Transistor Oscillator Research Articles

Thermostable Sensor-Converter of Optical Radiation with Frequency Output Based on Single-Junction Transistor Oscillator

Thermostable Sensor-Converter of Optical Radiation with Frequency Output Based on Single-Junction Transistor Oscillator

Development Board Implementation and Chip Design of IEEE 1588 Clock Synchronization System Applied to Computer Networking

With the vigorous development of industrial automation and the Internet of things, the transmission of data is more dependent on immediacy, so network devices have higher and higher requirements for time synchronization accuracy. The clock source of common network devices is provided by the transistor oscillator in the server, but the oscillator will change with factors such as aging and temperature, and it cannot be guaranteed that the oscillator in the server will work at the same frequency. Time synchronization can be achieved by technologies such as IRIG-B, NTP, or IEEE 1588 (PTP), but the hardware cost of building IRIG-B is high, and NTP has the lowest cost, but it can only provide time accuracy from milliseconds to microseconds. PTP can provide sub-microsecond or even nanosecond time precision. It is a system of time synchronization mechanisms through Ethernet transmission. In this article, we first propose a time synchronization system using the development board and PDP protocol. On the Xilinx Zynq-7000 SOC platform of Petalinux, we implement the hardware solution of Linux PTP. The hardware time stamp is 20 ns. To improve the accuracy, the congenital frequency error between the oscillators must be considered. Therefore, a PTP auxiliary time stamp with dynamic frequency compensation is proposed and designed into a chip. Experimental results show that at 45 nm (TN40G) it can operate at 370 MHz and achieve 2.7 ns resolution, which can be applied to more demands.

Matter waves, single-mode excitations of the matter-wave field, and the atomtronic transistor oscillator

A self-consistent theoretical treatment of a triple-well atomtronic transistor circuit reveals the mechanism of gain, conditions of oscillation, and properties of the subsequent coherent matterwaves emitted by the circuit. A Bose-condensed reservoir of atoms in a large source well provides a chemical potential that drives circuit dynamics. The theory is based on the ansatz that a condensate arises in the transistor gate well as a displaced ground state, that is, one that undergoes dipole oscillation in the well. That gate atoms remain condensed and oscillating is shown to be a consequence of the cooling induced by the emission of a matterwave into the vacuum. Key circuit parameters such as the transistor transconductance and output current are derived by transitioning to a classical equivalent circuit model. Voltage-like and current-like matterwave circuit wave fields are introduced in analogy with microwave circuits, as well as an impedance relationship between the two. This leads to a new notion of a classical coherent matterwave that is the dual of a coherent electromagnetic wave and which is distinct from a deBroglie matterwave associated with cold atoms. Subjecting the emitted atom flux to an atomic potential that will reduce the deBroglie wavelength, for example, will increase the classical matterwave wavelength. Quantization of the classical matterwave fields leads to the dual of the photon that is identified not as an atom but as something else, which is here dubbed a "matteron".

AlGaN/GaN high electron mobility transistor oscillator for high temperature and high frequency

A high-temperature 2.1 GHz oscillator based on a AlGaN/GaN high electron mobility transistor (HEMT) is successfully designed, implemented, and characterised for the first time. The system is explicitly designed such that the final circuit consists of a single transistor bonded to a printed circuit board (PCB), and no further passive components besides the transmission lines to attach the connectors are used. Extensive characterisation of the high electron mobility transistor has been carried out up to 300C in order to extract large- and small-signal models. Since the system does not rely on passive tolerances and a specific model of the used transistor has been extracted, a sustainable oscillation of the design at high temperature is assured. The capabilities of the designed circuit are verified by measurements up to 230C, showing a promising performance with around 0 dBm output power and a phase noise of −74 dBc/Hz at 1 MHz offset at the highest characterised temperature.

