Showing papers on "Phase noise published in 1998"

A general theory of phase noise in electrical oscillators

Abstract: A general model is introduced which is capable of making accurate, quantitative predictions about the phase noise of different types of electrical oscillators by acknowledging the true periodically time-varying nature of all oscillators. This new approach also elucidates several previously unknown design criteria for reducing close-in phase noise by identifying the mechanisms by which intrinsic device noise and external noise sources contribute to the total phase noise. In particular, it explains the details of how 1/f noise in a device upconverts into close-in phase noise and identifies methods to suppress this upconversion. The theory also naturally accommodates cyclostationary noise sources, leading to additional important design insights. The model reduces to previously available phase noise models as special cases. Excellent agreement among theory, simulations, and measurements is observed.

Radar interferogram filtering for geophysical applications

Abstract: The use of SAR interferometry is often impeded by decorrelation from thermal noise, temporal change, and baseline geometry. Power spectra of interferograms are typically the sum of a narrow-band component combined with broad-band noise. We describe a new adaptive filtering algorithm that dramatically lowers phase noise, improving both measurement accuracy and phase unwrapping, while demonstrating graceful degradation in regions of pure noise. The performance of the filter is demonstrated with SAR data from the ERS satellites over the Jakobshavns glacier of Greenland.

RF-CMOS oscillators with switched tuning

Abstract: Fully integrated CMOS oscillators are of great interest for use in single-chip wireless transceivers. In most oscillator circuits reported to date that operate in the 0.9 to 2 GHz frequency range, an integrated spiral inductor sets the frequency. It is generally believed that an LC oscillator, even when it uses a low-Q inductor, displays a lower phase noise than a ring oscillator. However, due to the absence of a good varactor compatible with CMOS technology, the integrated LC oscillator suffers from a very limited tuning range. Although this tuning range may encompass the limited frequency agility required in an RF oscillator, for instance to span the modulation bandwidth in a transmitter, it will seldom cover the much larger lot-to-lot process variations manifest as spreads of up to 20% in capacitance. Fortunately, the self-inductance of a metal spiral does not suffer spreads, because it depends on a precise number of turns and on the geometry of metal traces which is little affected by fluctuations in lithography. This work addresses the practical problem of how to design RF CMOS oscillators with a wide enough tuning range to reliably cover process variations, without compromising current drain or phase noise. Prototypes were developed in the 0.6 /spl mu/m MOSIS CMOS process to oscillate at up to 1.8 GHz with a sub-3V supply. The tuning method exploits digital capabilities and MOS analog switches.

A new technique for noise filtering of SAR interferometric phase images

Abstract: This paper addresses the noise filtering problem for synthetic aperture radar (SAR) interferometric phase images. The phase noise is characterized by an additive noise model. The model is verified with an L-band shuttle imaging radar (SIR)-C interferogram. An adaptive filtering algorithm based on this noise model is developed. It emphasizes filtering noise adaptively according to the local noise level and filtering along fringes using directionally dependent windows. This algorithm is effective, especially for the tightly packed fringes of X-band interferometry. Using simulated and SIR-C/X-SAR repeat-pass generated interferograms, the effectiveness of this filter is demonstrated by its capabilities in residue reduction, adaptive noise filtering, and its ability to filter areas with high fringe rates. In addition, a scheme of incorporating this filtering algorithm in iterative phase unwrapping using a least-squares method is proposed.

On the effect of Wiener phase noise in OFDM systems

Abstract: Multicarrier modulation exhibits a significant sensitivity to the phase noise of the oscillator used for frequency down-conversion at the portable receiver. For this reason, it is important to evaluate the impact of the phase noise on the system performance. We present an accurate method to determine the error probability of an orthogonal frequency-division multiplexing (OFDM) system in the presence of phase noise. In particular, four modulation schemes are analyzed and their performances are compared.

