The paper describes the possible use of a spintorque oscillator in the design of a radiofrequency macro-oscillator. The low consumption and the nanometric size of spintorque oscillators comparatively to LC circuits op...
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The paper describes the possible use of a spintorque oscillator in the design of a radiofrequency macro-oscillator. The low consumption and the nanometric size of spintorque oscillators comparatively to LC circuits open new perspectives for these devices. Unfortunately a single spintorque oscillator cannot be used for radiofrequency applications due to a very low power and a high level of phase noise. In order to improve the performance of the output signal a common synchronization approach is applied to an array of forced spintorque oscillators. The main issues for practical realization are presented and possible ways for their solution are proposed. (C) 2011 Elsevier Ltd. All rights reserved.
In this paper, an oscillator array using push-push oscillators and a directional phase shifters for the coupling circuits is presented. In the oscillator array, push-push oscillators are connected via the coupling cir...
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ISBN:
(纸本)9781457713309;9781457713316
In this paper, an oscillator array using push-push oscillators and a directional phase shifters for the coupling circuits is presented. In the oscillator array, push-push oscillators are connected via the coupling circuits consisting of directional couplers and a phase shifter. The phase shifter consists of a pi/2 hybrid circuit and varactor diodes. An oscillation signal of the push-push oscillator is injected into the adjoining push-push oscillator through the coupling circuit. The push-push oscillators are synchronized by the signal. The phase shifts between the signals of the oscillators are obtained by the phase shifters. In experiment, the phase shift about 140 degrees is obtained between the output signals of adjoining oscillators in Ku band.
We proposed and fabricated an oscillator array composed of three resonant-tunneling-diode terahertz oscillators integrated with slot-coupled patch antennas, which operates without the need for Si lens. We measured the...
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ISBN:
(纸本)9781479982721
We proposed and fabricated an oscillator array composed of three resonant-tunneling-diode terahertz oscillators integrated with slot-coupled patch antennas, which operates without the need for Si lens. We measured the radiation pattern for single and arrayed oscillators, and calculated the output power using the integration of the pattern. The output power of a single oscillator was similar to 15 mu W, while approximately three times higher output power of similar to 55 mu W was achieved at similar to 1 THz for the array configuration.
A direct-coupled technique for standing wave oscillator (SWO) arrays is presented in this paper. The oscillation currents of a unit cell in the SWO array directly inject to adjacent cells through the resonator. Two 2-...
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A direct-coupled technique for standing wave oscillator (SWO) arrays is presented in this paper. The oscillation currents of a unit cell in the SWO array directly inject to adjacent cells through the resonator. Two 2-D SWO arrays based on the technique are reported. The first SWO array can provide synchronous signals with identical frequencies, amplitudes, and phases at multiple locations over a chip. It is implemented in a 90-nm CMOS technology with 61.5-GHz oscillation frequency. Millimeter-wave radiators that consists of the proposed SWO array, an RF driver array, and an on-chip loop antenna array are implemented in a single chip to verify the synchronicity of the reported 2-D SWO via wireless measurement. The indirect evidence of synchronicity is provided from the correlation between the wireless measured effective isotropic radiated power (EIRP) and phase noise of 1 x 1, 2 x 2, and 3 x 3 arrays. The EIRP in the normal direction of the array is increasing by a factor of 10 log N-2 and the phase noise is reducing by a factor of 10 log N over that of a single cell, where is the number of unit cells in the array. The second SWO array can provide synchronous signals with identical frequencies, amplitudes, and multiple phases at multiple locations over a chip. It is implemented in a 65-nm CMOS technology with 132.5-GHz fundamental frequency. The SWO array is designed for a 2-D second-harmonic (265 GHz) spatial power radiating and combining array. The EIRPs of the fundamental frequency and second harmonic in the normal direction of the array are -34 and -6.5 dBm, respectively. The phase noise of the fundamental frequency and second harmonic at 1-MHz offset from the carrier frequency are -96 and -89 dBc/Hz, respectively.
This paper reports the development of oscillators for low-power microwave transmission and also research on an oscillator array based on the newly developed oscillators. The oscillators have a simple configuration wit...
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This paper reports the development of oscillators for low-power microwave transmission and also research on an oscillator array based on the newly developed oscillators. The oscillators have a simple configuration with an antenna directly connected to the output. For synchronization in an array, a new method is developed in which the oscillators are connected by band elimination filters (BEF) with specific phase characteristics. This structure is experimentally verified. The BEF used here has the characteristic of reflecting most of the generated signal while only a slight amount is leaked to other oscillators in an out-of-phase fashion. A locking experiment was performed with an oscillator array in which five oscillators are connected through BEF circuits, and the locking effect of the oscillators was observed. In addition, it was shown that the robustness to external disturbances and power supply voltage variations was improved. 2005 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 88(5): 1-9, 2005;Published online in Wiley InterScience (***).
A quasi-optical power combiner for a 4 X 4 IMPATT oscillator array has been designed and experimentally investigated. The combiner consists of a bi-periodic dielectric phase grating which transforms the near field- of...
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A quasi-optical power combiner for a 4 X 4 IMPATT oscillator array has been designed and experimentally investigated. The combiner consists of a bi-periodic dielectric phase grating which transforms the near field- of a rectangular horn array into a pseudoplane wave. The horn array is excited by oscillators which operate uniformly in both amplitude and phase. A parabolic mirror with a superimposed surface relief couples the pseudoplane wave into a rectangular output horn antenna. In principle, the combiner has no restriction in inter-element spacing and is hence scalable up to submillimeter wavelengths without degradation of power combining efficiency. The quasi-optical design has been verified by scalar field measurements in several planes. The oscillator matrix is injection-locked by a master oscillator from the output port. A continuous wave output power of 1.3 W with an overall power combining efficiency of 70% has been measured at 65 GHz.
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