CN116418308A - Impedance matching circuit - Google Patents
Impedance matching circuit Download PDFInfo
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- CN116418308A CN116418308A CN202111640380.1A CN202111640380A CN116418308A CN 116418308 A CN116418308 A CN 116418308A CN 202111640380 A CN202111640380 A CN 202111640380A CN 116418308 A CN116418308 A CN 116418308A
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- 238000001514 detection method Methods 0.000 claims abstract description 42
- 239000003990 capacitor Substances 0.000 claims description 64
- 230000001225 therapeutic effect Effects 0.000 claims description 9
- 230000001939 inductive effect Effects 0.000 claims description 6
- 238000010586 diagram Methods 0.000 description 18
- 238000000034 method Methods 0.000 description 4
- 230000004048 modification Effects 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 238000002560 therapeutic procedure Methods 0.000 description 2
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03H—IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS
- H03H7/00—Multiple-port networks comprising only passive electrical elements as network components
- H03H7/38—Impedance-matching networks
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Abstract
The invention provides an impedance matching circuit, which is characterized in that the impedance of a load is detected by an impedance detection module, the impedance of an adjustable impedance matching module can be adjusted by a control module according to the detection result of the impedance detection module, and even if the impedance of the load is changed, the impedance of the adjustable impedance matching module can be readjusted, so that the radio frequency reflected power can be effectively reduced, the maximization of radio frequency energy is kept, and meanwhile, the service life and the safety of the circuit are ensured.
Description
Technical Field
The present disclosure relates to electronic circuits, and particularly to an impedance matching circuit.
Background
The impedance matching circuit is generally connected between the radio frequency power supply and the load, and if the impedance between the radio frequency power supply and the load is not matched in the process of transmitting the radio frequency signal to the load, part of energy is reflected, so that the radio frequency energy cannot be utilized to the maximum extent, and the efficiency of the circuit is reduced; in addition, the larger reflected power may also cause damage to the circuit. Therefore, reducing the radio frequency reflected power through the impedance matching network is important in the impedance matching circuit.
Currently, when the impedance matching network is used for matching, the impedance of the load is generally considered to be fixed, and the impedance of the impedance matching network is adjusted by the fixed load impedance, so that the impedance of the impedance matching network is also fixed. However, in some situations, for example, when the impedance matching circuit is applied to the rf therapeutic apparatus, the load is a human body, during the treatment using the rf therapeutic apparatus, the impedance of the load changes due to different patients or different treatment sites, even the impedance of the load changes due to heat generated by the same treatment site of the same patient during the treatment, so that the impedance matching network with fixed impedance cannot effectively reduce the rf reflected power when the impedance of the load changes, and thus cannot keep the rf energy to be maximized, and the life and safety of the circuit are also or threatened.
Disclosure of Invention
The invention aims to provide an impedance matching circuit, which solves the problems that the existing impedance matching circuit cannot keep the maximum radio frequency energy when the impedance of a load changes, the service life of the circuit is short, the safety is low and the like.
In order to achieve the above object, the present invention provides an impedance matching circuit connected between a radio frequency output module and a load, which is characterized by comprising a control module, an impedance detection module and an adjustable impedance matching module, wherein the radio frequency output module, the impedance detection module, the adjustable impedance matching module and the load are sequentially connected, the impedance detection module is used for detecting the impedance of the load, and the control module is used for adjusting the impedance of the adjustable impedance matching module according to the detection result of the impedance detection module so as to match the impedance between the radio frequency output module and the load.
Optionally, the adjustable impedance matching module includes a first impedance adjustment path and at least one second impedance adjustment path;
two ends of the first impedance adjustment path are respectively connected with the impedance detection module and the load;
one end of the second impedance adjustment path is connected between the first impedance adjustment path and the impedance detection module, and the other end of the second impedance adjustment path is grounded; and/or the number of the groups of groups,
one end of the second impedance adjustment path is connected between the first impedance adjustment path and the load, and the other end of the second impedance adjustment path is grounded.
Optionally, the first impedance adjusting path includes a capacitance unit and an inductance unit connected in series, and a capacitance value of the capacitance unit is adjustable and/or a inductance value of the inductance unit is adjustable.
