Any antenna’s apparent signal increase is a redistribution of the available Radio Frequency (RF) signal in the desired direction rather than an increase in signal strength. In other words, antennas don’t produce radio energy; instead, they focus, concentrate, or redirect it in a specific direction.
Gain, expressed in dB, is the term for the signal’s enhancement when an antenna is used. An isotropic radiator (an idealized model with the same value when measured in different directions) at radio frequencies serves as the foundation for dBi measurements. The stronger signal is obtained at the expense of the majority of other directions since no new RF signal is created.
Some individuals believe that a higher gain antenna will provide them with the best connection and the strongest signal. This is sometimes the case, but in other instances, an excessive benefit might be detrimental. In actuality, your application will determine whether you want a larger or lower gain antenna.
What kind of gain and antenna do I need?
The high-gain antenna is unquestionably the most acceptable option if you want to concentrate all of the signals and direct it toward a distant target. As seen below, high-gain antennas must be aimed in the desired direction when transmitting an RF signal so that a weak signal may be amplified at the desired place.
However, you do not want significant gain (or its directivity) if you wish to broadcast equally across a whole room (or allow Omnidirectional access to your wireless signal). Keep in mind that “gain” is nothing more than the theft of radiated energy from some directions to amplify others. The signal intensity will go farther but in a tighter direction, as seen in the picture below. The higher dBi value of the antenna, the greater the gain, but the less broad the field pattern.
Example of an Antenna Application
MIMO vs. single
An antenna with a single output was enough during the 3G era. Today, with widespread 4G coverage, you need to make sure the antenna you purchase is MIMO (Multi-Input, Multi-Output) capable. The fact that almost all antennas on sale in 2019 are MIMO reflects this.
- Power Type
SMA or TS9 ports are used by the majority of 4G routers, with SMA perhaps being more prevalent. Just verify the ports your router has before making a purchase.
Most routers, as was already noted, employ SMA connections. There are SMA to TS9 converters available, so don’t worry if you find an antenna you like the look of, but it has a different kind of connection than your router.
