The synchronous tuning of the self-oscillating wireless power transfer (WPT) in a close-coupling condition is studied in this paper. The Hamel locus is applied to predict the self-oscillating points in the WPT system. In order to make the system operate stably at the most efficient point, which is the middle resonant point when there are middle resonant and split frequency points caused by freq...

We propose a piezoelectric transducer-(PZT-) based optoelectronic frequency synchronizer to control simultaneously change in the repetition rate, the relative pulse delay, and the phase noise of a passively mode-locked femtosecond Ti:sapphire laser with an intracavity saturable Bragg reflector absorber with respect to an electronic frequency reference. An optoelectronic phase-locked-loop-based ...

This paper describes the factors that limit the tuning range of monolithic LC voltage-controlled oscillators (VCOs), especially at low supply voltages, and introduces circuit techniques that alleviate this problem. Incorporating such techniques, a 1.8GHz CMOS oscillator achieves a tuning range of 120MHz with a relatively constant gain while exhibiting a phase noise of -100dBc/Hz at 500kHz offse...

A new concept for quadrature coupling of LC oscillators is introduced and demonstrated on a 5GHz CMOS VCO. It uses injection-locking through commonmode inductive coupling to enforce quadrature. The technique provides quadrature over a wide tuning range without introducing any phase noiseor power consumption increase. The realized VCO is tunable between 4.6GHz and 5.2GHz and measures a phase noi...

In this paper, a 4.2–5.4 GHz, Gm LC voltage controlled oscillator (VCO) for IEEE 802.11a standard is presented. The circuit is designed with AMS 0.35 lm SiGe BiCMOS process that includes high-speed SiGe Heterojunction Bipolar Transistors (HBTs). According to post-layout simulation results, phase noise is 110.7 dBc/Hz at 1 MHz offset from 5.4 GHz carrier frequency and 113.4 dBc/Hz from 4.2 GHz c...

The tuning and matching conditions of rf circuits, as well as the properties of the transmission lines connecting these to the preamplifier, have direct consequences for NMR probe sensitivity and as for the optimum delivery of rf power to the sample. In addition, tuning/matching conditions influence radiation damping effects, which manifest themselves as fast signal flip-back and line broadenin...

This paper describes the international co-operation experience in teaching control engineering with laboratories being conducted remotely by students via the Internet. This paper describes how the students ran the experiments, and their personal experiences with the laboratory. A tool for process identification and controller tuning based on spreadsheets like MS-Excel is outlined. Process ident...

This paper reports two techniques for optimizing harmonic termination in power amplifiers. In the jirst technique, the active antenna approach, the antenna element acts as radiator and as part of the output tuning circuit. The second method, based on photonic band-gap (PBG) structure, incorporates a periodic harmonic tuning structure for microstrip lines. In this structure, a periodic 2-D patte...

Introduction Radiofrequency planar microcoils are used to increase the resolution of magnetic resonance images of small samples. In this study, we aimed to design and fabricate a spiral planar microcoil constructed on a double-sided printed circuit board (PCB). It has four rings with an internal diameter of 241 microns tuned and matched at 63.8 MHz. Materials and Methods To achieve the maximum ...

Scaling and power reduction trends in future technologies will cause subthreshold leakage currents to become an increasingly large component of total power dissipation. As a result, new techniques are needed in order to provide high performance and low power circuit operation. This dissertation develops new circuit techniques that exploit dual threshold voltages and body biasing in order to red...