Optionally, the second impedance adjustment path includes a capacitance unit or an inductance unit, and a capacitance value of the capacitance unit is adjustable or a inductance value of the inductance unit is adjustable.
Optionally, the inductance unit is a mechanically sliding adjustable inductance.
Optionally, the capacitor unit is an adjustable vacuum motor capacitor.
Optionally, the inductance unit includes at least two inductors connected in series, each inductor is connected in parallel with a first switch unit, and the control module adjusts the inductance value of the inductance unit by controlling the opening and closing of each first switch unit.
Optionally, the inductance unit has m inductances, the inductance value of the (i+1) th inductance is f times of the inductance value of the (i) th inductance, i is more than or equal to 1 and less than or equal to m-1, and f is more than or equal to 2.
Optionally, the capacitance unit includes at least two parallel capacitance adjustment paths, each capacitance adjustment path includes a second switch unit and a capacitance connected in series, and the control module adjusts the capacitance value of the capacitance unit by controlling the opening and closing of each second switch unit.
Optionally, the capacitance adjustment paths have n, the capacitance value of the capacitance in the j+1th capacitance adjustment path is g times the capacitance value of the capacitance in the j th capacitance adjustment path, 1.ltoreq.j.ltoreq.n-1, and g.ltoreq.2.
Optionally, the impedance matching circuit is applied to a radio frequency therapeutic apparatus.
The impedance matching circuit provided by the invention has the following beneficial effects:
1) The impedance of the load is detected by the impedance detection module, the impedance of the adjustable impedance matching module can be adjusted by the control module according to the detection result of the impedance detection module, and even if the impedance of the load is changed, the impedance of the adjustable impedance matching module can be readjusted, so that the radio frequency reflected power can be effectively reduced, the radio frequency energy is kept to be maximized, and meanwhile, the service life and the safety of the circuit are ensured.
2) The adjustable impedance matching module can comprise a first impedance adjusting passage and a second impedance adjusting passage, one end of the second impedance adjusting passage is connected between the first impedance adjusting passage and the impedance detecting module, the other end of the second impedance adjusting passage is grounded, the first impedance adjusting passage and the second impedance adjusting passage form an L-shaped structure, the structure is simple, and the situation that the real part impedance is smaller than the preset system impedance (such as 50 omega) can be matched.
3) The adjustable impedance matching module can comprise a first impedance adjusting passage and a second impedance adjusting passage, one end of the second impedance adjusting passage is connected between the first impedance adjusting passage and the load, the other end of the second impedance adjusting passage is grounded, the first impedance adjusting passage and the second impedance adjusting passage form an inverse L-shaped structure, the structure is simple, and the situation that the real part impedance is larger than the preset system impedance can be matched.
4) The adjustable impedance matching module can comprise a first impedance adjusting passage and two second impedance adjusting passages, one end of one second impedance adjusting passage is connected between the first impedance adjusting passage and the impedance detecting module, the other end of the other second impedance adjusting passage is grounded, one end of the other second impedance adjusting passage is connected between the first impedance adjusting passage and the load, the other end of the other second impedance adjusting passage is grounded, the first impedance adjusting passage and the two second impedance adjusting passages form a pi-shaped structure, the form is more flexible, and the adjustable impedance matching module can match the situation that the real part impedance is larger than the preset system impedance or smaller than the preset system impedance.
5) The inductance unit can be a mechanical sliding adjustable inductance; the capacitance unit can be an adjustable vacuum motor capacitance; the control module can continuously adjust the inductance value of the inductance unit or the capacitance value of the capacitance unit, and has higher adjustment precision, wider range and simpler structure.
6) The inductance unit can comprise at least two inductors connected in series, each inductor is connected with a first switch unit in parallel, the control module can adjust the inductance value of the inductance unit by controlling the opening and closing of each first switch unit, and the control module can control the inductance value of the inductance unit by controlling the opening and closing of each first switch unit; the capacitance unit can comprise at least two capacitance adjusting paths which are connected in parallel, each capacitance adjusting path comprises a second switch unit and a capacitance which are connected in series, and the control module can adjust the capacitance value of the capacitance unit by controlling the opening and closing of each second switch unit; the price is less expensive than using a mechanically sliding adjustable inductance or adjustable vacuum motor capacitance.
