scholarly journals Integer- and Fractional-Order VCO Using Non-Inertial Amplitude Stabilization and Modern Active Elements

2020 ◽  
Vol 26 (2) ◽  
pp. 42-47
Author(s):  
Roman Sotner ◽  
Jiri Petrzela ◽  
Jan Jerabek ◽  
Lukas Langhammer ◽  
Josef Polak ◽  
...  
Keyword(s):  
Phase Shift ◽  
Fractional Order ◽  
Oscillation Frequency ◽  
Initial Study ◽  
Voltage Controlled Oscillator ◽  
Laboratory Measurements ◽  
Active Elements ◽  
Amplitude Stabilization ◽  
Gain Adjustment ◽  
Single Path

This paper introduces design of the linearly tunable quadrature voltage-controlled oscillator (VCO) using modern off-the-shelf active elements suitable for the design of electronically adjustable applications. The simplified topology was achieved using non-inertial stabilization of amplitude. It allows targeting adjustability of the oscillation frequency only into lossless integrator part of the topology. This arrangement simplifies the design and the tenability also. Derived symbolical expressions indicate that gain adjustment of used amplifiers (that are still in single path) does not influence amplitude and phase shift ratio of generated waveforms, which is a beneficial feature. The performances of the circuit are tested experimentally in band of units of MHz and results confirmed expected behavior. Initial study of the oscillator with fractional-order capacitors is presented and discussed. Results are supported by laboratory measurements.

Design and characteristics of reflectivity tunable mirror with MZI and loop waveguide on SOI

2021 ◽  
Author(s):  
Yutaka Makihara ◽  
Moataz Eissa ◽  
Tomohiro AMEMIYA ◽  
Nobuhiko Nishiyama
Keyword(s):  
Phase Shift ◽  
Coupling Coefficient ◽  
Integrated Circuit ◽  
Silicon Photonics ◽  
Silicon On Insulator ◽  
Zehnder Interferometer ◽  
Directional Couplers ◽  
Photonic Integrated Circuit ◽  
Active Elements ◽  
Measurement Results

Abstract To achieve a reconfigurable photonic integrated circuit with active elements, we proposed a reflectivity tunable mirror constructed using a Mach–Zehnder interferometer (MZI) with a micro heater and loop waveguide on a silicon photonics platform. In this paper, the principle of the operation, design, fabrication, and measurement results of the mirror are presented. In theory, the phase shift dependence of the mirror relies on the coupling coefficient of the directional couplers of the MZI. When the coupling coefficient κ2 was 0.5 and 0.15, the reflection could be turned on and off with a phase shift of π/2 and π, respectively. The reflection power of the fabricated mirror on the silicon on insulator (SOI) substrate was changed by more than 20 dB by a phase shift. In addition, it was demonstrated that the phase shift dependence of the mirror changes with the coupling coefficient of the fabricated devices.

A Ku-Band Low-Phase-Noise Cross-Coupled VCO in GaAs HBT Technology

2016 ◽  
Vol 25 (06) ◽  
pp. 1650053 ◽  
Author(s):  
Jincan Zhang ◽  
Yuming Zhang ◽  
Hongliang Lu ◽  
Yimen Zhang ◽  
Bo Liu ◽  
...  
Keyword(s):  
Phase Noise ◽  
Output Power ◽  
Oscillation Frequency ◽  
Heterojunction Bipolar Transistor ◽  
Voltage Controlled Oscillator ◽  
High Output Power ◽  
Fully Integrated ◽  
Low Phase Noise ◽  
High Output ◽  
Ku Band

In this paper, a fully integrated Ku-band voltage controlled oscillator (VCO) with low phase noise is presented in a GaAs heterojunction bipolar transistor (HBT) technology. A cross-coupled configuration is employed to achieve low phase noise, and to achieve high output power, the largest HBT and higher bias current are adopted. The implemented VCO demonstrates that the oscillation frequency is from 13.77[Formula: see text]GHz to 14.8[Formula: see text]GHz, with a maximum 4.83[Formula: see text]dBm output power at 13.77[Formula: see text]GHz. The phase noise of the VCO is [Formula: see text]100.2[Formula: see text]dBc/Hz at 1[Formula: see text]MHz offset from 14.36[Formula: see text]GHz oscillation frequency. The VCO consumes 61.2[Formula: see text]mW from 6[Formula: see text]V supply and occupies an area of 0.51[Formula: see text]mm[Formula: see text][Formula: see text]mm. Finally, the figure-of-merits (FOMs) for VCOs are discussed.

