Compensation of faulty elements in array antennas

• US 6,339,398 B1
• Filed: 03/30/2000
• Issued: 01/15/2002
• Est. Priority Date: 03/12/1999
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Svensson, Bengt Inge, Redvik, Jonatan
• Primary Examiner(s): Phan, Doa
• Application Number:
  US09/539,449
• Time in Patent Office: 656 Days
• Field of Search: 342/154, 342/165, 342/174, 342/368, 342/372
• US Class Current: 342/372
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices

Abstract

A method and a system are disclosed compensating for failed elements in an antenna array. The method assumes that at least the amplitude and, in most cases, the phase of, at least, some of the individual elements can be controlled to some extent. If one or more of the antenna array radiating elements are failed, at least some remaining elements are used to correct for this. The amplitude and phase radiation pattern of one of the failed elements is then synthesized using K of the remaining elements. The resulting excitation from this synthesis is superimposed on the failed array excitation at the positions of the K remaining elements. This procedure can be repeated for all the failed elements using the principle of superposition. A system utilizing the present method controls via a control unit a T/R module the phase and amplitude of each operating antenna array radiator

Claims

1. A method for compensating for failed elements in an antenna array comprising the steps of:

arranging a control unit, the control unit comprising a calculation means and the control unit via a control signal network controlling the amplitude and phase settings of each element of the array,

positioning a phase reference point of the array antenna in a failed element;

synthesizing by means of the calculation means a unity value for all angles and weighting the solution with a specific excitation exc^failed of a failed element, by formulating a correction excitation optimization problem as $\underset{k=1}{\overset{K}{\sum <br><br>}}<br><br>{\mathrm{exc}}_k^{\mathrm{corr}}·<br><br>{\mathrm{<br><br>}}^{-j<br><br>\text{\hspace{1em}<br><br>}·<br><br>k_0·<br><br>\left(x_k·<br><br>u_p+y_k·<br><br>v_p\right)}=1$

in which p=1, 2, . . . P and u_p, v_p are different angles and ko is a constant;

selecting K neighboring elements of the failed element and selecting the number of different angles P such that P=K to obtain a situation in which there exists only one solution to exc_n which denotes an excitation for an element n according to

2. The method according to claim 1, comprising the further step of using a least mean square error method or any other general method for solving the correction excitation according to

3. A system compensating for failed elements in an antenna array connected to a receiver and a transmitter for receiving and transmitting information, comprising

a control unit, the control, via a control signal network controlling amplitude and phase settings of each element of the antenna array,

a calculation means included in the control unit, the calculation means being programmed to synthesize a unity value for all angles and weighting the solution with a specific excitation exc^failed of a failed element, by means of a correction excitation optimization equation $\sum _{}^{}$

k=1K

exckcorr·



-j

 

·

k0·

(xk·

up+yk·

vp)=1

in which p=1, 2, . . . P and u_p, v_p are different angles and ok is a propagation constant,

said calculation means further selecting K neighboring elements of the failed element and selecting a number of different angles P such that P=K to obtain a situation in which there exists only one solution to exc_n which denotes an excitation for an element n according to

 

exc=[A]<sup>−

1</sup>·

{right arrow over (1)}

 

in which $A=[\text{\hspace{1em}<br><br>}<br><br>\begin{array}{cccc}{g}_1<br><br>\left(u_1,v_1\right)& g_2<br><br>\left(u_1,v_1\right)& \mathrm{\cdots <br><br>}& g_K<br><br>\left(u_1,v_1\right)\\ g_1<br><br>\left(u_2,v_2\right)& g_2<br><br>\left(u_2,v_2\right)& \mathrm{\cdots <br><br>}& g_K<br><br>\left(u_2,v_2\right)\\ \mathrm{⋮<br><br>}& \mathrm{⋮<br><br>}& \mathrm{\cdots <br><br>}& \mathrm{⋮<br><br>}\\ g_1<br><br>\left(u_p,v_p\right)& g_2<br><br>\left(u_p,v_p\right)& \mathrm{\cdots <br><br>}& g_K<br><br>\left(u_p,v_p\right)\end{array}<br><br>\text{\hspace{1em}<br><br>}]$ 

g_k(u_p,v_p)=e<sup>−

j·

k₀·

(x_k·

u_p+y_k·

v_p)</sup>

4. The system according to claim 3, wherein said calculation means uses a least mean square error method or any other general method for solving the correction excitation according to

5. The system according to claim 3, wherein said calculation means of is a microprocessor provided with an Arithmetic Logic Unit to be utilized for performing the necessary calculations.