TWM502971U - Electrostatic protection module of antenna - Google Patents

Description

Antenna electrostatic protection module

This creation is about the electrostatic protection technology of RF (GSM, CDMA, WCDMA, LTE, GPS, WiFi, BT) RF components of antennas, especially an electrostatic protection module for antennas. The utility model comprises a static suppressor, which is a single electrostatic module, which can be connected between the antenna and the radio frequency circuit, and is used for discharging static electricity from the antenna end without flowing into the radio frequency circuit. The group can also be designed for different RF bands and make the module an impedance matching line for the application frequency.

Antenna RF components such as FEM (front end module) or small signal amplifier (LNA), or SAW filter and baseband components are very sensitive to static electricity. Generally, RF components are less than 1KV (1000 volts). The EU CE electrostatic regulations are 8kv (8000 volts). The static electricity generated by nature often reaches 15KV. When static electricity is generated, the RF components are often destroyed, and the RF function is disabled. Therefore, an electrostatic component must be added between the antenna and the RF component to protect the RF component from electrostatic damage.

Generally, the antenna is usually used to transmit and receive high-frequency signals. At the same time, in the process of operation, it is also possible to discharge a large amount of external electrostatic charges to the antenna of the mobile phone. This static electricity will be transmitted along the transmission line connected to the back end to other radio frequencies connected to the back end. Electronic components that cause damage to these RF components or cause The distortion of the signal. Therefore, when the antenna is subjected to electrostatic attack, the electrostatic signal must be immediately suppressed to protect the RF component from electrostatic damage.

There is an ESD suppressor (such as TVS diode or varistor) in the prior art. Using a concept similar to a varistor, when static electricity occurs, the electrostatic current will be transmitted to the ground through the ESD suppressor, thereby preventing the electrostatic current from damaging the RF circuit. However, its electrostatic capacity is limited by the limited ESD suppression. Not all ranges of electrostatic voltage (ex 12kV~15kV) can be effectively suppressed. Therefore, the suppression effect of static current in some ranges is actually not ideal.

The general RF antenna or mobile phone antenna design is based on Pifa. Since the Pifa antenna itself has been grounded, there is no ESD problem after the system is formed. However, if the ESD is generated and discharged to the antenna signal shrapnel or pin pin during the assembly process of the Pifa antenna, it is easy to damage the RF component due to static electricity. If the antenna is designed as a monopole antenna, the antenna is generally shielded from the edge of the casing to achieve non-discharge, and electrostatic (ESD) protection is generated. General antenna ESD protection adds an ESD suppression component grounding method between the antenna and the RF circuit to solve the static problem. In order to reduce the influence of high frequency RF signals, ESD static suppression components must be designed with ultra-low capacitance values. Therefore, the capacitance value C of TVS, Varistor, Polymer, etc. must be less than or equal to 0.5 pF, and the ultra-low capacitance value makes the electrostatic suppression component extremely electrostatic. Poor, and will slightly affect the RF signal. Because the design curve of the mobile phone or RF device is miniaturized, the design of the mechanism-covered antenna is often limited, and the electrostatic protection effect IEC61000-4-2 L3 (Air +/- 8kV) is not achieved. Furthermore, ESD suppression components are expensive and have poor electrostatic protection (~Air 8kv) and cannot meet the IEC61000-4-2 L4 (Air 15kv) standard.

Therefore, this case hopes to propose a new electrostatic protection module for the antenna to solve the defects of the prior art.

Therefore, the purpose of the present invention is to solve the above-mentioned problems in the prior art, and propose an electrostatic protection module for an antenna, which can effectively solve the electrostatic discharge (ESD) problem of the radio frequency circuit. Generally, after a monopole (Monopole) antenna is subjected to an electrostatic shock, static electricity enters the RF component via the RF path, and the RF component such as an amplifier or a switcher, or a FEM (Front End Module) or SAW filter or the like is subjected to static electricity. damage. Inductive and capacitive C components of this case can be used as an impedance matching part of the RF signal line in addition to anti-static. And the static suppressor of this case does not affect the quality of the RF signal.