scholarly journals Fractional Describing Function Analysis of PWPF Modulator

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Xinsheng Wang ◽  
Danwei Wang ◽  
Senqiang Zhu ◽  
Eng Kee Poh
Keyword(s):  
Phase Shift ◽  
Fractional Order ◽  
Pulse Width ◽  
Function Method ◽  
Function Analysis ◽  
Pulse Frequency ◽  
Describing Function ◽  
Nonlinear Properties ◽  
Describing Function Method ◽  
Effective Analysis

Pulse-width pulse-frequency (PWPF) modulators are widely used in spacecraft thruster control. Their dynamic characteristic is still lack of effective analysis tools. This paper presents a fractional describing function method to describe the frequency characteristics of PWPF. A frequency-dependent gain and phase shift are clearly described by fractional-order expression, and the fractional-order behaviors depict the nonlinear properties of PWPF modulators. This fractional describing function method can also be applied to other kinds of modulators.

CHARACTERIZATION OF VOLTAGE-CONTROLLED OSCILLATOR USING RTD TRANSMISSION LINE

2007 ◽  
Vol 17 (03) ◽  
pp. 577-584 ◽  
Author(s):  
KOICHI NARAHARA ◽  
TAKUO YAMAKI ◽  
TATSUNORI TAKAHASHI ◽  
TORU NAKAMICHI
Keyword(s):  
Transmission Line ◽  
Oscillation Frequency ◽  
Resonant Tunneling ◽  
Numerical Calculations ◽  
Necessary Condition ◽  
Voltage Controlled Oscillator ◽  
Resonant Tunneling Diodes ◽  
Tunneling Diodes ◽  
Circuit Configuration

Widely-tunable voltage-controlled oscillator using resonant tunneling diodes in a distributed manner is discussed. The circuit configuration and the principle of operation of the VCO are described together with several results of numerical calculations, which include necessary condition of permanent oscillation and how much the oscillation frequency is tuned by the voltage.

scholarly journals On Systematic Design of Fractional-Order Element Series

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1203
Author(s):  
Jaroslav Koton ◽  
David Kubanek ◽  
Jan Dvorak ◽  
Norbert Herencsar
Keyword(s):  
Fractional Order ◽  
Performance Optimization ◽  
Cmos Technology ◽  
Integer Number ◽  
Systematic Design ◽  
Efficient Design ◽  
Operational Transconductance Amplifiers ◽  
Sensor Applications ◽  
Active Elements ◽  
Immittance Converter

In this paper a concept for the efficient design of a series of floating fractional-order elements (FOEs) is proposed. Using even single or a very limited number of so-called “seed” FOEs it is possible to obtain a wide set of new FOEs featuring fractional order α being in the range [−n,n], where n is an arbitrary integer number, and hence enables to overcome the lack of commercial unavailability of FOEs. The systematic design stems from the utilization of a general immittance converter (GIC), whereas the concept is further developed by proposing a general circuit structure of the GIC that employs operational transconductance amplifiers (OTAs) as active elements. To show the efficiency of the presented approach, the use of only up to two “seed” FOEs with a properly selected fractional order αseed as passive elements results in the design of a series of 51 FOEs with different α being in the range [−2,2] that may find their utilization in sensor applications and the design of analog signal processing blocks. Comprehensive analysis of the proposed GIC is given, whereas the effect of parasitic properties of the assumed active elements is determined and the optimization process described to improve the overall performance of the GIC. Using OTAs designed in 0.18 μm TSMC CMOS technology, Cadence Virtuoso post-layout simulation results of the GIC are presented that prove its operability, performance optimization, and robustness of the proposed design concept.

