrite phase shifter. Though, practically, the failure mode of microwave ferrite phase shifter can be described as the fracture of adhesive joint between ferrite and microwave dielectric ceramic, the failures of adhesive layer could be found in various ways and at various stages of manufacture, assembly and service. They may be due to the strength degradation caused by moisture environment, or the voids defects originated from dehydration effect of the adhesive as well as the contamination during manufacturing. With the help of SEM, FTIR and TGA, both the normal and failed samples of microwave ferrite phase shifter were selected, compared and analyzed. Recommendations for the structural design and the adhesive process are presented, and the responsibility of the failures was charged to the negligence of the manufacturer of the microwave ferrite phase shifters.

Hexagonal ferrite‐piezoelectric composites for dual magnetic and electric field tunable 8–25 GHz microstripline resonators and phase shifters

AbstractMicrowave magnetoelectric (ME) effects over 8–25 GHz have been studied in bilayers of single crystal Y‐type hexagonal ferrite Ba2Zn2Fe12O22 and polycrystalline lead zirconate titanate (PZT) or single crystal lead magnesium niobate–lead titanate (PMN–PT). The bilayers are made by epoxy bonding or eutecting bonding the ferrite and piezoelectric. The strength of ME interactions A has been measured from data on electric field E tuning of magnetic modes in the ferrite. The electric field produces a mechanical deformation in the piezoelectric and results in a shift in the ferromagnetic resonance. Bilayers of ferrite/PMN–PT have A = 10 MHz cm/kOe and is an order of magnitude higher than for ferrite‐PZT. The ferrite/PMN–PT resonators could be tuned by 120 MHz with E = 12 kV/cm. Data on differential phase shift versus E indicate a differential phase shift of 50° for E = 12 kV/cm, a linear variation in the phase shift with E and an insertion loss of 4–8 dB. The bilayers are of interest for 8–25 GHz dual E‐ and H‐tunable ferrite resonators and phase shifters. © 2012 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:1215–1218, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26793

기판 집적 도파관을 이용한 아날로그 페라이트 위상 천이기

Analog ferrite phase shifters based on rectangular waveguides which are used as component of passive phased array system have high power handling capability, but it is heavy and has high cost to fabricate. In this paper, we propose an analog ferrite phase shifter using substrate integrated waveguide(SIW), which has low cost and is easy to fabricate because it uses printed circuit board(PCB) process. The proposed structure is fabricated by using centeral dielectric material removal for inserting a ferrite bar. The measured results show that the proposed structure has not only /mm phase variation but also return loss variation under 12.9 dB. Therefore, it is expected that the proposed phase shifter can plays an role to reduce weight and to has low cost on the phased array system.

A strain engineered voltage tunable millimeter‐wave ferrite phase shifter

AbstractA 50‐GHz electric field tunable ferrite‐piezoelectric phase shifter based on a bilayer of single crystal M‐type hexagonal barium ferrite (BaM) and lead zirconate titanate (PZT) is discussed.A dc voltage applied to PZT results in a piezoelectric strain that manifests as an anisotropy field in BaM. A change in the voltage applied to PZT gives rise to variations in the anisotropy field and permeability of BaM and, therefore, a differential phase shift. A phase shift of 45° is measured when the voltage is increased from 0 to 400 V across a 0.5‐mm thick PZT. Theoretical estimates of the phase shift are in agreement with the data. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:261–264, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25725

Millimeter wave phase shifter based on ferromagnetic resonance in a hexagonal barium ferrite thin film

A hexagonal ferrite thin film-based planar millimeter-wave phase shifter was demonstrated. The device made use of an M-type barium ferrite (BaM) thin film prepared by pulsed laser deposition and a coplanar waveguide geometry. The phase tuning relied on ferromagnetic resonance in the BaM film. The device showed a phase tuning rate of 43°/(mm kOe) and an insertion loss of 3.1 dB/mm in the on-resonance regime. In off-resonance regimes, the device showed smaller loss and smaller tuning rates. The experimental results were confirmed by theoretical calculations.

Design and Simulation of Rotary Field Ferrite Phase Shifter using Ansoft HFSS

HFSS is a high-performance full-wave electromagnetic (EM) field simulator for arbitrary 3D volumetric passive device modeling.It employs the Finite Element Method (FEM), adaptive meshing, and brilliant graphics. This paper reports the measured phase shift characteristics of C-band phase shifters constructed from lithium ferrites. This is done by first magnetizing the ferrite rod in perpendicular (to direction of propagation) direction and then in longitudinal (parallel to direction of propagation). Thereby, giving a phase shift of 90 degrees. It has been proved that by giving a phase shift of 90 degrees to the magnetic field, we will get the phase shift of twice the rotation i.e. 180 degrees.

