According to [1, p.88-96] additional losses include:
Depends on characteristics of the certain antenna:
$$ L_b = 10log_{10}(1+ (2\theta/\theta_{0.5})^2) \qquad (1.7) $$where $ \theta$ is the beamwidth and $\theta_{0.5}$ is the halfpowered beamwidth (fig. 1.2.1).
Fig. 1.2.1. Antenna gain pattern [2]
According to [2] total antenna losses for large cassegrain antennas are equal to 1.65 dB.
Influence data rate, due to receiver bandwidth should be desirably selected according to table 1.2.1 [1, p. 91] to avoid phase distortions.
Table 1.2.1. Maximum receiver bandwidths for different ranges.
Carrier frequency, GHz | 0.5 | 1 | 5 | 10 |
---|---|---|---|---|
Receiver bandwidth (B), MHz | 10 | 25 | 270 | 750 |
Additionaly, to avoid Faradey effect for ranges less than 10 GHz only circular polarization should be used [1, p. 91].
Can be estimated by figure 1.2.2 ($e_1$ and $e_2$ are coefficients of elipticity).
Fig. 1.2.2. Dependence of losses due to inconsistency of the polarizations of the transmitting and receiving antennas from the polarity elepticity. [1, p. 93]
In general, this parameter is kind of reference data, e.g. in the link budget calculation for NanoCom AX100 polarization losses are equal to 3 dB (and athmospheric losses are 2.1 dB, ionospheric losses are 0.4 dB).
Can be evaluated by [3]. Fortunately, for ranges smaller than 10 GHz the losses are smaller than 1 dB (fig. 1.2.3 and 1.2.4).
Fig. 1.2.3. Specific attenuation due to atmospheric gases, calculated at 1 GHz intervals, including line centres [10].
Fig. 1.2.4. Zenith attenuation due to atmospheric gases, calculated at 1 GHz intervals, including line centres [3].
[1] L. Kantor, Satellite communication and broadcasting. Directory,Radio and communication,1988,
[2] Antennas - An Overview (date of the application is 09.07.2018)
[3] Attenuation by atmospheric gases, ITU 2016 (date of the application is 27.06.2017)