Research efforts addressing spin waves (magnons) in micro- and nanostructured ferromagnetic materials have increased tremendously in recent years. Corresponding experimental and theoretical work in magnonics faces significant challenges in that spin-wave dispersion relations are highly anisotropic and different magnetic states might be realized via, for example, the magnetic field history. At the same time, these features offer novel opportunities for wave control in solids going beyond photonics and plasmonics. In this topical review we address materials with a periodic modulation of magnetic parameters that give rise to artificially tailored band structures and allow unprecedented control of spin waves. In particular, we discuss recent achievements and perspectives of reconfigurable magnonic devices for which band structures can be reprogrammed during operation. Such characteristics might be useful for multifunctional microwave and logic devices operating over a broad frequency regime on either the macro- or nanoscale.

https://iopscience.iop.org/article/10.1088/0953-8984/26/12/123202/pdf

Review and prospects of magnonic crystals and devices with reprogrammable band structure

A Caughey–Thomas-like mobility model with temperature and composition dependent coefficients is used in this work to describe the dependence of electron and hole mobilities on temperature, doping concentration, and alloy composition. Appropriate parameter sets are given for a large number of III–V binary and ternary compounds, including: GaAs, InP, InAs, AlAs, GaP, Al0.3Ga0.7As, In0.52Al0.48As, In0.53Ga0.47As, and In0.49Ga0.51P. Additionally, physically justifiable interpolation schemes are suggested to find the mobilities of various ternary and quaternary compounds (such as AlxGa1−xAs, In1−xGaxP, In1−xGaxAs, In1−xAlxAs, and In1−xGaxAsyP1−y) in the entire range of composition. The models are compared with numerous measured Hall data in the literature and very good agreement is observed. The limitations of the present model are also discussed. The results of this work should be extremely useful in device simulation packages, which are currently lacking a reliable mobility model for the above materials.

Empirical low-field mobility model for III-V compounds applicable in device simulation codes

Integrated-Circuit Fabrication. Active Devices in Integrated Circuits. Passive Components: Diodes, Resistors, and Capacitors. Bias Circuits. Basic Gain Stages. Analog Design with MOS Technology. Operational Amplifiers. Wideband Amplifiers. Analog Multipliers and Modulators. Voltage Regulators. Integrated-Circuit Oscillators and Timers. Phase-Locked-Loop Circuits. Integrated-Circuit Filters. Data Conversion Circuits: Digital-To-Analog Converters. Data Conversion Circuits: Analog-To-Digital Converters. Index.

Bipolar and MOS Analog Integrated Circuit Design

Magnetostatic wave (MSW) technology has been under investigation for more than a decade. Using ferrimagnetic films such as liquid-phase epitaxial (LPE) yttrium iron garnet (YIG) films, MSW devices and subsystems offer instantaneous bandwidths of up to 1 GHz at operating frequencies in the microwave bands (0.5-26.5 GHz). Because MSWs travel with velocities two-to-four orders of magnitude slower than electromagnetic waves, compact devices can be built using hybrid and monolithic microwave integrated circuit (MMIC) techniques. These devices include delay lines, dispersive delay lines, filters, resonators, and directional couplers. Subsystems using these devices, such as electronically tunable delay lines channelized filter banks, delay-line discriminators, oscillators, and frequency multipliers can be used for applications in signal identification, control and processing directly at microwave frequencies. An overview of the MSW technology is presented and an assessment of the various devices and subsystems that can be built using thin and thick LPE-YIG films is provided. >

Magnetostatic wave technology: a review

This article describes the implementation and characterization of a new self-contained large-area wireless strain sensor, operating around 1.5 GHz, based on the concept of multi-layer microfluidic ...

A Microfluidic, Reversibly Stretchable, Large‐Area Wireless Strain Sensor

The feasibility of applying patch antennas for strain measurement is investigated. The resonance frequency of a patch antenna is determined by the size of its metallic patch. An applied strain changes the dimensions of the metallic patch, resulting in a shift in the antenna resonant frequency. Therefore, the applied strains can be measured from the changes in antenna resonant frequency. A dual-frequency patch antenna was designed and fabricated using conventional photolithography techniques. The application of the patch antenna for strain measurement was evaluated by bonding the patch antenna to an aluminum cantilever beam and applying loads at the free end of the cantilever beam. The shifts of the return loss S11 curves under loads were correlated to the strains experienced by the patch antenna. The strain sensitivity of the antenna obtained from experimental measurements agreed well with the analytical prediction.

http://iopscience.iop.org/article/10.1088/0957-0233/20/1/015201/pdf

Exploiting a patch antenna for strain measurements

This paper presents the simulation and experimental work that proved the feasibility of using a patch antenna for strain measurement. A patch antenna, besides serving as a data transmitting device, can function as a transducer that directly encodes the strain experienced into its resonant frequency. Printed on a flexible substrate, the antenna sensor is small in size, has a low profile and can be conformal to any attached surface. The technique for interrogating the antenna sensor using a wireless non-contact method is also demonstrated. Without needing electric wiring for power supply and data transmitting, the antenna sensor has a great potential for the realization of engineered sensor skins that imitate the sense of pain for structural health monitoring purposes.

https://iopscience.iop.org/article/10.1088/0964-1726/18/10/104026/pdf

Bio-inspired sensor skins for structural health monitoring

-This paper presents the design of a sinusoidal, triangular, and square wave generator using a high speed current feedback operational amplifier (CFOA). A macro model for the CFOA is developed as well. The frequency of oscillation in all cases are derived and compared with the simulated values. The achieved frequency of oscillation for sinusoidal wave is 9.4 MHz to 15 MHz and the achieved frequency of oscillation for the triangular/rectangular wave is 6.75 MHz to 59.5 MHz. The advantage of using the current feedback operational amplifier is to get higher frequency of sinusoidal, triangular, and square wave.

Design of Sinusoidal, Triangular, and Square wave Generator Using Current Feedback Operational Amplifier (CFOA)

Ion‐implanted bars have been used in fabricating magnetostatic surface wave normal incidence reflective array filters at 3.0 GHz. A theory is presented, based on a dispersion relation derived from a four layer model, and data taken agrees well with the theory. The ion‐implanted bars provide a solution to problems previously associated with etched grooves and metal bars.

Ion‐implanted magnetostatic wave reflective array filters

A new formula for electron and hole mobilities in semiconductors is presented. Although empirical, it is accurate and widely applicable to a number of semiconductors, such as Si, Ge, GaAs, InP, etc. The formula is simple, and yet predicts temperature and field dependence of electron and hole mobilities very well. To our knowledge, the present model is more general than any other model (both empirical and theoretical) available in the literature. Because of very simplistic nature, it promises to be highly useful for analytically modeling the current-voltage characteristics of transistors.

R.L. Carter

Papers

Exploiting a patch antenna for strain measurements

Bio-inspired sensor skins for structural health monitoring

Design of Sinusoidal, Triangular, and Square wave Generator Using Current Feedback Operational Amplifier (CFOA)

Ion‐implanted magnetostatic wave reflective array filters

Temperature, electric field, and doping dependent mobilities of electrons and holes in semiconductors