R. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994  Home/Search   Document Not in Database   Summary   Related Articles   Check

....noise at the rth receiver. Let y = y 1 , y 2 , y n R ] and w = w 1 , w 2 , w n R ] then we can write (5) in vector form y = Hx w (6) where H represents the n R n T channel matrix, with (r, t)th element H rt = #)e #) 7) The Rayleigh distance [11] gives the distance for farfield approximation from the array origin as d = 2# #, where # is the largest array dimension and # is the wavelength. r RS r R r TS scatterers x t receivers transmitters Fig. 1. Scattering model for a flat fading MIMO system. r T and r R are the ....

R.J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

....# the wavelength, # are a unit vectors pointing away from the origin of the transmitter and receiver arrays, respectively, and d# #) and d# #) are surface elements of the unit sphere# , with normals # respectively. A(# #, L (# represents the total The Rayleigh distance [8] gives the distance for farfield approximation from the array origin as d = 2# #, where # is the largest array dimension and # is the wavelength. complex gain due to the scatters for signals leaving the transmitter array from direction # and arriving at the receiver array from direction ....

R.J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

....stands for the modulo operation, is the number of beams per 120 sector, and Ito represents the amplitudes of the antenna weights that are tabulated in Table I. for each simulated . The antenna weights in Table I correspond to Dolph Chebyshev patterns with different side lobe levels, cf [8]. After calculating the pathloss of each combination of base station antennas beams and users, the active set (base station antennas beams which serve the user ) is determined according to the received pilot powers. For simplicity s sake, we assume equal pilot power for the sectors (beams ....

R. J. Mailloux, Phased Array Antenna Handbook. Boston, London: Artech House Publishers, 1993.

....free balls encompassing transmit antennas and receiver antennas, and the rest of the space assumed to be a complex scattering media. It is reasonable to assume that the surface of scattering free ball is in the farfield of either receiver or transmitter origin. The Rayleigh distance [5] gives the distance for farfield approximation from the array origin as d = 2# #, where # is the largest array dimension and # is the wavelength. r RS A( #) r T r R r TS scatterers x q z p receivers transmitters Fig. 1. Proposed scattering model for a flat fading MIMO system. ....

R.J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

....source is planar. This significantly simplifies the solution to the beamforming problem. The common rule of thumb for the approximate distance at which the farfield approximation begins to be valid is , where distance from an arbitrary array origin; largest array dimension; operating wavelength [1]. Manuscript received August 6, 1996; revised December 18, 1997. This work was supported in part by the Australian Research Council and the Cooperative Research Centre for Robust and Adaptive Systems at the Australian National University under the Australian Government s Cooperative Research ....

R. J. Mailloux, Phased Array Antenna Handbook. Boston: Artech House, 1994.

....point source is planar. This assumption significantly simplifies the beamformer design problem. The common rule of thumb is that farfield operation can be assumed for sources at a distance of where radial distance from an arbitrary array origin; largest array dimension; operating wavelength [1]. However, in many practical situations, the source is well within this distance and using the farfield assumption to design the beamformer results in severe degradation in the beampattern. Despite this, nearfield beamforming is a problem that has been largely ignored in the signal processing ....

R. J. Mailloux, Phased Array Antenna Handbook. Boston, MA: Artech House, 1994.

....presented, we believe the basic experiments already show how useful a phased microphone array can be for a wearable device. 2. Background and Methods The concept of phased arrays is quite old they have been heavily used and developed since the early days of radar. A guidebook such as [4] gives a complete description of various geometries and methods. However, there are three assumptions typically made in this work that are not satisfied here. Sumit Basu, SteveSchwartz, and Alex Pentland. Wearable Phased Arrays for Sound Localization and Enhancement. In Proceedings of the IEEE ....

P. Mailloux. PhasedArray Antenna Handbook. Artech House, Boston, 1994.

....adaptive arrays, and arbitrary sum and difference beams [47] In [10] constrained optimization was employed to improve the quiescent pattern characteristics of the distorted sum and difference beams that occur as a result of mainbeam jamming. Gabriel [20] employed a Butler matrix formulation [42] to arrive at adap3 tive sine cosine illuminated sum and difference monopulse beams. An investigation of adaptive monopulse in a mainbeam jamming scenario was presented in [40, 39, 41] with a derived set of Cramer Rao bounds that put a theoretical bound on achievable performance. In [40, 39] the ....

....mitigation, and three dimensional processing techniques such as the factored beamspace approach for combined MSC and TSI. The chapter concluded with a framework for evaluating mitigation performance. Additional information on topics covered here is available in the general literature. See ffl [29, 42] for array processing, ffl [61, 48, 54] for topics in radar, and ffl [66] for space time processing. 28 29 CHAPTER 3 Monopulse Ranging and direction finding are essential operations for almost any radar system. Whereas the previous chapter briefly discussed the concept of ranging, this ....