A fully integrated CMOS DCS-1800 frequency synthesizer

Abstract: A prototype frequency synthesizer for the DCS-1800 system has been integrated in a standard 0.4 /spl mu/m CMOS process without any external components. A completely monolithic design has been made feasible by using an optimized hollow-coil inductor low-phase-noise voltage-controlled oscillator (VCO). The frequency divider is an eight-modulus phase-switching prescaler that achieves the same speed as asynchronous dividers. The die area was minimized by using a dual-path active loop filter. An indirect linearization technique was implemented for the VCO gain. The resulting architecture is a fourth-order, type-2 charge-pump phase-locked loop. The measured settling time is 300 /spl mu/s, and the phase noise is up to -123 dBc/Hz at 600 kHz and -138 dBc/Hz at 3 MHz offset.

Integrated circuit technology options for RFICs-present status and future directions

Abstract: This paper will summarize the technology tradeoffs that are involved in the implementation of radio frequency integrated circuits for wireless communications. Radio transceiver circuits have a very broad range of requirements-including noise figure, linearity, gain, phase noise, and power dissipation. The advantages and disadvantages of each of the competing technologies-Si CMOS and bipolar junction transistors (BJTs), Si/SiGe HBTs and GaAs MESFETs, PHEMTS and HBTs will be examined in light of these requirements.

Micromachined electro-mechanically tunable capacitors and their applications to RF IC's

Abstract: Micromachined electro-mechanically tunable capacitors with two and three parallel plates are presented. Experimental devices have been fabricated using a standard polysilicon surface micromachining process. The two-plate tunable capacitor has a measured nominal capacitance of 2.05 pF, a Q-factor of 20 at 1 GHz, and achieves a tuning range of 1.5:1, The three-plate version has a nominal capacitance of 4.0 pF, a Q-factor of 15.4 at 1 GHz, and a tuning range of 1.87:1. The tuning ranges achieved here are near theoretical limits. Effects due to various physical phenomena such as temperature, gravity, and shock are examined in detail. An RF voltage-controlled oscillator with an integrated inductor and a micromachined tunable capacitor is also demonstrated. The active circuit and the inductor have been fabricated in a 0.5 /spl mu/m CMOS process. The voltage-controlled oscillator has been assembled by bonding together the CMOS and the micromachined parts. The 1.35 GHz voltage-controlled oscillator has a phase noise of -98.5 dBc/Hz at a 100 kHz offset from the carrier.

Frequency stability degradation of an oscillator slaved to a periodically interrogated atomic resonator

Abstract: Atomic frequency standards using trapped ions or cold atoms work intrinsically in a pulsed mode. Theoretically and experimentally, this mode of operation has been shown to lead to a degradation of the frequency stability due to the frequency noise of the interrogation oscillator. In this paper a physical analysis of this effect has been made by evaluating the response of a two-level atom to the interrogation oscillator phase noise in Ramsey and multi-Rabi interrogation schemes using a standard quantum mechanical approach. This response is then used to calculate the degradation of the frequency stability of a pulsed atomic frequency standard such as an atomic fountain or an ion trap standard. Comparison is made to an experimental evaluation of this effect in the LPTF Cs fountain frequency standard, showing excellent agreement.

Phase noise and sub-carrier spacing effects on the performance of an OFDM communication system

Abstract: This letter analyzes the phase noise effects on an orthogonal frequency division multiplexing (OFDM) signal and its dependence with the sub-carrier spacing. Pilot-based channel estimation, which has been suggested as a means of combating the channel effects, can also correct the phase noise effects under some circumstances, which are investigated.