7) The inductance unit is provided with m inductances, and the inductance value of the (i+1) th inductance is f times of the inductance value of the (i) th inductance, so that the inductance value of the inductance unit is wider in adjustment range; the capacitance value of the capacitance in the (j+1) th capacitance adjustment passage is g times of the capacitance value of the capacitance in the (j) th capacitance adjustment passage, so that the capacitance value adjustment range of the capacitance unit is wider.
8) When f=2 or g=2, the first switch unit or the second switch unit is easier to control, and the inductance value or the capacitance value is more accurate to adjust.
Drawings
Fig. 1 is a block diagram of an impedance matching circuit according to a first embodiment of the present invention;
fig. 2 is a block diagram of an adjustable impedance matching module according to a first embodiment of the present invention;
fig. 3 is a circuit diagram of an adjustable impedance matching module according to a first embodiment of the present invention;
fig. 4a is a block diagram of an adjustable impedance matching module according to a second embodiment of the present invention;
fig. 4b is a circuit diagram of an adjustable impedance matching module according to a second embodiment of the present invention;
fig. 5a is a block diagram of an adjustable impedance matching module according to a third embodiment of the present invention;
fig. 5b is a circuit diagram of an adjustable impedance matching module according to a third embodiment of the present invention;
fig. 6a is a circuit diagram of an inductance unit according to a fourth embodiment of the present invention;
fig. 6b is a circuit diagram of a capacitor unit according to a fourth embodiment of the present invention;
wherein, the reference numerals are as follows:
100-a control module; 200-a radio frequency output module; 300-an impedance detection module; 400-an adjustable impedance matching module; 401-a first impedance adjustment path; 402a, 402 c-a second impedance adjustment path i; 402b, 402 d-a second impedance adjustment path ii; 500-load;
c1, C2, C3, C21, C31, C11, C12, C1 n-capacitance; l1, L11, L12, L1 m-inductance; k11, K12 … K1 m-first switching unit; k21, K22 … K2 m-second switching unit.
Detailed Description
Specific embodiments of the present invention will be described in more detail below with reference to the drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and are all to a non-precise scale, merely for convenience and clarity in aiding in the description of embodiments of the invention.
Example 1
Fig. 1 is a block diagram of an impedance matching circuit according to the present embodiment. As shown in fig. 1, the impedance matching circuit is connected between the rf output module 200 and the load 500. The impedance matching circuit comprises a control module 100, an impedance detection module 300 and an adjustable impedance matching module 400, wherein the radio frequency output module 200, the impedance detection module 300, the adjustable impedance matching module 400 and the load 500 are sequentially connected, and the control module 100 is connected with the impedance detection module 300 and the adjustable impedance matching module 400. The rf output module 200 is configured to output an rf signal, the impedance detecting module 300 is configured to detect an impedance of the load 500, and the control module 100 may adjust the impedance of the adjustable impedance matching module 400 according to a detection result of the impedance detecting module 300, so as to match the impedance between the rf output module 200 and the load 500.
In this embodiment, the impedance matching circuit is applied to a radio frequency therapeutic apparatus, the load 500 is a human body, and in the therapeutic process using the radio frequency therapeutic apparatus, the impedance of the load 500 can be changed by different patients or different therapeutic parts, and even the impedance of the load 500 can be changed due to heating of the same therapeutic part of the same patient in the therapeutic process. Therefore, the impedance detection module 300 may detect the impedance of the load 500, and the control module 100 may adjust the impedance of the adjustable impedance matching module 400 according to the detection result of the impedance detection module 300, and even if the impedance of the load 500 changes, the impedance of the adjustable impedance matching module 400 may be readjusted, so that the rf reflected power may be effectively reduced, the rf energy may be kept to be maximized, and the life and safety of the circuit may be ensured.
It should be appreciated that the impedance matching circuit is not limited to use in the rf therapeutic apparatus, but may be used in any other possible application.
Alternatively, the impedance detection module 300 may be any existing circuit or device capable of impedance detection, and will not be explained here.