Robert J. Mailloux. Phased Array Antenna Handbook. Artech House Inc., Norwood, MA, 1994.

....both transmission and reception. Furthermore for a wider range of communication under emergency situations, such systems must have a 360 0 coverage in the azimuth plane [2] Consequently it is important to study conformal or multiface planar arrays which can additionally generate multiple beams [3] and also have low multipath effects. The subject of this report is to study an array of axial, 2 electric dipoles in presence of a conducting circular cylinder for applications to wireless systems. Adaptive array antennas have been studied earlier [4] 6] Adaptivity of antennas is realized by ....

....and hence suitable for rapidly deployment. To that end, for a 360 0 azimuth coverage, the cylindrical array of rectangular microstrip patches appears suitable. A conceptual view of such an antenna is shown in Fig. 2 2. Increased mutual coupling tends to degrade the bandwidth of antennas [1] [3]. Unfortunately, mutual coupling analysis is computationally too intensive and shall be addressed separately in future investigations. Other issues depicted in Fig. 2 1, are not investigated here, and will be reported in later investigations. A digital beamforming technique (DBF) for both ....

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R. J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, MA, USA, 1994.

....leads to a non convex optimization problem (e. g (10) and is considered more complicated than traditional design approaches [9] However, power synthesis is very important because pattern specifications for radar and communication systems are often defined in terms of magnitude only [9] [12], 13] Using the ideas in [10] we show that for uniform linear arrays, a reparametrization of the power synthesis task in (10) yields a convex optimization problem. D. Reparametrization (ULA) Consider the following reparametrization of P ( assuming a uniform linear array, i.e. Q i ( ....

R. Mailloux, Phased Array Antenna Handbook. Artech House, 1994.

....because the criterion does not appear to be directly related to any signi cant communication performance parameter. In contrast, the proposed approach minimizes the total inter sector interference subject to a ripple constraint on the in sector power pattern. This is an example of power synthesis [11, 12]. The proposed non convex problem can be converted into a convex fractional linear programming problem with linear constraints, via a suitable reparametrization. The convex reparametrization [13 15] guarantees that a globally optimal solution can be computed using a numerically ecient algorithm. ....

....generally leads to a non convex optimization problem (e. g, 10) and is considered more complicated than traditional design approaches [11] However, power synthesis is very important because pattern speci cations for radar and communication systems are often de ned in terms of magnitude only [11, 12, 16]. Using spectral factorization to reparametrize the power synthesis task [13 15] for uniform linear arrays, we recast (10) as a convex optimization problem. D. Reparametrization (ULA) Consider the following reparametrization of P ( assuming a uniform linear array, i.e. Q i ( Q( x i = ....

R. Mailloux, Phased Array Antenna Handbook. Artech House, 1994.

....form of adaptivity. Therefore, deterministic nulling will be used in the RF domain in order to suppress fixed and known interfering sources. Deterministic RF nulling algorithms used to determine the optimal complex weights are well known from literature and will not be repeated here [7] 8] [9]. The basic idea is to subtract cancellation beams from the quiescent beam in such a way that the interfering sources are canceled out. Deterministic RF nulling will only be successful for radio astronomy applications when the number of interfering sources is much smaller than the degrees of ....

....range as a result of the using true time delay beamforming. The measured frequency band for which the null depth at # RFI =10 # is more than 30 dB w.r.t. the main beam is equal to 320 MHz. This is in close agreement with the predicted bandwidth of 325 MHz according to the following expression [9]: #f = 2f 0 # 0 # S #L sin(# RFI ) 8) where L=0.6 m is the length of the array and S is the null depth below the original sidelobe pattern. q [deg] Frequency [GHz] 60 40 20 0 20 40 60 1.5 2 2.5 3 Received power [dB] 45 40 35 30 25 20 15 10 5 0 Fig. 11. ....

R. J. Mailloux, Phased Array Antenna Handbook. Artech House, 1994.

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R. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994

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R. J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

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R.J. Mailloux, Phased Array Antenna Handbook, Artech House.

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Robert J. Mailloux, Phased Array Antenna Handbook, Boston: Artech House, 1994

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R.J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

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R.J. Mailloux, Phased Array Antenna Handbook, Norwood MA, Massachusetts: Artech House, 1994, 524 p.

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R.J. Mailloux, Phased array antenna handbook, Norwood MA, Massachusetts: Artech House, 1994, 524 p.

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R. J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

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R. J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

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R. J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, MA, 1994.

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R. J. Mailloux. "Phased Array Antennas Handbook", Artech House, Inc., 1994.

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R.J. Mailloux, Phased Array Antenna Handbook, Artech House, Boston, 1994.

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Mailloux, Robert J., Phased array antenna handbook, Artech House, Boston, 1994.

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