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Selection of wireless communication wifi antenna

Date:2016-07-12

According to the antenna in the form of rubber antenna, rubber antenna, and another quarter-wavelength spiral rubber antenna. Quarter wavelength helical antenna rubber antenna relative to the general advantages of high efficiency, because under the principle of quarter wave antenna, the natural resonant antenna conductor with high radiation efficiency. Such a relatively slender body of the antenna to radiation, such as the 400MHz band using standard red 403KG/403KGP and MOTOROLAGP88/P110/GP300 slim antenna quarter-wave antenna are all class. Handheld walkie-talkie antenna is generally believed that a quarter wave antenna radiation efficiency is better than the actual shortened spiral antenna. This is the standard MOTOROLAGP88 superior radio performance, communication is relatively far away from one of the reasons. We did a simple comparison test: GP300 handheld radio sets with the same fixed location, has a quarter wavelength with GP88 first wife first wife rubber antenna and GP68 GP300 rubber helical antenna and the matching of the original spiral rubber, in meters Field Strength Meter measured using a fixed location field, the results quarter wavelength antenna has an obvious advantage of rubber.

  

The selection of wireless communication wifi antenna in the wireless communication network signal quality is one of the issues we are most concerned about, it is directly related to lower levels on the order issued by the reporting and accuracy and patency. In addition to determining the quality of the wireless communication transceiver performance, the antenna is a key factor in the wireless communications network engineering transit feeder system has been a considerable proportion of the budget.

From antenna theory, when the A radio system (output power 25W) are equipped with antenna gain of 3dB higher than the B radio system with the actual effect of B radio transmitter power output of 50W when the same system, that is the equivalent of radio antenna gain 3dB increase in output double the power, and because the signal reception on the role of signal amplification also have received so the actual use of relatively high gain antenna for signal reception there was a marked increase, in theory, high-gain antenna can increase the communication coverage, improve the weak signal area of communication quality. Performance of the antenna is directly related to the quality of communication signal. Different according to applications, the antenna can be divided into hand-held station wifi antenna, car wifi antenna, base wifi antenna three categories. First, the handheld wireless station antenna is hand-held units for personal use hand-held radio antenna, a common antenna and whip antenna rubber two categories.

However, this type of quarter wavelength antenna has its limitations, and spiral rubber antenna longer than the length of it. The so-called quarter wave antenna is the antenna length is a quarter wavelength frequency communications (the actual production but also according to shorten factor correction), commonly used in police communications bands 160MHz, 350MHz, 410MHz, 460MHz, respectively, the wavelength is 1. 875 m, 0.857 m, 0.7317 m, 0.652 m (with a constant frequency of 300 divided by the number of converted into a wavelength), the theoretical quarter wavelength antenna length of about 46.875 cm, 21.42857 cm, 18.29 cm, 16.304 cm. Seen by the length of a quarter wavelength in the 160MHz band using the form of handset antenna is obviously not suitable for rubber, so this type of wifi antenna are commonly used frequency bands above 400MHz (350MHz can also be applied.) There are many forms of rubber helical antenna is no longer in this segment, the overall spiral rubber antenna, the antenna can be shortened according to the size needed, so the antenna can be done relatively short length, more beautiful appearance. Spiral rubber antenna radiation efficiency and structure of the general form of its shortening is related to a longer antenna is usually more efficient. Rubber at low frequencies such as 160MHz antenna, most of the spiral structure, which can effectively control the antenna length. Above the 350MHz band has various forms of spiral rubber antenna, are known to short dimensions, such as 350MHz/380MHz the MOTOROLAGP300 (conventional) and PTX600 (clusters) are all standard spiral rubber radio antenna.

Rod wifi antenna generally have a higher than the rubber antenna radiation efficiency, can provide longer communication distance. Rod antenna is generally added in the lower part of the sense of a long dipole antenna, rubber antenna transceiver higher than the average efficiency. Although the launch rod antenna more efficient, but because of its longer, the lack of soft rubber antenna is not practical to use more flexible and easy to be broken. Hand-held radio communication system configuration for the antenna to the actual communication network and mobile radio coverage area may be expected to use. High-gain antenna can be configured to improve the hand-held radio communication in the effect of the weak signal area, but considering the shape and cost of the antenna and the actual situation it is generally in the configuration follow the "first wife antenna priority in special circumstances, special response" principle. Most of the wireless communication network in both the public security selection of imported hand-held radios, wifi antenna were equipped with the original. Original antenna for use of the radio frequency band, and the quality and performance are more assured, so under normal circumstances the original antenna is preferred. We are not superstitious original antenna, the antenna made a number of different wifi antenna as form or as a specially tailored so the frequency may be in performance over the original antenna, so the original antenna can not meet the actual requirements may wish to consider switching to other forms of antenna.