Added Noise in Oscillators Caused by the Transistor Base Emitter Breakdown Phenomenon

When increasing the RF power level in transistor oscillators to achieve better phase noise performance a reverse voltage breakdown of the base emitter junction of the oscillator transistor can occur. This results in increased phase noise and long term-transistor degradation. Common transistor simulation models/simulators do not have this effect included in their library, so the simulations fail to predict correct oscillator behavior. Starting from common oscillator topologies and active devices the critical waveforms were analyzed and related to the generated noise spectra. A theoretical explanation of the breakthrough process will be given, and the simulation models will be enhanced. Finally, recommendations are made how to avoid breakdown effects and the active device degradation in practical designs.

Silicon Carbide MESFET High Frequency Oscillator for Microwave Applications

The Gouriet oscillator is mainly dealing with 4H-SiC metal semiconductor field effect transistor is fabricated with HPSI substrate and passive integrated elements are based on design for demand of the required function of frequency 1GHz. This high frequency or temperature oscillator is operated from 30 to 200˚C, the gain of the delivered power of 21.8dbm at the frequency of 1GHz and the temperature of 200˚C. The oscillator transistor output response is at 200˚C, the improved percentage is 15%. This output response of the difference in between the frequency around the vary of temperature is less than 0.5%.

Low‐phase noise 8.22 GHz GaN HEMT oscillator using a feedback multi‐path transformer

AbstractThis article designs a low‐phase noise 8.22 GHz GaN high electron‐mobility transistor (HEMT) oscillator in the WIN 0.25 μm GaN HEMT process. The oscillator uses a HEMT amplifier with a transformer as the feedback network. The transformer uses a 3‐path secondary inductor and a single‐path primary inductor. The GaN oscillator consumes the power 4.328 mW and generates a signal at 8.22 GHz with an output power −11.35 dBm. At 1 MHz frequency offset from the carrier at 8.22 GHz the phase noise is −120.82 dBc/Hz, the figure of merit of the proposed oscillator is −192.76 dBc/Hz. The oscillator chip occupies an area of 2 × 1 mm2.

Fast start‐up analysis of resonator based oscillators using a power generation method

A power generation method based fast start-up analysis of resonator based oscillators is presented. The power generation analysis uses a small-signal two-port based approach and is design oriented. The analysis has been validated with detailed circuit level simulations. Several metal–oxide–semiconductor field-effect transistor oscillator architectures have been analysed and the start-up times compared using this analysis.

A 2.45-GHz Energy-Autonomous Wireless Power Relay Node

This paper describes the design and experimental characterization of a battery-less bidirectional 2.45-GHz circuit operating in oscillator mode as a wireless power transmitter or in rectifier mode as an energy harvester, with a measured efficiency greater than 50% in both operating states. The dc voltage harvested in rectifier mode provides the drain bias for the oscillator. The FET-gate self-bias mechanism is exploited in both functionalities, thus eliminating external gate bias. Bi-directionality is based on the time-reversal properties of a transistor oscillator. Energy autonomy is possible at received RF power levels as low as ${-}4$ dBm, by means of a bias-assisting feedback loop, consisting of a single matched low-power diode in shunt configuration. A hybrid prototype is demonstrated with the ability to operate as an energy-autonomous power relay node by switching between transmit and receive power modes.

Non-Boolean Associative Processing: Circuits, System Architecture, and Algorithms

We present the design and the performance of a hierarchical associative memory (AM) based on phase locking of coupled oscillators used for pattern recognition. The use of coupled oscillators, rather than Boolean logic, provides for implementations using emerging nanotechnology, such as magnetic spin-torque oscillators and resonant body transistor oscillators, which have the potential of lower energy and higher density than CMOS solutions. We develop a model for the general behavior of weakly coupled nonlinear oscillators that perform pattern matching using a simulation of coupled CMOS ring oscillators. We derive a simple analytic model for their phase locking behavior and use this reduced model in a hierarchical AM for image recognition tasks, such as identifying handwritten numbers.

