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We present the theoretical and experimental results of a new class of microwave oscillators called opto-electronic oscillators (OEO). We discuss techniques of achieving high stability single mode operation and demonstrate the applications of OEO in photonic communication systems.
We report on a frequency-stable temperature compensated sapphire oscillator (CSO) at temperatures above 77 K. Previously, high stability in sapphire oscillators had only been obtained with liquid helium cooling.
EDFA-based coupled opto-electronic oscillator (COEO), an integrated optical and microwave oscillator that can generate picosecond optical pulses, is presented. the phase noise measurements of COEO show better performance than synthesizer-driven mode-locked laser.
Multiple-degree-of-freedom oscillator for tests of sloshing in scale model Saturn lox fuel tanks - oscillator and test vessel support design
During a flight with a Van Berkel W. B. seaplane it was observed that the wing could perform violent oscillations. A theoretical and experimental investigation led to the conclusion, that in some cases an unstable oscillation of the wing-aileron system under the influence of the elastic and aerodynamic forces is possible without further external causes.
Some years ago it was proposed that an array of electronic oscillators coupled to nearest neighbors can be made to mutually injection lock and oscillate as an ensemble thus implementing spatial power combining.
Our purpose in coupling oscillators together is to achieve high radiated power through the spatial power combining which results when the oscillators are injection locked to each other.
Our purpose in coupling oscillators is to achieve high radiated power through the spatial power combining which results when the oscillators are injection locked to each other.
Two WDM channels at 1320 nm and 1312 nm carring RF signals are simultaneously up/down converted by a fiber-based optoelectronic oscillator. The conversion efficiency are found to be ~ -8 dB and the incoming signals has no effects on the local oscillator spectral purity.
York and Liao have shown both theoretically and experimentally that one can control the phases of an array of coupled oscillators by tuning the oscillators on the perimeter of the array.
We report on tests of a compensated saphirre oscillator (CS) which shows frequency-stable operation at temperatures above 77k.The frequency stability for this oscillator shows an apparent flicker floor of 7.5X10(sup -14) for measuring times between 3 and 10 seconds, and stability is better than 2X10(sup -13) for all measuring times between 10 and 100 seconds... Frequency sensitivities os the microwave sapphire resonator to temperature and temperature rate have been characterized, and a careful analysis of several aspects of the ac frequency-lock.
It has been shown that arrays of voltage controlled oscillators coupled to nearest neighbors can be used to produce useful aperture phase distributions for phased array antennas. However, placing information of the transmitted signal requires that the oscillations be modulated.
We describe and demonstrate a novel device in which a microwave oscillation is generated and is directly coupled with an optical oscillation, and vise versa.
In this paper, we will describe our recent phase-noise measurements of photonic microwave oscillators. We will aslo discuss our investigation of the frequency stability link between the optical and microwave frequencies in the coupled oscillator.
We present recent progress on the 10 Kelvin Cryocooled Sapphire Oscillator (10K CSO). Included are incorporation of a new pulse tube cryocooler, cryocooler vibration comparisons between G-M and pulse-tube types, phase noise, and frequency stability tests. For the advantage of a single stage pulse tube cryocooler, we also present results for a 40K Compensated Sapphire Oscillator (40K CSO).
We theoretically propose and discuss properties of two schemes of an all-optical self-oscillating magnetometer based on an opto-electronic oscillator stabilized with an atomic vapor cell. Proof of the principle DC magnetic field measurements characterized with 2 x 10(exp -7) G sensitivity and 1 - 1000 mG dynamic range in one of the schemes are demonstrated.
We demonstrated low threshold optical photonic hyper-parametric oscillator in a high-Q 10(exp 10) CaF2 whispering gallery mode resonator which generates stable 8.5 GHz signal. The oscillations result from the resonantly enhanced four wave mixing occurring due to Kerr nonlinearity of the material.
The last decade has seen a number of technological advancements that have now made it possible to implement fully solid state local oscillator chains up to 2 THz. These chains are composed of cascaded planar multiplier stages that are pumped with W-band high power sources. The high power W-band sources are achieved by power combining MMIC amplifiers and can provide in access of 150 mW with about 10% bandwidth. Planar diode technology has also enabled novel circuit topologies that can take advantage of the high input power and demonstrate significant efficiencies well into the THz range. Cascaded chains to 1.9 THz have now been demonstrated with enough output power to successfully pump hot-electron bolometer mixers in this frequency range. An overview of the current State-of-the-Art of the local oscillator technology will be presented along with highlighting future trends and challenges.