Pioneering Evaluation of GaN Transistors in Geostationary Satellites

In this paper, we present the results of a 6-year experiment in space that studied the effects of radiation in GaN electronics in geostationary orbit. Four GaN transistors in a Colpitts oscillator configuration were flown in the Component Technology Test-Bed aboard the Alphasat telecommunication satellite. A heuristic analysis was performed by observing the variation in the power output of the oscillators with the total ionizing dose gathered during the mission. The total ionizing dose was measured with a RADFET placed close to the GaN devices. The experiment showed that GaN is a robust technology that can be used in the space radiation environment of a geostationary orbit. The work presented here starts with a brief introduction of the subject, the motivation and the main goal. This is followed by the description of the experimental setup, including the details of the oscillator design and simulations, as well as the implementation of the test bead and the Components Technology Test Bed. Finally, the results obtained during the 6 years of experience in space are discussed.

Implementation of types of VCO

A Voltage Controlled Divider (VCO) is a basic building block in most of the electronic systems. Phase-locked loop (PLL), tone synthesizers, Frequency Shift Keying (FSK), frequency synthesizers, etc make use of VCO’s to generate an oscillating frequency that can be decided with the help of components. Voltage Controlled Divider can be implemented for analog applications. The project proposes three types of VCO using Electric tool and LT Spice XVII tool. The three VCO’s that are implemented are CMOS Ring Oscillator, Colpitts Oscillator and Relaxation Oscillator. These circuits generate two oscillating frequencies that is decided by the circult components. Keywords: Voltage Controlled Divider (VCO), CMOS Ring Oscillator, Colpitts Oscillator, Relaxation Oscillator, oscillating frequency.

Hybrid Cross Coupled Differential Pair and Colpitts Quadrature Digitally Controlled Oscillator Architecture

Growing importance of wireless communication systems forces reduction of power consumption of the designed integrated circuits. The paper focuses on minimization of power consumption in a digitally controlled oscillator (DCO) that can be employed as oscillator in GPS/Galileo receiver. The new hybrid architecture of DCO combines good phase noise performance of a Colpitts oscillator and relaxed startup conditions of a cross-coupled differential pair oscillator. The proposed new DCO generates a quadrature signal in a current reused frequency divider. Such solution allows of the dissipated power to be reduced. The DCO has been implemented in 110 nm CMOS technology. It generates output signal in frequency range from 1.52 GHz to 1.6 GHz and consumes 1.1 mW from 1.5 V supply voltage. The measured phase noise equals −116 dBc/Hz at 1 MHz offset from 1.575 GHz output signal.

Robust Control Methods for Finite Time Synchronization of Uncertain Nonlinear Systems

This chapter addresses the dynamic analysis and two different control strategies for the synchronization of new topology of Colpitts oscillator submitted to uncertainties and external disturbances. The diagrams obtained reveal precisely spirals bifurcation and chaos when for a specific values of the system parameters. Based on the relevant control, the authors have controlled this striking phenomenon in the system. The first (control) deals with the sliding mode control (SMC) method. Some important aspects of the design and implementation are considered to reach a suitable controller for the applications. The second presents an adaptive robust tracking control strategy based on a modified polynomial observer which tends to follow exponentially the chaotic Colpitts circuits brought back to a topology of the Chua oscillator with perturbations. To highlight the contribution, they also present some simulation results with the purpose to compare the proposed method to the classical polynomial observer.

An approach to model and optimization of manufacturing of an enhanced swing differential Colpitts oscillator. on influence of miss-match induced stress

In this paper we introduce an approach to increase density of field-effect transistors framework an enhanced swing differential Colpitts oscillator. Framework the approach we consider manufacturing the oscillator in heterostructure with specific configuration. Several required areas of the heterostructure should be doped by diffusion or ion implantation. After that dopant and radiation defects should by annealed framework optimized scheme. We also consider an approach to decrease value of mismatch-induced stress in the considered heterostructure. We introduce an analytical approach to analyze mass and heat transport in heterostructures during manufacturing of integrated circuits with account mismatch-induced stress