The mobile communication base station antenna and the mobile phone users to use the radio base station apparatus connected to the information (downlink transmitter) into (up, receive) port is an electromagnetic wave energy converter contains a variety of information. 4g cell phone jammer
When the base station transmitting RF energy modulated by the current base station antenna is converted to electromagnetic energy, and to a certain intensity to a predetermined area (cell phone) is radiated; electromagnetic energy of mobile phone users through the modulated information received by the base station antenna, effectively RF energy is converted to electric current, is transmitted to the master device. Air is the first base station antenna the electromagnetic wave transmission gate, it is good or bad performance, seriously affect the quality of mobile communication.
4g cell phone jammer Since the antenna is open distributed parameter circuit, a "sports electromagnetic field" category, while the lumped parameter circuit components (resistors, inductors, capacitors, wires, etc.), a "circuit" category. EMF invisible, intangible, seemingly simple, but much of its theoretical calculation and testing means more complex than circuit. This antenna features a professional, and the particular requirements of mobile communications coverage, the mobile communication base station antenna having a high-tech features.
Additionally, outdoor base station antenna height harsh environment, its reliability has put forward higher requirements. Tech plus high reliability requirements, the higher the threshold of entering the base station antenna manufacturing, there is no strong technical strength and financial strength, it is very difficult to enter.
Principles of communication antenna
As an important part of the communications antenna wireless communications indispensable, and its basic function is to transmit and receive radio waves auxiliary. When transmitting, high frequency current is converted to electromagnetic waves: when receiving the electromagnetic wave is converted to a high-frequency current.
Type of communication of the antenna
Use can be divided into the base station antenna (base station antenna) and mobile antenna (mobile and portable antennas); according to the working frequency band can be divided into long wave, long wave, medium wave, shortwave, FM and microwave antenna; their directionality can be divided for omni-directional and directional antennas; their structural properties can be divided into wire antennas and antenna.
How to choose the communication antenna 4g cell phone jammer
Antenna as an important part of the communication system, its performance directly affects the quality of communication, the user must first pay attention to the choice of antenna performance. Specifically, there are two aspects, first select the type of antenna; electrical performance of the second selection of the antenna. Select the antenna type of meaning is: the direction of the selected antenna diagram meets the system requirements for the design of radio coverage; select antenna electrical properties of meaning is: choose to use the antenna frequency, bandwidth, gain, rated power and other electrical indicator system design meets Claim. Therefore, users in the choice of antenna is best advice to contact the manufacturer.
Communication antennas basic performance indicators
Antenna gain
Is one of the main indicators of the antenna gain, which is the product of the directivity and efficiency, is the size of the antenna to radiate or receive radio performance. Gain selection depends on the size of the system design requirements for radio coverage area, simply put, under the same conditions, the higher the gain, the more distant radio wave propagation distance. General base station antennas with high gain antenna, mobile antenna with low-gain antenna.
Antenna VSWR 4g cell phone jammer
When the characteristic impedance of the antenna input impedance of the feeder is inconsistent with the reflected wave and incident wave to form a standing wave in the feed line, the maximum value and the minimum value of the voltage ratio of the voltage standing wave ratio is adjacent. It is based on the transmission efficiency of the feeder test. VSWR and power relations in the following table.
The company's products meet national standards, working band VSWR less than 1.5, the working frequency VSWR less than 1.2. Voltage standing wave ratio is too large, will shorten the communication distance, and reflected power will return to the transmitter power amplifier section, easy to burn amplifier tube, affecting the normal operation of communication systems
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