Direct digital frequency synthesizers

Abstract: Preface. INTRODUCTION AND TUTORIAL. Synthesis Techniques (V. Kroupa). DIRECT DIGITAL SINGLE--FREQUENCY SYNTHESIZERS. A Frequency Synthesizer for 10/2PI kHz (G. Small). Approximating Frequency Synthesizers (V. Kroupa). WIDE--RANGE DIRECT DIGITAL FREQUENCY SYNTHESIZERS. A Digital Frequency Synthesizer (J. Tierney, et al.). CMOS/SOS Frequency Synthesizer LSI Circuit for Spread Spectrum Communications (D. Sunderland, et al.). High--Speed Direct Frequency Synthesizer (P. Saul and D. Taylor). Single Chip 500 MHz Function Generator (P. Saul, et al.). Low--Latency, High--Speed Numerically Controlled Oscillator Using Progression--of--States Technique (M. Thompson). SPURIOUS SIGNALS IN DIRECT DIGITAL FREQUENCY SYNTHESIZERS. Spectra of Pulse Rate Frequency Synthesizers (V. Kroupa). Noise Spectra of Digital Sine--Generators Using the Table--Lookup Method (S. Mehrgardt). An Analysis of the Output Spectrum of Direct Digital Frequency Synthesizers in the Presence of Phase--Accumulator Truncation (H. Nicholas III and H. Samueli). The Optimization of Direct Digital Frequency Synthesizer Performance in the Presence of Finite Word Length Effects (H. Nicholas III, et al.). Methods of Mapping From Phase to Sine Amplitude in Direct Digital Synthesis (J. Vankka). A 150--MHz Direct Digital Frequency Synthesizer in 1.25--mum CMOS with --90--dBc Spurious Performance (H. Nicholas III and H. Samueli). An Exact Spectral Analysis of a Number Controlled Oscillator Based Synthesizer (J. Garvey and D. Babitch). REDUCTION OF SPURIOUS SIGNALS IN DIRECT DIGITAL FREQUENCY SYNTHESIZERS. Spurious Suppression in Direct Digital Synthesizers (C. Wheatley & D. Phillips). A Low--Frequency, High Resolution Digital Synthesizer (R. Giffard and L. Cutler). A Spurious Reduction Technique for High--Speed Direct Digital Synthesizers (L. Kushner and M. Ainsworth). A Direct--Digital Synthesizer with Improved Spectral Performance (P. O'Leary and F. Maloberti). Spur--Reduced Digital Sinusoid Synthesis (M. Flanagan & G. Zimmerman). Spectral Properties of DDFS: Computer Simulations and Experimental Verifications (V. Kroupa). COMBINATION OF DDFS WITH PHASE LOCKED LOOPES (PLLs). Principles of Phase Locked Loops (PLL) (V. Kroupa). Low--Noise Microwave--Frequency Synthesizers: Design Principles (V. Kroupa). A J--Band Spread--Spectrum Synthesizer Using a Combination of DDS and Phaselock Techniques (M. Harris). Principles of Fractional--N Frequency Synthesizers (V. Kroupa). A Multiple Modulator Fractional Divider (B. Miller and R. Conley). A Fast--Settling GaAs--Enhanced Frequency Synthesizer (J. Naber, et al.). PHASE AND BACKGROUND NOISE IN DDFS. Introduction to the Noise Properties of Frequency Sources (V. Kroupa). Close--to--the--Carrier Noise in DDFS (V. Kroupa). Phase Noise in Direct Digital Synthesizers (E. Mattison and L. Coyle). A Direct Digital Synthesizer with 100--MHz Output Capability (P. Saul and M. Mudd). An Analysis Methodology to Identify Dominant Noise Sources in D/A and A/D Converters (J. Connelly and K. Taylor). DIGITAL--TO--ANALOG CONVERTERS. Digital--to--Analog Converters (V. Kroupa). A Monolithic 10--b Digital--to--Analog Convertor Using Ion Implantation (G. Kelson, et al.). An Inherently Monotonic 12 Bit DAC (J. Schoeff). An 8--Bit, 5 ns Monolithic D/A Converter Subsystem (P. Saul, et al.). A 500--MHz 8--Bit D/A Converter (K. Maio, et al.). An 8--Bit 2--ns Monolithic DAC (T. Kamoto, et al.). STATE OF THE ART AND SOME APPLICATIONS. A High Purity, High Speed Direct Digital Synthesizer (G. Kent and N. Sheng). A 200 MHz Quadrature Digital Synthesizer/Mixer in 0.8 mum CMOS (L. Tan and H. Samueli). An 800--MHz Quadrature Digital Synthesizer with ECL--Compatible Output Drivers in 0.8 mum CMOS (L. Tan, et al.). A Dual Frequency Synthesis Scheme for a High C--Field Cesium Resonator (E. Rubiola, et al.). NEW IDEAS FOR THE DDFS DESIGN. A 700--MHz 24--b Pipelined Accumulator in 1.2--mum CMOS for Applications as a Numerically Controlled Oscillator (F. Lu, et al.). An Integrated GaAs 1.25 GHz Clock Frequency FM--CW Direct Digital Synthesizer (N. Caglio, et al.). The Composite DDS--A New Direct Digital Synthesizer Architecture (L. Kushner). A Narrow Band High--Resolution Synthesizer Using a Direct Digital Synthesizer Followed by Repeated Dividing and Mixing (R. Karlquist). A 3 to 30 MHz High--Resolution Synthesizer Consisting of a DDS, Divide--and--Mix Modules, and a M/N Synthesizer (R. Karlquist). A New Architecture for a Sinewave Output DDS With a High Spectral Purity (L. Presti, et al.). MATHEMATICAL BACKGROUND. Quasiperiodic Omission of Pulses (V. Kroupa). Useful Computer Programs for Investigations of Spurious Signals in DDFS (V. Kroupa). Author Index. Subject Index. About the Editor.

