What is Quadrifilar helical antenna or omni directional GPS antenna

Quadrifilar helical antenna or omni directional GPS antenna, generally according to specific rules it consists of 4 curved metal lines welded to cylindical base,without any grounding.It has both Zapper antenna and vertical antenna characteristics.Its ingenious structure enables any direction of the antenna has 3dB gain and a good pattern! Quadrifilar helical antenna has a omni directional ability to the reception, so when combined with pda, regardless of the placement of the PDA, quadrifilar helical antenna can receive GPS signal, which different from GPS antenna requires the use of flat restrictions in order to better reception. To use such antennas, when the satellite appeared in the ground plane 10 degrees, you can receive signals transmitted by satellite.


Quadrifilar helical antenna is an integrated high gain and optimized low noise performance amplifiers active antenna, adopt for the following applications:
Handheld, wearable device or conventional antenna offset environment
Intensive integration with other antennas, such as Bluetooth, GSM
Application equipment size or distribution and integration space is limited
Need 20dB even higher preamp output GPS receiver
Direction of the antenna device can be any installation


High gain – typical 25dBic
Conducted noise suppression systems for various applications
Broad beamwidth (>135 degrees)
Negligible interference near the body
Built with an external two installation options
Compatible SMT production process
Low power consumption

GPS antenna and GSM antenna difference


The interface is different, GPS satellite navigation antenna, you and your satellite navigation or GPS Bluetooth module external antenna connector match.


GSM mobile phone external antenna, car phone hands-free system is generally connected to an external antenna to match select the external antenna connector of your car phone via Bluetooth hands-free system the way with your phone.


In fact, GPS Antenna and GSM Antenna have different functions, GPS antenna if for GPS device navigation ,but GSM Antenna is for telecommunication.

What is the difference between GPS active antenna and GPS passive antenna

GPS external antenna currently plays in agriculture, aviation, the environment, maritime transport, public safety and disaster relief, railways, space, and other surveying and drawing a very important role in the field; some friends do not know what the characteristics of the GPS antenna is? It is not only high positioning accuracy, fast closing Star; and can be divided into active and passive, then what difference does it both?
Passive GPS antenna: When using passive GPS antenna, as only one ceramic piece of the sky to receive satellite signals directly connected to the module’s RF-IN pin, this coupler is simple structure, and the standard ceramic 25 * 25 * 4 low-cost chip, the technology is mature, the duty is small, compact space suitable for stressed GPS navigation products, Bluetooth GPS, GPS mobile phones and other small GPS consumer products.
Layout of this antenna is connected to the antenna pin module RF-IN pin, which wires need to be 50 ohms impedance matching, but not near the antenna electromagnetic interference, PCB design and machine design requirements more EMI high, but if the design was excellent passive antenna GPS products also have a very good performance results, and power save mode.
Active GPS antenna: Generally for devices or in-vehicle device, since the device before the GPS receiver module often distance, taking into account the ease of installation may be more than one meter distance, in this case we can only choose Source GPS antenna, the signal attenuation antenna length compensation is required, generally have two low-noise amplifier (LNA) an antenna front-end signal amplification, signal output amplified by cable, sync cable provides DC voltage LNA need.
Since the signal received at the antenna active antenna reception complete within the first signal receiving antenna amplification, and away from GPS devices or other electrical equipment, the source of interference minimum distance between the antenna and the installation location can be selected to extend the installation location ideal environment, so often feel a strong signal in actual use.
externalgps antenna