Fig. 2 is a block diagram of an adjustable impedance matching module 400 according to the present embodiment. As shown in fig. 2, the adjustable impedance matching module 400 includes a first impedance adjustment path 401 and two second impedance adjustment paths i and ii, which are a second impedance adjustment path i 402a and a second impedance adjustment path ii 402b, respectively. Wherein, two ends of the first impedance adjustment path 401 are respectively connected to the impedance detection module 300 and the load 500; one end of the second impedance adjustment path i 402a is connected between the first impedance adjustment path 401 and the impedance detection module 300, and the other end is grounded; one end of the second impedance adjusting path ii 402b is connected between the first impedance adjusting path 401 and the load 500, and the other end is grounded.
Further, the first impedance adjustment path 401 includes a capacitance unit and an inductance unit connected in series, and the capacitance value of the capacitance unit and/or the inductance value of the inductance unit in the first impedance adjustment path 401 are/is adjustable. The second impedance adjustment path i 402a and the second impedance adjustment path ii 402b include a capacitance unit or an inductance unit, and when the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b include a capacitance unit, the capacitance values of the capacitance units in the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b are adjustable; when the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b include an inductance unit, inductance values of the inductance unit in the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b are adjustable. The control module 100 may adjust the impedance of the adjustable impedance matching module 400 by adjusting the capacitance of the capacitive element or the inductance of the inductive element in the first impedance adjustment path 401 and by adjusting the capacitance of the capacitive element or the inductance of the capacitive element in the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b, such that the sum of the impedance of the adjustable impedance matching module 400 and the impedance of the load 500 detected by the impedance detection module 300 matches the output impedance of the radio frequency output module 200.
Fig. 3 is a circuit diagram of an adjustable impedance matching module 400 according to the present embodiment. As shown in fig. 3, in this embodiment, the capacitance unit of the first impedance adjustment path 401 is a capacitance C1, the inductance unit of the first impedance adjustment path 401 is an inductance L1, the capacitance C1 and the inductance L1 are connected in series, the capacitance C1 is an adjustable vacuum motor capacitance, and the inductance L1 is a constant value inductance. The second impedance adjustment path i 402a and the second impedance adjustment path ii 402b each include a capacitor unit, the capacitor unit of the second impedance adjustment path i 402a is a capacitor C2, the capacitor unit of the second impedance adjustment path ii 402b is a capacitor C3, and the capacitor C2 and the capacitor C3 are both adjustable vacuum motor capacitors.
Further, since the capacitor C1, the capacitor C2 and the capacitor C3 are all adjustable vacuum motor capacitors, the control module 100 can continuously adjust the capacitance values of the capacitor C1, the capacitor C2 and the capacitor C3, so as to change the impedance of the adjustable impedance matching module 400, and the adjustable impedance matching module has higher adjustment precision, wider range and simpler structure. The first impedance adjustment path 401, the second impedance adjustment path i 402a, and the second impedance adjustment path ii 402b form a pi-type structure, which is more flexible and can match a case where the real impedance is greater than a predetermined system impedance (e.g., 50Ω) or less than a predetermined system impedance.
As an alternative embodiment, the inductance L1 may be a mechanically sliding adjustable inductance, the capacitance C1 is a constant capacitance, and the control module 100 may adjust the impedance of the adjustable impedance matching module 400 by adjusting the inductance value of the inductance L1, the capacitance values of the capacitance C2 and the capacitance C3.
As an alternative embodiment, the inductance L1 may be a mechanically sliding adjustable inductance, the capacitance C1 may also be an adjustable vacuum motor capacitance, and the control module 100 may adjust the impedance of the adjustable impedance matching module 400 by adjusting the inductance value of the inductance L1, the capacitance values of the capacitance C1, the capacitance C2 and the capacitance C3.
As an alternative embodiment, the capacitance units of the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b may be replaced by inductance units, for example: the inductance units of the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b may be mechanically sliding adjustable inductances, and the control module 100 adjusts the impedance of the adjustable impedance matching module 400 by adjusting the capacitance value of the capacitor C1 and the inductance value of the mechanically sliding adjustable inductances in the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b.
As an alternative embodiment, the second impedance adjustment path i 402a and the second impedance adjustment path ii 402b may also include a capacitance unit and an inductance unit, which are not described herein.