Low-phase-noise millimeter-wave generation at 64 GHz and data transmission using optical sideband injection locking

Abstract: The 60-GHz band is proposed for the radio link frequency in broad-band cellular systems. 140-155-Mb/s transmission experiments are reported with optically generated millimeter-waves at frequencies in the 60-GHz band. By applying the sideband injection locking technique, the remotely generated millimeter-wave signals depict quartz accuracy and low phase noise <-100 dBc/Hz at offset frequencies 21 MHz.

Microwave interferometry: application to precision measurements and noise reduction techniques

Abstract: A concept of interferometric measurements has been applied to the development of ultra-sensitive microwave noise measurement systems. These systems are capable of reaching a noise performance limited only by the thermal fluctuations in their lossy components. The noise floor of a real time microwave measurement system has been measured to be equal to -193 dBc/Hz at Fourier frequencies above 1 kHz. This performance is 40 dB better than that of conventional systems and has allowed the first experimental evidence of the intrinsic phase fluctuations in microwave isolators and circulators. Microwave frequency discriminators with interferometric signal processing have proved to be extremely effective for measuring and cancelling the phase noise in oscillators. This technique has allowed the design of X-band microwave oscillators with a phase noise spectral density of order -150 dBc/Hz at 1 kHz Fourier frequency, without the use of cryogenics. Another possible application of the interferometric noise measurements systems include "flicker noise-free" microwave amplifiers and advanced two oscillator noise measurement systems.

Phase noise in oscillators: a unifying theory and numerical methods for characterisation

Abstract: Phase noise is a topic of theoretical and practical interest in electronic circuits, as well as in other fields such as optics. Although progress has been made in understanding the phenomenon, there still remain significant gaps, both in its fundamental theory and in numerical techniques for its characterisation. In this paper, we develop a solid foundation for phase noise that is valid for any oscillator, regardless of operating mechanism. We establish novel results about the dynamics of stable nonlinear oscillators in the presence of perturbations, both deterministic and random. We obtain an exact, nonlinear equation for phase error, which we solve without approximations for random perturbations. This leads us to a precise characterisation of timing jitter and spectral dispersion, for computing which we develop efficient numerical methods. We demonstrate our techniques on practical electrical oscillators, and obtain good matches with measurements even at frequencies close to the carrier, where previous techniques break down.

Spectrum folding and phase noise in LC tuned oscillators

Abstract: We present a theory of the noise transfer in LC tuned oscillators accounting for the nonlinear operation of the transconductor. We show that the transconductor switching causes a folding of the wide-band noise such as the thermal noise of the spreading resistance of the bipolar transistors and the noise of the tail current generator. The effect is similar to what happens in sampled systems, however, for a careful evaluation of the oscillator phase noise, the correlations between the folded terms is of chief importance. We show how to account for the effect, we assess the impact on the oscillator noise performance and we give the guidelines for the circuit optimization.

