Onboard antenna and electronic device
By designing LC band-stop filter circuit and flexible matching unit in the onboard antenna, the problems of onboard antenna testing accuracy and impedance debugging are solved, and the high-impedance open circuit state is achieved, which reduces energy leakage and line loss and improves the conduction test. Accuracy and stability.
Patent Information
- Application Number
- CN202111599663.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-12-24
- Publication Date
- 2024-12-24
- Estimated Expiration
- 2041-12-24
AI Technical Summary
During the testing process, existing onboard antennas have problems such as limited accuracy, inability to fully debug and converge, antenna matching changes require re-debugging and line loss, which affects the accuracy and flatness of the conduction test.
Design an on-board antenna, including the motherboard, connecting circuit and test pad group, and form an LC band-stop filter circuit through the test pad group and the matching unit to ensure that the antenna is in a high-impedance open-circuit state during testing, reduce radiation, and pass flexibility Adjust the matching unit to ensure the accuracy and flatness of the conduction test, avoiding fixture debugging and line loss.
The accuracy and flatness of the conduction test are achieved, energy leakage is reduced, structure and operation are simplified, line loss is avoided, and the accuracy and stability of the test are improved.
Smart Images
Figure CN114243291B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of antenna technology, and in particular to a board-mounted antenna and electronic equipment. Background Art
[0002] In the prior art, the onboard antenna needs to be tested for RF conduction indicators in the factory before leaving the factory to detect defective products. Figure 1 As shown, the input and output power have the following relationship: P in =P out1 +P out2 , P in is the power input to the RF front-end circuit, P out1 is the output power radiated by the antenna, P out2 For the conduction test, we need P out2 ≈P in , so it is necessary to reduce P as much as possible out1 , that is, suppressing the radiation of the antenna during the test.
[0003] At present, the method for testing the power of the onboard antenna is to use a fixture to connect the wire to short-circuit the antenna end, adjust the onboard antenna to the high resistance area as much as possible, and reduce the energy leakage during the test conduction process. However, this method has the following defects:
[0004] (1) The accuracy of the physical length of the wire is limited and difficult to control. The impedance at the antenna end cannot be fully debugged and converged, which affects the absolute value and flatness of the conduction test. At the same time, the antenna without series capacitors cannot be debugged to the high resistance area.
[0005] (2) Changes in antenna matching will result in changes in antenna end impedance, which requires re-debugging based on the factory fixture environment.
[0006] (3) The minimum line length is limited by the minimum distance between the two short-circuit points. In some cases, this solution cannot be debugged to high resistance. Summary of the invention
[0007] The present invention provides a board-mounted antenna and electronic equipment. The board-mounted antenna can ensure the accuracy and flatness of the absolute value of the conduction test, avoids the use of fixture debugging and line loss, has a simple structure, and is easy to operate.
[0008] In order to achieve the above object, the present invention provides the following technical solutions:
[0009] A board-mounted antenna, comprising:
[0010] A main board, the main board comprising a main body area and a panel area connected to the main body area;
[0011] A connection circuit located in the main body area, the connection circuit comprising a radio frequency front-end circuit, an antenna matching circuit and an antenna circuit connected in sequence, the antenna circuit having a first matching unit;
[0012] A test pad group is located in the panel area, the input end of the test pad group is electrically connected to the input end of the first matching unit, the output end of the test pad group is electrically connected to the output end of the first matching unit, and the test pad group is used to connect a second matching unit that can form an LC band-stop filter circuit with the first matching unit.
[0013] Optionally, the test pad group includes at least one pad pair, and each pad pair includes two connecting pads.
[0014] Optionally, the test pad group includes a first pad pair, a second pad pair and a third pad pair;
[0015] Two connecting pads in the first pad pair are electrically connected to an input end of the first matching unit and an output end of the first matching unit respectively;
[0016] The second pad pair is connected in series with the third pad pair, and the second pad pair and the third pad pair connected in series are connected in parallel with the first pad pair.
[0017] Optionally, the first matching unit includes at least one capacitor, and each of the pad pairs can be used to connect to an inductor element.
[0018] Optionally, the first matching unit includes at least one inductor, and each of the pad pairs can be used to connect to a capacitive element.
[0019] Optionally, the antenna circuit is a ceramic antenna or a left-handed antenna.
[0020] Optionally, the antenna circuit can be reused as the first matching unit.
