Antenna Tuning System

Abstract

An antenna tuning system includes an antenna module and a tuning module. The antenna module has a feed path and a ground path, and the tuning module is connected to the ground path of the antenna module. The tuning module includes a plurality of passive component circuits and a switching circuit. The plurality of passive component circuits are connected to the ground path of the antenna module, and the switching circuit is connected to the plurality of passive component circuits. The common contact of the switching circuit is connected to a ground terminal, wherein the switching circuit is used to selectively connect at least one of the plurality of passive component circuits to the ground terminal.

Description

[Technical Field]

[0001] This invention relates to an antenna tuning system. [Previous Technology]

[0002] In existing communication products, to enable broadband applications, the antenna is connected to an impedance tuner or an aperture tuner. Generally, an impedance tuner or aperture tuner has a switching element and a plurality of passive component circuits. The antenna is connected to the common contact of the switching element, while the normally open and normally closed contacts of the switching element are respectively connected to the plurality of passive component circuits. The antenna frequency band can be switched by selectively connecting one of the plurality of passive component circuits through the switching element. That is, the antenna is connected to a passive component circuit with a specific impedance through the switching element to support the frequency band corresponding to that impedance.

[0003] However, the aforementioned designs using impedance tuners or aperture tuners can only support a limited frequency band. To increase the frequency band supported by the antenna, the number of passive component circuits must be increased, which contradicts the need to reduce the size of communication products. Therefore, how to provide an antenna tuning system that can still support wideband design in a limited space environment has become an urgent issue for the industry to solve. [Summary of the Invention]

[0004] In order to solve the various problems of the aforementioned prior art, one of the objectives of the present invention is to provide an antenna tuning system that can still support wideband design in a limited space environment.

[0005] To achieve the aforementioned objective, an antenna tuning system of the present invention includes an antenna module and a tuning module. The antenna module has a feed path and a ground path, and the tuning module is connected to the ground path of the antenna module. The tuning module includes a plurality of passive component circuits and a switching circuit. The plurality of passive component circuits are connected to the ground path of the antenna module, and the switching circuit is connected to the plurality of passive component circuits. The common contact of the switching circuit is connected to a ground terminal, wherein the switching circuit is used to selectively connect at least one of the plurality of passive component circuits to the ground terminal.

[0006] In one embodiment of the present invention, the antenna module is a PIFA antenna.

[0007] In one embodiment of the present invention, the plurality of passive element circuits include a plurality of single capacitor circuits.

[0008] In one embodiment of the present invention, the capacitance values ​​of the plurality of single capacitor circuits are arranged in powers of 2.

[0009] In one embodiment of the present invention, a plurality of passive element circuits include a single zero-ohm circuit.

[0010] In one embodiment of the present invention, the switching circuit is composed of a single-axis four-pole switch (SP4T), a single-axis three-pole switch (SP3T), a single-axis double-pole switch (SPDT), or a single-axis single-pole switch (SPST).

[0011] In one embodiment of the present invention, the switching circuit is composed of a single-axis four-way switch, and the RFC pin of the single-axis four-way switch is connected to the ground terminal through the GND pin.

[0012] In one embodiment of the present invention, the antenna tuning system further includes a flexible flat cable, and the antenna module and the tuning module are connected through the flexible flat cable.

[0013] In one embodiment of the present invention, the antenna tuning system further includes a circuit board disposed on the flexible flat cable, and the tuning module is disposed on the circuit board.

[0014] In one embodiment of the present invention, each of the plurality of passive element circuits includes a connection terminal connected to the antenna module, and the connection terminals are interconnected on the circuit board.

[0015] Compared to the prior art, the tuning module of the antenna tuning system of the present invention includes a plurality of passive element circuits and a switching circuit. The plurality of passive element circuits are connected to the ground path of the antenna module, and the switching circuit is connected to the plurality of passive element circuits. The common contact of the switching circuit is connected to a ground terminal. The switching circuit is used to selectively connect at least one of the plurality of passive element circuits to the ground terminal. More specifically, in addition to selectively connecting a single passive element circuit, the switching circuit of the present invention can simultaneously select a plurality of passive element circuits, allowing the plurality of passive element circuits to be connected in parallel to achieve an equivalent impedance different from that of a single passive element circuit. Therefore, the antenna tuning system of the present invention can support more frequency bands without the need for additional passive element circuits, effectively solving the problems of the prior art.

Implementation Method

[0020] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0021] Please refer to Figure 1, which is a schematic diagram of the antenna tuning system according to the first embodiment of the present invention. As shown in the figure, the antenna tuning system of the present invention includes an antenna module 10 and a tuning module 11. The antenna module 10 has a feed path 100 and a ground path 101. The tuning module 11 is connected to the ground path 101 of the antenna module 10. The tuning module 11 includes a plurality of passive element circuits 110a, 110b, 110c, 110d and a switching circuit 111. A plurality of passive element circuits 110a, 110b, 110c, and 110d are connected to the grounding path 101 of the antenna module 10. A switching circuit 111 is connected to the plurality of passive element circuits 110a, 110b, 110c, and 110d, and the common contact of the switching circuit 111 is connected to a grounding terminal 112. In one embodiment of the present invention, the switching circuit 111 can be used to selectively connect at least one of the plurality of passive element circuits 110a, 110b, 110c, and 110d to the grounding terminal 112.