It should be noted that, after the impedance detection module 300 performs impedance detection to obtain the impedance of the load 500, the control module 100 may randomly adjust the capacitance values of the capacitor C1, the capacitor C2 and the capacitor C3, or gradually increase the capacitance values of the capacitor C1, the capacitor C2 and the capacitor C3 from small to large, or gradually decrease the capacitance values of the capacitor C1, the capacitor C2 and the capacitor C3 from large to small, and adjust the detection once until the impedance between the rf output module 200 and the load 500 is matched.
Example two
Fig. 4a is a block diagram of an adjustable impedance matching module 400 according to the present embodiment. As shown in fig. 4a, the difference from the first embodiment is that in this embodiment, the adjustable impedance matching module 400 includes a first impedance adjustment path 401 and a second impedance adjustment path, where the second impedance adjustment path is a second impedance adjustment path i 402c. One end of the second impedance adjustment path i 402c is connected between the first impedance adjustment path 401 and the impedance detection module 300, and the other end is grounded.
Fig. 4b is a circuit diagram of the adjustable impedance matching module 400 according to the present embodiment. As shown in fig. 4b, the second impedance adjustment path i 402C includes a capacitor unit, the capacitor unit of the second impedance adjustment path i 402C is a capacitor C21, and the capacitor C21 is an adjustable vacuum motor capacitor.
Further, in fig. 4b, since the capacitor C1 and the capacitor C21 are both adjustable vacuum motor capacitors, the control module 100 can continuously adjust the capacitance values of the capacitor C1 and the capacitor C21, so as to change the impedance of the adjustable impedance matching module 400, so that the adjustment accuracy is higher, the range is wider, and the structure is simpler. The first impedance adjustment path 401 and the second impedance adjustment path 402 form an L-shaped structure, which has a simple structure and can match a situation that the real impedance is smaller than the system impedance.
It should be understood that in this embodiment, the second impedance adjustment path i 402C may also include an inductance unit, the inductance unit in the second impedance adjustment path i 402C may be a mechanically sliding adjustable inductance, and the control module 100 may also adjust the impedance of the adjustable impedance matching module 400 by adjusting the capacitance value of the capacitor C1 and the inductance value of the mechanically sliding adjustable inductance in the second impedance adjustment path i 402C.
Example III
Fig. 5a is a block diagram of an adjustable impedance matching module 400 according to the present embodiment. As shown in fig. 5a, the difference from the first embodiment is that in this embodiment, the adjustable impedance matching module 400 includes a first impedance adjustment path 401 and a second impedance adjustment path, and the second impedance adjustment path is a second impedance adjustment path ii 402d. One end of the second impedance adjustment path ii 402d is connected between the first impedance adjustment path 401 and the load 500, and the other end is grounded.
Fig. 5b is a circuit diagram of the adjustable impedance matching module 400 according to the present embodiment. As shown in fig. 5b, the second impedance adjustment path ii 402d includes a capacitor unit, the capacitor unit of the second impedance adjustment path ii 402d is a capacitor C31, and the capacitor C31 is an adjustable vacuum motor capacitor.
Further, in fig. 5b, since the capacitor C1 and the capacitor C31 are both adjustable vacuum motor capacitors, the control module 100 may continuously adjust the capacitance values of the capacitor C1 and the capacitor C31, so as to change the impedance of the adjustable impedance matching module 400, so that the adjustment accuracy is higher, the range is wider, and the structure is simpler. The first impedance adjusting path 401 and the second impedance adjusting path ii 402d form an inverse L-shaped structure, which has a simple structure and can match a situation that the real impedance is larger than the system impedance.
It should be understood that in this embodiment, the second impedance adjustment path ii 402d may also include an inductance unit, the inductance unit in the second impedance adjustment path ii 402d may be a mechanically sliding adjustable inductance, and the control module 100 may also adjust the impedance of the adjustable impedance matching module 400 by adjusting the capacitance value of the capacitor C1 and the inductance value of the mechanically sliding adjustable inductance in the second impedance adjustment path ii 402d.
Example IV
Fig. 6a is a circuit diagram of an inductance unit according to the present embodiment, and fig. 6b is a circuit diagram of a capacitance unit according to the present embodiment. As shown in fig. 6a and 6b, the difference between the first embodiment and the third embodiment is that in this embodiment, at least part of the inductance unit and the capacitance unit may be replaced by the circuit structures shown in fig. 6a and 6 b. The price is less expensive than using a mechanically sliding adjustable inductance or adjustable vacuum motor capacitance.