[0021] Optionally, it further includes a conductive test point arranged in the main body area, and the conductive test point is electrically connected to the input end of the antenna matching circuit.
[0022] Optionally, the antenna matching circuit is a π-type matching circuit.
[0023] The present invention also provides an electronic device, comprising any one of the onboard antennas provided in the above technical solutions.
[0024] Beneficial effects of the present invention:
[0025] An embodiment of the present invention provides an on-board antenna and an electronic device, wherein the on-board antenna includes a main board, a connecting circuit located on the main board, and a test pad group, wherein the main board includes a main body area and a panel area connected to the main body area, the connecting circuit is located in the main body area of the main board, the connecting circuit includes a radio frequency front-end circuit, an antenna matching circuit, and an antenna circuit connected in sequence, the antenna circuit has a first matching unit, the test pad group is located in the panel area of the main board, the input end of the test pad group is electrically connected to the input end of the first matching unit, the output end of the test pad group is electrically connected to the output end of the first matching unit, and the second matching unit is connected to the test pad. , so that the first matching unit and the second matching unit are matched to form an LC band-stop filter circuit, which can make the antenna circuit in a high-impedance open-circuit state during the conduction index test before leaving the factory, inhibit the antenna radiation during the test, reduce energy leakage, and thus reduce the impact of the on-board antenna on the conduction index test. When the antenna matching circuit is changed, the second matching unit that cooperates with the first matching unit can be flexibly adjusted to ensure the accuracy and flatness of the absolute value of the conduction test. Moreover, after the factory test is completed, the panel area of the mainboard can be cut off, avoiding the use of fixture debugging and line loss. The structure is simple and the operation is convenient. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 The relationship between the input power and output power of the onboard antenna is shown in the figure;
[0027] Figure 2 A schematic structural diagram of a board-mounted antenna provided by an embodiment of the present invention;
[0028] Figure 3 A schematic structural diagram of a second matching unit provided in an embodiment of the present invention.
[0029] icon:
[0030] 1-main board; 11-main body area; 12-panel area; 21-RF front-end circuit; 22-antenna matching circuit; 23-first matching unit; 24-conduction test point; 3-second matching unit; 31-first electronic component; 32-second electronic component; 33-third electronic component. DETAILED DESCRIPTION
[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0032] Please refer to Figure 2, an embodiment of the present invention provides a board-mounted antenna, comprising:
[0033] A main board 1, comprising a main body area 11 and a panel area 12 connected to the main body area 11;
[0034] A connection circuit located in the main body area 11, the connection circuit includes a radio frequency front-end circuit 21, an antenna matching circuit 22 and an antenna circuit connected in sequence, and the antenna circuit has a first matching unit 23;
[0035] The test pad group is located in the panel area 12, the input end of the test pad group is electrically connected to the input end of the first matching unit 23, the output end of the test pad group is electrically connected to the output end of the first matching unit 23, and the test pad group is used to connect the second matching unit 3 that can form an LC band-stop filter circuit with the first matching unit 23.
[0036] The on-board antenna provided by the above-mentioned embodiment of the invention includes a main board 1, a connecting circuit located on the main board 1, and a test pad group, wherein the main board 1 includes a main body area 11 and a panel area 12 connected to the main body area 11, the connecting circuit is located in the main body area 11 of the main board 1, the connecting circuit includes a radio frequency front-end circuit 21, an antenna matching circuit 22 and an antenna circuit connected in sequence, the antenna circuit has a first matching unit 23, the test pad group is located in the panel area 12 of the main board 1, since the input end of the test pad group is electrically connected to the input end of the first matching unit 23, the output end of the test pad group is electrically connected to the output end of the first matching unit 23, the second matching unit 3 is connected to the test pad, so that the first matching unit 23 and the second matching unit 3 are matched to form an LC band-stop filter circuit, which can make the antenna circuit in a high-impedance open circuit state (i.e., the antenna Smith) during the conduction index test before leaving the factory. Chart can converge in the high-resistance open-circuit area), which inhibits antenna radiation during the test and reduces energy leakage, thereby reducing the impact of the on-board antenna on the conduction index test when it is in place, and when the antenna matching circuit 22 is changed, the second matching unit 3 coordinated with the first matching unit 23 can be flexibly adjusted to ensure the accuracy and flatness of the absolute value of the conduction test. Moreover, after the factory test is completed, the panel area 12 of the mainboard 1 can be cut off, avoiding the use of fixture debugging and line loss, with a simple structure and easy operation.
