Topic
Active antenna
About: Active antenna is a research topic. Over the lifetime, 2246 publications have been published within this topic receiving 26493 citations.
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05 Dec 2019
TL;DR: This work characterize the rate achievable in a bidirectional quasi-static link where several user equipments communicate with a massive multiple-input multiple-output base station (BS) and presents a novel rate expression that relies on the generalized mutual-information framework.
Abstract: We characterize the rate achievable in a bidirectional quasi-static link where several user equipments communicate with a massive multiple-input multiple-output base station (BS). In the considered setup, the BS operates in full-digital mode, the physical size of the antenna array is limited, and there exists a rate constraint on the fronthaul interface connecting the (possibly remote) radio head to the digital baseband processing unit. Our analysis enables us to determine the optimal resolution of the analog-to- digital and digital-to-analog converters as well as the optimal number of active antenna elements to be used in order to maximize the transmission rate on the bidirectional link, for a given constraint on the outage probability and on the fronthaul rate. We investigate both the case in which perfect channel-state information is available, and the case in which channel-state information is acquired through pilot transmission, and is, hence, imperfect. For the second case, we present a novel rate expression that relies on the generalized mutual-information framework.
2 citations
01 Oct 1974
TL;DR: In this article, a method of phase interpolation locking is proposed for transmit arrays where each element would normally have its own r.f. source and phase shifter in a linear array, so the number of phase shifters is halved as is the locking power required.
Abstract: A severe constraint on the use of electronically scanned active phased arrays is the high cost per element. This paper describes a method of r.f. phase interpolation locking applicable to transmit arrays where each element would normally have its own r.f. source and phase shifter. In a linear array, the technique requires phase shifters for alternate elements only, so the number of phase shifters is halved as is the locking power required. Furthermore, if n-bit phase shifters are used, the system performance approximates to that obtainable conventionally with (n+1)-bit phase shifters. Both theory of the method and experimental results for a 5-element X-band waveguide array are discussed.
2 citations
2 citations
01 Dec 2009
TL;DR: In this article, an active integrated antenna based on an infinite wavelength composite right/left-handed metamaterial structure was designed, simulated and fabricated, which does not show a resonance behavior at the second and third harmonic.
Abstract: We designed, simulated and fabricated an active integrated antenna based on an infinite wavelength composite right/left-handed metamaterial structure. Due to its nonlinear dispersion characteristic, the realized antenna does not show a resonance behavior at the second and third harmonic. This property can be exploited for the profitable termination of the higher harmonics as used in class-F or inverse class-F power amplifier concepts. The advantage over classical high efficiency concepts is the reduced circuit complexity since there is no need for an additional resonator tank.
2 citations
14 Mar 2016
TL;DR: A 1×8 active antenna array based on frequency shiftable vector modulator (FSVM) module with a RF path beamforming structure is developed and shows that the RF signal performance almost remains the same before and after entering the FSVM module.
Abstract: In this paper, a 1×8 active antenna array based on frequency shiftable vector modulator (FSVM) module is demonstrated. The FSVM module can flexibly shift the operating frequency band of the vector modulator (VM) while not deteriorating the signal performance. By employing the FSVM module, a 1×8 active antenna array with a RF path beamforming structure is developed. Since the magnitude and phase of the RF signal in each transceiver can be adjusted independently through the FSVM module, the radiation pattern of the array is controllable. For the verification of the proposed active antenna array, a prototype operating at 2.6 GHz band is fabricated and measured. Measured results show that the RF signal performance almost remains the same before and after entering the FSVM module. Furthermore, the active antenna array is capable of steering the main beam from −50° to 50° with a gain fluctuation less than 1.5 dB and a beam position error better than 0.5°.
2 citations