Specifically, the inductance unit includes at least two series-connected inductances, each inductance is connected in parallel with a first switch unit, and the control module 100 adjusts the inductance value of the inductance unit by controlling the opening and closing of each first switch unit. As shown in FIG. 6a, the inductance unit has m (m is greater than or equal to 2) inductances, the m inductances are inductance L11 and inductance L12 … inductance L1m respectively, inductance L11 and inductance L12 … inductance L1m are connected in series, the inductance L11 is connected in parallel with a first switch unit K11, the inductance L12 is connected in parallel with a first switch unit K12 …, and the inductance L1m is connected in parallel with a first switch unit K1m. As long as the first switching unit is closed, the corresponding inductance thereof is shorted, and thus, the control module 100 may change the inductance value of the inductance unit by controlling the opening and closing of the first switching unit K11, the first switching unit K12, …, and the first switching unit K1m.
Further, the inductance value of the (i+1) th inductor is f times of the inductance value of the (i) th inductor, i is more than or equal to 1 and less than or equal to m-1, and f is more than or equal to 2. For example: the inductance value of the inductor L12 is 2 times the inductance value of the inductor L11. The inductance value of the inductance L11, the inductance L12 … and the inductance L1m is increased in an equal ratio series. In this way, the inductance value adjustment range of the inductance unit is wider.
In this embodiment, f=2, the first switch units K11, K12 and …, the first switch unit K1m is easier to control, and the inductance value is more accurate to adjust.
Specifically, the capacitance unit includes at least two capacitance adjustment paths connected in parallel, each capacitance adjustment path includes a second switch unit and a capacitance connected in series, and the control module 100 adjusts the capacitance value of the capacitance unit by controlling the opening and closing of each second switch unit. As shown in FIG. 6b, the capacitance unit has n (n.gtoreq.2) capacitance adjustment paths, the first capacitance adjustment path includes a second switch unit K21 and a capacitance C11 connected in series, the second capacitance adjustment path includes a second switch unit K22 and a capacitance C12 … connected in series, and the nth capacitance adjustment path includes a second switch unit K2n and a capacitance C1n connected in series. As long as the second switch unit is turned off, the corresponding capacitance adjustment path is opened, so the control module 100 may change the capacitance value of the capacitance unit by controlling the second switch unit K21, the second switch unit K22, and the …, and the second switch unit K2n to be turned on or off.
Further, the capacitance adjustment paths are n, the capacitance value of the capacitance in the j+1th capacitance adjustment path is g times of the capacitance value of the capacitance in the j th capacitance adjustment path, 1.ltoreq.j.ltoreq.n-1, and g.ltoreq.2. For example: the capacitance of the capacitor C12 is g times the capacitance of the capacitor C11. The capacitance values of the capacitor C11 and the capacitor C12 … capacitor C1n are increased in an equal ratio array mode. In this way, the capacitance value of the capacitor unit has a wider adjustment range.
In this embodiment, g=2, the second switch units K21, K22 and … and the second switch unit K2n are easier to control, and the capacitance value is more accurate.
Specifically, if the capacitance value of the capacitor unit needs to be adjusted to the corresponding required capacitance value, the control word may be obtained by dividing the required capacitance value of the capacitor unit by the capacitance value of the capacitor in the first capacitor adjustment path; and then converting the control word into a binary number, wherein the control module 100 outputs n level signals to control the on/off of the second switch units of the n capacitance adjustment paths respectively, and the level values of the level signals corresponding to the first to n-th capacitance adjustment paths are binary values corresponding to the low bits to the high bits of the binary number.
For example, n=4 and g=2 of a certain capacitor unit, the capacitance values of the capacitors on the first to fourth capacitor adjusting paths are respectively 10pF, 20pF, 40pF and 80pF, and the required capacitance value is 80pF. Dividing 80pF by 10pF to obtain a control word 8; then, the control word 8 is converted into a binary number 1000, the second switch unit is a high-level switch, the control module 100 outputs 4 level signals to control the second switch units on the first to fourth capacitance adjustment paths, and the level values of the 4 level signals are respectively low level, low level and high level, so that the second switch units on the first to third capacitance adjustment paths are turned off, the second switch unit on the fourth capacitance adjustment path is turned on, and the capacitance value of the capacitance unit is equal to the capacitance value of the capacitance on the fourth capacitance adjustment path, namely 80pF, so that the capacitance value of the capacitance unit is adjusted to the required capacitance value.