[0037] In the above-mentioned invention embodiment, the test pad group may include at least one pad pair, and each pad pair includes two connecting pads. For example, the test pad group includes a pad pair, and the two connecting pads in a pad pair are respectively connected to the input end and the output end of the first matching unit 23. When the antenna matching circuit 22 is changed, the accuracy and flatness of the absolute value of the conduction test can be guaranteed by flexibly adjusting the second matching unit 3 connected to the pad pair.
[0038] Specifically, in order to ensure the accuracy of the conduction test, the above-mentioned test pad group may include a first pad pair, a second pad pair and a third pad pair; wherein, the two connecting pads in the first pad pair may be electrically connected to the input end of the first matching unit 23 and the output end of the first matching unit 23 respectively; the second pad pair is connected in series with the third pad pair, and the second pad pair and the third pad pair connected in series are connected in parallel with the first pad pair.
[0039] In the above-mentioned embodiment of the invention, three pad pairs are reserved in the panel area 12, which can match a series-parallel combination. By utilizing the relationship between the first pad pair, the second pad pair and the third pad pair in the test pad group in the circuit, different electronic components can be flexibly connected to the first pad pair, the second pad pair and the third pad pair, and the electronic components connected to the test pad group form different second matching units 3, so that the values of various second matching units 3 can be accurately equivalent, which is conducive to controlling the frequency of the LC band-stop filter circuit, thereby ensuring the accuracy of the conduction test. For example, when performing a conduction test, electronic components can be connected to the second pad pair and the third pad pair respectively, and the two electronic components are connected in series to form the second matching unit 3, and the second matching unit 3 can cooperate with the first matching unit 23 to form an LC band-stop filter circuit; or, electronic components are connected to the first pad pair, the second pad pair and the third pad pair, and the three electronic components form the second matching unit 3, and the second matching unit 3 can cooperate with the first matching unit 23 to form an LC band-stop filter circuit.
[0040] Optionally, the first matching unit 23 may include at least one capacitor, and the first matching unit 23 may be equivalent to a capacitor. Then, each connecting pad pair in the test pad group can be used to connect to an inductive element, and the inductive element connected to the test pad group can form a second matching unit 3. The second matching unit 3 may be equivalent to an inductor. The first matching unit 23 and the second matching unit 3 may cooperate to form an LC band-stop filter circuit.
[0041] Optionally, the first matching unit 23 includes at least one inductor, and the first matching unit 23 can be equivalent to an inductor. Then, each connecting pad pair in the test pad group can be used to connect to a capacitive element, and the capacitive element connected to the test pad group can form a second matching unit 3. The second matching unit 3 can be equivalent to a capacitor. The first matching unit 23 and the second matching unit 3 can cooperate to form an LC band-stop filter circuit.
[0042] In a specific embodiment, Figure 3As shown, assuming that the first pad pair, the second pad pair and the third pad pair in the above-mentioned test pad group can be connected to the first electronic component 31, the second electronic component 32 and the third electronic component 33 respectively, the first electronic component 31, the second electronic component 32 and the third electronic component 33 belong to the same type of components (capacitive component or inductive component), wherein the value of the first electronic component 31 is a, the value of the second electronic component 32 is b, the value of the third electronic component 33 is c, and the equivalent value of the first matching unit 23 is d. By flexibly adjusting the first electronic component 31, the second electronic component 32 and the third electronic component 33 of different numerical values to be connected to the test pad group, the values of various inductive components or capacitive components can be accurately equivalent, the frequency of the LC band-stop filter circuit can be accurately controlled, and the accuracy of the conduction test can be ensured.
[0043] The matching theoretical calculation formula of the first matching unit 23 and the second matching unit 3 can be as follows, assuming that the center frequency of the frequency band to be tested is f m , then . The values of each electronic component of the second matching unit 3 can be calculated by the above matching theory calculation formula under different first matching units 23 and the center frequency of the frequency to be tested. Table 1 shows some exemplary examples of the calculated values of the electronic components in the second matching unit 3, and NC indicates that no electronic component is attached to the corresponding pad pair. In practical applications, the values of each electronic component in the second matching unit 3 can be calculated according to the above matching theory calculation formula, and the corresponding electronic component is connected to the corresponding pad pair in the test pad group, which can improve the accuracy, stability and adjustability of the test when performing power testing.
