A 2.4GHz antenna is a device that receives or transmits radio frequency at 2.4GHz.

Wi-Fi technology typically uses two frequency bands the 2.4GHz and the 5.7 - 5.8GHz band. 2.4GHz is an older protocol that is an unregulated frequency.

Advantages and Disadvantages of 2.4 GHz versus 5.7 - 5.8GHz band

Note: In this article, we will sometimes refer to 5.7-5.8GHz band as 5GHz band).

When it comes to wireless networks, higher frequency bands will have shorter ranges while lower frequency signals will have longer ranges (if not considering signal-interference (also called "channel noise"), which is more likely to be an issue with 2.4GHz than with the 5.7-5.8 GHz band). As such, the 2.4GHz frequency provides better range than the 5.7-5.8 GHz band, and it passes through obstructions better. 5GHz is a higher frequency and thus provides faster speeds, and is less susceptible to channel noise, but does not penetrate obstacles very well.

The 2.4 GHz band is used not only by WiFi but also Bluetooth, and tends to have more wireless network devices crowding the channels. In spite of all this noise and traffic, 2.4GHz tends to be the better option for range in a network for home or a small business.

The general rule of thumb when you are doing home networking is that WiFi routers on the 2400 MHz have a range of about 300 feet outdoors and 150 feet indoors. Conventional 5GHz frequencies could only have a range of about one third those of the 2.4GHz frequencies. Obstructions such as metal frames, sidings, and brick walls reduce the range of the signal by as much as 25%.

Many Wireless Applications and Household Items use 2.4GHz frequency Band

These include Internet of Things (IoT) devices, Bluetooth, Phones, Wi-Fi, Car alarms, Microwave ovens, and video devices. Of course, all of this usage creates "noise" on the 2.4GHz that can impair range and performance.

1. Bluetooth – Used to be limited to special use equipment but is now used in all manner of devices from trackballs, trackpads, wireless mice and keyboards and wearables.
2. Phones – Many cordless phones and other household wireless items such as baby items use the 2.4GHz frequency.
3. Wi-Fi – Application that use Wi-Fi technologies on the 2.4GHz include modern printers, cars, digital audio players, smart TVs, tablets, smartphones, video game consoles, laptops, and desktops.
4. Car Alarm – Most vehicle manufacturers make their car alarms on the 2.4GHz wireless frequency.
5. Video Devices – Video senders are designed to use an FM carrier on the 2.4GHz frequency to carry signals from closed circuit television and satellite TV from room to room. Amateur Radio operators are also allowed to transmit signals on the 2.4GHz band.