Wide-band array antenna

• US 20050200551A1
• Filed: 03/29/2005
• Published: 09/15/2005
• Est. Priority Date: 02/28/2001
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Ghavami, Mohammad
• Granted Patent: US 6,978,158 B2
• Time in Patent Office: Days
• US Class Current: 343/893
• CPC Class Codes: H01Q 3/22 varying the orientation in accordance with variation of frequency of radiated wave
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

A wide-band array antenna using a single real-valued multiplier for each antenna element is simple in construction and suitable for wide-band code division multiple access (WCDMA) mobile communication systems. A rectangular array antenna is formed by N×M antenna elements. Each antenna element has a frequency dependent gain which is the same for all elements. Each antenna element is connected to said single real-valued multiplier with a single real-valued coefficient, which is determined by properly selecting a number of points on a u-v plane defined for simplifying the design procedure according to the selected design algorithm.

Claims

1. A wide-band array antenna comprising:

N×

M antenna elements arranged for receiving and transmitting signals according to the wide band code division multiple access (WCDMA) communication system, and

a plurality of multipliers, one multiplier connected to each said antenna element, and each multiplier having a real-valued coefficient, wherein

when said antenna elements are placed at distances of d1 and d2 in directions of N and M, respectively, the real-valued coefficient of each multiplier is C_nm, and by defining two variables as v=ω

d₁ sin θ

/c, and u=ω

d₂ cos θ

/c, the response of said wide-band array antenna can be given as;

$\begin{array}{cc}H<br><br>\left(u,v\right)=\underset{n=1}{\overset{N}{\sum <br><br>}}<br><br>\underset{m=1}{\overset{M}{\sum <br><br>}}<br><br>C_{\mathrm{nm}}<br><br>{\mathrm{e<br><br>}}^{j<br><br>\left(n-1\right)<br><br>v}<br><br>{\mathrm{e<br><br>}}^{-j<br><br>\left(m-1\right)<br><br>u}& \left(5\right)\end{array}$

by selecting points (u_0l, v_0l) on a u-v plane according to a predetermined angle of beam pattern and a center frequency of a predetermined frequency band for use in the WCDMA communication system, elements b_l of an auxiliary vector B=(L<

<

N×

M) are calculated and the coefficient C_nm of each said multiplier corresponding to each antenna element is calculated as

$\begin{array}{cc}C<br><br>\left(n,m\right)=\underset{l=1}{\overset{L}{\sum <br><br>}}<br><br>G_a^{-1}<br><br>b_l<br><br>{\mathrm{e<br><br>}}^{-j<br><br>\left(n-1\right)<br><br>v_{0<br><br>l}}<br><br>{\mathrm{e<br><br>}}^{j<br><br>\left(m-1\right)<br><br>u_{0<br><br>l}}& \left(17\right)\end{array}$

2. The wide-band array antenna as set forth in claim 1, wherein

each of said antenna elements has a frequency dependent gain which is the same for all antenna elements.

3. The wide-band array antenna as set forth in claim 1, wherein

each of said antenna elements has a gain set to a predetermined value at a predetermined frequency band, including the center frequency, at a predetermined angle.

4. The wide-band array antenna as set forth in claim 1, further comprising

an adder for adding output signals from said plurality of multipliers.

5. The wide-band array antenna as set forth in claim 1, wherein

a signal to be sent is input to said plurality of multipliers and an output signal of each said multiplier is applied to a corresponding antenna element.

6. The wide-band array antenna as set forth in claim 1, wherein

said selected points (u_0l, v_0l) on the u-v plane for computing the elements of said auxiliary vector B are symmetrically distributed on the u-v plane.