Fiber ring interferometer

This expanded and thoroughly revised edition of Thomas H. Lee's acclaimed guide to the design of gigahertz RF integrated circuits features a completely new chapter on the principles of wireless systems. The chapters on low-noise amplifiers, oscillators and phase noise have been significantly expanded as well. The chapter on architectures now contains several examples of complete chip designs that bring together all the various theoretical and practical elements involved in producing a prototype chip. First Edition Hb (1998): 0-521-63061-4 First Edition Pb (1998); 0-521-63922-0

The Design of CMOS Radio-Frequency Integrated Circuits: RF CIRCUITS THROUGH THE AGES

Low-cost chip-scale optoelectronic gyroscopes having a resolution ≤ 10 °/h and a good reliability also in harsh environments could have a strong impact on the medium/high performance gyro market, which is currently dominated by well-established bulk optical angular velocity sensors. The R&D activity aiming at the demonstration of those miniaturized sensors is crucial for aerospace/defense industry, and thus it is attracting an increasing research effort and notably funds. In this paper the recent technological advances on the compact optoelectronic gyroscopes with low weight and high energy saving are reviewed. Attention is paid to both the so-called gyroscope-on-a-chip, which is a novel sensor, at the infantile stage, whose optical components are monolithically integrated on a single indium phosphide chip, and to a new ultra-high Q ring resonator for gyro applications with a configuration including a 1D photonic crystal in the resonant path. The emerging field of the gyros based on passive ring cavities, which have already shown performance comparable with that of optical fiber gyros, is also discussed.

https://www.jeos.org/index.php/jeos_rp/article/download/14013/1170

Recent advances in miniaturized optical gyroscopes

We show that a certain fundamental limit applies to the accuracy of all optical rotation sensors which use laser light as a probe. We derive this fundamental rotation-rate uncertainty from the Heisenberg uncertainty relations and Glauber's minimum uncertainty states. The same relationship is obtained from a spontaneous-emission noise formulation. We present experimental data on a (nondithered) four-frequency ring laser gyroscope for which this limit is attained.

Laser gyro at quantum limit

Iron deficiency anemia

Electromagnetic theory is one of the core subjects in Electrical/Electronics and Communication Engineering. It involves many concepts that are abstract and difficult to visualize, hence learning or teaching it is a challenge. This paper presents a web based virtual laboratory for electromagnetic theory course taught at undergraduate level, which can be used as a didactic tool by teachers and as a self learning tool by students. A set of ten topics have been chosen which broadly cover the basics of electromagnetic theory. The laboratory helps the students to visualize and experiment with abstract concepts of electromagnetic theory. It also contains theory supporting the experiment to aid teaching-learning process. The laboratory contains evaluation sections to assess student's understanding before and after performing virtual experiment. Assessment of the virtual lab done by evaluating students and feedback about the laboratory collected from both teachers and students are presented.

A Web-Based Virtual Laboratory for Electromagnetic Theory

Designing RFID tag antenna for metallic objects is a challenging task as antenna parameters are highly affected by metallic surface. This paper presents a miniaturized slotted RFID tag antenna with overall dimensions of 33 mm × 16 mm × 3.2 mm for metallic objects. The proposed design contains two coplanar metallic patches which are electrically connected to the ground plane through a copper via. Multiple slots are created on metallic patches which help in improving overall antenna inductance. A non-connected metallic plate is present between the ground and the patches. The proposed antenna design is simulated and fabricated, and its parameters are analyzed. It is concluded that this design can be reused for different tag chips having different input impedances simply by varying slot length without changing any other antenna dimensions. The read range of the proposed design, when the tag antenna is mounted on the metallic surface, is approximately 80 cm.

Miniature slotted RFID tag antenna for metallic objects

We present a mathematical analysis and comparison of the performance of integrated on-chip semiconductor ring laser gyroscope (SRLG) fabricated using GaAs/AlGaAs and InP/InGaAsP technologies. The performance parameters of the gyro are modeled in terms of fundamental material, waveguide, and resonator parameters. In addition to this, influence of phenomena specific to semiconductor lasers such as nonlinear coupling, spatial hole burning, gain grating formation, and carrier induced index change on the gyro performance is also included. The analysis helps in identifying critical parameters, which must be optimized to improve the gyro performance.Best achievable performance of integrated SRLG is calculated, and design modifications are suggested to enhance it for high-performance military applications.

Performance Evaluation of Integrated Semiconductor Ring Laser Gyroscope

In CMOS radio frequency integrated circuits, inductors are a barrier in achieving better monolithic solutions because of the large area occupied and the associated parasitics. For better performance of on-chip inductors, soft magnetic materials are incorporated with them. In an earlier work, it was shown that by tailoring the shape and size of the permalloy patterns, formation of magnetic domains can be controlled. When such domain patterns are incorporated with inductors, they have varied effects on inductor performance. In this paper, it is demonstrated that by depositing 60 nm thick domain-controlled permalloy patterns, better performance of inductors can be obtained at higher frequencies (>5 GHz). About 2× increment in inductance and 7× increment in quality factor is obtained at frequencies >5 GHz by incorporating appropriate domain-controlled permalloy patterns with inductors.

Performance Boost of Spiral Inductors With Thickness-Controlled Domain-Patterned Permalloy

The sensitivity of a monolithically integrated semiconductor ring laser gyro is severely limited by the high value of the lock-in threshold. In this work, we calculate the lock-in threshold using perturbation theory and coupled mode theory analysis. It is shown that gyro sensitivity is limited to an input rotation rate of 108 deg / h due to nonlinear coupling between the countertraveling modes. This coupling arises due to the backreflection of modes from moving index gratings, induced by rotation. Lock-in threshold is directly proportional to the strength of nonlinear coupling and spatial overlap of the modes’ energy densities with periodic index perturbations.

Azeemuddin Syed

Papers

A Web-Based Virtual Laboratory for Electromagnetic Theory

Miniature slotted RFID tag antenna for metallic objects

Performance Evaluation of Integrated Semiconductor Ring Laser Gyroscope

Performance Boost of Spiral Inductors With Thickness-Controlled Domain-Patterned Permalloy

Limits imposed by nonlinear coupling on rotation sensitivity of a semiconductor ring laser gyroscope.