Injection locking

About: Injection locking is a research topic. Over the lifetime, 4567 publications have been published within this topic receiving 60942 citations.

Continuum modeling of the dynamics of externally injection-locked coupled oscillator arrays

Abstract: Mutually injection-locked arrays of electronic oscillators provide a novel means of controlling the aperture phase of a phased-array antenna, thus achieving the advantages of spatial power combining while retaining the ability to steer the radiated beam. In a number of design concepts, one or more of the oscillators are injection locked to a signal from an external master oscillator. The behavior of such a system has been analyzed by numerical solution of a system of nonlinear differential equations which, due to its complexity, yields limited insight into the relationship between the injection signals and the aperture phase. In this paper, we develop a continuum model, which results in a single partial differential equation for the aperture phase as a function of time. Solution of the equation is effected by means of the Laplace transform and yields detailed information concerning the dynamics of the array under the influence of the external injection signals.

Optical communication by injection-locking to a signal which modulates an optical carrier

Abstract: An optical communication system is disclosed including an all-optical device whose output modulated optical beam is locked to an input modulated optical beam. In a specific embodiment of the system, the device may be a self-electro-optic effect device (SEED), which is operated as an oscillator by means of an associated tank circuit. Such an embodiment permits recovery of a clock frequency from a bit stream which is input into the device. When the output of the device is directed into an optical decision element, an all-optical regenerator may be realized.

Injection-locked oscillator chain: a possible solution to millimeter-wave MMIC synthesizers

Abstract: An injection-locked oscillator (ILO) monolithic-microwave integrated-circuit (MMIC) chain-a cascade of low- and high-frequency-band ILOs-is proposed for simple and cost-effective millimeter-wave local oscillators and synthesizers. Primary 5, 20, and 50 GHz-band ILO MMICs are designed and fabricated as an ILO-chain chip set. Improvements made to the active combiner/dividers (A-C/D's), the heart of the MMIC, in the external feedback path for an amplifier to suppress spurs at the output port of 5 and 20 GHz band ILOs, and enhance the loop gain and layout flexibility at millimeter-wave frequencies. Fabricated 5 and 20 GHz-band ILO MMICs are chain-connected to confirm the design techniques. The ILO chain provides a 20 GHz-band output signal for an injection signal of 571 MHz, as well as a very low level of spurs of less than -45 dBc around the output signal. The measured results show that the proposed ILO chain is extremely suitable for developing full millimeter-wave MMIC frequency synthesizers.

Homodyne OFDM with Optical Injection Locking for Carrier Recovery

Abstract: Homodyne detection provides the simplest digital signal processing (DSP) solution to optical coherent detection and minimizes the receiver bandwidth requirements. These features make it promising for high spectrally efficient formats such as optical orthogonal frequency domain multiplexing (OFDM), which has a flat optical spectrum and which is thus inherently sensitive to high-frequency distortions, e.g., due to limited detector bandwidth. The key to homodyne detection is recovery of the carrier from the received signal all optically (as opposed to frequency offset compensation via DSP. Herein, we use optical injection locking (OIL) in conjunction with carrier tone-assisted OFDM to achieve this. In contrast to previous reports, we show that OIL carrier recovery with subsequent homodyne detection can operate without the need for any optical prefiltering. First, we evaluate the performance as a function of the carrier tone guardband bandwidth. Further, we improve the robustness of this technique using a slow-phase lock loop that compensates for drift in the laser's temperature/current control electronics. Using this improved setup, we compare our all-optical-carrier-recovered homodyne and the “traditional” DSP-assisted intradyne detection for the case of OFDM-16QAM signals. Finally, we compare the computing complexity necessary for both approaches and estimate the intradyne performance limitations due to the carrier-local oscillator frequency offset.

The laser oscillator with an external signal

Abstract: The problem considered is that of a laser oscillator with an externally applied signal. Calculations are made 1) to determine the conditions for quenching the natural oscillation, 2) to evaluate the frequency pulling and pushing effects, and 3) to determine the power gain at the forcing frequency.