Multiferroic heterostructure fringe field tuning of meander line microstrip ferrite phase shifter

Magnetic fringe fields emanating from a multiferroic heterostructure composite of Terfenol-D and lead magnesium niobate-lead titanate were utilized to actively tune a meander line microstrip ferrite phase shifter operating above ferrimagnetic resonance at C-band. Differential phase shifts of 65° were measured when tuned with an applied voltage to the multiferroic heterostructure. This demonstration of magnetoelectric field generation provides an alternative approach to tuning broadband planar microwave magnetic devices where neither strain nor direct electromagnetic coupling is experienced between device and multiferroic transducer.

Analog/Digital Ferrite Phase Shifter for Phased Array Antennas

A planar ferrite phase shifter is designed to exhibit simultaneous analog and digital phase tuning properties. Analog phase control is achieved by using an external magnetizing field, and digital phase change is realized by switching the phase shifter operation from microstrip to waveguide mode. Simulated and experimental results are presented to demonstrate the impedance matching and dual-phase tuning properties. At 9-GHz, a differential digital phase shift of 100°/bit and an analog phase control of 16°/mT is exhibited. When applied in phased array antennas, these easily integrated low-cost planar phase shifters can produce high-resolution wide-angle beam scan by employing analog/digital phase control circuits.

Low Bias Field Hexagonal Y-Type Ferrite Phase Shifters at ${K}_{U}$-Band

A microstrip line fabricated on a single crystal hexagonal Y-type ferrite substrate was utilized to achieve phase shifts of ~65deg/cm at KU-band with an external bias field of only 100 Oe. This approach utilizes the rapid variation of the Y-type ferrite tensor permeability near the ferromagnetic antiresonance frequency. The magnetic and microwave properties of the substrate material were characterized by vibrating sample magnetometry and ferromagnetic resonance measurements. Numerical methods based on Galerkin's approach adapted to spectral domain were utilized to model the performance of the device while taking into account the correct form of the tensor magnetic permeability of the anisotropic and gyromagnetic substrate material. Good agreement between the numerical results and experimental data was obtained. A miniature electromagnet, based on a Metglastrade laminated yoke to minimize demagnetizing fields, was fabricated. Phase shifts of 50deg/cm were achieved with continuous drive currents of only 100 mA.

Variable toroidal ferrite phase shifter

Careful design of the magnetic bias circuit used in ferrite phase shifters can help to reduce space, weight and energy consumption. Low reluctance circuits must avoid air-gaps and this can be achieved using toroidal-shaped ferrite inserts positioned inside a rectangular waveguide. Here, these ferrite inserts are fabricated using a viscous plastic processing method that avoids machining and produces a continuous magnetic circuit. Finite-element methods are used to initially model the magnetostatic solution for the bias circuit before being used to analyse the microwave performance of a double toroid phase shifter. A closed-form technique is introduced to model the dielectric slab waveguide impedance transformer. The final insertion loss was < 1 < dB over the 9.5 < 10.3 <GHz band and return loss of 20 < dB was achievable. The phase shift calculation agrees to within 10< of the measured values.

E-plane and H-plane slab loaded waveguide solutions

A full design capability for electromagnetic waveguides should include the field solution, the modal hierarchy, impedance models, the cut-off and propagation planes with the ability to optimise parameters and synthesise designs. As cut-off frequencies and optimisation are problematic for numerical methods, closed-form solutions are always preferred. In this article, we reformulate Maxwell's equations into two coupled potential equations to characterise both E-plane and H-plane slab loaded waveguides. An experimental resonant cavity is constructed to confirm the dispersion characteristics of the single broadwall H-plane slab and a quarter wavelength impedance transformer is designed to match a toroidal ferrite phase shifter to rectangular waveguide.

Low-Cost Microstrip-Line-Based Ferrite Phase Shifter Design for Phased Array Antenna Applications

High-gain, electronically scanned phased array antennas are commonly used for radar and communications applications. These systems often require thousands of radiating elements, thousands of phase shifters, and hence, reduction in cost, size, and weight of the phase shifters are important goals in reducing the cost of the overall system. This letter presents a new ferrite phase shifter design based on microstrip-line technology that provides reduction in cost, size, and weight as compared to typical ferrite (analog) phase shifters. The design is based on the use of three microstrip lines arranged and fed with phase differences so as to produce circular polarization in the ferrite region. The proposed ferrite phase shifter was designed and simulated at 3 GHz to achieve a phase shift of approximately 360deg in less than an effective wavelength. A prototype was designed and fabricated to provide optimal circular polarization in the ferrite region and measured results show 309deg of phase shift in a wavelength, thus fulfilling the requirements. It is also shown that after calibrating measured values to account for the ratio between the applied external Ampere/turn values to the internally applied H-field value used in the high-frequency structure simulator (HFSS), good agreement may be seen between the simulation and experimental results. Based on this successful initial development, suggestions are made for further design improvements including reducing the number of turns in the biasing coil and minimizing the required input power

Nonlinear Ferrite Film Microwave Signal Processing for Advanced Communications—Physics and Devices

Microwave ferrite devices, including circulators, isolators, and phase shifters, have played a crucial role in the development of radar and other microwave signal processing applications. Recent work has advanced the basic understanding and applications for a wide range of new nonlinear spin wave phenomena in ferrite films. With the help of feedback and parametric pumping interactions, these spin wave phenomena can serve as the basis for phase locked frequency comb generators, wideband chaotic microwave oscillators, and microwave pulse multiplexers, among other devices.