scholarly journals Reduction of the auto seismic component of error of a ballistic laser gravimeter by excitation of an induction-dynamic catapult from an AC voltage source

2021 ◽  
pp. 20-27
Author(s):  
Vladimir Bolyukh ◽  
Оleksandr Vinnichenko ◽  
Anatolii Omelchenko
Keyword(s):  
Mathematical Model ◽  
Phase Shift ◽  
Short Pulse ◽  
Test Body ◽  
Voltage Source ◽  
Gravitational Acceleration ◽  
Electrodynamic Force ◽  
Active Elements ◽  
Recoil Force ◽  
Maximum Value

The purpose of the study is to analyse the influence of the excitation of an induction-dynamic catapult of a ballistic laser gravimeter from an AC voltage source at different frequencies on electromechanical indicators that provide a reduced value of the auto seismic component of error in measuring the gravitational acceleration g due to a decrease in the recoil force. A mathematical model of the gravimeter catapult when excited from an AC voltage source is proposed, taking into account the interrelated electrical, magnetic and mechanical processes. The nature of the electromechanical processes in the catapult of the gravimeter with such excitation has been established. It is shown that a phase shift occurs between the currents in active elements, as a result of which positive (repulsive) pulses of the electrodynamic force alternate with negative (attractive) pulses of force. A criterion for the efficiency of the gravimeter catapult has been introduced, taking into account the maximum value of push of the test body at the smallest values of the electrodynamic force and current of the inductor winding. It was found that the highest efficiency of the gravimeter catapult is provided at a frequency of 250 Hz, at which the catapult efficiency is 3.5 times higher than at a frequency of 50 Hz. It is shown that the transition from the method of excitation of an induction-dynamic catapult with one short pulse to excitation from an AC voltage source makes it possible to reduce the uncertainty in measuring the gravitational acceleration.

scholarly journals Analysis of high-order sub-harmonically injection-locked oscillators

2020 ◽  
Vol 12 (8) ◽  
pp. 695-706
Author(s):  
Silvia Hernández ◽  
Mabel Pontón ◽  
Sergio Sancho ◽  
Almudena Suárez
Keyword(s):  
Phase Shift ◽  
Phase Noise ◽  
Oscillation Frequency ◽  
High Order ◽  
Noise Sources ◽  
Oscillation Phase ◽  
Noise Spectral Density ◽  
Input Noise ◽  
Input Source ◽  
Injection Locked Oscillators

AbstractHigh-order sub-harmonically injection-locked oscillators have recently been proposed for low phase-noise frequency generation, with carrier-selection capabilities. Though excellent experimental behavior has been demonstrated, the analysis/simulation of these circuits is demanding, due to the high ratio between the oscillation frequency and the frequency of the input source. This work provides an analysis methodology that covers the main aspects of the circuit behavior, including the detection of the locking bands and the prediction of the phase-noise spectral density. Initially, the oscillator in the presence of a multi-harmonic input source is described with a reduced-order envelope-domain formulation, at the oscillation frequency, based on an oscillator-admittance function extracted from harmonic-balance simulations. This allows deriving an expression for the oscillation phase shift with respect to the input source, and the average of this phase shift is shown to evolve continuously in the distinct synchronization bands obtained when varying a tuning voltage. This property can be used to detect the locking bands in circuit-level envelope-domain simulations, which, as shown here, can be done through different Fourier decompositions and sampling rates. The phase noise of the high-order sub-harmonic injection-locked oscillator under an arbitrary periodic input waveform is investigated in detail. The frequency response to the noise sources is described with a semi-analytical formulation, relying on the oscillator-admittance function in injection-locked conditions. The input noise is derived from the timing jitter of the injection source and the phase-noise response is shown to exhibit a low-pass characteristic, which initially follows the up-converted input noise and then the oscillator own noise sources. A method is proposed to identify the key parameters of the derived phase-noise spectrum from envelope-domain simulations. The various analysis methodologies have been applied to a prototype at 2.7 GHz at the sub-harmonic order N = 30 which has been manufactured and measured.

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