In order to achieve the above object, an electrostatic protection module for an antenna is provided in the present invention, comprising: an antenna for receiving an external signal; an RF circuit for receiving a high frequency signal from the antenna, and the high frequency The signal is converted to a baseband signal to facilitate subsequent signal processing of the electronic component; a static suppressor is a single electrostatic module that is connected between the antenna and the RF circuit; wherein the static suppressor includes one day a line end connection port, a radio frequency end port, a ground end, and a suppression circuit; an antenna end transmission line is connected between the output end of the antenna and the antenna end connection of the static suppressor; and an RF end transmission line connection Between the input and output ends of the RF circuit and the RF terminal of the static suppressor; wherein the suppression circuit includes a capacitor C connected across the antenna terminal and the RF terminal One end of the capacitor C is an antenna connection end and the other end is an RF connection end. The capacitor C can pass another high frequency signal to block the low frequency electrostatic current; a first inductor L1, the first end of the first inductor L1 Connected to the antenna connection of the capacitor C, and the other end is introduced to the ground. The electrostatic module can replace a plurality of electrostatic TVS and impedance matching components with a small part, which is more economical and miniaturized.

The features of the present invention and its advantages can be further understood from the description below, and please refer to the attached drawings when reading.

10‧‧‧Antenna

30‧‧‧Electrostatic suppressor

31‧‧‧Antenna connection埠

32‧‧‧RF terminal 埠

33‧‧‧ Grounding terminal

34‧‧‧Suppression circuit

Figure 1 shows a block diagram of the components of the present invention.

Figure 2 shows a block diagram of the components of the present invention, which also includes an impedance matching circuit and an RF switch.

Figure 3 shows the structure of the electrostatic suppressor of the present invention.

Figure 4 shows that the second inductor is still set in this case.

Figure 5 shows a schematic diagram of the application of the static suppressor of the present invention.

Figure 6 shows a schematic view of the application of the static suppressor of the present invention, which shows no installation direction limitation.

Figure 7 shows a conventional technique.

In view of the structural composition of the case, and the functions and advantages that can be produced, in conjunction with the drawings, a preferred embodiment of the present invention is described in detail below.

Referring to FIG. 1 to FIG. 6, the electrostatic protection module of the antenna of the present invention includes the following components: an antenna 10 for receiving an external signal.

In addition to the high frequency signal, the antenna 10 may also have a large amount of static electricity due to external sensing. When the static electricity is too large, the static electricity will be transmitted to the other electronic components connected to the back end along with the transmission line connected at the back end, resulting in the radio frequency component. Damage, or cause distortion of the signal. Therefore, it is necessary to suppress the static electricity.

In the present case, the antenna 10, such as the monopole antenna 10, can be used to perform electrostatic protection of the RF circuit 20 of the RF (GSM, CDMA, WCDMA, GPS, WiFi, BT, NFC) lines of the monopole antenna 10.

An RF circuit 20 is configured to receive the high frequency signal from the antenna 10 and convert the high frequency signal to a baseband signal to facilitate subsequent signal processing of the electronic component.

An electrostatic suppressor 30, as shown in FIG. 3, is a single electrostatic module that is connected between the antenna 10 and the RF circuit 20 and is used to ground the static electricity from the antenna end without Flow into the RF circuit 20.

The static suppressor 30 includes an antenna end connection port 31, a radio frequency end connection port 32, a ground end 33, and a suppression circuit 34. When connecting, connecting an antenna end transmission line to the output end of the antenna 10 and the static The antenna end of the electrical suppressor 30 is connected between the ports 31; and an RF terminal transmission line is connected between the input and output ends of the RF circuit 20 and the RF terminal port 32 of the static suppressor 30. The circuit of its overall combination is shown in Figure 2.

The suppression circuit 34 includes a capacitor C connected between the antenna end connector 31 and the RF terminal port 32. One end of the capacitor C is an antenna connection end and the other end is a radio frequency connection end. The capacitor C The high frequency signal can be passed through to block the low frequency electrostatic current. a first inductor L1, the first end of the first inductor L1 is connected to the antenna connection end of the capacitor C, and the other end is connected to the ground end 33; a second inductor L2, the first end of the second inductor L2 Connected to the RF connection of the capacitor C, and the other end is connected to the ground terminal 33. The first inductor L1 and the second inductor L2 can pass a low-frequency electrostatic current and block the high-frequency signal.

Preferably, as shown in FIG. 5 and FIG. 6, the static suppressor 30 can be realized in a modular manner, and replacing a plurality of electrostatic TVS and impedance matching components with a small component will be more economical and miniaturized. The static suppressor 30 can be designed as an industry standard SOD883 (size 1x0.6x0.5mm) package, and its internal equivalent circuit is composed of a capacitor C and two inductors L to form a π type, which has no directionality and is convenient for engineers to use. . The antenna end port 31 (A end) can be connected to the input end of the antenna 10. The RF end port 32 (B end) can be connected to the input and output end of the RF circuit 20, and the ground end 33 (C end) is grounded. Since the component has no directionality, the antenna end port 31 (A end) can also be connected to the input and output end of the RF circuit 20, and the RF end port 32 (B end) can also be connected to the input and output end of the antenna 10. Ground terminal 33 (C terminal) is also connected Ground.

