Efficiency of Patch Antennas

[ab5r]

I appreciate the response from many (too numerous to list) of the "experienced" people on this thread, and submit the following question.

There has been a discussion on AMSAT-BB threads regarding the OUTERNET (www.outernet.is) and the gear needed for access. One of which is a patch antenna. I am not blessed with knowledge about patch antennas or microwave, in general.

I was just wondering about the efficiency of a patch antenna vs. other types.

Thanks for enlightening me.

Regards,
Jerry

 

[Rred]

Don't know the db factors, but in handheld GPSes and cell phones? External whips, quadrifilars, whatever else was available always outperformed a patch. Patches were used when you needed an antenna that was "built in", slim, couldn't trip or impale anyone, wouldn't break off. You can get "adequate" gain from an design, one way or another, but patches were always chosen for convenience. No one wants a whip antenna or even a rubber duck stub on their cell phone anymore, do they? So, they complain about dropped calls on their slim pretty patches.

 

[ab5r]

Thank you Rred. GOOD response.

However, I am primarily interested in space and INMARSAT, specifically.

 

[PACNWDude]

For INMARSAT and other satcom systems patch antennas allowed the units to be packaged into a suitcase or small box. The patch either embedded into the case lid like the Mitsubishi units, or multiple panels like the Thrane units. Larger panels meant higher gain and better signal at the edge of the satellite transponder footprint.

Not needing an umbrella looking dish or a long "Christmas tree" antenna like Trivec units meant these could be placed on a window sill or balcony for use. However, patch antennas often do not work as well as a larger dish or antenna with directing elements. For monitoring INMARSAT, I use a Trivec AV-2011 antenna. This is over six feet long and resides in the back yard. It takes up space, and is a large aluminum anodized antenna that would not work well in a portable setting.

 

[prcguy]

The AV-2011 is a UHF 240-318Mhz antenna and INMARSAT is L-band. How does that work?
prcguy

For INMARSAT and other satcom systems patch antennas allowed the units to be packaged into a suitcase or small box. The patch either embedded into the case lid like the Mitsubishi units, or multiple panels like the Thrane units. Larger panels meant higher gain and better signal at the edge of the satellite transponder footprint.

Not needing an umbrella looking dish or a long "Christmas tree" antenna like Trivec units meant these could be placed on a window sill or balcony for use. However, patch antennas often do not work as well as a larger dish or antenna with directing elements. For monitoring INMARSAT, I use a Trivec AV-2011 antenna. This is over six feet long and resides in the back yard. It takes up space, and is a large aluminum anodized antenna that would not work well in a portable setting.

 

[Flatliner]

A patch antenna is a great solution to a problem, but it's not a great antenna.