[0022] The feed path 100 of the antenna module 10 is connected to the feed point for receiving or transmitting signals. In the embodiment shown in Figure 1, four passive element circuits 110a, 110b, 110c, and 110d are used as an example, but this is not a limitation. In other embodiments, there may be more or fewer passive element circuits. For example, passive element circuits 110a, 110b, 110c, and 110d can be composed of passive elements such as resistors, capacitors, and inductors, and can be designed to have different impedances to correspond to more frequencies.

[0023] More specifically, in order to tune the frequency used by the antenna tuning system of the present invention, the switching circuit 111 can selectively connect to one of the passive element circuits 110a, 110b, 110c, and 110d, for example, only connecting the passive element circuit 110a. In other words, when the passive element circuits 110a, 110b, 110c, and 110d are designed to have different impedances, the switching circuit 111 can connect to a single passive element circuit 110a, 110b, 110c, or 110d to correspond to four different frequencies. In other embodiments, the switching circuit 111 can also selectively connect to a plurality of passive element circuits 110a, 110b, 110c, and 110d simultaneously. For example, simultaneously connecting passive element circuits 110a and 110b, or simultaneously connecting passive element circuits 110a, 110b, and 110c, etc. When passive element circuits 110a and 110b are connected simultaneously, the equivalent impedance of the tuning module 11 is the parallel impedance of passive element circuits 110a and 110b. Therefore, connecting two arbitrary passive element circuits 110a, 110b, 110c, and 110d simultaneously can generate six different equivalent impedances. Connecting three arbitrary passive element circuits 110a, 110b, 110c, and 110d simultaneously can generate four different equivalent impedances. Connecting four passive element circuits 110a, 110b, 110c, and 110d simultaneously can generate one equivalent impedance. Therefore, taking four passive element circuits 110a, 110b, 110c, and 110d as an example, the antenna tuning system of this invention can correspond to 15 different frequencies. Compared to existing tuning methods that can only correspond to the same frequency as the passive element circuit, the antenna tuning system of this invention can support more frequency bands without the need for additional passive element circuits.

[0024] In one embodiment, the antenna module 10 may be a PIFA antenna, but is not limited thereto.

[0025] Please refer to Figure 2, which is a schematic diagram of the structure of the tuning module according to the second embodiment of the present invention. As shown in the figure, the tuning module 21 includes a plurality of passive element circuits 210a, 210b, 210c, 210d and a switching circuit 211. The passive element circuits 210a, 210b, 210c, 210d are connected to the grounding path 101 of the antenna module 10.

[0026] In one embodiment, the capacitance values ​​of the plurality of single-capacitor circuits 210b, 210c, and 210d may be arranged in powers of 2, but are not limited thereto. For example, passive element circuit 210a may be constructed with a zero-ohm resistor, passive element circuit 210b may be constructed with a 4pF capacitor, passive element circuit 210c may be constructed with a 2pF capacitor, and passive element circuit 210d may be constructed with a 1pF capacitor. Through such a design, the equivalent impedance of the tuning module 21 can be flexibly and finely adjusted, allowing the antenna to maintain good matching over a wider frequency band, suitable for broadband applications.

[0027] In one embodiment, the switching circuit 211 may be composed of a single-axis quad-switch (SP4T), a single-axis triple-switch (SP3T), a single-axis double-switch (SPDT), or a single-axis single-switch (SPST), but is not limited thereto. In the embodiment of FIG2, to correspond to the four passive element circuits 210a, 210b, 210c, and 210d, the switching circuit 211 is composed of a single-axis quad-switch. However, in other embodiments, the switching circuit 211 may be composed of two single-axis double-switches or four single-axis single-switches to also correspond to the four passive element circuits 210a, 210b, 210c, and 210d. When corresponding to three passive element circuits 210a, 210b, and 210c, the switching circuit 211 may be a single-axis triple-switch.

[0028] In one embodiment, the switching circuit 211 is composed of a single-axis four-way switch, and the RFC pin of the switching circuit 211 is connected to the ground terminal 212 through the GND pin. The RF1 pin of the switching circuit 211 is connected to the passive component circuit 210a, the RF2 pin is connected to the passive component circuit 210d, the RF3 pin is connected to the passive component circuit 210c, and the RF4 pin is connected to the passive component circuit 210b.

[0029] Please refer to Figure 3, which is a schematic diagram of the antenna tuning system according to the third embodiment of the present invention. As shown in the figure, the antenna tuning system may further include a flexible flat cable 32, and the antenna module 30 and the tuning module 31 are connected through the flexible flat cable 32. Generally speaking, in the extremely small space within communication or laptop products, it is more advantageous to connect the antenna module 30 and the tuning module 31 through a flexible flat cable 32.

