-
-
-
-
-
-
-
-
-
-
-
-
-
- Permalink
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- Find file
-
-
- Copy path
-
-
-
- - SHARC/sharc/antenna/antenna_f1245.py -
- -
-
- Find file
-
-
- Copy path
-
-
-
-
-
-
-
-
-
-
-
- 
- CalilQ
-
- Integrate GW and CPE antennas to simulator
-
-
-
- 4655726
- Apr 6, 2018
-
-
-
-
- CalilQ
-
- Integrate GW and CPE antennas to simulator
-
-
-
- 4655726
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- | - | # -*- coding: utf-8 -*- | -
| - | """ | -
| - | Created on Wed Apr 4 17:08:00 2018 | -
| - | - |
| - | @author: Calil | -
| - | """ | -
| - | - | -
| - | from sharc.antenna.antenna import Antenna | -
| - | from sharc.parameters.parameters_imt import ParametersImt | -
| - | from sharc.parameters.parameters_antenna_imt import ParametersAntennaImt | -
| - | - | -
| - | import numpy as np | -
| - | import math | -
| - | - | -
| - | class AntennaF1245(Antenna): | -
| - | """ | -
| - | Implements reference radiation patterns for HAPS gateway antennas | -
| - | for use in coordination studies and interference assessment in the | -
| - | frequency range from 1 GHz to about 70 GHz. (ITU-R F.1245-2) | -
| - | """ | -
| - | - | -
| - | def __init__(self, param: ParametersImt, param_ant: ParametersAntennaImt): | -
| - | super().__init__() | -
| - | self.peak_gain = param_ant.peak_gain | -
| - | lmbda = 3e8 / ( param.frequency * 1e6 ) | -
| - | self.d_lmbda = param_ant.diameter / lmbda | -
| - | - | -
| - | self.g_l = 2 + 15 * math.log10(self.d_lmbda) | -
| - | self.phi_m = (20 / self.d_lmbda) * math.sqrt(self.peak_gain - self.g_l) | -
| - | self.phi_r = 12.02 * math.pow(self.d_lmbda, -0.6) | -
| - | - | -
| - | def calculate_gain(self, *args, **kwargs) -> np.array: | -
| - | phi_vec = np.absolute(kwargs["phi_vec"]) | -
| - | theta_vec = np.absolute(kwargs["theta_vec"]) | -
| - | beams_l = np.absolute(kwargs["beams_l"]) | -
| - | - |
| - | off_axis = self.calculate_off_axis_angle(phi_vec,theta_vec) | -
| - | - | -
| - | if self.d_lmbda > 100: | -
| - | gain = self.calculate_gain_greater(off_axis) | -
| - | else: | -
| - | gain = self.calculate_gain_less(off_axis) | -
| - | - |
| - | idx_max_gain = np.where(beams_l == -1)[0] | -
| - | gain[idx_max_gain] = self.peak_gain | -
| - | - | -
| - | return gain | -
| - | - | -
| - | def calculate_gain_greater(self, phi: float) -> np.array: | -
| - | """ | -
| - | For frequencies in the range 1 GHz to about 70 GHz, in cases where the | -
| - | ratio between the antenna diameter and the wavelength is GREATER than | -
| - | 100, this method should be used. | -
| - | - |
| - | Parameter | -
| - | --------- | -
| - | phi : off-axis angle [deg] | -
| - | - |
| - | Returns | -
| - | ------- | -
| - | a numpy array containing the gains in the given angles | -
| - | - |
| - | """ | -
| - | gain = np.zeros(phi.shape) | -
| - | - | -
| - | idx_0 = np.where(phi < self.phi_m)[0] | -
| - | gain[idx_0] = self.peak_gain - 2.5e-3 * np.power(self.d_lmbda * phi[idx_0], 2) | -
| - | - | -
| - | phi_thresh = max(self.phi_m,self.phi_r) | -
| - | idx_1 = np.where((self.phi_m <= phi) & (phi < phi_thresh))[0] | -
| - | gain[idx_1] = self.g_l | -
| - | - | -
| - | idx_2 = np.where((phi_thresh <= phi) & (phi < 48))[0] | -
| - | gain[idx_2] = 29 - 25 * np.log10(phi[idx_2]) | -
| - | - | -
| - | idx_3 = np.where((48 <= phi) & (phi <= 180))[0] | -
| - | gain[idx_3] = -13 | -
| - | - | -
| - | return gain | -
| - | - | -
