In order to receive satellite radio, you need a special antenna. Your standard car radio antenna won't cut it because, unlike FM radio and HD radio, satellite radio and FM radio aren't broadcast on the same frequency bands. This is why you don't need a special HD radio antenna to listen to HD radio stations, but you do need a special satellite radio antenna for your satellite radio receiver to work.
Satellite radio, unlike satellite television, doesn't make use of dishes, so you don't need to install a dish on your car. The main reason is bandwidth, but suffice it to say that satellite radio uses small, non-directional antennas that are similar to many satellite phones you may have seen.
Why You Need a Satellite Radio Antenna
Both terrestrial radio and satellite radio use omnidirectional antennas, which can be contrasted with the directional antennas used by satellite television services. However, your existing car antenna that's designed to receive AM and FM signals isn't capable of receiving satellite radio transmissions.
The issue is that the FM broadcast band occupies part of the very high frequency (VHF) radio spectrum, the AM band utilizes part of the medium frequency (MF) band, and satellite radio occupies the S-band.Grant Faint/Digital Vision/Getty Images
Although there are slight variations between different countries and regions, the North American bands are:AM radio: 535 kHz to 1705 kHzFM radio: 87.9 to 107.9 MHzSatellite radio: 2.31 to 2.36 GHz
The other reason that you can't receive satellite radio over a traditional car radio antenna is that the connectors are different. Even if you wanted to plug a regular antenna into a satellite receiver, you wouldn't be able to. Regular car radio antennas use Motorolla plugs, also referred to as DIN 41585, while Satellite radio antennas use SMB connectors.
Since satellite radio receivers use a special type of connector, it's important to buy an antenna that's specifically designed for satellite radio. Even then, some satellite radio antennas require an adapter.
Why Satellite Radio Doesn't Use Dishes
First of all, it's important to understand that a satellite dish is actually just a specialized type of antenna. They're referred to as directional antennas because they are designed to receive signals in a cone that projects outward from the edges of the dish, which is why you have to aim a satellite dish at a particular portion of the sky for it to work.
The main benefit of a directional antenna is that it's capable of receiving a greater amount of information from a weaker signal than an omnidirectional antenna would be able to. In that same vein, directional antennas can actually be used to receive weak television and radio signals in remote areas, distant Wi-Fi signals, and other types of weak or distant signals.
As to why satellite radio uses omnidirectional antennas and satellite television uses dishes, it really comes down to the amount of information that has to be transmitted for the different services.
The fact is that audio transmissions take up less bandwidth than television transmissions that include both an audio and video component. So while satellite television providers could have used omnidirectional antennas, they wouldn't have been able to offer very many channels.
With lower bandwidth requirements, satellite radio was free to rely on omnidirectional antennas that are much easier to use in mobile applications like cars.
Installing a Satellite Radio Antenna
Since satellite radio antennas are omnidirectional, you don't have to worry about pointing them in any particular direction. However, it is important to position a satellite radio antenna so that it has an unimpeded view of the sky, and it just as vital to choose a location where it won't receive any sort of interference.
If you drive a vehicle with a hard top, then the antenna should be installed:Near the front or rear of the roof.Three inches or more from the edge of the roof.Three inches or more away from other antennas.Somewhere that a roof rack (or another similar accessory) won't block the sky.
If you drive a convertible, you obviously can't mount a satellite antenna to the roof. In that case, you'll want to install it:On the trunk near the base of the windshield.On the hood near the back edge.Three inches or more from the edge of the hood or trunk.
Places to Avoid When Installing a Satellite Antenna
If you're still having trouble figuring out where to put your satellite antenna, just make sure to avoid these locations:Inside the vehicle: Placing a satellite antenna inside your vehicle makes it more difficult to receive satellite signals. Even if it's near a window, your reception will suffer and may not work at all.Close to metal objects: Always keep your antenna more than three inches from antennas, roof racks, and other accessories. Placing it near these objects may subject it to interference.On an a, b, or c pillar: These are the pillars that separate your windshield from your front windows, your front windows from your back windows, and your back windows from your rear windows. You need to place the antenna on a horizontal surface to orient it correctly to the sky, so these pillars are off limits.