In summary, in the impedance matching circuit provided by the embodiment of the invention, the impedance of the load is detected by the impedance detection module, the control module can adjust the impedance of the adjustable impedance matching module according to the detection result of the impedance detection module, and even if the impedance of the load is changed, the impedance of the adjustable impedance matching module can be readjusted, so that the radio frequency reflected power can be effectively reduced, the radio frequency energy is kept to be maximized, and meanwhile, the service life and the safety of the circuit are ensured.
Further, the adjustable impedance matching module may include a first impedance adjustment path and a second impedance adjustment path, where one end of the second impedance adjustment path is connected between the first impedance adjustment path and the impedance detection module, and the other end of the second impedance adjustment path is grounded, where the first impedance adjustment path and the second impedance adjustment path form an L-shaped structure, and the adjustable impedance matching module has a simple structure and is capable of matching a situation that the real part impedance is smaller than a predetermined system impedance (such as 50Ω).
Further, the adjustable impedance matching module may include a first impedance adjustment path and a second impedance adjustment path, where one end of the second impedance adjustment path is connected between the first impedance adjustment path and the load, and the other end of the second impedance adjustment path is grounded, and the first impedance adjustment path and the second impedance adjustment path form an inverse L-shaped structure, which has a simple structure and can match a situation that the real part impedance is greater than a predetermined system impedance.
Further, the adjustable impedance matching module may include a first impedance adjustment path and two second impedance adjustment paths, where one end of one second impedance adjustment path is connected between the first impedance adjustment path and the impedance detection module, the other end is grounded, one end of the other second impedance adjustment path is connected between the first impedance adjustment path and the load, the other end is grounded, the first impedance adjustment path and the two second impedance adjustment paths form a pi-type structure, and the form is more flexible, so that the adjustable impedance matching module can match the situation that the real part impedance is greater than the predetermined system impedance or less than the predetermined system impedance.
Further, the inductance unit may be a mechanically sliding adjustable inductance; the capacitance unit can be an adjustable vacuum motor capacitance; the control module can continuously adjust the inductance value of the inductance unit or the capacitance value of the capacitance unit, and has higher adjustment precision, wider range and simpler structure.
Further, the inductance unit may include at least two series-connected inductances, each inductance is connected in parallel with a first switch unit, the control module adjusts the inductance value of the inductance unit by controlling the opening and closing of each first switch unit, and the control module may control the inductance value of the inductance unit by controlling the opening and closing of each first switch unit; the capacitance unit can comprise at least two capacitance adjusting paths which are connected in parallel, each capacitance adjusting path comprises a second switch unit and a capacitance which are connected in series, and the control module can adjust the capacitance value of the capacitance unit by controlling the opening and closing of each second switch unit; the price is less expensive than using a mechanically sliding adjustable inductance or adjustable vacuum motor capacitance.
Further, the inductance unit is provided with m inductances, and the inductance value of the (i+1) th inductance is f times of the inductance value of the (i) th inductance, so that the inductance value of the inductance unit is wider in adjustment range; the capacitance value of the capacitance in the (j+1) th capacitance adjustment passage is g times of the capacitance value of the capacitance in the (j) th capacitance adjustment passage, so that the capacitance value adjustment range of the capacitance unit is wider.
Further, when f=2 or g=2, the first switch unit or the second switch unit is easier to control, and the inductance value or the capacitance value is more accurate to adjust.
It should be noted that, in the present description, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different manner from other embodiments, and identical and similar parts between the embodiments are all enough to refer to each other. For the system disclosed in the embodiment, the description is relatively simple because of corresponding to the method disclosed in the embodiment, and the relevant points refer to the description of the method section.
It should be further noted that although the present invention has been disclosed in the preferred embodiments, the above embodiments are not intended to limit the present invention. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art without departing from the scope of the technology, or the technology can be modified to be equivalent. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention still fall within the scope of the technical solution of the present invention.
