DocumentCode :
546589
Title :
Active parasitic arrays for low cost compact MIMO transmitters
Author :
Han, B. ; Barousis, V. ; Kalis, A. ; Kanatas, A.G.
Author_Institution :
Aalborg Univ. & Athens Inf. Technol., Athens, Greece
fYear :
2011
fDate :
11-15 April 2011
Firstpage :
3663
Lastpage :
3667
Abstract :
Recently, electronically steerable passive array radiator antennas have been considered for beam-forming and spatial multiplexing, in order to reduce the size, cost and power consumption of smart antenna systems. However, the re-configurability of such antenna is limited, since parasitic elements were constrained to use only passive loads. If we are to integrate such systems to cost-sensitive devices (as for example in wireless sensor nodes for structural or urban microclimate monitoring), we should be able to fully emulate traditional smart antenna systems, using a single RF feed. This paper presents a method for generating parasitic loads with a negative real part using active circuit blocks. The proposed method could be used for increasing the modulation order of the aforementioned systems, decrease the required number of parasitic elements or even optimize the antenna efficiency in energy-constraint applications. Two alternative designs are presented: a consumer-off-the-shelf JFET based resistance circuit block, which could generate a load real part of up to -15 Ohm with power consumption of 40mW, and a CMOS based negative resistance circuit, which could generate negative resistances of up to -30 Ohm with power consumption around 1mW.
Keywords :
CMOS integrated circuits; MIMO communication; adaptive antenna arrays; antenna feeds; antenna radiation patterns; array signal processing; junction gate field effect transistors; negative resistance circuits; radio transmitters; space division multiplexing; CMOS based negative resistance circuit; active circuit blocks; active parasitic arrays; beam-forming; consumer-off-the-shelf JFET; electronically steerable passive array radiator antennas; energy-constraint applications; low cost compact MIMO transmitters; modulation order; power 40 mW; resistance circuit block; single RF feed; smart antenna systems; spatial multiplexing; structural microclimate monitoring; urban microclimate monitoring; wireless sensor nodes; Antenna arrays; CMOS integrated circuits; MIMO; Modulation; Power demand; Resistance; Transistors; active parasitic array; negative resistance; positive feedback;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Antennas and Propagation (EUCAP), Proceedings of the 5th European Conference on
Conference_Location :
Rome
Print_ISBN :
978-1-4577-0250-1
Type :
conf
Filename :
5782362
Link To Document :
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