STK Antenna Models

Gaussian Optical Antenna Pattern

The Gaussian Optical Antenna Model uses an analytical model of a Gaussian beam. The model is like a parabolic antenna within about -6 dB relative to the boresight. This antenna is specific to a Laser transmitter or receiver.

This antenna uses a polar coordinate system.

Field Description
Design Frequency

This is the frequency of the antenna. The antenna design frequency is independent of the operational frequency of a transmitter, receiver, or radar. Changing the frequency of a transmitter, receiver, or radar does not update an embedded antenna's design frequency, nor vice versa. The design frequency is solely used at antenna configuration time to compute the antenna size from its max gain or beamwidth settings. A mismatch between signal frequency and antenna design frequency typically causes performance degradation.

Gain The maximum gain of the antenna. This value is valid if Compute Gain is not selected.
Area The area of the main light-focusing optical aperture, measured in m2. Valid if Compute Gain is selected.
Efficiency A measure of the light transmittance through the optical path, ranging from 0 (no light transmitted) to 100 percent (no attenuation, that is, all light transmitted).

The gain value is queried first. If it is specified as zero, the gain is computed from:

Gxmtr = (4A/2)

where A = optics aperture area, = laser wavelength = c/f, and = optics efficiency.

Lambert, S.G., Laser Communication in Space, equation 3.88.

Valid if Compute Gain is selected.

Computed Gain Computed from the Design Frequency, Area, and Efficiency values. It overrides the Gain value if Compute Gain is selected.