Taylor_taylor天线_泰勒天线阵列_泰勒阵列_天线_天线阵列_

function [Lin_Volts,dB_POWER] = modtaylor(N,R); % Calculation of modified Taylor distribution for monotonically decreasing % sidelobe levels. Ref JASIK 20-9 % % Usage : [Lin_Volts,dB_POWER]=modtaylor(N,R) % % N....Number of elements in array % R....Sidelobe ratio of 1st sidelobe w.r.t. main beam (dB) % % Valid range for R is : 15 < R < 60 % Calculation of modified Taylor distribution for monotonically decreasing % sidelobe levels. Ref JASIK 20-9 % % N = number of elements in whole array % % x = Distance measured from centre of aperture % L = Total length of aperture % Jo = Zero-order Bessel function of first kind % B = Parameter that fixes ratio of R of main beam amplitude to amplitude % of first side lobe by R = 4.60333 sinh(pi.B)/pi.B For B=0 the value % of R is simply 4.60333 (lin V) or 13.2dB (dB pwr) characteristic of % a uniform distribution. % % 1st Sidelobe ratio dB Value of B % 15 0.355769 % 20 0.738600 % 25 1.022920 % 30 1.276160 % 35 1.513630 % 40 1.741480 % % Note :- For an N source array of length 2 the spacing is 2/N not! % 2/(N-1) i.e the end element is (2/N)/2 in from the end. % L=2; % Total aperture length in units (dimensionless) % 6th order polynomial fit to give B as a function of sidlobe % level R in dB Cp6=-8.6865e-10; Cp5=+2.3255183e-7; Cp4=-2.519124552e-5; Cp3=+1.41192273253e-3; Cp2=-4.329667260471e-2; Cp1=+7.3879146026700e-1; Cp0=-4.66189278748759e-0; B=Cp6*(R.^6)+Cp5*(R.^5)+Cp4*(R.^4)+Cp3*(R.^3)+Cp2*(R.^2)+Cp1*R+Cp0; deltax=2/(N); x1=(deltax/2-1:deltax:1-deltax/2); [R,C]=size(x1); J=1; for I=1:C, if x1(1,I)>=0, x(1,J)=x1(1,I); J=J+1; end end x; AxLINAMP=(1./(2.*pi)).*bessel(0,(j.*pi.*B.*sqrt(1-(2.*x./L).^2))); AxLINAMPnorm=AxLINAMP./max(AxLINAMP); Lin_Volts=[AxLINAMPnorm(N./2:-1:1) AxLINAMPnorm]'; dB_POWER=20.*log10(Lin_Volts);