Application of Microwave Ferrite Phase Shifter for Wireless Communication

In this paper, the operation principles of several kinds of phase shifters (PS) are introduced, and the application of the microwave ferrite phase shifter in wireless communication is investigated. Some problems existing in the ferrite phase shifters have been discussed, which are required to solve critically. In addition, some comparisons of the performance and applications between different kinds of phase shifters have been proposed.

Development of a Millimeter-Wave Ferrite-Filled Antisymmetrically Biased Rectangular Waveguide Phase Shifter Embedded in Low-Temperature Cofired Ceramic

The theory of a new ferrite-filled rectangular waveguide phase shifter is presented, showing that the device offers more than twice the maximum phase shift of a classical dual-slab ferrite-loaded waveguide phase shifter. The complete analytical field derivation of the new phase shifter is presented. The prototype 36-GHz phase shifter has been completely embedded in an uncharacterized experimental low-temperature cofired ferrite ceramic material, essentially becoming an integral part of a chip package. The fabricated prototype is only 3.5-cm long, 5-mm wide, and 1-mm high. Preliminary measurements of the nonoptimized prototype reveal a controllable, nonreciprocal phase shift of 52.8/spl deg/ at 36 GHz for a bias current of 500 mA, and an insertion loss of approximately 3.6 dB, including transition loss. This paper marks the first time that a ferrite waveguide phase shifter has been realized as a lightweight, compact, and rugged module that can be easily mass produced at low cost. Since it is embedded in a package, the phase shifter can be readily integrated with other active and passive system components that would ideally be contained within the same package.

Effect of Waveguide Tolerance on Characteristics of the Latching Ferrite Phase Shifter in a Rectangular Waveguide

In this paper, the effects of waveguide height tolerance on characteristics of the ferrite phase shifter in a rectangular waveguide have been investigated. It has been indicated that larger height tolerance usually results in bigger insertion loss. In addition, the emphasis has also been focused on the theoretical analysis and experimental verification of the effects on insertion phase of ferrite phase shifter, caused by the height tolerance. Two kinds of models have been employed to analyze the effects with finite element method (FEM), and the results have been compared with measured data, respectively. The practical model has been proved to provide more accurate results and agree better with experiments, the results shown that the height tolerance has great effect on the insertion loss.

Low-cost nonplanar microstrip-line ferrite phase shifter utilizing circular polarization

A low-cost microwave ferrite phase shifter is proposed in this paper. The phase shifter is comprised of three parallel nonplanar microstrip lines separated from a ground plane by a substrate containing a ferrite rod/slab. The amount of phase shift between the input and output ports is determined by the strength of the magnetic bias field applied to the ferrite. A three-way power divider was designed to feed the microstrip lines with different magnitudes and phases. By combining the effects of the nonplanar geometry and the phase offsets introduced by the feed network, circularly polarized waves can be produced in the ferrite. These waves strongly interact with the biased ferrite resulting in a large phase shift over a short distance-90/spl deg//cm based on current simulation results. This device will be best suited for use in high-gain phased-array radar systems.

Novel semiconductor phase shifters for millimeter‐wave devices

AbstractMicrowave and millimeter‐wave ferrite phase shifters are essential components in phased‐array antennas for telecommunication and radar applications. However, the extremely high cost and frequency limitations have limited their use to military applications. In this study, potentially low‐cost, miniaturized semiconductor phase shifters are analyzed and compared with their ferrite counterparts. Ferrite‐semiconductor composite phase shifters are also envisaged. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 39: 300–303, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11197

Analysis of a high power ferrite differential phase shift circulator operating above ferrimagnetic resonance

Abstract Magnetic losses limit the power handling/frequency performance of all ferrite phase shift and control components. At high power levels nonlinear loss is prevalent but this can be avoided using a technique called ‘mode segregation’. It is noted that this is achieved by biasing the ferrite above ferrimagnetic resonance. A combined magnetostatic/microwave finite element scheme is used to model this mode of operation in a differential phase shift structure used in air traffic control surveillance radars. Starting from the nonlinear material magnetisation curve, the magnetic state of the ferrite is evaluated as a prerequisite to calculating the full microwave solution. Above resonance operation avoids nonlinear loss but this study indicates that the differential phase shift is reduced and larger magnetic bias fields are required. Calculations agree well with the experimental data.