Why is the antenna of the intercom not inside the fuselage?
The birth of the walkie-talkie is almost a hundred years old, half a century earlier than the time when the mobile phone was invented. But since the last century, the mobile phone has evolved from the previous "Big Brother" to today's smartphone, and the intercom is still the same old and stupid old, the antenna is still external.
So is the external antenna of the walkie-talkie because of the technical bottleneck or is it intentionally caused?
First of all, the walkie-talkie is a kind of radio communication equipment, and the radio on which this equipment communicates has an important indicator called "working frequency", and the working frequency of domestic mobile phones has a national standard.
Mobile phones generally communicate on two frequencies, 900MHz and 1800MHz, and the state stipulates that the operating frequency of public walkie-talkies (that is, civil walkie-talkies) is between 409 and 410MHz.
In order to be able to transmit radio signals with as much energy as possible, the antenna needs to be designed at half the wavelength.
The wavelength is equal to the speed of light divided by the frequency. The higher the frequency, the longer the wavelength. In other words, the wavelength of the mobile phone is more than half smaller than the intercom. However, when designing an antenna, it is not possible to design the antenna to be as long as the wavelength, but it must be as long as possible.
Of course, mobile phone design cannot simply pursue signal priority. After all, the current mobile phone is a necessity.
The iPhone 4 began to make the appearance of the mobile phone beautiful, so many mobile phone manufacturers will put the mobile phone antenna into the body or integrate it with the outer case, which can more please consumers. After all, humans are visual animals, and good-looking things can naturally sell better.
In the early days of Big Brother ’s era, antennas were external, on the one hand, because the priority of mobile phone design was not as high as it is now, on the other hand, the signal coverage of mobile phones at that time was not as good as it is now.
The working frequency of the wireless signal used in the mobile cellular network is not as high as it is now, so that the signal boost brought by the larger antenna is obvious, so the mobile phone antenna in the era of the big brother is external, or even retractable.
The antenna design requirements of the walkie-talkie are similar to those of the older Brother University. Since the use scenario of the walkie-talkie does not have any high requirements on the appearance of the walkie-talkie, the priority of the appearance design is lower than the priority of the antenna design.
Moreover, the working frequency of the intercom is much lower than that of the mobile phone, and a larger and longer antenna is needed to make the signal better transmitted.
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