It should be further understood that the terms "first," "second," "third," and the like in this specification are used merely for distinguishing between various components, elements, steps, etc. in the specification and not for indicating a logical or sequential relationship between the various components, elements, steps, etc., unless otherwise indicated.
It should also be understood that the terminology described herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. It must be noted that, as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to "a step" or "an apparatus" means a reference to one or more steps or apparatuses, and may include sub-steps as well as sub-apparatuses. All conjunctions used should be understood in the broadest sense. And, the word "or" should be understood as having the definition of a logical "or" rather than a logical "exclusive or" unless the context clearly indicates the contrary. Furthermore, implementation of the methods and/or apparatus in embodiments of the invention may include performing selected tasks manually, automatically, or in combination.
Claims (11)
1. The impedance matching circuit is connected between a radio frequency output module and a load and is characterized by comprising a control module, an impedance detection module and an adjustable impedance matching module, wherein the radio frequency output module, the impedance detection module, the adjustable impedance matching module and the load are sequentially connected, the impedance detection module is used for detecting the impedance of the load, and the control module is used for adjusting the impedance of the adjustable impedance matching module according to the detection result of the impedance detection module so as to match the impedance between the radio frequency output module and the load.
2. The impedance matching circuit of claim 1, wherein said adjustable impedance matching module comprises a first impedance adjustment path and at least one second impedance adjustment path;
two ends of the first impedance adjustment path are respectively connected with the impedance detection module and the load;
one end of the second impedance adjustment path is connected between the first impedance adjustment path and the impedance detection module, and the other end of the second impedance adjustment path is grounded; and/or the number of the groups of groups,
one end of the second impedance adjustment path is connected between the first impedance adjustment path and the load, and the other end of the second impedance adjustment path is grounded.
3. The impedance matching circuit of claim 2, wherein the first impedance adjustment path comprises a capacitive element and an inductive element in series, the capacitance of the capacitive element being adjustable and/or the inductance of the inductive element being adjustable.
4. The impedance matching circuit of claim 2, wherein the second impedance adjustment path comprises a capacitive element or an inductive element, the capacitance of the capacitive element being adjustable or the inductance of the inductive element being adjustable.
5. The impedance matching circuit of claim 3, wherein said inductive element is a mechanically sliding adjustable inductance.
6. The impedance matching circuit of claim 3 or 4, wherein said capacitive element is an adjustable vacuum motor capacitor.
7. The impedance matching circuit of claim 3, wherein said inductance unit comprises at least two series-connected inductances, each of said inductances being connected in parallel with a first switching unit, said control module adjusting the inductance value of said inductance unit by controlling the opening and closing of each of said first switching units.
8. The impedance matching circuit of claim 7, wherein said inductance unit has m inductances, and the inductance value of the i+1th inductance is f times the inductance value of the i-th inductance, 1.ltoreq.i.ltoreq.m-1, and f.gtoreq.2.
9. The impedance matching circuit of claim 3 or 4, wherein the capacitance unit comprises at least two capacitance adjustment paths connected in parallel, each capacitance adjustment path comprising a second switching unit and a capacitance connected in series, the control module adjusting the capacitance value of the capacitance unit by controlling the opening and closing of each of the second switching units.
10. The impedance matching circuit according to claim 3 or 4, wherein the capacitance adjustment paths have n, the capacitance value of the capacitance in the j+1th capacitance adjustment path is g times the capacitance value of the capacitance in the j-th capacitance adjustment path, 1.ltoreq.j.ltoreq.n-1, g.gtoreq.2.
11. The impedance matching circuit of claim 1, wherein said impedance matching circuit is used in a radio frequency therapeutic device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111640380.1A CN116418308A (en) | 2021-12-29 | 2021-12-29 | Impedance matching circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111640380.1A CN116418308A (en) | 2021-12-29 | 2021-12-29 | Impedance matching circuit |
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| Publication Number | Publication Date |
|---|---|
| CN116418308A true CN116418308A (en) | 2023-07-11 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111640380.1A Pending CN116418308A (en) | 2021-12-29 | 2021-12-29 | Impedance matching circuit |
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| CN (1) | CN116418308A (en) |
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- 2021-12-29 CN CN202111640380.1A patent/CN116418308A/en active Pending
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