# Tag Info

## Hot answers tagged antenna

5

Why do AST's Space Mobile satellites have antennas much larger than Starlink's satellites, whereas they both aim at providing network coverage anywhere on earth? Physics. "ultra-powerful SpaceMobile satellites will provide 2G/3G/4G LTE/5G and NB-IoT connectivity (directly) to standard mobile phones and IoT devices." (sources below) Starlink ...

4

Mars and Earth are the only destinations humanity has sent probes where the following two conditions apply: The destination has an atmosphere where storms can occur The expected mission length is long enough that action to mitigate storm damage might be considered. The primary concern from Martian storms appears to be the degradation of solar panel ...

3

I found a reference on page 1 of this paper: 2010 Ishizawa Paper stating that, "(b) Germanium coated polyimide: After a MIDORI-2 (ADEOS-2) malfunction caused by a discharging event, conductive materials should be used for thermal control of JAXA’s satellites. Germanium (Ge)coated black Kapton XC film (conductive) is selected for substitution of Beta-cloth (...

3

As said above, RapidScat measured wind speed and relative wind direction. Scatterometers relate the reflected power (backscatter coefficient in the picture below) with the relative wind direction with a cosine dependency. This means that there is an ambiguity when resolving the direction, as up to four different directions translate into the same ...

3

Off the top of my head, here are a number of things you would need to address "apart from the electrical specifications". In reality, this is a great case for strong systems engineering in your satellite. Since there will be major tradeoffs between power, pointing, mass, and RF performance/throughput. Materials. This is mostly easy, since by ...

2

Read this book and then learn about link budgets and EM interference. Consider: The band you are transmitting on The type of antenna (your cubesat will likely significantly impact the choices you have here, but there are many types of antenna with many advantages and disadvantages) The output power (if it is an isotropic antenna, this is simpler, but if it ...

1

Your question seems to answer itself in some respects: '...a power transmission of 13.1dBW (20 watts)...' But an antenna doesn't really draw power, it gets fed power (energy) from a source and radiates it into space. I think the question you really are asking is: "How much power will my amplifier need to power my 20 $W_{RF}$ communications system?" ...

1

https://en.wikipedia.org/wiki/Beam_waveguide_antenna The wiki article is short but I think it answers the question. Non-"beam waveguide" antennas don't allow use of different receivers simultaneously. For example DSN 70-meter dishes can't receive Ka-band, but only X-band. They would require long operation of receiver change. Also receivers and ...

1

Here is what I've found after specifically researching a bit about PCB antennas specifically: Temperature Variation: Important to any discussion of small spacecraft structure is the material of the structure itself. Typically a spacecraft’s structure is made up of both metallic and non-metallic materials. Metals are commonly homogeneous and isotropic, ...

1

A real probe would have an emergency mode. If there was no communication at all for a given time interval, the probe would execute its routine for reetablishing communication. There should be a routine for checking antenna status including unfolding it if neccessary. It is a matter of good software design. But unfortunately despite all that carefull planing ...

1

You may be thinking of the Galileo probe. The plan was for the high-gain antenna to stay closed while it did a early Venus flyby, then open up after using Earth for a gravitational assist, but the high-gain antenna failed to open properly. They were able to make use of a low-gain antenna to transmit most of what they wanted back to earth, but it did limit ...

Only top voted, non community-wiki answers of a minimum length are eligible