China Telecom said to install a 4g signal amplifier on the wall of my store. Will there be any radiation from installing these?

In densely populated cities, weak signals are prone to occur. In order to alleviate this phenomenon, many people have installed signal amplifiers, and many people live in large areas, so general low-power signal amplifiers If it cannot meet people's needs, it will be replaced by a high-power signal amplifier. Many people have doubts. Will high-power signal amplifiers also have strong radiation?

Of course there is radiation, but generally speaking, the stronger the signal, the greater the radiation, so why use a booster? If you want to use a booster device, it is best to place it away from the room. The farther away you are, the less radiation you'll get to the human body.

Code Division Multiple Access technology only widens the communication frequency band, but the total power within the frequency band remains the same. Confidentiality is based on spreading codes. The pseudo code generator of the CDMA technology standard has 4 trillion combinations, but in fact only 128 sets of spreading codes are used. You can think about confidentiality yourself. GSM is a combination of technologies, not a single technology. The smart antenna technology used in 4G can reduce radiation to people to a certain extent. The most critical thing is the habit of using mobile phones, because the transmission power control of mobile phones is determined based on the field strength information fed back by the base station. If the base station is near you and you are not in a blocked location, the mobile phone's transmit power is usually only 0.05w. If there is obstruction, the signal-to-noise ratio received by the base station is very poor, and your mobile phone will transmit at full power. Usually it can reach 1-1.5w; eating grains can cause all kinds of diseases. Don’t worry about whether these are available or not. The effective radio frequency power of a microwave oven is at least 500w. Is there anyone who hasn’t used it? Radiation protection is a joke to me, as people themselves are radiators.

When the output impedance is 50 ohms and the load impedance is terminated at 50 ohms, to obtain an amplitude of 10VP-P, the output amplifier must have an output amplitude of 20VP-P. If it is low-frequency amplification, a voltage booster can be added to the OP amplifier to meet the requirements. If it is a broadband amplifier, it must have fast switching and large output current. This circuit uses a composite amplifier, which requires fast switching and large output current. This circuit uses a composite amplifier method. The main amplifier mainly considers the high-frequency characteristics, and the OP amplifier is used to improve the DC characteristics, so that the two characteristics can coexist. The circuit frequency band is DC~20MHZ. It can be used as a function generator output circuit or pulse output amplifier.

The entire circuit is an inverting amplifier. The AC voltage at the summing point is amplified by the AC broadband amplifier through C2. The lowest frequency of the signal amplified by the AC amplifier should be the frequency that the DC OP amplifier cannot respond to. DC and very low frequency signals are invertedly amplified by the DC OP amplifier and sent to the non-phase end of the AC amplifier. The overall frequency characteristic is the composite signal of these two amplifications fed back by resistor R2.

The main amplifier circuit has differential input terminals, and the output of the OP amplifier is input to the non-inverting input terminal. The amplification factor fed back from the output terminal to the summing point is A=-R2/R1. The main amplifier circuit is a full-stage symmetrical push-pull circuit. If DC drift like the OP amplifier is not required, a single tube can also be used in the main amplifier circuit. The focus of setting operating points at all levels is to ensure bandwidth. For example, the collector resistors of TT1 and TT2 use low resistance values. The output amplitudes of TT3 and TT4 are the same. The collector current is increased to increase the conversion speed instead of using the collector-base resistor. Inter-pole phase compensation method.

In order to adjust the performance of this circuit to the best state, it must be equipped with a signal generator or pulse generator with a frequency of up to 30MHZ. Connect a 50 ohm terminal resistor to the input end and add a phase compensation circuit to ensure flat frequency characteristics. The bias adjustment of the output stage is also related to the circuit characteristics, and R15 must be adjusted as needed. In fact, all items with radiation above 0 degrees are radiated, so it is impossible to be 100% radiation-free. If you want to reduce the radiation, you can stay a little farther away, or it will be much better to isolate them.