Design, performance, and applications of a coherent ultra-wideband random noise radar

Abstract: Ram M. NarayananYi XuPaul D. HoffmeyerUniversity of Nebraska—LincolnCenter for Electro-OpticsDepartment of Electrical EngineeringLincoln, Nebraska 68588-0511E-mail: rnarayanan@unl.eduJohn O. CurtisU.S. Army Waterways Experiment StationEnvironmental LaboratoryVicksburg, Mississippi 39180-6199Abstract. A novel coherent ultra-wideband radar system operating inthe 1- to 2-GHz frequency range has been developed recently at theUniversity of Nebraska. The radar system transmits white Gaussiannoise. Detection and localization of buried objects is accomplished bycorrelating the reflected waveform with a time-delayed replica of thetransmitted waveform. Broadband dual-polarized log-periodic antennasare used for transmission and reception. A unique signal-processingscheme is used to inject coherence into the system by frequency trans-lation of the ultrawideband signal by a coherent 160-MHz phase-lockedsource prior to performing heterodyne correlation. The system coher-ence allows the extraction of a target’s polarimetric amplitude and phasecharacteristics. This paper describes the unique design features of theradar system, develops the theoretical foundations of noise polarimetry,provides experimental evidence of the polarimetric and resolution capa-bilities of the system, and demonstrates results obtained in subsurfaceprobing applications.

Coupled opto-electronic oscillators

Abstract: We present experimental results of coupled optoelectronic oscillators (COEO) constructed with a semiconductor optical amplifier based ring laser and a semiconductor colliding pulse mode-locked laser. Each COEO can simultaneously generate short optical pulses and spectrally pure RF signals. With these devices, we obtained optical pulses as short as 6.2 picoseconds and RF signals as high, in frequency, as 18 GHz with a spectral purity comparable with a HP8561B synthesizer. These experiments demonstrate that COEOs are promising compact sources for generating low jitter optical pulses and low phase noise RF/millimeter wave signals.

Cyclostationary noise analysis of large RF circuits with multitone excitations

Abstract: This paper introduces a new, efficient technique for analyzing noise in large RF circuits subjected to true multitone excitations. Noise statistics in such circuits are time-varying, hence cyclostationary stochastic processes, characterized by harmonic power spectral densities (HPSDs), are used to describe noise. HPSDs are used to devise a harmonic-balance-based noise algorithm with the property that required computational resources grow almost linearly with circuit size and nonlinearity. Device noises with arbitrary spectra (including thermal, shot, and flicker noises) are handled, and input and output correlations, as well as individual device contributions, can be calculated. HPSD-based analysis is also used to establish the nonintuitive result that bandpass filtering of cyclostationary noise can result in stationary noise. Results from the new method are validated against Monte Carlo simulations. A large RF integrated circuit (>300 nodes) driven by a local oscillator (LO) tone and a strong RF signal is analyzed in less than two hours. The analysis predicts correctly that the presence of the RF tone leads to noise folding, affecting the circuit's noise performance significantly.

Method and apparatus for providing coarse and fine tuning control for synthesizing high-frequency signals for wireless communications

Abstract: A method and apparatus for synthesizing high-frequency signals is disclosed that overcomes integration problem associated with prior implementations while meeting demanding phase noise and other impurity requirements. In one embodiment, a phase-locked loop (PLL) frequency synthesizer is disclosed having a voltage controlled oscillator (VCO) with a variable capacitance that includes a discretely variable capacitance in conjunction with a continuously variable capacitance. The discretely variable capacitance may provide coarse tuning adjustment of the variable capacitance, and the continuously variable capacitance may provide a fine tuning adjustment of the variable capacitance. In a more general terms, a frequency synthesizer is disclosed having a first variable and a second capacitance circuits and frequency control circuitry to coarsely tune the output frequency by adjusting the first control signal and to finely tune the output frequency by adjusting the second control signal.