| - | def calculate_gain_less(self, phi: float) -> np.array: | -
| - | """ | -
| - | For frequencies in the range 1 GHz to about 70 GHz, in cases where the | -
| - | ratio between the antenna diameter and the wavelength is LESS than | -
| - | or equal to 100, this method should be used. | -
| - | - |
| - | Parameter | -
| - | --------- | -
| - | phi : off-axis angle [deg] | -
| - | - |
| - | Returns | -
| - | ------- | -
| - | a numpy array containing the gains in the given angles | -
| - | - |
| - | """ | -
| - | gain = np.zeros(phi.shape) | -
| - | - | -
| - | idx_0 = np.where(phi < self.phi_m)[0] | -
| - | gain[idx_0] = self.peak_gain - 0.0025 * np.power(self.d_lmbda * phi[idx_0], 2) | -
| - | - | -
| - | idx_1 = np.where((self.phi_m <= phi) & (phi < 48))[0] | -
| - | gain[idx_1] = 39 - 5 * math.log10(self.d_lmbda) - 25 * np.log10(phi[idx_1]) | -
| - | - | -
| - | idx_2 = np.where((48 <= phi) & (phi < 180))[0] | -
| - | gain[idx_2] = -3 - 5 * math.log10(self.d_lmbda) | -
| - | - | -
| - | return gain | -
| - | - |
| - | def add_beam(self, phi: float, theta: float): | -
| - | self.beams_list.append((phi, theta)) | -
| - | - |
| - | def calculate_off_axis_angle(self,Az,b): | -
| - | Az0 = self.beams_list[0][0] | -
| - | - | -
| - | a = 90 - self.beams_list[0][1] | -
| - | C = Az0 - Az | -
| - | - | -
| - | off_axis_rad = np.arccos(np.cos(np.radians(a))*np.cos(np.radians(b)) \ | -
| - | + np.sin(np.radians(a))*np.sin(np.radians(b))*np.cos(np.radians(C))) | -
| - | off_axis_deg = np.degrees(off_axis_rad) | -
| - | - |
| - | return off_axis_deg | -
| - | - | -
| - | - |
| - | - | -
| - | if __name__ == '__main__': | -
| - | import matplotlib.pyplot as plt | -
| - | - | -
| - | phi = np.linspace(0.1, 180, num = 100000) | -
| - | theta = 90*np.ones_like(phi) | -
| - | beams_idx = np.zeros_like(phi, dtype=int) | -
| - | - | -
| - | # initialize antenna parameters | -
| - | param = ParametersImt() | -
| - | param.frequency = 10700 | -
| - | param_gt = ParametersAntennaImt() | -
| - | param_gt.peak_gain = 49.8 | -
| - | param_gt.diameter = 3 | -
| - | antenna_gt = AntennaF1245(param,param_gt) | -
| - | antenna_gt.add_beam(0,0) | -
| - | - | -
| - | gain_gt = antenna_gt.calculate_gain(phi_vec = phi, | -
| - | theta_vec = theta, | -
| - | beams_l = beams_idx) | -
| - | - |
| - | param.frequency = 27500 | -
| - | param_lt = ParametersAntennaImt() | -
| - | param_lt.peak_gain = 36.9 | -
| - | param_lt.diameter = 0.3 | -
| - | antenna_lt = AntennaF1245(param,param_lt) | -
| - | antenna_lt.add_beam(0,0) | -
| - | - |
| - | gain_lt = antenna_lt.calculate_gain(phi_vec = phi, | -
| - | theta_vec = theta, | -
| - | beams_l = beams_idx) | -
| - | - | -
| - | fig = plt.figure(figsize=(8,7), facecolor='w', edgecolor='k') # create a figure object | -
| - | - | -
| - | plt.semilogx(phi, gain_gt, "-b", label = "$f = 10.7$ $GHz,$ $D = 3$ $m$") | -
| - | plt.semilogx(phi, gain_lt, "-r", label = "$f = 27.5$ $GHz,$ $D = 0.3$ $m$") | -
| - | - | -
| - | plt.title("ITU-R F.1245 antenna radiation pattern") | -
| - | plt.xlabel("Off-axis angle $\phi$ [deg]") | -
| - | plt.ylabel("Gain relative to $G_m$ [dB]") | -
| - | plt.legend(loc="lower left") | -
| - | plt.xlim((phi[0], phi[-1])) | -
| - | plt.ylim((-20, 50)) | -
| - | - | -
| - | #ax = plt.gca() | -
| - | #ax.set_yticks([-30, -20, -10, 0]) | -
| - | #ax.set_xticks(np.linspace(1, 9, 9).tolist() + np.linspace(10, 100, 10).tolist()) | -
| - | - | -
| - | plt.grid() | -
| - | plt.show() | -
-