[0030] In one embodiment, the antenna tuning system may further include a circuit board 33 disposed on the flexible flat cable 32, and the tuning module 31 disposed on the circuit board 33. Although the flexible flat cable 32 is advantageous for connecting the antenna module 30 and the tuning module 31 in a confined space, it is prone to loosening of contacts or poor contact. Therefore, a circuit board 33 may be further disposed on the flexible flat cable 32, and the tuning module 31 may be disposed on the circuit board 33 to increase the contact area between the tuning module 31 and the flexible flat cable 32, thereby improving the situation of loosening of contacts or poor contact.

[0031] Please refer to Figure 4, which is a structural schematic diagram of the antenna tuning system according to the fourth embodiment of the present invention. Referring also to Figures 3 and 4, the tuning module 41 is disposed on the circuit board 43. The tuning module 41 includes a plurality of passive component circuits 410a, 410b, 410c, 410d, a switching circuit 411, and a ground terminal 412. The passive component circuits 410a, 410b, 410c, and 410d respectively include connection terminals 430a, 430b, 430c, and 430d. The connection terminals 430a, 430b, 430c, and 430d are connected to the flexible flat cable 32 and connected to the antenna module 30 through the flexible flat cable 32. The connection terminals 430a, 430b, 430c, and 430d are interconnected on the circuit board 43 through wires 431.

[0032] More specifically, the connection terminals 430a, 430b, 430c, and 430d are directly connected to the flexible flat cable 32. If any of the connection terminals 430a, 430b, 430c, or 430d becomes loose or has poor contact, since the connection terminals 430a, 430b, 430c, and 430d are interconnected on the circuit board 43 through wires 431, all passive component circuits 410a, 410b, 410c, and 410d are tightly connected to the flexible flat cable 32, thus completely improving the occurrence of poor contact.

[0033] Compared to the prior art, the tuning module of the antenna tuning system of the present invention includes a plurality of passive element circuits and a switching circuit. The plurality of passive element circuits are connected to the ground path of the antenna module, and the switching circuit is connected to the plurality of passive element circuits. The common contact of the switching circuit is connected to a ground terminal. The switching circuit is used to selectively connect at least one of the plurality of passive element circuits to the ground terminal. More specifically, in addition to selectively connecting a single passive element circuit, the switching circuit of the present invention can simultaneously select a plurality of passive element circuits, allowing the plurality of passive element circuits to be connected in parallel to achieve an equivalent impedance different from that of a single passive element circuit. Therefore, the antenna tuning system of the present invention can support more frequency bands without the need for additional passive element circuits, effectively solving the problems of the prior art.

[0034] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Any person skilled in the art can modify and vary the above embodiments without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be as set forth in the following patent claims. [Simplified Explanation of the Diagram]

[0016] Figure 1 is a schematic diagram of the antenna tuning system according to the first embodiment of the present invention.

[0017] Figure 2 is a schematic diagram of the structure of the tuning module of the second embodiment of the present invention.

[0018] Figure 3 is a schematic diagram of the antenna tuning system according to the third embodiment of the present invention.

[0019] Figure 4 is a schematic diagram of the antenna tuning system of the fourth embodiment of the present invention.

Claims

1. An antenna tuning system, comprising: The antenna module has a feed path and a ground path; The antenna module includes a tuning module connected to the grounding path of the antenna module. The tuning module comprises: a plurality of passive element circuits connected to the grounding path of the antenna module; and a switching circuit connected to the plurality of passive element circuits, wherein the common contact of the switching circuit is connected to a ground terminal. The switching circuit is used to select at least two of the plurality of passive element circuits to be connected to the ground terminal. The switching circuit is composed of a single-axis four-way switch (SP4T), a single-axis three-way switch (SP3T), or a single-axis double-way switch (SPDT). The plurality of passive element circuits include a plurality of single-capacitor circuits, and the capacitance values ​​of the plurality of single-capacitor circuits are arranged in powers of 2.

2. The antenna tuning system as described in claim 1, wherein, This antenna module is a PIFA antenna.

3. The antenna tuning system as described in claim 1, wherein, The plurality of passive element circuits includes a single zero-ohm circuit.

4. The antenna tuning system as described in claim 1, wherein, The switching circuit consists of a single-axis four-way switch, and the RFC pin of the single-axis four-way switch is connected to the ground terminal through the GND pin.

5. The antenna tuning system as described in claim 1, wherein, The antenna tuning system also includes a flexible flat cable, and the antenna module and the tuning module are connected through the flexible flat cable.

6. The antenna tuning system as described in claim 5, wherein, The antenna tuning system also includes a circuit board disposed on the flexible flat cable, and the tuning module is disposed on the circuit board.

7. The antenna tuning system as described in claim 6, wherein, Each of the plurality of passive component circuits includes a connection terminal connected to the antenna module, and these connection terminals are interconnected on the circuit board.

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