A fully integrated VCO at 2 GHz

Abstract: An integrated voltage-controlled oscillator (VCO) at a frequency of 2 GHz is implemented in a f/sub T/= 25 GHz standard bipolar process. The phase noise of the VCO is -136 dBc/Hz at 4.7 MHz frequency offset. The LC-resonator uses vertically coupled on-chip inductors and integrated tuning diodes. Due to the poor performance of integrated resonators on silicon ICs, oscillators with phase noise meeting requirements of wireless applications are difficult to integrate. With fully integrated designs only the standards for cordless phones, for instance DECT, can be achieved. The critical point in the DECT-specification is the emission of the transmitter due to intermodulation in the third adjacent channel, that must be <-47 dBm. This value is measured with an integration bandwidth of 1 MHz centered at the nominal center frequency. With a channel-spacing of 1.728 MHz the third adjacent channel is located 5.184 MHz from the actual transmit channel frequency. The beginning of the integration bandwidth is at an offset frequency of 4.684 MHz related to the nominal frequency of the transmit channel. This is the offset frequency, at which the specification must be met. The resulting noise requirement is -132 dBc/Hz at a offset frequency of 4.684 MHz, when the integration bandwidth and the transmit output power of 25 dBm are taken into account.

The effects of phase noise in COFDM

Abstract: It is shown that the amounts of these effects can be deduced from the spectrum of the phase noise using a pair of weighting functions. Use of these weighting functions simplifies the process of computation; it also makes it easier to visualize the consequences of any modifications to the phase-noise spectrum. Some illustrations are given of the two phase-noise effects on the constellation of a DVB-T digital television signal, along with some practical observations on receiver implementation.

Noise Enhanced Propagation

Abstract: We use noise to extend signal propagation in one- and two-dimensional arrays of two-way coupled bistable oscillators. In a numerical model, we sinusoidally force one end of a chain of noisy oscillators. We record a signal-to-noise ratio at each oscillator. We demonstrate that moderate noise significantly extends the propagation of the sinusoidal input. Oscillators far from the input, where noise extends the signal, exhibit a classical stochastic resonance. We obtain similar results with two-dimensional arrays. The simplicity of the model suggests the generality of the phenomenon.

Applications of interferometric signal processing to phase-noise reduction in microwave oscillators

Abstract: To enhance the sensitivity of oscillator phase-noise measurements, an interferometric frequency-discriminator system may be implemented. Such systems consist of a microwave interferometer, incorporating a high-Q resonator and a phase-sensitive microwave readout. Suppressing the carrier at the output of the interferometer enables the microwave readout to operate in the small-signal regime with an effective noise temperature close to its physical temperature, When used as a sensor of a frequency-control system to lock the oscillator to a selected resonant mode of a high-Q resonator, the interferometric frequency discriminator has enabled more than two orders of magnitude improvement in oscillator phase-noise performance as compared with the state-of-the-art. Thus, the phase noise of an S-band oscillator was reduced to -150 dBc/Hz at 1-kHz Fourier frequency without the use of cryogenics, and was limited by the thermal noise in the microwave interferometer. To facilitate tuning and locking, an automatically balanced microwave frequency discriminator was developed using voltage-controlled attenuators and phase shifters. Rapid frequency tuning of the oscillator was achieved by varying the interferometer phase mismatch and automatically controlling the carrier suppression without tuning the high-Q resonator.

An agile ISM band frequency synthesizer with built-in GMSK data modulation

Abstract: In this paper, a high-resolution fractional-N RF frequency synthesizer is presented which is controlled by a fourth-order digital sigma-delta modulator. The high resolution allows the synthesizer to be digitally modulated directly at RF. A simplified digital filter which makes use of sigma-delta quantized tap coefficients is included which provides built-in GMSK pulse shaping for data transmission. Quantization of the tap coefficients to single-bit values not only simplifies the filter architecture, but the fourth-order digital sigma-delta modulator as well. The synthesizer makes extensive use of custom VLSI, with only a simple off-chip loop filter and VCO required. The synthesizer operates from a single 3-V supply, and has low power consumption. Phase noise levels are less than -90 dBc/Hz at frequency offsets within the loop bandwidth. Spurious components are less than -90 dBc/Hz over a 19.6-MHz tuning range.

