Formulating wideband array-pattern optimizations

Scholnik, Dan P.; Coleman, J.O.

doi:10.1109/past.2000.859003

Cited by 24 publications

(31 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…is the wave number with wavelength ; and is the position vector of the th element. More generally, if we denote and respectively as the co-and cross-polarization unit vectors and assume is orthogonal to , then the corresponding polarization components can be expressed as: (2)(3)(4)(5)(6)(7)(8) which are also linear functions of . On the other hand, if either one of the polarization components is considered, the corresponding radiation pattern is given by:…”

Section: Radiation Pattern Of Conformal Arraymentioning

confidence: 99%

Pattern Synthesis of Narrowband Conformal Arrays Using Iterative Second-Order Cone Programming

Tsui

Chan

2010

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

A new design method is proposed for the power or shaped beam pattern synthesis problem of narrowband conformal arrays, where only the magnitude response is specified. The proposed method iteratively linearizes the non-convex power pattern function to obtain a convex subproblem in the design variables, which can be solved optimally using second-order cone programming (SOCP). In addition, a wide variety of magnitude constraints such as non-convex lower bound magnitude constraints can be incorporated. An efficient technique for determining a reasonably good initial guess to the problem is also proposed to further improve the reliability of the method. Computer simulations show that the initial guesses so obtained converge to satisfactory solutions while satisfying various prescribed magnitude constraints. Design results show that the performance of the proposed method is comparable to the optimal solution previously obtained for uniform linear arrays with isotropic elements. Moreover, we show by means of examples that the proposed method is also applicable to general non-convex power pattern synthesis problems involving arbitrary array geometries, arbitrary polarization characteristics and mutual coupling effect. Index Terms-Conformal antenna arrays, mutual coupling, narrowband design, polarization, power pattern synthesis, second-order cone programming, shaped beam pattern synthesis.

show abstract

Section: Radiation Pattern Of Conformal Arraymentioning

confidence: 99%

Pattern Synthesis of Narrowband Conformal Arrays Using Iterative Second-Order Cone Programming

Tsui

Chan

2010

IEEE Trans. Antennas Propagat.

View full text Add to dashboard Cite

show abstract

“…Another solution to the problem is to design a broadside main beam first, and then steer the array to the desired direction by means of appropriate delays implemented by either some analogue devices or FIR/IIR filters [1,7]. Thus, the main beam is shifted to the desired direction.…”

Section: Solutions To the Off-broadside Main Beam Design And Examplesmentioning

confidence: 99%

“…One of the suggested methods is to optimize the array parameters with respect to the desired response using available convex optimization methods [1,2,3]. However, for large arrays, the number of coefficients to be optimized is extremely large.…”

Section: Introductionmentioning

confidence: 99%

Off-broadside main beam design for frequency invariant beamformers

Liu

Weiss²

2008

2008 International ITG Workshop on Smart Antennas

View full text Add to dashboard Cite

In a previously proposed design method for frequency invariant beamforming, the design for the case of an off-broadside main beam is not satisfactory. After a detailed analysis, we propose two methods to overcome this problem: one is to increase the length of the FIR filter attached to each sensor, as a result, we need to sample the transformed desired response more densely in the associated direction; the other one is to design a broadside main beam first, then it is convolved with appropriate steering delay filters. Design examples show that the two methods can provide satisfactory results.

show abstract

“…Time-domain broadband beamforming methods [6,12,22,23,33] have mostly been derived from the early basic delay-and-sum concept [7] and, although they can be adapted in real time, the errors between the required exact time delays and the corresponding realized approximate time delays typically cause considerable distortion of the desired beamformed signal [17,18,22]. As a remedy, frequency-invariant broadband beamforming methods [25,26,[31][32][33] have been proposed, which extrapolate the conventional narrowband beamformer design methods at several different temporal frequencies over the desired frequency band using iterative optimization techniques. Even though these broadband frequency-invariant beamforming methods minimize distortion, the design process is typically too computationally intensive for real-time adaptive beamforming.…”

Section: Introductionmentioning

confidence: 99%

Adaptive Complex-Coefficient 2D FIR Trapezoidal Filters for Broadband Beamforming in Cognitive Radio Systems

Gunaratne

Bruton

2010

Circuits Syst Signal Process

View full text Add to dashboard Cite

A novel design method is proposed for an adaptive discrete-domain beamformer for the beamforming of temporally broadband-bandpass signals in cognitive radio (CR) systems. The method is based on a complex-coefficient 2D finite impulse response (FIR) filter having a trapezoidal-shaped passband. The temporally broadband-bandpass signals are received by a 1D uniformly distributed antenna array (1D UDAA), where the outputs of the antennas are complex-quadrature sampled by the front end of the CR system. This CR system is based on a software defined radio (SDR) architecture and can be instantly reconfigured by the control system to select the appropriate frequency band and the required sampling rate. The subsequent beamforming enhances the spectral components of the desired temporally broadbandbandpass signals by arranging for the asymmetric trapezoidal-shaped passband of the 2D filter transfer function to closely enclose the region of support (ROS) of the spectrum of the desired signal, whereas the ROSs of the spectral components of the interfering signals are enclosed by the stopband. The proposed novel closed-form design method facilitates instant adaptation of the shape and orientation of the passband of the beamforming 2D FIR trapezoidal filter in order to match the time-varying frequency band and the time-varying bandwidth of the signal, as well as to track and enhance received signals with time-varying directions of arrival (DOAs). Simulated results confirm that, compared with previously reported methods, the proposed method achieves the best overall tradeoff with respect to the instantaneous adaptations of the operating frequency band, the bandwidth, and the time-varying DOAs, the distortion of the desired passband signal, and the stopband attenuation of interfering signals.

show abstract

Formulating wideband array-pattern optimizations

Cited by 24 publications

References 7 publications

Pattern Synthesis of Narrowband Conformal Arrays Using Iterative Second-Order Cone Programming

Pattern Synthesis of Narrowband Conformal Arrays Using Iterative Second-Order Cone Programming

Off-broadside main beam design for frequency invariant beamformers

Adaptive Complex-Coefficient 2D FIR Trapezoidal Filters for Broadband Beamforming in Cognitive Radio Systems

Contact Info

Product

Resources

About