Example #1
0
def FS_Zolotarev(N, R, x_min, x_max, x_num, plot_far=False, dB_limit=-40):
    """Function to evaluate Fourier series coefficients of Chebyshev far-field
       pattern"""

    if (N % 2 == 0):
        print("Order needs to be an ODD number for null patterns")
    else:
        m_start = -N  # make this (2*P+1) ... and take fourier for only half period
        m_stop = N
        m = zl.z_m_frm_R(N, R, a=0.1, b=0.9999999999999)
        m = str(m)
        N = str(N)
        fun_str_re = 'zl.z_Zolotarev(' + N + ',' + 'np.sin(x)' + ',' + m + ')'
        m_index, zm = FS(fun_str_re,
                         m_start=m_start,
                         m_stop=m_stop,
                         err_lim=1e-5)

    if (plot_far):
        x, AF = IFS(zm, 2 * np.pi, m_start, m_stop, x_min, x_max, x_num)
        AF = 20 * np.log10(abs(AF))
        AF = pl.cutoff(AF, dB_limit)
        plt.plot(x * (180 / np.pi), AF)
        plt.axis('tight')
        plt.grid(True)
        plt.title('Far-field Pattern')
        plt.xlabel(r'$\phi$')
        plt.ylabel('AF')
        plt.show()

    return m_index, zm
Example #2
0
def FS_Zolotarev(N, R, x_min, x_max, x_num, plot_far=False, dB_limit= -40):
    """Function to evaluate Fourier series coefficients of Chebyshev far-field
       pattern"""    
           
    if(N % 2 == 0):
        print "Order needs to be an ODD number for null patterns"
    else:
        m_start = -N # make this (2*P+1) ... and take fourier for only half period
        m_stop = N
        m = zl.z_m_frm_R(N, R, a=0.1, b=0.9999999999999)
        m = str(m)        
        N = str(N)
        fun_str_re = 'zl.z_Zolotarev(' + N + ',' + 'np.sin(x)' + ',' + m +')'
        m_index, zm = FS(fun_str_re, m_start=m_start, m_stop=m_stop, err_lim=1e-5)
        
    if(plot_far):
        x, AF = IFS(zm, 2 * np.pi, m_start, m_stop, x_min, x_max, x_num)        
        AF = 20 * np.log10(abs(AF))
        AF = pl.cutoff(AF, dB_limit)
        plt.plot(x * (180 / np.pi), AF); plt.axis('tight'); plt.grid(True)        
        plt.title('Far-field Pattern')
        plt.xlabel(r'$\phi$')
        plt.ylabel('AF')
        plt.show()        
                     
    return m_index, zm
Example #3
0
def FS_Chebyshev(N, R, x_min, x_max, x_num, plot_far=False, dB_limit= -40):
    """Function to evaluate Fourier series coefficients of Chebyshev far-field
       pattern"""
       
    c = np.cosh(np.arccosh(R) / (N))
    c = str(c)     
           
    if(N % 2 == 0):
        m_start = int(-N / 2)
        m_stop = int(N / 2)
        N = str(N)       
        fun_str_re = 'special.eval_chebyt(' + N + ',' + c + '*np.cos(x/2))'
        m_index, zm = FS(fun_str_re, m_start=m_start, m_stop=m_stop, err_lim=1e-5)        
    else:
        m_start = -N # make this (2*P+1) ... and take fourier for only half period
        m_stop = N
        N = str(N)
        fun_str_re = 'special.eval_chebyt(' + N + ',' + c + '*np.cos(x))'
        m_index, zm = FS(fun_str_re, m_start=m_start, m_stop=m_stop, err_lim=1e-5)
        
    if(plot_far):
        x, AF = IFS(zm, 2 * np.pi, m_start, m_stop, x_min, x_max, x_num)        
        AF = 20 * np.log10(abs(AF))
        AF = pl.cutoff(AF, dB_limit)
        plt.plot(x * (180 / np.pi), AF); plt.axis('tight'); plt.grid(True)        
        plt.title('Far-field Pattern')
        plt.xlabel(r'$\phi$')
        plt.ylabel('AF')
        plt.show()        
                     
    return m_index, zm
Example #4
0
def FS_Bayliss(N, R, mbar, alpha_x, x_min, x_max, x_num, plot_far=False, dB_limit= -40):
    """Function to evaluate Fourier series coefficients of Chebyshev far-field
       pattern"""
       