A CMOS–MEMS arrayed resonant-gate field effect transistor (RGFET) oscillator

A high-frequency CMOS–MEMS arrayed resonant-gate field effect transistor (RGFET) fabricated by a standard 0.35 μm 2-poly-4-metal CMOS–MEMS platform is implemented to enable a Pierce-type oscillator. The proposed arrayed RGFET exhibits low motional impedance of only 5 kΩ under a purely capacitive transduction and decent power handling capability. With such features, the implemented oscillator shows impressive phase noise of −117 dBc Hz−1 at the far-from-carrier offset (1 MHz). In this work, we design a clamped–clamped beam (CCB) arrayed resonator utilizing a high-velocity mechanical coupling scheme to serve as the resonant-gate array. To achieve a functional arrayed RGFET, a corresponding FET array is directly placed underneath the resonant gate array to convert the motional current on the resonant-gate array into a voltage output with a tunable transconductance gain. To understand the behavior of the proposed device, an equivalent circuit model consisting of the resonant unit and FET is also provided. To verify the effects of the post-CMOS process on device performance, a conventional MOS ID current measurement is carried out. Finally, a CMOS–MEMS arrayed RGFET oscillator is realized by utilizing a Pierce oscillator architecture, showing decent phase noise performance that benefits from the array design to alleviate the nonlinear effect of the resonant gate.

Hybrid-Type Temperature Sensor Using Thin-Film Transistors

We have developed a hybrid-type temperature sensor using thin-film transistors. First, we evaluate temperature dependences of transistor characteristics and find that the temperature dependence of the off-leakage current is much larger than that of the on current. Next, we combine a transistor, capacitor, and ring oscillator to develop the hybrid-type temperature sensor and detect the temperature by measuring the oscillation frequency. The large temperature dependences of the off-leakage currents can be utilized, and simultaneously only a digital circuit is required to count the digital pulse.

Quasi-planar K-band push-push low phase noise oscillator stabilized by cavity resonator

The results of developing a K-band (24 GHz) push-push low phase noise transistor oscillator have been presented. This oscillator is stabilized by a rectangular resonant metallic cavity. The power level of output signal is −9.5 dBm, the fundamental harmonic suppression is 21 dB. Single sideband (SSB) phase noise spectral density of −98 dBc/Hz at 10 kHz and −128 dBc/Hz at 100 kHz offset from the carrier frequency is at the level of dielectric resonator oscillators (DRO) scaled to the same frequency. The oscillator features a compact size, low cost quazi-planar design and it is built using commercially available off the shelf parts.

P‐3: Hybrid‐Type Temperature Sensor using Thin‐Film Transistors

AbstractWe have developed a hybrid‐type temperature sensor using TFTs. We combined a transistor, capacitor, and ring oscillator and detected the temperature by measuring the oscillation frequency. The large temperature dependences of the off‐leakage currents can be utilized, and simultaneously only a digital circuit is required to count the digital pulse.

Solution-processed high-performance flexible 9, 10-bis(phenylethynyl)anthracene organic single-crystal transistor and ring oscillator

Organic semiconductor of 9, 10-bis(phenylethynyl)anthracene (BPEA) single crystal ribbon with ultra-long length has been prepared by solution drop casting method, where the growth direction was controlled with the seed crystal. The BPEA single crystal ribbon based field-effect transistors show high hole mobility up to 3.2 cm2/V·s, and the inverters exhibited the highest gain of 92. The complex device such as 5-stage ring oscillator consisting of 10 transistors was also constructed on a single crystal ribbon. This straightforward methodology was applied to fabricate plastic transistors on the flexible substrate, showing high performance even after repeatedly bending of 300 times.

ANALOG CONVERTER OF LIGHT ON THE BASE OF UNIJUNCTION TRANSISTOR

The principle of action of the analog converter of light based on the base of unijunction transistor oscillator with current driving element and the capacitor in the emitter circuit is shown. The output parameter is the frequency of oscillation as a function of light intensity. Maximum sensitivity is achieved when the element is used as a current driving bipolar phototransistor and the capacitance decreases with decreasing voltage.