[0044] Table 1
[0045] <![CDATA[f m ]]> d a b c 2450MHz 0.5pF NC 6.2nH 2.2nH 2450MHz 2.2nH 0.5pF 3pF 2.7pF 1575MHz 0.5pF 6.8nH NC NC
[0046] In a specific implementation, the antenna circuit may be a ceramic antenna or a left-handed antenna, realizing the functions of antenna radiation and tuning.
[0047] In addition, the above-mentioned antenna circuit can be reused as the first matching unit 23, that is, when the antenna circuit is a ceramic antenna or a left-handed antenna, the antenna circuit as a whole can act as the first matching unit 23, and the two ends of the second matching unit 3 are respectively connected to the two ends of the antenna circuit, and the second matching unit 3 and the antenna circuit can cooperate to form an LC band-stop filter circuit.
[0048] That is to say, the first matching unit 23 may be a partial electronic component in the antenna circuit, or may be the entire antenna circuit, which is not limited here and may be determined according to actual conditions.
[0049] In a specific implementation, the antenna matching circuit 22 is used for antenna tuning and may be a π-type matching circuit or other matching circuits, which are not limited here and are determined according to actual conditions.
[0050] In the above-mentioned embodiment of the invention, the onboard antenna may further include a conduction test point 24 arranged in the main body area 11. Specifically, the conduction test point 24 may be a copper leaking dot on the main board. The conduction test point 24 is electrically connected to the input end of the antenna matching circuit 22, that is, the RF test point is placed at the input end of the antenna matching circuit 22. During the test, the test can be performed by pushing the pin of the fixture on the conduction test point, and the antenna circuit cannot be disconnected during the test. The test pad group reserved on the panel area 12 is connected to the components in the second matching unit 3, so that the second matching unit 3 is combined with the first matching unit 23 in the antenna circuit to form an LC band-stop filter circuit, so that the antenna is in a high-impedance open circuit state during the conduction index test, and the RF conduction performance of the single board can be accurately tested.
[0051] The present invention also provides an electronic device, comprising any one of the onboard antennas provided in the above technical solutions.
[0052] Obviously, those skilled in the art can make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A board-mounted antenna, characterized in that: include: A main board, the main board comprising a main body area and a panel area connected to the main body area; A connection circuit located in the main body area, the connection circuit comprising a radio frequency front-end circuit, an antenna matching circuit and an antenna circuit connected in sequence, the antenna circuit having a first matching unit; A test pad group located in the panel area, wherein the input end of the test pad group is electrically connected to the input end of the first matching unit, the output end of the test pad group is electrically connected to the output end of the first matching unit, and the test pad group is used to connect a second matching unit that can form an LC band-stop filter circuit with the first matching unit; A conduction test point is arranged in the main body area, and the conduction test point is electrically connected to the input end of the antenna matching circuit; when the conduction test point is tested, the LC band-stop filter circuit can put the antenna circuit in a high-impedance open circuit state.
2. The onboard antenna according to claim 1, characterized in that: The test pad group includes at least one pad pair, and each of the pad pairs includes two connection pads.
3. The onboard antenna according to claim 2, characterized in that: The test pad group includes a first pad pair, a second pad pair and a third pad pair; Two connecting pads in the first pad pair are electrically connected to an input end of the first matching unit and an output end of the first matching unit respectively; The second pad pair is connected in series with the third pad pair, and the second pad pair and the third pad pair connected in series are connected in parallel with the first pad pair.
4. The onboard antenna according to claim 3, characterized in that: The first matching unit includes at least one capacitor, and each of the pad pairs can be used to connect to an inductor element.
5. The onboard antenna according to claim 3, characterized in that: The first matching unit includes at least one inductor, and each of the pad pairs can be used to connect to a capacitive element.
6. The onboard antenna according to any one of claims 1 to 5, characterized in that: The antenna circuit is a ceramic antenna or a left-handed antenna.
7. The onboard antenna according to claim 6, characterized in that: The antenna circuit can be reused as the first matching unit.
8. The onboard antenna according to any one of claims 1 to 5, characterized in that: The antenna matching circuit is a π-type matching circuit.
9. An electronic device, characterized in that: Comprising the onboard antenna as described in any one of claims 1-8.