    R = str(R)
    mbar = str(mbar)
    alpha_x = str(alpha_x)
           
    if(N % 2 == 0):
        print "Order needs to be an ODD number for null patterns"
    else:
        m_start = -N
        m_stop = N
        N = str(N)
        fun_str_re = 'eval_Bayliss(' + N + ',' + R + ',' + mbar + ',' + alpha_x + ',' + 'x' +')'
        print fun_str_re
        m_index, zm = FS(fun_str_re, m_start=m_start, m_stop=m_stop, err_lim=1e-5)
        
    if(plot_far):
        x, AF = IFS(zm, 2 * np.pi, m_start, m_stop, x_min, x_max, x_num)        
        AF = 20 * np.log10(abs(AF))
        AF = pl.cutoff(AF, dB_limit)
        plt.plot(x * (180 / np.pi), AF); plt.axis('tight'); plt.grid(True)        
        plt.title('Far-field Pattern')
        plt.xlabel(r'$\phi$')
        plt.ylabel('AF')
        plt.show()        
                     
    return m_index, zm
Example #5
0
def FS_Taylor(N,
              R,
              mbar,
              alpha_x,
              x_min,
              x_max,
              x_num,
              plot_far=False,
              dB_limit=-40):
    """Function to evaluate Fourier series coefficients of Chebyshev far-field
       pattern"""

    R = str(R)
    mbar = str(mbar)
    alpha_x = str(alpha_x)

    if (N % 2 == 0):
        m_start = int(-N / 2)
        m_stop = int(N / 2)
        N = str(N)
        fun_str_re = 'eval_Taylor(' + N + ',' + R + ',' + mbar + ',' + alpha_x + ',' + 'x' + ')'
        print(fun_str_re)
        m_index, zm = FS(fun_str_re,
                         m_start=m_start,
                         m_stop=m_stop,
                         err_lim=1e-5)
    else:
        m_start = -N
        m_stop = N
        N = str(N)
        fun_str_re = 'eval_Taylor(' + N + ',' + R + ',' + mbar + ',' + alpha_x + ',' + 'x' + ')'
        print(fun_str_re)
        m_index, zm = FS(fun_str_re,
                         m_start=m_start,
                         m_stop=m_stop,
                         err_lim=1e-5)

    if (plot_far):
        x, AF = IFS(zm, 2 * np.pi, m_start, m_stop, x_min, x_max, x_num)
        AF = 20 * np.log10(abs(AF))
        AF = pl.cutoff(AF, dB_limit)
        plt.plot(x * (180 / np.pi), AF)
        plt.axis('tight')
        plt.grid(True)
        plt.title('Far-field Pattern')
        plt.xlabel(r'$\phi$')
        plt.ylabel('AF')
        plt.show()

    return m_index, zm
Example #6
0
def FS_Chebyshev(N, R, x_min, x_max, x_num, plot_far=False, dB_limit=-40):
    """Function to evaluate Fourier series coefficients of Chebyshev far-field
       pattern"""

    c = np.cosh(np.arccosh(R) / (N))
    c = str(c)

    if (N % 2 == 0):
        m_start = int(-N / 2)
        m_stop = int(N / 2)
        N = str(N)
        fun_str_re = 'special.eval_chebyt(' + N + ',' + c + '*np.cos(x/2))'
        m_index, zm = FS(fun_str_re,
                         m_start=m_start,
                         m_stop=m_stop,
                         err_lim=1e-5)
    else:
        m_start = -N  # make this (2*P+1) ... and take fourier for only half period
        m_stop = N
        N = str(N)
        fun_str_re = 'special.eval_chebyt(' + N + ',' + c + '*np.cos(x))'
        m_index, zm = FS(fun_str_re,
                         m_start=m_start,
                         m_stop=m_stop,
                         err_lim=1e-5)

    if (plot_far):
        x, AF = IFS(zm, 2 * np.pi, m_start, m_stop, x_min, x_max, x_num)
        AF = 20 * np.log10(abs(AF))
        AF = pl.cutoff(AF, dB_limit)
        plt.plot(x * (180 / np.pi), AF)
        plt.axis('tight')
        plt.grid(True)
        plt.title('Far-field Pattern')
        plt.xlabel(r'$\phi$')
        plt.ylabel('AF')
        plt.show()

    return m_index, zm