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ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / Current IRIG standards provide guidelines for system phase noise and several manufactures provide receivers and transmitters that perform within this standard. However, legacy receivers and transmitters that do not meet the current IRIG standards are sometimes still used during a mission. This paper will address how phase noise outside of the current IRIG standard affects the performance of an FM data link when using a trellis demodulator, as well as the performance of an SOQPSK data link in a high phase noise environment. Bit error rate performance and test results at several different rates with various phase noise masks are presented in this paper.

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Phase noise from radio frequency (RF) oscillators is one of the major limiting factors affecting communication system performance. Phase noise directly effects short-term frequency stability, Bit-Error-Rate (BER), and phase-locked loop adjacent-channel interference. RF oscillator circuits contain at least one active device, usually a transistor. The active device has noise properties which generally dominate the noise characteristic limits of an oscillator. Since all noise sources, except thermal noise, are generally proportional to average current flow through the active device, it is logical that reducing the current flow through the device will lead to lower noise levels. A theory based on the time-varying properties of oscillators proposes that narrowing the current pulse width in the active device will decrease the time that noise is present in the circuit and therefore, decrease phase noise even further. The time-domain waveforms and phase noise of an active-biased 700MHz oscillator are analyzed, showing heavy saturation and high harmonic content. Redesigns of the example oscillator in active-bias and four-resistor-bias configurations show improved phase noise and lower harmonic levels at the output. Five oscillator designs of each bias configuration, each having a different pulse width, are simulated. As predicted by the theory, the narrowest current pulse corresponds to the lowest phase noise of the simulated oscillators. / Master of Science

Oscillator phase noise is an important factor in designing radio frequency (RF) communications hardware. Phase noise directly contributes to adjacent-channel interference and an increase in bit error rate (BER). Understanding the operation of an oscillator can help with the oscillator design process. Also, the understanding of the noise processes within an oscillator can add insight to the design process, allowing an intelligent low-noise design. It will be shown that although simulation software can be helpful, the understanding of the oscillator operation is a valuable tool in the design process. Oscillator design will be discussed, and then the noise processes of the oscillator will be investigated. A new method of decomposing shot noise into in-phase and quadrature components will be discussed. The noise processes discussed for a non-saturating bipolar junction transistor (BJT) Colpitts oscillator will be extended to the case of a saturating BJT Colpitts oscillator. This new method gives insight into the design of low-noise oscillators, and provides guidelines for design of low-noise oscillators. Example oscillators will support the theory and low-noise design guidelines. It will be seen that although designing an oscillator to saturate can provide a stable output level over a wide bandwidth, the added noise production may degrade the performance of the oscillator through both a lower effective Q and restricted signal level compared to the noise. / Master of Science

In this thesis, voltage-controlled oscillators (VCOs) with improved phase noise are designed and implemented. In the design of the resonant circuit varactor diodes are employed. In practice, a real VCO has to be packaged. The parasitic effect of the package may generate crosstalk inside the VCO and result in frequency shifting. To obtain an accurate prediction, a full wave model is developed. A simulation procedure is established combining High Frequency Structure Simulator (HFSS) with Advance Design System (ADS) software to predict the frequency response at the initial stage of the VCO design. Prototypes have been constructed and the characteristics measured. The simulation agrees with the measured results well. The obtained result show that our study can be used to cut the development time and cost.