Quarter-wave antenna based on high efficiency rubber helical antenna size for small size features and aesthetic considerations as well as most of the radio antenna supplied with the status of spiral rubber. Relay station in a network of police communication network, the signal strength coverage area can use the spiral rubber antenna to ensure call quality in the case of reducing the overall volume of the purpose of hand-held radio. The edge of the communications network coverage or weak signal coverage area consider using a quarter wavelength antenna rubber to improve the efficiency of the radio transmitter to improve signal quality, remote areas or if the rubber antenna with quarter wavelength effect is still not ideal recommend using rod antenna. If there is no direct communication between the relay station by radio communication, the proposed distance communication situations in the best rubber antenna with quarter wavelength in order to ensure smooth communication and voice discernible degree. For some special cases, of course, need to hide the radio antenna as short as possible to choose an antenna.

Using the 800MHz MOTOROLA SMART NET (ZONE) cluster system are the length of two rubber hand-held radio wifi antenna are available, through the test antenna radiation efficiency is higher than the short length of the antenna. Farther away from the base station with a short duty point of the antenna if the radio signal is often difficult or weak voice the Internet phenomenon of unclear proposals to switch to a long antenna. As hand-held radio antenna easily damaged, and the original antenna parts are expensive, so often used in homemade antenna as a substitute. First, the antenna should be noted that domestic use interface to the same antenna, the radio, such as Japanese C150/450, C160/460, TK-208/308 and other multi-Q9 bayonet, N888, C260, use the interface with the rib, MOTOROLA series is used rib mouth. Second is to determine the frequency band antenna, absolutely can not use an antenna instead of the other bands, though sometimes the appearance of various frequency bands close to the antenna. Finally, test the performance of the antenna, antenna manufacturers of different product quality and price vary greatly. Indicators in handheld wireless station and the actual communication is the radiation efficiency is most closely, it is directly related to the signal quality and communication distance. In the case of professional equipment to quantify the test antenna on the working frequency SWR standing wave ratio and gain, there is no grass-roots units in the case of professional equipment we can use Strength Meter (with a very low cost or even make simple Field Strength Meter, as shown) to compare the same switch to a different radio antenna in the same location from a fixed point on the test field, we can use the antenna as a reference object Original contrast, if the substitute and the original antenna can be very different initial determine the substitute failed. This comparison method can be widely used with the handheld wireless station and car comparison between the antenna, although not quantitative, but still has the use of very large significance.

Using this simple method of testing the antenna from the antenna and the body field into the test point is, sometimes the body position change will affect the change of field test point, the introduction of large errors, so try to keep simple test station and were relatively fixity in the surrounding environment. Second, car antenna, car antenna is the original design and installation of communications antenna on the vehicle, the most common is the most common sucker antenna. There are some folders and a glass antenna side of the antenna used for special occasions. Actual use of the display is easy to install the antenna suction cup, so in some simple situations are often used to establish the radio antenna instead of suction cup base antenna. Car antenna structure also has shortened, a quarter wavelength, plus a sense of the central type, five eighths wavelength, dual-half wavelength in the form of antenna. Theory, in order to increase their efficiency (the nominal gain increased), the same frequency band and antenna also were increased (due to the improved production technology and different forms, the antenna gain to the measured results, or gain nominal index date) . Limited vehicle itself, coupled with the antenna size is too large high-speed road vehicle may encounter a great drag, so the high-gain antenna size car working band in accordance with a different design. Although the small size reduced antenna gain is not high, but to hide the antenna suitable for use in the occasion. General police vehicle is recommended to install the antenna, especially in the high growth region-wide activities, the larger the vehicle, 350MHz high-gain antenna and more plus for the five eighths wavelength of a sense of form, the top two points away from the antenna and there is a long wave Add a sense coil.

