GPS modules with Active Antenna and without Active Antenna


After so much research, I've found out that GPS modules have so many factors that depend their performance on.

But I was initially under the impression that GPS devices with active antennas are always much better at receiving in harsh environments. But there are some companies that do not make GPS devices to support active antennas yet! have sensitivity levels higher than the ones with Active Antennas.

I'm truly confused.

Here is one such GPS receiver that has the highest sensitivity i've seen so far.

Its data sheet:

My SIM908 even with an Active Antenna has lower acquisition sensitivity than this one does with only passive Antenna! Even the UBlox and my other Linx GPS module has far less efficiency than this.

Is it that these people have put so much effort and this device is actually better than any of those I mentioned later? I meant better in the sense of obtaining faster fix times. I mean the same throughout.

Does this mean I can dump all these active antenna devices and start using this passive Antenna device (linked above & which I would love to do!) and expect higher performance? it even has inbuilt jamming protection and many other important features including A-GPS, online ephemeris download, client generated ephemeris down etc.

If you can shed some light, it would be so much helpful.

Best Answer

Generally, "support for active antenna" means that the receiver can supply DC power (typically 3.3V or 5.0V, current-limited to about 30 mA) up the antenna cable. With a highly-integrated module like this, that support is generally done on the PCB that it's mounted on, rather than inside the module itself.

While this module may work perfectly well with passive antennas (especially if the connection is short), active antennas will pretty much always give you a slightly better noise figure.