Showing papers on "Injection locking published in 1975"

Spectral narrowing and electro‐optical tuning of a pulsed dye laser by injection locking to a cw dye laser

Abstract: It is shown that the single‐element electro‐optical birefringent filter can be used to tune the relatively high‐gained flashlamp‐pumped pulsed dye laser across the entire dye emission band, but the resulting laser line width is relatively wide as might be expected. However, this line width could be drastically reduced without losing the tunability by injection locking the pulsed laser to an electro‐optically tuned cw dye laser. The beam direction, collimation, spectral width, and stability of the pulsed laser can, therefore, all be precisely controlled through the cw laser beam.

Quaternary phase-shift keying with time delayed channel

Abstract: A digital data communication system employing quaternary phase-shift keying for transmission by a microwave radio link. The digital modulation of the quadrature channel is delayed from the in-phase channel by one-half the time duration of a bit so that the transmitted phase does not experience a quantum shift in excess of 90°. This permits the use of an injection locked oscillator as an amplifier of the microwave transmission.

Injection locked Josephson oscillator systems

Abstract: Various injection locking arrangements employing Josephson oscillators are disclosed for achieving signal amplification, frequency conversion and the detection of extremely low level signals at high frequency ranges.

Oscillator for non-sinusoidal movements

Abstract: An oscillator for generating non-sinusoidal, preferably triangular movements from a harmonic synthesis of individual sine oscillations. The oscillator comprises a plurality of mechanically intercalated resilient oscillator systems which each comprise an exciter drive means drivingly coupled to an oscillatable element. Each oscillator system has a natural frequency chosen in accordance with Fourier analysis of the oscillatory motion to be synthesized. From the total of the natural frequencies the desired motion is generated.

Power spectrum of an injection-locked Josephson oscillator

Abstract: Previous experiments have shown that a Josephson oscillator, exposed to a weak narrow-band input signal, exhibits behavior characteristic of an injection-locked oscillator. When in lock, Adler's theory of injection locking describes the experimental observations reasonably well. This paper extends the range of applicability of the theory to the out-of-lock regime where a spectrum of output frequencies is observed. Obtaining the theoretical output power spectrum requires solving a differential equation having the same form as the equation describing the resistively shunted junction model of Stewart and of McCumber. Experimental measurements of the output spectrum of a nearly locked Josephson oscillator are shown to be in reasonable agreement with the theory. Additional results discussed briefly include the observation of a frequency dependence of the locked Josephson oscillator output, and experiments in which a Josephson oscillator-mixer was injection locked by a weak signal at the if.

Frequency Stable M.I.C. S-Band and C-Band Pulsed Trapatt Oscillators

Abstract: Microstrip pulsed TRAPATT oscillators using devices designed for S-band have been operated in the fundamental and second harmonic extraction modes to give efficient high power operation at S and C-band frequencies. Conversion efficiencies of greater than 30% in the fundamental mode at 2.5 GHz and 10% in the second harmonic mode at 5 GHz have been achieved. Both planar and mesa device structures have been used to achieve TRAPATT operation at current densities in excess of 10 kA.cm-2 without the problems of premature burn out. A pulse duty cycle of 1000:1 was used. The importance of low loss parasitic diode resistance for efficient operation at high current levels is demonstrated. Finally, a frequency injection locking techniques is employed to overcome the frequency chirp of the free running oscillator and locking gains in excess of 20 dB are reported.

A Study on Mechanism of Oscillation in Sonic Oscillators : 1st Report, Mathematical Model of Oscillators Operated by Water

Abstract: A wall-attached fluidic element is caused to oscillate by interconnecting two control ports with a conduit. The oscillator is termed a sonic oscillator, which is usually operated by air. In this study, however, a mathematical model of the oscillator operated by water is introduced and its propriety is examined experimentally. The basic equation describing the behaviour of the oscillator is derived from several assumptions and it results in the generalised equation of Lienard. On the basis of this equation, the mechanism of oscillations is theoretically investigated and it is shown that oscillations are caused by the negative resistance in the input characteristics of the wall-attached element. Theoretical results are in satisfactory agreement with experimental results.

Logical phase-controlled oscillator

Abstract: The output from a data selector driven by a polyphase binary oscillator and addressed by a digital counter enables the sum or difference of two frequencies to be selected.

Further remarks on injection locking

Abstract: There are two topics covered here. First, asymmetrical locking properties of an injection-locked oscillator (ILO) are dealt with. It is shown that these properties can be partly explained by the asymmetry in the phase response of the oscillator tuned circuit. Second, the Shaw-Stover's locking figure of merit is briefly discussed. A general expression for the said figure is given. It can be used for optimization purposes when maximum locking figure of merit is the main goal of a particular design.

Computer simulation of Adler's generalized equation for the interaction of oscillators with injected signals

Abstract: A computer simulation that solves Adler's generalized equation describing the interaction of an injected signal with a free running oscillator is presented [1]. The simulation, performed on a digital computer, offers the advantage of a fast turn-around, great flexibility, and a high degree of accuracy. In contrast to analog computer simulations, no scaling is required. The simulation is demonstrated by determining the injection locking properties of an avalanche diode oscillator and of a pulsed magnetron with injected CW signals. The results concerning avalanche diode oscillator injection locking are in good agreement with other computational methods reported in current literature. The injection locking simulation of pulsed magnetrons, the results of the simulation, appear to confirm experimental data reported in the literature.

Calculation and measurement of locking time in injection-locked negative-resistance oscillators

Abstract: The locking time of an injection-locked negative-resistance oscillator is defined and calculated by solving the locking equation for Kurokawa's model of microwave oscillators. The locking time is also experimentally measured for a low-frequency simulation of the negative-resistance oscillator model. The calculated and experimental values of locking time agree, thereby validating the method of calculation.