The static suppressor 30 can be packaged in a SOD883 package, but is not limited to SOD883. And to achieve a compact design. Traditionally, engineers have implemented RF impedance matching and electrostatic protection with multiple 0201 or 0402 inductors or capacitors or TVS parts. The present invention can effectively solve the electrostatic problem and impedance matching problem of the antenna by a SOD883 component.

In practice, the inductance L and the capacitance value C can be varied with different frequency bands such as GSM, CDMA, WCDMA, GPS, WiFi, BT. . Some adjustments are made, but the inductance L and the capacitance value C are maintained at the following values to achieve better ESD protection (at least Air +/- 8 kV). Preferably, L<56nH and C<39pF, wherein the inductors L1 & L2, if designed in a winding configuration (High Q), will provide a lower direct current impedance of the electrostatic signal to achieve an optimum static suppression effect.

In this case, the capacitance C value, the first inductance L1 value and the second inductance L2 value of the suppression circuit 34 can be designed for different frequency band applications, and the module is convenient for use by the research and development personnel. In this case, the capacitor C value, the first inductor L1 value, and the second inductor L2 value can also be adjusted, so that the static suppressor 30 does not affect the RF signal and has a good electrostatic effect.

The case also has the function of adjusting the C value of the capacitor, the value of the first inductor L1 and the value of the second inductor L2 to achieve the impedance matching function of the antenna 10, which can solve the problem of static electricity and impedance matching for the R&D engineer at the same time, and save a lot of problems. Adjust the matching line and the time to solve the ESD problem (impedance match, ex: 50Ω).

Therefore, the high frequency signal from the antenna 10 can be applied to the RF circuit 20 through the capacitor when the device is connected, and most of the low frequency electrostatic current is blocked by the capacitor and flows into the ground terminal 33 via the first inductor L1. The RF circuit 20 is entered to cause damage to the subsequent electronic components. A small portion of the low-frequency electrostatic current may still be discharged from the second inductor L2 to the ground terminal 33 through the capacitor C, so the electrostatic signal can be eliminated by applying the circuit of the present invention. Therefore, the static suppressor 30 of the present application can effectively transmit the high frequency signal between the antenna 10 and the RF circuit 20, and the harmful electrostatic current is guided to the ground through the first inductor L1 and the second inductor L2. End 33, so it can protect the safe operation of the circuit from damage.

As shown in FIG. 2, in the present case, the second inductor L2 may not be used, and only the first inductor L1 may be used.

As shown in FIG. 4, in the present case, an impedance matching circuit 40 may be added to the RF end transmission line or the antenna end transmission line to perform impedance matching between the high frequency components at both ends; or the RF end transmission line or the antenna end transmission line may be used. The RF switch 50 is added to perform the switching operation of the circuit.

In the present case, an electrostatic suppressor 30 is added between the RF circuit 20 and the antenna 10, and the inductor L (inductance) and the capacitor C (Capacitor) are combined to protect the RF circuit 20 from static electricity received from the antenna 10 (ESD). ) Damage caused by electric shock. The module made by appropriately adjusting the inductance L and the capacitance C value can be used as an impedance matching of the RF signal in addition to the electrostatic protection. Its application range includes: mobile phones, wireless products The static electricity (ESD) of the monopole antenna 10 is eliminated. This case is applicable to GSM, CDMA, WCDMA, GPS, LTE, WiFi, BT and other high frequency communication bands. Its electrostatic protection capability is up to +/-15kV.

The advantage of this case is that the RF circuit 20 can be applied to a wide range of RF (GSM, CDMA, WCDMA, GPS, WiFi, BT, NFC) lines of the monopole antenna 10 for electrostatic protection. ESD modules can be designed for different frequency band applications for developers to use. For example, the L1, L2, and C values can be adjusted for the GPS frequency, so that the electrostatic protection module does not affect the RF signal and has a good electrostatic effect. The case also has the function of adjusting the C value of the capacitor, the value of the first inductor L1 and the value of the second inductor L2 to achieve the impedance matching function of the antenna 10, which can solve the problem of static electricity and impedance matching for the R&D engineer at the same time, and save a lot of problems. Adjust the time to match the line and solve the ESD problem. The price is extremely low, and the anti-ESD effect is excellent. Generally, the static electricity protection can reach IEC61000-4-2 L4 Air +/- 15kV or more (still depending on the electrostatic resistance of the RF circuit 20). The lower ground inductance of the equivalent circuit of this ESD module is best if it uses a wound-high Q inductor.