What parameters does External GPS Antenna needs to pay attention to

What parameters does External GPS Antenna needs to pay attention to
GPS receiving antenna, electromagnetic energy is converted to a satellite radio signal to the receiver electronics ingestible current applications. The size and shape of the antenna is very important, because these characteristics determine the ability of the antenna can get a weak GPS signal. If necessary, the antenna can be designed to work on a single L1 frequency, also it can work on two frequencies L1 and L2. Because GPS signals are circularly polarized waves, so all receive antennas are circularly polarized work. Although there are a variety of conditions, there are still many different antenna types exist, e.g. unipolar, bipolar, spiral, quadrifilar helical, and the microstrip antenna.
The market saw a GPS receiver built-in antennas are generally two – plate antenna and four arm helical antenna.
Flat antenna due to its durability and relatively easy to make, so became the most common type of antenna. Its shape can be round or rectangular can also be square, as a copper printed circuit boards. It consists of one or more metal sheets constituted, so the most common shape is a GPS antenna junction block, like biscuits. Since the antenna can be made small, and therefore suitable for aerospace applications and personal handheld applications.
Another major characteristic of the antenna, its gain pattern, i.e., directivity. The use of directional antennas to improve its anti-dry and anti-multipath capability. Precise positioning, antenna phase center stability is a very important indicator. However, the general navigation applications, it is desirable to use an omnidirectional antenna capable of receiving at least all the sky within five degrees above the horizon antenna Vision visible satellite signal, but when the flat-panel antenna above the satellite antenna, the signal gain is the greatest , which has two problems:
1, the reception range of the flat top of the plate, the plate must face the sky, which for handheld and car will bring trouble, we can see that CF adjustable angle of the receiver more and more, it is because of this feature makes the flat antenna The receiver manufacturers in order to have better reception effect was thought out move.
2, although the satellite signal that we are on top of the head is better, easier to lock, but in fact satellites are overhead is the most useless, if not low angle of the satellite, the error will be relatively high, the accuracy will be poor. Therefore, based on these shortcomings, the GPS receiver can start using the quadrifilar helical antenna.
Quadrifilar helical antenna consists of four specific bent metal lines formed. Without any grounding. It has had Zapper antenna characteristics, but also with vertical antenna characteristics. Such ingenious structure, so any direction of the antenna has a gain of 3dB, increasing the time the satellite signal reception. Quadrifilar helical antenna has a full 360 degrees to the reception, so when combined with the PDA, PDA regardless of placement, the four-arm spiral antenna Jieneng received is different from the use of flat GPS antenna needs to relatively flat The good restriction received. The use of such antennas, when the satellite appeared in the ground plane 10 degrees, you can receive the signal transmitted by satellite.
If the ground station near sources of interference more quadrifilar helical antenna is not applicable because the quadrifilar helical antenna with a horizontal direction of the gain will amplify noise together, but interferes with the reception of satellite signals. However, advances in science and technology, and now the production of four-arm spiral antenna can break out a number of conventional antennas. The antenna is made of ceramic, Near-Field is extremely small, only about 3-5mm, and some conventional antennas Near-Field even up to 1m. Near-Field smaller, hand-held GPS device when the user, the more the body will not cause interference. Features now four-arm spiral antenna also includes complete balun circuit (Balun) design, this design can isolate the noise surrounding the antenna, so the antenna can allow the coexistence of various functions in a very small space without interfering with each other . For integration increasingly diverse, and emphasize slim and light handheld electronic products, the importance of this feature of the ineffable.

GPS antenna solutions

According to ABI and IEK report notes, GPS car navigation system has been identified as future car factory standard formulation of the imported equipment, the United States E911 regulations require mobile phones and other handheld consumer products must be equipped with GPS navigation, plus built-in GPS function Each system terminal product prices fell and other market power, prompting market share GPS and other related products rapidly.
In addition, the global industry for electronic products require light, thin, short, small, under characteristics, coupled with highly integrated mixed signal chip as the RF front-end functions, the entire GPS system includes GPS, processing cores, embedded memory chips, and small electronic elements, which makes GPS miniaturization formed a trend, but also because it shares trends, the relationship between the scope of the future GPS market is about depth personal use, GPS will one day become the people’s daily necessities.

GPS antenna design is better imagined simple

GPS has become the entire system from a single integrated product development system gradually integrated solutions; from product design side view, GPS navigation device manufacturers can choose GPS modules, chips (Smart antenna module) in order to achieve the goal of system integration.

Strict opinion, the current market GPS navigation solution has its advantages and disadvantages; therefore, before selecting the vendor must then make the whole system designed to assess the environmental conditions in accordance with, and that which went GPS antenna and receiver modules is considered navigation system, an important components, GPS antenna design both receivers and they must match each other in the case, was able to design a GPS navigation technology.
From the GPS antenna technology design point of view to assess its antenna strict requirements applicable characteristics, ease of use and quantitative performance criteria, accuracy, startup performance, location tracking sensitivity and low power consumption products. Therefore, this GPS antenna module design, the result in no small impact.

For example: antenna design miniaturization may lead to reduced sensitivity; reduce power consumption though permeable reduce hardware architecture can be achieved, but the pursuit of low-power yet another performance lead to a compromise, such as: reducing the number of channels and Search channel, in terms of start-up performance will be affected.

Helix spiral from the past to the present day Patch technology thin type technology, we can see the future GPS antenna design, there are still many problems to be solved and R & D space.

