Exploring the 700MHz Band:Why It Is Regarded as the"Golden"Frequency in the Communication World https://www.whwireless.com/ Estimated 15minutes to finish reading In today's era of rapidly developing communication technology,frequency bands are like"magic keys"in the world of communication,unlocking different"treasures"of communication.Among them,the 700MHz band is particularly favored and is hailed as the"golden"frequency band.What are the secrets behind this?Let's delve into it together.  Superior Propagation Characteristics:Signals Travel Unimpeded Just as marathon runners experience fatigue,signals also attenuate during propagation.The 700MHz band can be regarded as a"long-distance runner"in the communication world.According to the free-space propagation loss formula,the lower the frequency,the smaller the propagation loss.Compared to higher-frequency bands such as 2.6GHz and 3.5GHz,the 700MHz band experiences much less signal attenuation.This means it can cover longer distances and deliver signals stably to their destinations.Whether in remote mountainous areas or vast rural regions,it can easily provide coverage. Strong Diffraction:Overcoming Obstacles When signals encounter obstacles like high-rise buildings or towering mountains,high-frequency signals often get blocked.However,the 700MHz band,with its longer wavelength,demonstrates strong diffraction capabilities.Like a nimble dancer,it can cleverly bypass obstacles and continue on its way.This characteristic ensures stable signal propagation in complex urban environments,preventing communication signals from being easily"intercepted"by obstacles. Deep Penetration:Full Signal Strength Indoors Indoor signal weakness is a common problem.However,the 700MHz band has excellent penetration capabilities,allowing it to easily pass through building walls and reach every corner of the interior.This means that indoors,we can enjoy smooth communication services without worrying about weak signals.Whether streaming videos,playing games,or making video calls,the signal remains strong. Cost-Effective Network Deployment In communication network construction,base stations are the key"signal fortresses."The low propagation loss and wide coverage of the 700MHz band bring significant cost advantages for network deployment.Calculations show that with the 700MHz band,building 450,000 to 500,000 base stations is sufficient to cover the entire country.If other frequency bands were used,achieving the same coverage would require a much larger number of base stations.This would not only significantly increase construction costs but also lead to higher maintenance and management expenses.The 700MHz band,with its advantages,greatly reduces the burden on operators,making communication network construction more economical and efficient. Wide-Area Coverage:A Boon for Remote Areas  In rural and mountainous regions with vast areas and sparse populations,as well as high-speed scenarios like high-speed rail and hig...

Antenna Popular Science - Operating Bandwidth https://www.whwireless.com/ Estimated 15minutes to finish reading I. Definition and Classification 1. Definition: Antenna bandwidth generally refers to the frequency range corresponding to when a certain parameter of the antenna (such as gain, voltage standing wave ratio, etc.) meets specific requirements. 2. Classification Absolute Bandwidth: It is the actual frequency range within which the antenna can operate. The calculation formula is Δf = fmax - fmin, where fmax is the highest frequency at which the antenna can operate, and fmin is the lowest frequency at which the antenna can operate. Relative Bandwidth**: It is expressed as the ratio of the difference between the upper and lower limit frequencies to the center frequency. The calculation formula is Relative Bandwidth = (f_high - f_low) / f_center. II. Influencing Factors and Representation Methods 1. Influencing Factors: The bandwidth of an antenna is affected by various factors, including the physical size, shape, material of the antenna, and design objectives. For example, techniques such as using thicker metal wires, metal “wire cages” to approximate even thicker metal wires, and integrating multiple antennas into a single component can all increase the antenna's bandwidth. 2. Representation Methods: Voltage Standing Wave Ratio (VSWR) Condition: Under the condition that the voltage standing wave ratio VSWR ≤ 1.5, the operating frequency band width of the antenna is called the antenna's bandwidth. This is a commonly used definition in mobile communication systems. Gain Drop Condition: The frequency band width within which the antenna gain drops by 3 decibels is also called the antenna's bandwidth. This representation method focuses on the characteristic of the antenna gain changing with frequency. III. Practical Applications and Significance 1. Practical Applications: In communication systems, the selection of antenna bandwidth is crucial for the system's performance. If the antenna bandwidth is too narrow, it may not be able to cover the required communication frequency range, resulting in a decline in communication quality or failure to establish a communication connection. Therefore, when choosing an antenna, comprehensive consideration should be given to factors such as the communication frequency range, bandwidth requirements, and antenna performance of the system. 2. Significance: Antenna bandwidth is one of the important indicators for measuring the performance of an antenna. It determines the radiation and reception capabilities of the antenna at different frequencies and is of great significance for ensuring the stability and reliability of the communication system. Types of Antenna Bandwidth I. Absolute Bandwidth 1. Definition: Absolute bandwidth refers to the actual frequency range within which the antenna can operate, that is, the difference between the highest frequency and the lowest frequency when the antenna's performance indi...