In summary, the innovative design of this case is quite in line with actual needs. The specific improvement of the existing defects is obviously a breakthrough improvement advantage compared with the prior art, and it has an improvement in efficacy and is not easy to achieve. The case has not been disclosed or disclosed in domestic and foreign literature and market, and has complied with the provisions of the Patent Law.

The detailed description above is a detailed description of one of the possible embodiments of the present invention, and the embodiment is not intended to limit the scope of the patents, and the equivalent implementations or modifications that are not included in the spirit of the present invention should be included in The patent scope of this case.

10‧‧‧Antenna

30‧‧‧Electrostatic suppressor

Claims (10)

An electrostatic protection module for an antenna includes: an antenna for receiving an external signal; and an RF circuit for receiving a high frequency signal from the antenna and converting the high frequency signal to a fundamental frequency signal to For the subsequent electronic components to perform signal processing; an electrostatic suppressor, which is a single electrostatic module, which internally contains a capacitor and an inductor component, the static suppressor is connected between the antenna and the RF circuit for receiving from the antenna The static discharge of the terminal is grounded, and does not flow into the RF circuit, and the static suppressor has the impedance matching function of the antenna, and the capacitance value and the inductance value are adjusted to achieve the impedance matching purpose. The electrostatic protection module of the antenna of claim 1, wherein the static suppressor comprises an antenna end connection port, a radio frequency end connection port, a ground end, and a suppression circuit; and an antenna end transmission line is connected to the antenna. The output end is connected between the antenna end of the static suppressor; and an RF end transmission line is connected between the input end of the RF circuit and the RF end port of the static suppressor, and the ground is connected to the suppression circuit. The suppression circuit includes a capacitor connected between the antenna end connection port and the RF end connection port. One end of the capacitor is an antenna connection end and the other end is an RF connection end, and the capacitor can be another high frequency signal. Through Blocking the low frequency electrostatic current; a first inductor, one end of the first inductor is connected to the antenna connection end of the capacitor, and the other end is introduced to the ground end. The electrostatic protection module of the antenna of claim 1, wherein the static suppressor comprises an antenna end connection port, a radio frequency end connection port, and a ground end, wherein the internal circuit of the static suppressor comprises a capacitor and 2 The inductors are combined into a π-type circuit, wherein the antenna end is connected to the output end of the antenna, and the RF end is connected to the input and output end of the RF circuit, and the ground is grounded; wherein the antenna end is connected The input end of the RF circuit can also be connected, and the RF end port can also be connected to the input and output end of the antenna, and the ground end is also grounded. The static suppressor has no limitation of installation directivity. The electrostatic protection module of the antenna of claim 2, further comprising a second inductor, one end of the second inductor being connected to the RF connection end of the capacitor, and the other end being introduced to the ground end; the first The inductor and the second inductor allow a low frequency electrostatic current to flow through and block high frequency signals. The electrostatic protection module of the antenna of claim 2, wherein the capacitance value, the first inductance value, and the second inductance value can be adjusted, so that the static suppressor does not affect the RF signal and has a good electrostatic effect. . For example, the electrostatic protection module of the antenna of claim 2, wherein the capacitance value of the suppression circuit can be adjusted for different frequency bands, The first inductance value and the second inductance value. The electrostatic protection module of the antenna of claim 2, further comprising an impedance matching circuit, wherein the impedance matching circuit is disposed in the RF end transmission line or the antenna end transmission line to perform impedance matching of the high frequency components at both ends . For example, the electrostatic protection module of the antenna of claim 2 includes an RF switch, and the RF switch is disposed in the RF end transmission line or the antenna end transmission line to perform a switching operation of the circuit. For example, the electrostatic protection module of the antenna of claim 2, wherein the capacitance value and the first inductance value can be adjusted to achieve impedance matching of the antenna, thereby eliminating the need for an additional configuration impedance matching circuit. The electrostatic protection module of the antenna of claim 4, wherein the capacitance value, the first inductance value and the second inductance value are all adjustable to achieve impedance matching of the antenna, and the impedance matching circuit is additionally configured. Demand.