Design chose to use wisdom antenna module

Because of rapid and low-risk system integration features, required to achieve rapid product in stereotypes, a small amount of production and market access time-critical applications, GPS antenna module wisdom is the most appropriate choice. Even wisdom antenna module includes a GPS function completely independent, in the course of some of the design work is still to be done, including the antenna type (patch antenna or helical antenna) antenna module selection and the wisdom embedded in the end product to go .
Most wisdom antenna module instead of using a ceramic patch antenna is a helical antenna. Directional patch antenna, in the orthogonal plane radiating element has the maximum gain. In other words, the radiation level of the surface of the element from the sky apex sent signals having the greatest gain. When the level of the surface elevation receiving narrow range, this highly centric sensitivity will cause a greater impact.

Patch antenna suitable for major upward of end products, such as used in car navigation, relying on the windshield installed in the exhaust hood. In addition, the antenna aperture (antenna aperture) by the radiating element size and its radiation passes underneath the ground plane size together determine the size, it will also affect the signal reception sensitivity.
The helical antenna has a relatively wide directional characteristics: receiving a wider elevation, but the peak gain is relatively low. The helical antenna suitable end products are required for the respective directions can be freely used in handheld devices such action.

Since the human body can interfere with the signal near the reception, in which case the impact of the use of helical antenna is relatively small, and therefore the distance near or far human tissue location, handheld end products can be achieved in all directions GPS reception. However, the helical antenna also has a drawback: small antenna aperture, limits the overall receiver sensitivity.

GSP wisdom encapsulated antenna design
Packaged wisdom antenna is an alternative to the wisdom of the antenna OEM module. In the case of the requirements of embedded GPS products do not do hardware changes, select packaged wisdom antenna has certain advantages. There are two antenna encapsulated wisdom:the wisdom of separate antenna and tight coupling wisdom antenna.

Packaged wisdom antenna is ideal for portable systems like the implementation of such a standard PC and a PDA portable hardware platform solution in.
GSP navigation and guidance system in the process of integration, the use of well-designed GPS antenna, but also enables the GPS module and antenna design and chipset achieve the same performance levels. When GSP was asked must quickly realize the end product design, to lower development costs or limited internal research and development resources, the wisdom antenna module is feasible option, carefully selected wisdom antenna module can provide traditional GPS chip group and compared to the performance of integrated modules.

Car GPS no signal? Teach you to deal with a small car problem

Car GPS no signal? Teach you to deal with a small car problem
With the popularity of the automobile, automobile parts industry development subsidiary also in full swing, the owners are also happy to use or cool all kinds of accessories, such as solar film, alarm, xenon lamp, etc. in the car tops. However, with the increase in car decoration, the owners use when the car may encounter some problems or minor annoyances. This article lists the three more common cases, and put forward relevant countermeasures.

Case I: Car GPS signal gone?

Owner Mr. Chen has been a very depressed. Into the summer, the weather is getting hot, Mr. Chen wound to his car posted a set of solar film, in order to step in place, but also specially selected a high-grade goods. Really a penny stock, this film is a senior, outside the sun is bigger, the car is not so hot, Chen feel this is money well spent! But not long after happy, Chen found the problem came, posted a film, a car GPS navigator could not search the satellite signal. For Chen this often busy man ran field operations, there is no navigation directions, but unable to move ah. He is now very confused and very tangled, doubt that this navigation signal interruption, whether it is related with the new post of Solar Films. Tangled solar film break the curse if it is, it would mean that expensive film give this new paste tear? How could this not make people depressed.

As we all know, car film can play insulation, cooling and many other effects. Currently on the market to control daylight many film brands. One of the most low-end of the staining film. The principle of the dyed film is the use of special colored pigments to avoid glare, although able to isolate dazzling vision, but can not isolate the heat, one or two years after installation, it is prone to fading, delamination. While the other metal film is to avoid these situations. However, because the car film contains a metal layer, will play the role of shield, it will regularly affect the spread and use of radio signals. Not to mention the GPS navigation signals, and even cell phone signals are likely to be affected.


The best solution is to choose the natural way no wireless signal shielding solar film, if not in fact affect some metal solar film, solar film does not have a majority of the wireless signal. Only need to ask before buying loudly product sales, it will answer you truthfully, shielding salesperson wireless signals several natural heart. However, like Mr. Chen is so mature rice raw rice has cooked the owners, nor is no room for redemption. Go and see if your car navigation system has an external signal receiver socket. If so, adjust the installation position of the GPS signal receiver to not affect the position of the sun film, car navigation will be able to normal use.