Integrated Microwave Atmospheric Plasma Source (IMAPlaS): thermal and spectroscopic properties and antimicrobial effect on B. atrophaeus spores

The Integrated Microwave Atmospheric Plasma Source (IMAPlaS) operating with a microwave resonator at 2.45 GHz driven by a solid-state transistor oscillator generates a core plasma of high temperature (T > 1000 K), therefore producing reactive species such as NO very effectively. The effluent of the plasma source is much colder, which enables direct treatment of thermolabile materials or even living tissue. In this study the source was operated with argon, helium and nitrogen with gas flow rates between 0.3 and 1.0 slm. Depending on working gas and distance, axial gas temperatures between 30 and 250 °C were determined in front of the nozzle. Reactive species were identified by emission spectroscopy in the spectral range from vacuum ultraviolet to near infrared. The irradiance in the ultraviolet range was also measured. Using B. atrophaeus spores to test antimicrobial efficiency, we determined log10-reduction rates of up to a factor of 4.

Theoretical investigation of terahertz amplifier by carbon nanotubes within transmission line metamaterials

AbstractTerahertz (THz) power amplification in coplanar waveguide composite right left‐handed transmission line (CPW CRLH TL) metamaterials with carbon nanotubes (CNTs) has been investigated. The negative differential resistance (NDR) behavior of the CNTs with appropriate DC voltage bias, which can be characterized as the feature of the Gunn‐type oscillator, Esaki‐like diode, or field effect transistor (FET), is used to provide the THz loss compensation/gain. From introducing gaps in the central signal line and short‐circuited stubs connected between the CPW central signal line and the ground are used to realize the left‐handed (LH) series capacitance CL and LH shunt inductance LL, respectively. The equivalent circuits model approach and effective medium method are employed to study the propagation constant γ = α + jβ of the CNT‐based active THz metamaterials, which are validated by three‐dimensional (3D) full‐wave finite element (FEM) and circuit model co‐design. Results indicate not only the negative attenuation constant α (gain) provided by CNTs but also the negative phase constant β (backward wave propagation with anti‐parallel phase and group velocities) by artificial TL configuration at THz frequency region. This planar structure could be used to design tunable THz devices with different DC bias voltage and also easily extended to two‐dimensional (2D) and 3D active microwave, IR, or optical metamaterials at room temperature. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:815–818, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25870

Pseudolinear Circuit Theory for Sinusoidal Oscillator Performance Maximization

This paper introduces a theory for fast optimization of the circuit topology and parameters in sinusoidal oscillators. The theory starts from a system model composed of standard active and passive elements. We then include even the output load in the circuit, so that there is no longer any interaction with the outside of the system through the port. This model is thus called no-input-no-output (NINO) oscillator. The circuit is cut at an arbitrary branch, and is characterized in terms of the scalar impedance from the cut point. This is called active impedance because it is a function of not only the stimulating frequency but also the active device gain. The oscillation frequency and necessary device gain are estimated by solving impedance-domain Barkhausen equilibrium equations. This estimation works for the adjustment of circuit elements to meet the specified oscillation frequency. The estimation of necessary device gain enables us to maximize the oscillation amplitude, thanks to the inherent negative-slope nonlinearity of active devices. The active impedance is also used to derive the oscillation Q (quality) factor, which serves as a key criterion for sideband noise minimization i.e. frequency spectrum purification. As an alternative measure to active impedance, we also introduce branch admittance matrix determinant. This has the same numerical effect as the scalar impedance but can be used to formulate oscillator characteristics in a more elegant fashion, and provides a lucent picture of the physical behavior of each element in the circuit. Based on the proposed theory, we provide the tabled formulas of oscillation frequency, necessary device gain, active Q factor for a variety of typical Colpitts, Hartley, and cross-coupled twin-FET (field-effect transistor) oscillators.

A 500 MHz carbon nanotube transistor oscillator

Operation of a carbon nanotube field effect transistor (FET) oscillator at a record frequency of 500 MHz is described. The FET was fabricated using a large parallel array of single-walled nanotubes grown by chemical vapor deposition on ST-quartz substrates. Matching of the gate capacitance with a series inductor enabled greater than unity net oscillator loop gain to be achieved at 500 MHz.