400MHz dual-half the wavelength band has a high gain antenna, which is characterized by the appearance of the oscillator has two plus a sense coil. Five eighths add a sense of the central wavelength of the antenna and antenna has higher gain and the price is relatively cheap so widely used. Some forms of the antenna in the lower part of a spring can play a role in the crash. In a temporary fixed station wifi antenna should use the occasion to use high-gain antenna, suction-type vehicle, in favor of fixed communication units, the length of the antenna do not have special requirements. As sucker antenna is designed based on the vehicle use of the environment, so when used as fixed under the smoke in their inner product of a diameter larger than the working wavelength band of a metal plate (such as iron) will have better actual results. Original car antenna as imports very expensive so generally used homemade antenna, the antenna selection at the main stage appearance and gain reference antenna. Sometimes manufacturers nominal gain and the actual gain a clear gap between the actual test it is necessary to compare samples of different antenna gain of the antenna, the test method in the case of no professional equipment can be compared with reference to hand-held antenna field test, the test environment should simulate the vehicle environment. Radio output power as a larger vehicle, in addition to the test field, but if there are standing wave ratio table can also test the antenna SWR (Standing Wave Ratio) value, standing closer to 1 more than the ideal, the general should not be large antenna VSWR at 2. VSWR is too large and not only the effects of launch opportunities on the radio emission damage.

Third, the base station antenna base station antenna in the whole communication system has a key role, especially as the communications hub of the communication stations. High-gain antenna can enhance the emission signal not only to increase the coverage area of radio waves and the received signal amplification has some better reception weak uplink signals, to improve the mobile station and base station wireless communication quality. Under normal circumstances the base station are equipped with high-gain antenna, the interference situation can be considered according to the actual installation of narrow-band filter or moving the antenna position to reduce interference. Common base station antenna with high gain antenna fiberglass, Fourth array antenna (h ring array antenna), directional antenna. FRP high-gain antenna, the antenna is not omni directional, suitable for base station location is in the communication network centers. According to the different antenna gain into high-gain antenna (8dB above) and the gain of days (6.5dB below). In the same band high-gain antenna fiberglass antenna gain higher the longer the 350MHz band 10.15DB general length of the antenna gain of about 4.7 meters, 8.5DB gain antenna length of about 2.4 meters, 7.8DB gain antenna length of about 1.7 meters or so.


400MHz band 10.15DB gain antenna length of about 4 meters, 8.5DB gain antenna length of about 2.4 meters, 6.5DB gain antenna length of about 1 meter. FRP high-gain antenna is the most frequently used as a base station antenna, the price is relatively modest. Taking into account the higher the antenna, fiberglass antenna gain and the longer the price is rapidly increasing, it is generally the case for high-gain antenna communications hub fiberglass main units (branches and Urban and relay stations), the fixed-point gain antenna for the station (the police station ) use. Because it basically non-directional so it can ensure that all sub-stations and main platform communication and exchange between sub-units (no relay case). City of Victoria to bear the characteristics of the antenna array power, high gain, gain adjustable direction. When the transmitter is greater than 100W when the number of glass fiber reinforced high-gain antenna is not used, then use the array antenna safer Victoria, the general array antenna Maximum Power Ring in the 300W-500W. Ring oscillator array antenna transmitting direction of the four adjustable, when the 90-degree intervals of four oscillator installed base for the omni-directional antenna characteristics, when all four oscillator installed in the same direction with a directional antenna characteristics, while the gain in the main radiation increased. The direction of use of its adjustable gain feature can better adapt to the irregular service area. If the Ring Array Antenna gain is not high enough to consider eight-ring array antenna, which features a similar array, but with the City of Victoria provides a higher gain. Victoria General 350MHz band array gain 8dB (omni) / 10dB (directional), a gain of eight-ring array 12dB (omnidirectional) / 15dB (directional), for communications hub (Branch and Urban and relay stations) to use , but its price is relatively high. Directional antenna with high directivity, the main direction of radiation gain is high. The number of directional antenna units the higher the gain the more directional the more intense, more suitable for long distance point to point communication. Many parts of the police station to police station by wireless communication between the repeater station forwarding completed, can be considered a sub-station and the repeater point to point communications. The remote location of the police station if there are radio station set up far away from the general location of the repeater gain omnidirectional antenna can not meet the communication requirements may wish to consider the use of directional antenna. General 350MHz and 400MHz 8 units can reach 12dB directional antenna directional gain. Directional antenna suitable for the more remote sub-stations and the main station or relay station to contact, the price of steel and glass, the same antenna gain compared to a lot cheaper, for the installation of fiberglass gain directional antenna, ineffective communication stations may be considered for use of directional antenna.

Without the support of the relay station, if the communication object is not suitable for use scattered scattered directional antenna. As a base station antenna to the manufacturer if you can custom fine-tune the communications frequency to get the best resonance. Although many wifi antenna have a nominal more than a 10MHz bandwidth, but the actual work in a different frequency than the gain and VSWR there are some changes, generally not well tailored to the antenna effect.

Flexible use of various features of the antenna can improve police communications with the wireless communication network quality, expanding network coverage area, and can reduce network costs.

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