Wi-Fi is the wireless communication technique which is most widely used at present. Along with the evolution of the technique, it has come into the sixth generation with increasingly faster transmission speed. However, the problem of signal interference still has a strong impact on transmission efficiency. This will introduce the latest development of Wi-Fi technique and 5GHz noise filters launched by Murata.
Eliminate noise interference in 5GHz frequency band Endow Wi-Fi with more stable transmission speed
IEEE 802.11, the first version of Wi-Fi, was published in 1997, in which Media Access Control and the physical layer were defined. The physical layer defined two wireless frequency modulation modes and one infrared ray transmission mode of 2.4GHz in ISM frequency band, of which the total data transmission speed was designed as 2Mbit/s. Along with the revolution of the technique, the second generation named 802.11b improved the transmission speed to 11Mbit/s while the third generation named 802.11g/a added 5GHz frequency band which improved the maximum transmission speed to 54Mbit/s. The fourth generation named 802.11n (Wi-Fi 4) could use 2.4GHz or 5GHz, of which the maximum transmission speed was separately 72 and 150Mbit/s in 20 and 40MHz channels. The fifth generation named 802.11ac (Wi-Fi 5) could use 2.4GHz or 5GHz with the maximum transmission speed of 866.7Mbit/s. The latest sixth generation named 802.11ax (Wi-Fi 6) could use 2.4GHz or 5GHz (6GHz may also be absorbed in the future) with the maximum transmission speed of 1000Mbit/s.
Undated Wi-Fi standards indicate faster data transmission speed. Compared with Wi-Fi 5, the maximum transmission speed of the latest Wi-Fi 6 standard has improved for 40%. Meanwhile, Wi-Fi 6 improves transmission quantity via more effective data coding technique as well as the speed of 5GHz and 2.4GHz, making it the best Wi-Fi standard at present.
The earlier Wi-Fi signals commonly adopted 2.4GHz frequency band. However, many electronic devices also commonly adopted the wireless frequency of 2.4GHz, such as microwave ovens and Bluetooth devices etc., which would interfere with the Wi-Fi in 2.4GHz band and influence the signal to some extent. The transmission speed was thus reduced, leading to the result that video and audio might by out-of-step during streaming video transmission or longer time might be needed to display the webpage etc. In order to solve this problem, the third generation launched a Wi-Fi standard with 5GHz frequency band because there were only 3 non-interfering frequency band resources in 2.4GHz while there were 22 in 5GHz. Thus, it was obviously less easier for 5GHz to have the problem of channel jam, which had higher transmission speed.
Although 5GHz has obvious advantages in the aspect of transmission speed, its Wi-Fi also has a disadvantage that the diffraction and reflection of its signal are not as strong as that of 2.4GHZ Wi-Fi. Due to the reason that the diffraction and reflection ability of 2.4GHz low-frequency signals are better than that of high-frequency 5GHz signals, 2.4GHz Wi-Fi has more outstanding performance in the aspects of wall penetration and signal coverage. In other words, the transmission distance of 2.4GHz Wi-Fi is relatively far, which leads to less signal attenuation and lower transmission speed. Relatively speaking, the transmission distance of 5GHz Wi-Fi is fairly short, leading to obvious signal attenuation and higher transmission speed.
The characteristic of using Wi-Fi in 5GHz frequency band is to conduct high speed communication. However, when the device itself has noise in this band, interference will appear between the Wi-Fi and receiving radio wave, leading to the reduction of data handling capacity and transmission speed. Therefore, if the noise in 5GHz frequency band that interfering Wi-Fi communication can be eliminated, it will contribute to the improvement of data handling capacity and data transmission speed.
In order to solve the noise problem in Wi-Fi 5GHz frequency band, Murata specially develops the “BLF03VK series” compact noise filters, specially used for reducing the noise in 5GHz frequency band among kinds of Wi-Fi communication frequency. The noise filters include two products that are 5GHz frequency with the impedance of 220 ohms and the rated current of 0.8A as well as 5GHz frequency with the impedance of 60 ohms and the rated current of 1.2A. They can be used to control impedance frequency characteristics in order to maximize the effect of noise countermeasure in 5GHz frequency band. The compact size is only 0.6 * 0.3mm.
Murata has locked the target frequency band and guaranteed the commercialization of the resistant noise filters in this band, including “BLF02RD_GN series” coping with 2.4GHz frequency band as well as “BLF03JD_GN series” and “BLF02GD_GN series” coping with 700MHz frequency band. On this occasion, the commercialization of “BLF03VK series” products, noise filters coping with 5GHz frequency band, will further improve the communication sensitivity of smart phones and things like that in Wi-Fi connection environment.
More and more devices will use wireless communication simultaneously, making the noise suppression of power circuits seem to be more important because noise leakage will influence other circuits. The receiving sensitivity of 5G/Wi-Fi can be improved through using BLF03VK as the power circuit and the PA peripheral circuit supplied to RF circuits.
BLF series is designed to almost serve as a resistor in noise frequency, which greatly reduces the possibility of resonance and prevents the signal waveform from distortion. It can be operated effectively in the circuit without stable ground lines because it does not need ground connection and the nickel barrier structure of the external electrode has excellent solder heat resistance. BLF03VK series has high impedance specification in the high frequency range of 5GHz, which can be used for noise immunity measurement up to 5GHz. “BLF03VK”, the noise filter in 5GHz frequency band provided by Murata, has outstanding performance, which will be your best solution for solving 5GHz noise problems.
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