How does a antenna watertight breather valve work? Read this and you'll understand!  https://www.whwireless.com/ Estimated 2minutes to finish reading With the development of the times, the pursuit of users is getting higher and higher, in the waterproof function above is also the same, from the beginning of IP54 to nowadays IP68 level waterproof. These days, some friends ask what is the working principle of waterproof ventilation valve? Let's solve this problem today! Waterproof relief valve is a two-way waterproof breathable pressure relief from the surface, not considered a one-way valve. Waterproof vent valve (also known as PUW vent valve) is mainly used eptfe membrane injection molding, ultrasonic welding and other forms of combination to become a sealed component. There are mainly threaded, press-in, snap-in, twist-in, etc. PUW valves are mainly used to measure whether a valve is good or not by two indicators: 1. Waterproof ventilation valve working principle. PUW waterproof permeable valve uses imported expanded polytetrafluoroethylene (E-PTFE) microporous membrane carefully manufactured, the imported E-PTFE membrane microporous diameter between 0.1-10 μm, however, the molecules of the gas is only about 0.0004 μm, EPTFE membrane pore size than the diameter of the gas 250-25000 times, so the gas can pass smoothly; and the diameter of the mauve has 400 μm, 40-4000 times larger than the film's microporous diameter, in addition, because the EPTFE film material surface energy is very low, the contact angle of 135.6 °, because the surface tension effect (water molecules pull each other) water vapor condensation into small droplets in the EPTFE film surface shape large larger water droplets, can effectively prevent liquid water wetting and capillary penetration, so has a good waterproof breathable performance. puw waterproof breathable valve has been widely used in electronic products, outdoor lamps, automotive manufacturing, solar photovoltaic, electronic appliances, communication equipment, security equipment and many other industries with waterproof needs https://www.whwireless.com/ 

SMD is what is the difference between SMT and SMD https://www.whwireless.com/  Estimated 2minutes to finish reading   When it comes to SMD, you may not know what it is? But mention the SMT mounter, may be a lot of people know, today by the SMT mounter of the editor to tell you what is the difference between SMD and SMT, the following we come together to understand it:.   Speaking of SMD, we may not know what it is? But mention the SMT mounter, many people may know, today by the SMT mounter of the editor to tell you what is the difference between SMD and SMT, the following we come together to understand it. SMD is the abbreviation of Surface Mounted Devices, meaning: surface mount devices, it is SMT (Surface Mount Technology) components in one, including CHIP, SOP, SOJ, PLCC, LCCC, QFP, BGA, CSP, FC, MCM, etc..   Surface mount components were introduced some twenty years ago and have since ushered in a new era. From passive components to active components and integrated circuits, they eventually became surface mount devices (SMD) and could be assembled by pick-and-place devices. For a long time it was thought that all pinout components would eventually be available in SMD packages.   SMT stands for Surface Mount Technology and is currently one of the most popular technologies and processes in the electronic assembly industry.   SMT is a new generation of electronic assembly technology that compresses traditional electronic components into devices that are only a few tenths of their size, thus achieving high density, high reliability, miniaturisation, low cost and automation in the assembly of electronic products. Such miniaturised components are called: SMD devices (or SMC, sheet devices). The process method for assembling the components onto a printed board PCB is called the SMT process https://www.whwireless.com/ 

Antenna transmission distance not ideal? It may be due to the following 6 reasons https://www.whwireless.com/  Estimated 2minutes to finish reading When using wireless modules, communication distance has always been an important indicator. Many engineers ensure that the wireless module itself has no problems, but still the communication distance is unsatisfactory, the packet loss rate is high, the signal is weak and so on. At this time, we should consider whether the performance of the antenna has affected the communication distance of the module. Affect the performance of the antenna often have the following 6 factors, I hope it will help you! 1. the antenna frequency must be matched with the frequency of the wireless module. 2. the higher the antenna frequency, the faster the rate; the lower the frequency, the longer the wavelength, the better the bypass performance. 3. when there is a linear communication barrier, the communication distance will be correspondingly attenuated. 4. pay attention to the direction of antenna radiation, incorrect antenna installation direction leads to close transmission distance 5. there are metal objects near the antenna or placed in the metal shell, the signal attenuation will be very serious. 6. poor impedance matching between antenna and communication equipment will lead to poor communication effect. 7. The ground absorbs radio waves, the effect of testing near the ground is poor, it is recommended to raise the height of the antenna. 8. Water will absorb electromagnetic waves, the higher the frequency, the more obvious the electromagnetic wave attenuation phenomenon. www.whwireless.com 

Principle and calculation of quarter wavelength antennas https://www.whwireless.com/  Estimated 5 minutes to finish reading Quarter wavelength antennas are more common in areas such as walkie-talkies, and their name is more technical than that of antennas that are distinguished by their shape. In this article, we will further discuss the characteristics of the quarter wavelength antenna by looking at the principles and applications of this antenna. First, the antenna's transmission principle Regarding the quarter wavelength antenna, we need to understand the basic principle of the antenna's emission first. Electricity travels through a conductor at a speed close to that of light, and when it encounters a discontinuity in the conductor, it is reflected back to the signal source. If the current is alternating and the reflected current returns to the origin or feed point at the right moment, then the current is reinforced by the subsequent cycles so that only a small amount of energy is required to maintain a standing wave within the antenna. That is, due to the presence of standing waves so that the antenna is in a resonant state. Thus transmitting electric waves into space. In the resonant state, the voltage in the current for the maximum of the midpoint (oscillator of the midpoint) is very little, but at both ends there is a great value, Ohm's law applies to the antenna, in the midpoint due to the current, the voltage is low, so the resistance is small, at both ends of the situation is exactly the opposite, thus the impedance is high.   Second, the principle and application of quarter wavelength antenna According to the theory of transmission line, 1/4 wavelength open line is equivalent to a series resonant circuit, so its entire load is purely resistive, in some occasions, due to environmental factors, the length of the antenna is often limited, so there is a loaded antenna. According to the theory of transmission line, the length of the antenna is less than 1/4 wavelength multiples of its impedance is capacitive, when the antenna does not resonate, for this reason we can add an inductor on the antenna to balance with the antenna, so that the antenna resonance, we call this antenna for loading antenna. Theoretical and practical evidence, when the length of the antenna for the radio signal wavelength of 1/4, the antenna transmission and reception conversion efficiency is high. Compared to one-half wavelength, full wavelength, antenna size is much smaller, compared to the antenna transmitting and receiving efficiency and the highest ratio of antenna size, so commonly used quarter wavelength antenna. Third, how to calculate the quarter wavelength A quarter wavelength can be calculated by frequency, the formula is: the length of the antenna (in meters) = (300/f) * 0.25 * 0.96, f indicates the frequency in MHz, 0.96 is the wavelength shortening rate (electromagnetic wave propagation in the antenna, some factors lead to wavelength shortening...