Showing papers on "Injection locking published in 1971"

The Single-Cavity Multiple-Device Oscillator

Abstract: The output power from 12 IMPATT diodes has been combined in a single-cavity multiple-device oscillator. The oscillator is free from the well-known moding problem of multiple-device oscillators. The objective of this paper is to present the oscillator-circuit theory, which clearly indicates why this particular circuit configuration can give a stable operation free from moding problems. To handle the formidable equations necessary for the analysis, the eigenfunction approach is extensively used. The condition for stable operation, the noise performance, and the locking behavior of the oscillator are all discussed. The noise performance is similar and the locking behavior identical to those of single-device oscillators.

Injection locking of microwave solid-state oscillators

Abstract: Simple theory indicates a phase range of from 0° to ±90° when phase locking oscillators, but these limits do not apply where Q(ΔΩ/ω 0 ) is not small. This can cause problems in multiple-source devices and other locked oscillator systems where small phase angles are desirable.

Properties of injection locking in the non-linear oscillator†

Abstract: The detailed behaviours of a non-linear oscillator which is injection-locked by sub-harmonic or harmonic frequency is presented and analysed. The theory, based, on a simple model of the equivalent circuit, can well explain various experimental results. Non-linear oscillator admittance, the combination of both non-linear negative conductance and non-linear susceptance, is found to be a satisfactory model for the injection-locked avalanche diode oscillator.

A new type of frequency-stabilized Gunn oscillator

Abstract: A new type of frequency-stabilization method for a Gunn oscillator consisting of a high-Q single-tuned oscillator circuit is described. The frequency stability of this stabilized osciilator was 5 × 10-5over a temperature change from -10 to 60°C at 20.970 GHz. This result satisfies the requirement for a 20-GHz radio relay system.

Combination Injection Locking with Indirect Synchronization Techniques

Abstract: A new technique Of combining injection locking with indirect synchronization has been proposed. A detailed analysis of the system in a noisy environment is presented. Also considered is the effect of the low-frequency time constant of the self-bias circuit of the oscillator on the system performance.

Amplification of high-speed PCM phase-shift-keyed millimeter-wave signals through an injection-locked IMPATT oscillator

Abstract: This paper will discuss results of an IMPATT oscillator injection-locked by 200 and 400-MHz clock-rate phase-shift-keyed millimeter-wave signals.

Frequency stabilisation of a reflex-klystron oscillator by a superconducting cavity

Abstract: A powerful X band oscillator is reported, with a frequency stability comparable to a quartz clock of high quality. It is realised by coupling externally a standard reflex klystron 2K 25 to a high-Q factor (108) superconducting cavity. The observed frequency standard deviations in one second (10?10 in relative value) are in accordance with the theory.

F.m. noise in an injection-locked oscillator when reverse locking exists

Abstract: A suppression factor for f.m. noise in an injection-locked oscillator is derived under the assumption that the locking source is influenced by some reverse locking. The electrical length between the oscillators is found to have a considerable effect on the noise.

Injection type frequency locked oscillator apparatus

Abstract: An injection-type frequency-locked oscillator provided with novel means for monitoring the operation of the oscillator. An injection input wave is applied through a directional coupler to an auxiliary terminal of the oscillator having a separate output terminal connected to a load. The coupler separates the injection input wave from the oscillator output wave. The output impedance of the oscillator is matched to the load impedance; however, the input impedance of the oscillator at the auxiliary terminal is mismatched to the output impedance of the coupler with respect to the injection input wave, thereby producing in the coupler a reflected injection input wave which is 180 DEG out of phase with the oscillator output wave when the oscillator is frequency-locked at the center frequency of the injection input wave. The signal level at a monitoring terminal of the coupler provides a monitoring signal indicative of the degree of frequency-locking of the oscillator.

Hybrid injection locking

Abstract: A new injection-locking technique for frequency stabilizing CO 2 laser oscillators is discussed. In contrast to more conventional injection locking, in which the injected signal pulls the laser oscillation into phase, in hybrid operation the drive signal is applied to a wavelength which does not oscillate because of competition with higher gain transitions. With the aid of the injected signal, oscillation switches to the frequency of the injected signal and its normal oscillation is completely quenched. This hybrid stabilization is inherently flexible and allows frequency stabilized operation on a large number of lines. Furthermore, the difficult to implement optical phase comparison technique required by ordinary injection-locking approaches is replaced by a simple amplitude discriminant. To demonstrate the potential of this technique, a 60 W sealed-off CO 2 laser was locked in frequency by the injection of a 0.5 W signal. Expressions for the frequency locking range, the extracted power and the gain-bandwidth product are derived as a function of injected power, the undriven laser power, and the resonator coupling. Experimental data in agreement with theoretical analysis are presented.

A new method of AM-PM conversion by using a locking oscillator

Abstract: Phase modulated output can be obtained from an injection locked oscillator which has an amplitude modulated external force. The principle of AM-PM conversion and its experimental results are shown.

Injection phase locking device in an fm-transmitter for a self-oscillating oscillator modulated by a modulation signal

Abstract: A phase locking arrangement in which a free-running oscillator running with a frequency fo is injection phase locked by a synchronizing oscillator with a free-running frequency fs and a multiplier giving a multiplied frequency n . fs. A modulating frequency fm modulates both the free-running oscillator and the synchronizing oscillator through two direct coupled FMmodulators, so that the free-running oscillator will be continuously tuned to a frequency f1 which is chosen so that the synchronizing band Delta f f1 - fo of the free-running oscillator is narrow, so that the synchronizing power from the synchronizing oscillator can be kept low.

New Alarm Circuit Used for Injection Locking Oscillator of Microwave Communication Equipment

Abstract: Cavity-controlled microwave local oscillators are widely used since they are tunable over a wide frequency range with excellent output characteristics and generate little noise. However, the maximum frequency stability is limitted to /spl plusmn/5x10/sup -5/. To increase the frequency stability, a crystal-controlled oscillator is used to perform injection locking in the cavity-controlled oscillator. This paper describes a new injection locking method, explains the theory of injection locking alarm circuit and compares the experimental results with mathematical calculations. The injection locking method and alarm circuit based on this technique are very simple and easy to incorporate into high frequency-stability microwave local oscillator.

Digital phase control by harmonic locking

Abstract: The principle of phase control by harmonic locking is verified experimentally, using a 1 GHz transistor oscillator locked to a 4 GHz source. Phase steps of ±90° can be obtained by the application of positive- or negative-voltage pulses to the locked transistor. Phase switching can be achieved in 40 ns.