<p> A unique approach for the modeling of phase noise is examined in this thesis. In previous work regarding phase noise theory, the memory property of phase is virtually ignored. The thesis introduces the Discrete Recursive Procedure (DRP): a systematic approach or methodology to predict phase noise using a discrete recursive algorithm taking into account the memory property of phase. This discrete recursive algorithm is a general extension of the Linear Time Varying (LTV) model and is referred to as the NonLinear Time Varying (NLTV) model. </p> <p> Simulations are performed using the DRP method. Phase fluctuation comparisons are made between the LTV and the NLTV models for an ideal oscillator. The simulation results show that the NLTV model taking into account the memory property of phase makes more realistic phase noise predictions than the LTV model for asymmetrical Impulse Sensitivity Function (ISF) cases. Phase noise simulation results using the NLTV model are given for a modified 810-MHz CMOS cross-coupled LC oscillator design. At 90kHz offset, the simulation prediction (-89 dBc/Hz) and the measurement readings (-93 dBc/Hz) are closely matched with a difference of approximately 4 dBc/Hz while the CAD simulation prediction ( -101. 8) has a difference of 9 dBc/Hz from the measurements. In the phase noise simulation for the 62-MHz BIT Colpitts oscillator design, the NLTV model predicts a -26 dBc/decade and -19.5 dBc/decade for the flicker noise and thermal noise regions in accordance with the theoretical -30 dBc/decade and -20 dBc/decade slopes. </p> / Thesis / Master of Applied Science (MASc)

Wireless communication systems are based on frequency synthesizers that generate carrier signals, which are used to transmit information. Frequency synthesizers use voltage controlled oscillators (VCO) to produce the required frequencies within a specified period of time. In the process of generating frequency, the VCO and other electronic components such as amplifiers produce some unwanted short-term frequency variations, which cause frequency instability within the frequency of interest known as phase noise (PN). PN has a negative impact on the performance of the overall wireless communication system. A literature study conducted on this research reveals that the existing PN cancellation techniques have some limitations and drawbacks that require further attention. A new PN correction technique based on the combination of least mean square (LMS) adaptive filtering and single-loop single-bit Sigma Delta (SD) modulator is proposed. The new design is also based on the Cascaded Resonator Feedback (CRFB) architecture. The noise transfer function (NTF) of the architecture was formulated in way that made it possible to stabilize the frequency fluctuations within the in-band (frequency of interest) by locating its poles and zeros within the unit circle. The new design was simulated and tested on a commercially available software tool called Agilent Advanced Design System (ADS). Simulation results show that the new technique achieves better results when compared with existing techniques as it achieves a 104 dB signal-to-noise (SNR), which is an improvement of 9 dB when compared with the existing technique accessed from the latest publications. The new design also achieves a clean signal with minimal spurious tones within the inband with a phase noise level of -141 dBc/Hz (lower phase noise level by 28 dBc/Hz) when compared with the existing techniques. / Thesis (MEng)--University of Pretoria, 2017. / Electrical, Electronic and Computer Engineering / MEng / Unrestricted

International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper describes a kind of Microwave Digital Frequency Synthesizer used for S-band telemetry receivers. As well known many modern electronic systems employ a Frequency Synthesizer whose spectral purity is critical. The characteristics of a PLL (Phase-Locked Loop) Frequency Synthesizer, such as frequency resolution, phase noise, spurious suppression and switch time, should be compromised in our design. A heterodyne Frequency Synthesis is often considered as a good approach to solve the problem. But it is complicated in structure and circuit. A variable-reference-driven PLL Frequency Synthesizer was introduced which can give an improved trade-off among frequency resolution, phase noise, spurious suppression. In this paper the phase noise and spurious suppression characteristic of variable-reference-driven PLL Frequency Synthesizer is analyzed theoretically and compared with that of the heterodyne Frequency Synthesizer. For engineering application, a practical Microwave Digital Frequency Synthesizer used for telemetry receiver has been designed, which is characterized by simply structure, low phase noise and low spurious output. The output spectrum of experimental measurements is given.

International Telemetering Conference Proceedings / October 22-25, 2001 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Today’s telemetry specifications are requiring electronic systems to not only survive, but operate through severe dynamic environments. Pyrotechnic shock and Random Vibration are among these environments and have proven to be a challenge for systems that rely on highly stable, low phase noise signal sources. This paper will mathematically analyze how Pyrotechnic shock and Random Vibration events deteriorate the phase noise of crystal oscillators (XO).