With the popularity of the automobile, it is no longer a simple means of transport. It is an extension of the owner’s personal image, the carrier may be the owner of fun, and even, it is itself Toys! Therefore, with the change of status of the car, the corresponding vehicle modification upgrade also gaining in popularity. Change of sound, dig a skylight, and even upgraded suspension, to add a turbocharger engine, it now appears this is not a surprising thing, as a leather bag attached to a film or something, a mere trifle, even modification can not be called. But often that these humble little change, it may bring unexpected results to the owners. Ranging from spending money wasted, while affecting the normal use of the vehicle, even dangerous. The following situations, do you understand it?

Case II: CD Audio Why is intermittent?
Liu also recently encountered a strange question, how long did not buy his own car, CD player when they often put the disc off. To check the CD player was told there is no fault. This is really strange, just six months a new car, in addition to the installation of a xenon lamp outside, nothing moving off, CD player not aging so quickly it! As everyone knows, which the culprit being converted from Liu self-xenon lamp.

Xenon lamps have high brightness, light close to natural light, low power consumption, but will bring a lot of interference problems due to the modified xenon lamp brings, such as electronic equipment not working properly and so on. For example, some models of cars after opening modified xenon lamp, lamp abnormalities can cause vehicle breakdown lighting, audio equipment noise does not even appear to work, work, etc. for no reason wiper strange phenomenon. Xenon Why is there so much interference? Here we must say that under xenon lamp emitting principle: we know, usually with a halogen incandescent lamp belongs, is by converting electrical energy into heat, light, radiate outward glowing. The xenon lamp is different ballast 12V DC vehicle will convert tens of thousands of volts of high-voltage, gas ionization within an arc lamp light. Due to the presence of tens of thousands of volts of high pressure at work, it is easy to interfere with nearby electronic equipment. There are two basic ways of interference: First, like radio as electromagnetic radiation. Another is to directly interfere with other electronic devices through the circuit.


Of course, we would recommend owners who install qualified quality xenon lamp products, especially to get the original certification of lighting assembly. Such products are not only strictly into account the issue of electromagnetic radiation interference, and sophisticated light pattern and excellent quality and better able to ensure the safety and comfort for everyday use. But already by the xenon lamp electromagnetic interference for people who also have remedial measures. For radiation interference, interference sources can (ballast) shielding, simply put, is to metal objects or metal mesh wrap the interference source, and the metal mesh and the frame is connected to ground. Thus, the internal high-frequency high voltage signal is not propagated to the outer metal nets. For interference circuit, it can also be installed in the supply lines ring. Here is the ring around the magnetic material on a number of leads, since the frequency of the interfering signal is relatively high, so it can also play a normal power supply signal isolation interference effect, the device will not be affected. The method can also deal with the circuit interference by changing the wiring position, etc. to solve, the terminal far away from sources of interference.

Case 3: car alarm Tiantian Han “crying wolf”

Ms. Wu this time with relation neighbors very nervous, because all the people love to hate in the car alarm. Ms. Wu as saying a car there for some time, but since the district have a car stolen after, Ms. Wu to the car started to have the idea to install anti-theft devices. Also, now in the area, unlike in the past, with the increase in tenants, the district will be a variety of unfamiliar faces every day, plus a cell but not property management, car free access, the risk of car theft than ever lot. Let Ms. Wu absolutely unexpected, since the anti-theft device installed, which not only did not mind less exercise, but became more panic than ever. Now beware not car thieves, it is something between the child downstairs, vehicles and all possible audible. Because as long as a sign of trouble, newly installed in the ultra-high decibel alarm will sound the alarm window, press the remote control it is not Ms. Wu refused to stop. This is no problem during the day, at night the alarm also occasionally called Liang Sangzi, but may be due to the night the cat jumped on the hood! So down, Ms. Wu’s car in the district famous, scratches, Tanji and garbage, the car will not become less of “dress”, once, there are people upstairs throwing beer bottles smashed car rear windshield. So, Ms. Wu now produces anxiety at home, afraid to hear the siren sound.


For most of the vibration sensor as an alarm trigger mechanism alarm, the single from the machine itself, there is not much room adjustable. But one thing the owner should pay attention to, for particularly sensitive vibration sensor, we must try to make it far easier to feel the vibration and acoustic area, for example, close to the door or windshield, it is very easy an alarm is triggered. But if it is installed in the center console or the steering wheel beneath these little hidden place, it is equivalent to reducing its sensitivity. Of course, such an approach can only take effect to some extent, too sensitive for anti-theft device, the best method is deprecated. Because for professional thieves, the crack anti-theft device which is pediatrics. So, might as well install a sturdy lock the steering wheel, do not forget to buy a car pilfer, under which sit back and relax.