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...

How is the antenna length calculated? https://www.whwireless.com/ Estimated 15minutes to finish reading Meaning of half wavelength and quarter wavelength Half wavelength and quarter wavelength are widely used in engineering for antenna system design. Chalf Wavelength Chalf wavelength refers to the half wavelength distance of electromagnetic wave in the propagation direction. Specifically, for a certain frequency electromagnetic wave, its wavelength is the distance between two peaks or valleys in the propagation direction. Half wavelength is often used in the design of antenna systems, such as tuners or the selection of antenna lengths. Quarter Wavelength Quarter wavelength is the quarter wavelength distance in the propagation direction of an electromagnetic wave. Similar to half wavelength, quarter wavelength is also used in the design of antenna systems. Specifically, setting the antenna length to a quarter wavelength in some antenna designs allows it to resonate at a specific frequency for better waveguide characteristics. In addition, quarter-wavelength is also used to design components such as reflectors, transmission lines, and impedance matchers. We all know that the length of an ideal antenna is half a wavelength. The quarter-wavelength antenna we usually talk about actually needs to consider the “ground” in order to constitute a complete antenna, which is what we often call “unbalanced antenna”; the antenna itself is only a part of the antenna. Wavelength λ = speed of light c/frequency f 5GHz wifi antenna length calculation Wavelength λ = (3* 100,000,000)/ 5GHz Wavelength λ = 0.06 meters Generally use 1/4 wavelength ordinary wire, that is, the length of the wire used is about 1.5 centimeters 2.4GHz witi antenna length calculation Wavelength λ= (3 * 100,000,000) / 2.4GHz Wavelength λ = 0.125 meters Generally use 1/4 wavelength common wire, i.e. use a wire length of about 3.125 cm Why do antennas need half wavelength? The antennas we commonly use are generally resonant antennas, that is to say, they are in the form of standing waves, and the half-wavelength is the smallest unit that can constitute a standing wave. The reason for this is shown below: Can be seen, for the normal transmission of the signal, in the half-wavelength metal structure, the signal into the negative half-cycle, just to the end of the conductor, need to be reflected back to the reverse propagation; “negative half-cycle + reverse propagation” and become a positive signal, just can be superimposed, thus forming a standing wave. In this way, the signal can be gradually enhanced in this conductor structure, and the maximum amount of energy can be radiated per cycle. Why does an antenna need resonance? Oscillating charges on the antenna can radiate less energy per cycle (with reference to the ratio of the size of the radiated field to the near field), and only more charge pairs can participate in the radi...

Antenna Direction Diagram - How to see the antenna direction diagram? https://www.whwireless.com/ Estimated 15minutes to finish reading Antenna direction map, also known as radiation direction map or far field direction map, is to describe the antenna radiation characteristics (such as field strength amplitude, phase, polarization) and the relationship between the space angle of the graph. It is an important tool to measure the performance of antenna. By observing the antenna direction diagram, we can understand the parameters and performance characteristics of the antenna. The following is how to understand and view the antenna direction diagram of some key points: First, the basic concept of antenna direction diagram - Definition: antenna direction map refers to a certain distance from the antenna (far-field conditions), the relative field strength of the radiated field (normalized modulus) with the direction of change of the graph. - Representation: Usually represented by the power direction graph or field strength direction graph, but also used to describe the phase or polarization direction graph. - Graph type: the complete direction map is a three-dimensional space graph, but in practice, usually only focus on the two main planes (such as horizontal and vertical plane) on the direction map, called plane direction map. Second, how to view the antenna direction graph 1. Identify the type of graph: o Three-dimensional directional diagram: with the antenna phase center as the center of the sphere, the radiation characteristics are measured point by point on a sphere with a sufficiently large radius to be plotted. Three-dimensional directional diagrams can fully demonstrate the radiation characteristics of the antenna, but are more complex to draw and view. o two-dimensional directional map: from the three-dimensional directional map to take a certain profile (such as horizontal or vertical plane) to get the graphics. Two-dimensional direction diagram is simple and clear, easy to quickly understand the radiation characteristics of the antenna. 2. 2. Observe the key parameters: o Main flap: the radiating flap that contains the desired direction of maximum radiation, also known as the main flap of the antenna or antenna beam. The width of the main flap is a physical quantity that measures the sharpness of the largest radiating region of the antenna. o Auxiliary flap: The flap outside the main flap is called the secondary flap or side flap. Vice valve level is the closest to the main valve and the level of the highest level of the first side of the level of the valve. o before and after the ratio: the maximum radiation direction (forward) level and its opposite direction (backward) level ratio. o Direction coefficient: a measure of the antenna in the maximum radiation direction of the concentration of the density of the radiated power flow. 3. Analyze the radiation characteristics: o Directionality: the ability of the antenna to radiate electromagn...

