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K. Kurokawa

Bio: K. Kurokawa is an academic researcher from Bell Labs. The author has contributed to research in topics: Injection locking & Gunn diode. The author has an hindex of 1, co-authored 1 publications receiving 640 citations.

Papers
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Journal ArticleDOI
K. Kurokawa1
01 Oct 1973
TL;DR: Injection locking of microwave solid-state oscillators is discussed in this article, based on the familiar theorem that the total impedance times the current is equal to the applied voltage, based on which the locking range, large-signal injection, locking stability, and AM and FM noise are analyzed.
Abstract: Injection locking of microwave solid-state oscillators is discussed, based on the familiar theorem that the total impedance times the current is equal to the applied voltage. Both quasi-static and dynamic analyses of the locking range, large-signal injection, locking stability, and AM and FM noise are given, and recent experimental work is reviewed briefly. No applications of injection locking are discussed in detail.

654 citations


Cited by
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Journal ArticleDOI
TL;DR: In this paper, an identity obtained from phase and envelope equations is used to express the requisite oscillator nonlinearity and interpret phase noise reduction, and the behavior of phase-locked oscillators under injection pulling is also formulated.
Abstract: Injection locking characteristics of oscillators are derived and a graphical analysis is presented that describes injection pulling in time and frequency domains. An identity obtained from phase and envelope equations is used to express the requisite oscillator nonlinearity and interpret phase noise reduction. The behavior of phase-locked oscillators under injection pulling is also formulated.

1,159 citations

Journal ArticleDOI
TL;DR: In this paper, the authors describe a novel photonic oscillator that converts continuous-light energy into stable and spectrally pure microwave signals, which can be used for high-frequency reference regeneration and distribution, high gain frequency multiplication, comb frequency and pulse generation, carrier recovery, and clock recovery.
Abstract: We describe a novel photonic oscillator that converts continuous-light energy into stable and spectrally pure microwave signals. This optoelectronic oscillator (OEO) consists of a pump laser and a feedback circuit including an intensity modulator, an optical-fiber delay line, a photodetector an amplifier, and a filter. We present the results of a quasi-linear theory for describing the properties of the oscillator and their experimental verifications. Our findings indicate that the OEO can generate ultrastable, spectrally pure microwave-reference signals up to 75 GHz with a phase noise lower than -140 dBc/Hz at 10 KHz. We show that the OEO is a special voltage-controlled oscillator with an optical-output port and can be synchronized to a reference source by means of optical injection locking, electrical injection locking, and a phase-locked loop. Other OEO applications include high-frequency reference regeneration and distribution, high-gain frequency multiplication, comb frequency and pulse generation, carrier recovery, and clock recovery.

562 citations

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TL;DR: Active integrated antenna (AIA) technologies have been extensively studied in the past decade or so as discussed by the authors, with a brief introduction on the definition and some historical remarks on the research effort on the past decades or so.
Abstract: This paper provide a review of the active integrated antenna (AIA) technologies. After a brief introduction on the definition and some historical remarks, the paper concentrates on the research effort on the past decades or so. The AlAs are reviewed in its various functions. First, an oscillator-type AIA is presented, followed by very interesting aspects of coupled oscillator arrays for phase control. Use of an AIA concept for efficient RF front ends is described with examples on high-power amplifier AlAs. Next, a phase-conjugation-based retrodirective array is reviewed. Finally, AIA systems for receiving, transmitting, and duplexing are reviewed.

436 citations

Journal ArticleDOI
TL;DR: In this paper, a theoretical and experimental investigation of injection locking of semiconductor lasers is presented, taking into account the dependence of refractive index on the carrier density expressed by the linewidth enhancement factor α.
Abstract: We present a theoretical and experimental investigation of injection locking of semiconductor lasers. The theoretical analysis takes into account the dependence of refractive index on the carrier density expressed by the linewidth enhancement factor α. Locking conditions and dynamic stability are analyzed. The nonzero value of α results in an increased locking bandwidth, where only part of the range corresponds to a dynamically stable state. Asymmetric characteristics are obtained for the locked power and phase as a function of frequency detuning between the master and slave laser. Outside the stable range, light injection gives rise to beat phenomena and intensity pulsations. The theoretical results were confirmed by experiments on 830 nm CSP lasers and 1.3 μm BH lasers. The experiments include the first measurements of locking bandwidth characteristics reported for 1.3 μm lasers. Power spectra are recorded under locked and near-locked conditions and compared with theory. The 1.3 μm lasers are found to have a better dynamic stability than 830 nm lasers. Even so, the stability problems may exclude the particular application of injection locking where phase modulation is generated for coherent transmission.

432 citations

Journal ArticleDOI
TL;DR: In this paper, a method for electronic beam scanning in linear arrays of antenna-coupled oscillators is introduced which eliminates the need for phase shifters, and it is shown that a constant phase progression can be established by slightly detuning the peripheral array elements, while maintaining mutual synchronization.
Abstract: A method for electronic beam scanning in linear arrays of antenna-coupled oscillators is introduced which eliminates the need for phase shifters. It is shown that a constant phase progression can be established by slightly detuning the peripheral array elements, while maintaining mutual synchronization. This unusual nonlinear behavior is explained using coupled Van der Pol equations. A stability analysis provides theoretical limitations on the achievable interelement phase shift. When the phase of the coupling is zero, the theory predicts an interelement phase shift that can be varied continuously over the range -90 degrees > Delta theta >

306 citations