A novel psychoacoustically motivated audio enhancement algorithm preserving background noise characteristics

Abstract: In this paper we propose an algorithm for reduction of noise in audio signals. In contrast to several previous approaches we do not try to achieve a complete removal of the noise, but instead our goal is to preserve a pre-defined amount of the original noise in the processed signal. This is accomplished by exploiting the masking properties of the human auditory system. The speech and noise distortions are considered separately. The spectral weighting rule, adapted by utilizing only estimates of the masking threshold and the noise power spectral density, has been designed to guarantee complete masking of distortions of the residual noise. Simulation results confirm that no audible artifacts are left in the processed signal, while speech distortions are comparable to those caused by conventional noise reduction techniques.

Phase noise in oscillators: DAEs and colored noise sources

Abstract: Oscillators are key components of electronic systems. Undesired perturbations, i.e. noise, in practical electronic systems adversely affect the spectral and timing properties of oscillators resulting in phase noise, which is a key performance limiting factor, being a major contributor to bit-error-rate (BER) of RF communication systems, and creating synchronization problems in clocked and sampled data systems. We first present a theory and numerical methods for nonlinear perturbation and noise analysis of oscillators described by a system of differential algebraic equations (DAEs), which extends our recent results on perturbation analysis of autonomous ordinary differential equations (ODEs). In developing the above theory, we rely on novel results we establish for linear periodically time varying (LPTV) systems: Floquet theory for DAEs. We then use this nonlinear perturbation analysis to derive the stochastic characterization, including the resulting oscillator spectrum, of phase noise in oscillators due to colored (e.g., 1/f noise), as opposed to white noise sources. The case of white noise sources has already been treated by us in a recent publication (A. Demir et al., 1998). The results of the theory developed in this work enabled us to implement a rigorous and effective analysis and design tool in a circuit simulator for low phase noise oscillator design.

Phase locked backward wave oscillator pulsed beam spectrometer in the submillimeter wave range

Abstract: We have developed a new submillimeter wave pulsed molecular beam spectrometer with phase stabilized backward wave oscillators (BWOs). In the frequency ranges of 260–380 and 440–630 GHz, the BWOs output power varies between 3 and 60 mW. Part of the radiation was coupled to a novel designed harmonic mixer for submillimeter wavelength operation, which consists of an advanced whiskerless Schottky diode driven by a harmonic of the reference synthesizer and the BWO radiation. The resulting intermediate frequency of 350 MHz passed a low noise high electron mobility transistor amplifier, feeding the phase lock loop (PLL) circuit. The loop parameters of the PLL have been carefully adjusted for low phase noise. The half power bandwidth of the BWO radiation at 330 GHz was determined to be as small as 80 MHz, impressively demonstrating the low phase noise operation of a phase locked BWO. A double modulation technique was employed by combining an 80 Hz pulsed jet modulation and a 10–20 kHz source modulation of the BWO and reaching a minimum detectable fractional absorption of 2×10−7. For the first time, a number of pure rotational (Ka=3←2, Ka=4←3) and rovibrational transitions in the van der Waals bending and stretching bands of the Ar–CO complex were recorded.

A wide-band tuning system for fully integrated satellite receivers

Abstract: The building blocks for a low-power tuning system that reduces the phase noise of integrated VCO's are described. The multimodulus prescaler, the phase frequency detector, and the wide-band charge pump have been integrated in a standard bipolar technology with 9-GHz n-p-n transistors and 200-MHz p-n-p transistors. The maximum input frequency of the multimodulus prescaler is 3.2 GHz, the maximum reference frequency of the phase frequency detector is 380 MHz, and the 3-dB bandwidth of the charge pump is 41 MHz at a reference frequency of 300 MHz. The achieved performance enables the use of fully integrated VCO's with relatively high phase noise for reception of satellite digital signals.

Phase noise in CMOS differential LC oscillators

Abstract: An analysis of phase noise in differential cross-coupled tuned tank voltage controlled oscillators is presented. The effect of active device noise sources as well as the noise due to the passive elements are taken into account. The predictions are in good agreement with the measurements for different tail currents and supply voltages. The effect of the complementary cross-coupled pair is analyzed and verified experimentally. A 1.8 GHz LC oscillator with a phase noise of -121 dBc/Hz at 600 kHz is demonstrated, dissipating 6 mW of power using spiral inductors.