tidy3d.rf.DirectivityData

tidy3d.rf.DirectivityData#

class DirectivityData[source]#

Bases: FieldProjectionAngleData

Data associated with a DirectivityMonitor.

Parameters:

Example

>>> from tidy3d import FluxDataArray, FieldProjectionAngleDataArray
>>> f = np.linspace(1e14, 2e14, 10)
>>> r = np.atleast_1d(1e6)
>>> theta = np.linspace(0, np.pi, 10)
>>> phi = np.linspace(0, 2*np.pi, 20)
>>> coords = dict(r=r, theta=theta, phi=phi, f=f)
>>> coords_flux = dict(f=f)
>>> values = (1+1j) * np.random.random((len(r), len(theta), len(phi), len(f)))
>>> flux_data = FluxDataArray(np.random.random(len(f)), coords=coords_flux)
>>> scalar_field = FieldProjectionAngleDataArray(values, coords=coords)
>>> monitor = DirectivityMonitor(center=(1,2,3), size=(2,2,2), freqs=f, name='n2f_monitor', phi=phi, theta=theta)
>>> data = DirectivityData(monitor=monitor, flux=flux_data, Er=scalar_field, Etheta=scalar_field, Ephi=scalar_field,
...     Hr=scalar_field, Htheta=scalar_field, Hphi=scalar_field, projection_surfaces=monitor.projection_surfaces)

Attributes

axial_ratio

Axial Ratio (AR) in the frequency domain as a function of angles theta and phi.

directivity

Directivity in the frequency domain as a function of angles theta and phi.

fields_circular_polarization

Electric and magnetic fields in the circular polarization basis.

left_polarization

Electric far field for left-hand circular polarization (counterclockwise component) with an angle-based projection grid.

radiated_power

Total radiated power in the frequency domain with units of Watts.

radiation_intensity

Radiation intensity in the frequency domain as a function of angles theta and phi.

right_polarization

Electric far field for right-hand circular polarization (clockwise component) with an angle-based projection grid.

monitor

flux

projection_surfaces

Er

Etheta

Ephi

Hr

Htheta

Hphi

medium

is_2d_simulation

Methods

calc_gain(power_in)

The gain figure of merit for antennas.

calc_partial_gain(power_in[, pol_basis, ...])

The partial gain figures of merit for antennas.

calc_radiation_efficiency(power_in)

Calculate radiation efficiency as the ratio of radiated power to input power.

fields_linear_polarization_tilted(tilt_angle)

Electric and magnetic fields in the linear polarization basis that is rotated at the pole of the radiation sphere by tilt_angle.

from_spherical_field_dataset(monitor, ...)

Creates a DirectivityData instance from a spherical field dataset.

normalize(source_spectrum_fn)

Return a copy of self after normalization is applied using the source spectrum function, for both field components and flux data.

partial_directivity([pol_basis, tilt_angle])

Directivity in the frequency domain as a function of angles theta and phi.

partial_radiation_intensity([pol_basis, ...])

Partial radiation intensity in the frequency domain as a function of angles theta and phi.
monitor#
flux#
static from_spherical_field_dataset(monitor, field_dataset)[source]#

Creates a DirectivityData instance from a spherical field dataset.

Parameters:

  • monitor (DirectivityMonitor) – Monitor defining measurement parameters.

  • field_dataset (xr.Dataset) – Dataset containing spherical field components (Er, Etheta, etc.). Must sample the entire spherical surface to compute flux correctly.

Returns:

New DirectivityData instance with computed flux from spherical field integration.

Return type:

DirectivityData

normalize(source_spectrum_fn)[source]#

Return a copy of self after normalization is applied using the source spectrum function, for both field components and flux data.

partial_radiation_intensity(pol_basis='linear', tilt_angle=None)[source]#

Partial radiation intensity in the frequency domain as a function of angles theta and phi. The partial radiation intensities are computed in the linear or circular polarization bases. If tilt_angle is not None, the radiation intensity is computed in the linear polarization basis rotated by tilt_angle from the theta-axis. Radiation intensity is measured in units of Watts per unit solid angle.

Parameters:

  • pol_basis (PolarizationBasis) – The desired polarization basis used to express partial radiation intensity, either linear or circular.

  • tilt_angle (float) – The angle by which the co-polar vector is rotated from the theta-axis. At tilt_angle = 0, the co-polar vector coincides with the theta-axis and the cross-polar vector coincides with the phi-axis; while at tilt_angle = pi/2, the co-polar vector coincides with the phi-axis.

Returns:

Dataset containing the partial radiation intensities split into the two polarization states.