Basic knowledge of antenna measurement https://www.whwireless.com/ Estimated 25minutes to finish reading The basic knowledge of antenna measurement involves multiple aspects, including antenna functions, performance parameters, measurement methods, and testing environments. The following is a detailed explanation of the basic knowledge of antenna measurement: 1、 The function of the antenna Antenna is a key component of wireless communication systems, and its main functions include: Directional radiation or reception of radio wave signals: In the transmitting state, the antenna converts high-frequency electromagnetic energy in the transmission line into electromagnetic waves in free space; In the receiving state, the electromagnetic waves in free space are converted into high-frequency electromagnetic energy in the transmission line. Energy Conversion: Antennas need to efficiently convert the guided wave energy propagated by the feeder system into electromagnetic wave energy, or convert the received electromagnetic wave energy into current signals. • Directionality: Antennas can radiate or receive electromagnetic waves in a directional manner, concentrating them in the desired direction as much as possible. Polarization: The antenna should be able to emit or receive electromagnetic waves of the specified polarization. 2、 Performance parameters of the antenna The performance parameters of an antenna are important indicators for measuring its performance, mainly including: Gain: Refers to the ability of an antenna to amplify the received signal, usually closely related to directionality. Directionality: Describes the radiation power intensity of an antenna in a specific direction relative to its omnidirectional radiation state. Efficiency: includes antenna radiation efficiency and overall efficiency, with the former considering antenna losses and the latter considering overall losses such as conductor and dielectric losses of the antenna. Impedance: The ratio of voltage to current at the antenna input terminal, which is the load of the feeder system and requires good impedance matching with the feeder system. Standing wave ratio (VSWR): reflects the degree of matching between the antenna and the feeder system. Polarization: The polarization method by which an antenna emits or receives electromagnetic waves. Operating Frequency Band: The frequency range within which an antenna can operate normally. 3、 Antenna measurement method The measurement of antenna parameters is usually carried out using instruments such as field strength meters, power meters, impedance meters, or network analyzers, as well as specialized testing equipment such as standard antennas. The measurement methods include: Radiation directional pattern measurement: By using fixed antenna method or rotating antenna method, measure the radiation intensity of the antenna in different directions and draw the radiation directional pattern. Gain measurement: Using the comparison method, comp...

What is a third-order intermodulation antenna? https://www.whwireless.com/ Estimated 15minutes to finish reading 1、 Definition and Principle 1. Definition: Third Order Inter modulation refers to the interference signal of the third frequency caused by the nonlinear characteristics of the antenna or its related passive components (such as connectors, feeders, etc.) when the antenna receives signals of two different frequencies. 2. Principle: The generation of third-order intermodulation signals is due to the presence of nonlinear factors, which cause the second harmonic of one signal to produce a parasitic signal after beating (mixing) with the fundamental wave of another signal. This intermodulation phenomenon can cause two or more carrier frequencies outside the frequency band to mix and fall within the frequency band, generating new frequency components and resulting in a decrease in system performance. 2、 Indicators and Evaluation 1. Indicator: The third-order intermodulation indicator is usually represented by IP3 (third cut-off point). It refers to the interference signal power generated by the third intermodulation on the input-output curve, which is equal to three times the original signal power, when the nonlinear distortion of the output power is severe to a certain extent. 2. Evaluation method: Evaluating the third-order intermodulation index of the antenna requires a series of experiments and tests. Usually, a signal generator is used to input two signals of different frequencies, and then the non-linear distortion of the output signal is received and measured through an antenna to obtain the third-order intermodulation index of the antenna. In addition, the third-order intermodulation performance of the antenna can be evaluated through simulation and theoretical analysis. 3、 Influencing factors and optimization 1. Influencing factors: The third-order intermodulation performance of an antenna is influenced by various factors, including the design, materials, manufacturing processes, and the quality and performance of the passive components (such as connectors, feeders, etc.) connected to it. In addition, environmental factors such as temperature, humidity, etc. may also affect the third-order intermodulation performance of the antenna. 2. Optimization method: In order to optimize the third-order intermodulation performance of the antenna, the following measures can be taken: Optimize antenna design by using materials and manufacturing processes with better linearity. Improve the quality and performance of passive components, ensuring tight and smooth connections. Regularly maintain and inspect the antenna system, promptly identify and address potential issues. 4、 Application and Prospect 1. Application areas: Large antennas for third-order systems have a wide range of applications in communication, radar, and other fields. In the field of communication, it can be applied to satellite communication, mobile communication, radio communica...