Regarding dB, dBm, and dBi https://www.whwireless.com/ Estimated 15minutes to finish reading DB (decibels) DB is a relative unit used to represent the ratio between two quantities. It is usually used to describe the ratio of power or voltage (or current). Definition: (dB=10 \ log_ {10} \ left (\ frac {P_2} {P_1} \ right)) or (dB=20 \ log_ {10} \ left (\ frac {V_2} {V_1} \ right)) Among them, (P_1) and (P_2) are two power values, and (V_1) and (V_2) are two voltage or current values. Note: dB is a relative unit that represents the ratio between two quantities, not an absolute value. 1. The decibel calculation formula for power ratio: When comparing two power values, the decibel calculation formula is: DB=10log10 (P1P2), where (P_1) is the reference power (usually a fixed value), and (P_2) is the power to be measured. If (P_1) is 1 watt, the above formula can be simplified as: dB=10log10 (P2), where (P_2) is the power value in watts.   2. The decibel calculation formula for voltage (or current) ratio: When comparing two voltage (or current) values, the decibel calculation formula is: dB=20log10(V1V2) perhaps dB=20log10(I1I2) Among them, (V_1) and (I_1) are reference voltages and currents (usually fixed values), while (V_2) and (I_2) are the voltages and currents to be measured. If (V_1) or (I_1) is 1 volt or 1 ampere, the above formula can be simplified as: dB=20log10(V2) perhaps dB=20log10(I2) Here (V_2) and (I_2) are voltage and current values in volts or amperes. Note: In these formulas, (\ log_ {10}) represents the logarithm based on 10. If (P_2/P_1) or (V_2/V_1) (or (I_2/I_1)) is greater than 1, then the decibel value is positive; If it is less than 1, the decibel value is negative. The larger the decibel value, the greater the multiple of (P_2) relative to (P_1) (or (V_2) relative to (V_1), or (I_2) relative to (I_1)). DBm (decibels milliwatts) DBm is an absolute unit used to represent power values, with a reference point of 1 milliwatt (0.001 watt). Definition: (dBm=10 \ log_ {10} \ left (\ frac {P} {1mW} \ right)) Where (P) is the power value to be measured. For example, if the power of a signal is 1 watt, then its power is (10 \ log_ {10} (1000)=30 dBm). DBm is commonly used to describe the power of wireless signals or the sensitivity of receivers. DBm calculation formula dBm=10log10(1mWP) Among them, (P) is the power value to be measured, in milliwatts (mW). (1mW) is the reference power value, which corresponds to the power of 0dBm. Related information 1. Unit conversion: 0dBm corresponds to 1 milliwatt (1mW). For every 3dBm increase, the power doubles; For every reduction of 3dBm, the power is halved. For example, 30dBm corresponds to 1 watt (1W), because (10 \ log_ {10} (1000)=30) (because 1W=1000mW). 2. Common conversion values: o     30dBm = 1W o     40dBm = 10W o     50dBm = 100W 3. Precautions: DBm represents the absolute value of power, not the power ratio. In the cal...