Return type:

xarray.Dataset

property radiation_intensity#

Radiation intensity in the frequency domain as a function of angles theta and phi. Radiation intensity is measured in units of Watts per unit solid angle.

property radiated_power#

Total radiated power in the frequency domain with units of Watts.

partial_directivity(pol_basis='linear', tilt_angle=None)[source]#

Directivity in the frequency domain as a function of angles theta and phi. The partial directivities are computed in the linear or circular polarization bases. If tilt_angle is not None, the radiation intensity is computed in the linear polarization basis rotated by tilt_angle from the theta-axis. Directivity is a dimensionless quantity defined as the ratio of the radiation intensity in a given direction to the average radiation intensity over all directions.

Parameters:

  • pol_basis (PolarizationBasis) – The desired polarization basis used to express partial directivity, either linear or circular.

  • tilt_angle (float) – The angle by which the co-polar vector is rotated from the theta-axis. At tilt_angle = 0, the co-polar vector coincides with the theta-axis and the cross-polar vector coincides with the phi-axis; while at tilt_angle = pi/2, the co-polar vector coincides with the phi-axis.

Returns:

Dataset containing the partial directivities split into the two polarization states.

Return type:

xarray.Dataset

property directivity#

Directivity in the frequency domain as a function of angles theta and phi. Directivity is a dimensionless quantity defined as the ratio of the radiation intensity in a given direction to the average radiation intensity over all directions.

calc_radiation_efficiency(power_in)[source]#

Calculate radiation efficiency as the ratio of radiated power to input power.

Parameters:

power_in (FreqDataArray) – Power supplied to the radiating element in the frequency domain, in units of Watts.

Returns:

Radiation efficiency (dimensionless) in the frequency domain, computed as radiated_power / power_in.

Return type:

FreqDataArray

calc_partial_gain(power_in, pol_basis='linear', tilt_angle=None)[source]#

The partial gain figures of merit for antennas. The partial gains are computed in the linear or circular polarization bases. If tilt_angle is not None, the partial directivity is computed in the linear polarization basis rotated by tilt_angle from the theta-axis. Gain is dimensionless.

Parameters:

  • power_in (FreqDataArray) – Power, in units of Watts, supplied to the radiating element in the frequency domain.

  • pol_basis (PolarizationBasis) – The desired polarization basis used to express partial gain, either linear or circular.

  • tilt_angle (float) – The angle by which the co-polar vector is rotated from the theta-axis. At tilt_angle = 0, the co-polar vector coincides with the theta-axis and the cross-polar vector coincides with the phi-axis; while at tilt_angle = pi/2, the co-polar vector coincides with the phi-axis.

Returns:

Dataset containing the partial gains split into the two polarization states.

Return type:

xarray.Dataset

calc_gain(power_in)[source]#

The gain figure of merit for antennas. Gain is dimensionless.

Parameters:

power_in (FreqDataArray) – Power, in units of Watts, supplied to the radiating element in the frequency domain.

property axial_ratio#

Axial Ratio (AR) in the frequency domain as a function of angles theta and phi. AR is a dimensionless quantity defined as the ratio of the major axis to the minor axis of the polarization ellipse.

Note

The axial ratio computation is based on:

Balanis, Constantine A., “Antenna Theory: Analysis and Design,” John Wiley & Sons, Chapter 2.12 (2016).

property left_polarization#

Electric far field for left-hand circular polarization (counterclockwise component) with an angle-based projection grid.

property right_polarization#

Electric far field for right-hand circular polarization (clockwise component) with an angle-based projection grid.

fields_linear_polarization_tilted(tilt_angle)[source]#

Electric and magnetic fields in the linear polarization basis that is rotated at the pole of the radiation sphere by tilt_angle.

Parameters:

tilt_angle (float) – The angle by which the co-polar vector is rotated from the theta-axis. At tilt_angle = 0, the co-polar vector coincides with the theta-axis and the cross-polar vector coincides with the phi-axis; while at tilt_angle = pi/2, the co-polar vector coincides with the phi-axis.

Returns:

Dataset containing (Eco, Ecross, Hco, Hcross)

Return type:

xarray.Dataset

property fields_circular_polarization#

Electric and magnetic fields in the circular polarization basis.

Note

Uses IEEE handedness convention for polarization state, which means right-handed circularly polarization is associated with a clockwise rotation of the electric field vector from the point of the view of the source. However, we use the physics convention for time evolution of time-harmonic fields, which modifies the computation when compared to engineering references.

Returns:

xarray dataset containing (Eleft, Eright, Hleft, Hright) in Spherical coordinates.

Return type:

xarray.Dataset