CN113489469B - Antenna matching network and matching design method thereof - Google Patents
Antenna matching network and matching design method thereof Download PDFInfo
- Publication number
- CN113489469B CN113489469B CN202110772327.0A CN202110772327A CN113489469B CN 113489469 B CN113489469 B CN 113489469B CN 202110772327 A CN202110772327 A CN 202110772327A CN 113489469 B CN113489469 B CN 113489469B
- Authority
- CN
- China
- Prior art keywords
- network
- matching
- impedance
- value
- antenna
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- 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
Landscapes
- Details Of Aerials (AREA)
Abstract
The invention provides an antenna matching network structure and a matching design method thereof. The antenna matching network structure comprises a pre-adjusting network, a filter network, a correction network and an impedance matching network; the pre-conditioning network is connected with the filter network through a first node (1); the filtering network is connected to the correction network via a second node (2); the correction network is connected to an impedance matching network through a third node (3); the impedance node of the impedance matching network is a fourth node (4). The matching design method comprises the steps that equivalent impedance parameters of the first node and the third node meet the requirement of a low Q value to the maximum extent, and equivalent impedance parameters of the second node meet the requirement of a high Q value of interference signal frequency, so that the bandwidth, the standing-wave ratio index and the anti-interference signal index of the antenna matching network are improved, and the matching network which meets the technical index requirement and has more frequencies and can work with the antenna is designed.
Description
Technical Field
The invention belongs to the technical field of antennas, and particularly relates to an antenna matching network and a matching design method thereof.
Background
The antenna matching network realizes better sending or receiving of radio signals with certain frequency bandwidth by carrying out impedance matching on the antenna, and simultaneously inhibits interference signals outside a working frequency band. Theoretically, the antenna matching network belongs to a band-pass filter, the technical indexes mainly comprise a frequency bandwidth (bandwidth), an in-band flatness index and an out-of-band attenuation index, wherein the in-band flatness index reflecting the antenna matching network is expressed by a standing wave ratio index (or a traveling wave coefficient index) in the radio measurement technology.
However, the current antenna matching network design method mainly has the following two problems: firstly, when the standing-wave ratio index of the antenna end is larger, the design method for realizing the bandwidth index and the in-band flatness index of a better antenna matching network is more complex and is difficult to master by general technicians; secondly, in the existing antenna matching network design method, strong suppression by using a high-Q filter can seriously affect the bandwidth index and the standing-wave ratio index to meet the design requirements, so that the matching network of the multi-frequency shared antenna with better technical indexes is difficult to design, and the waste of antenna field resources and antenna resources is caused in some application scenes (such as high-power radio transmission).
Disclosure of Invention
In order to solve the above technical problems, the present invention provides an antenna matching network and a matching design method thereof. The antenna matching network structure comprises a pre-adjusting network, a filter network, a correction network and an impedance matching network; the pre-conditioning network is connected with the filter network through a first node (1); the filtering network is connected to the correction network via a second node (2); the correction network is connected to an impedance matching network through a third node (3); the impedance node of the impedance matching network is a fourth node (4). The matching design method comprises the steps that equivalent impedance parameters of the first node and the third node meet the requirement of a low Q value to the maximum extent, and the equivalent impedance parameter of the interference signal frequency of the second node meets the requirement of a high Q value, so that the bandwidth, the standing-wave ratio index and the anti-interference signal index of the antenna matching network are improved, and the matching network which meets the technical index requirement and has more frequencies sharing the antenna to work is designed.
In a first aspect of the present invention, an antenna matching network structure is provided, which includes a pre-tuning network, a filter network, a correction network, and an impedance matching network; the preset network is connected with the filter network through a first node; the filter network is connected to the correction network through a second node; the correction network is connected to the impedance matching network through a third node; an impedance node of the impedance matching network is a fourth node.
The pre-adjusting network is an antenna impedance pre-adjusting network, and the antenna impedance pre-adjusting network adjusts real frequency data of antenna impedance of a plurality of working frequency points, so that the Q value of the equivalent impedance parameter of the plurality of working frequency points at the first node is a first Q value;
the filter network is a high-Q-value impedance matching filter network, and the high-Q-value impedance matching filter network performs blocking filtering on interference frequencies outside the plurality of working frequency points, so that the Q value of an interference signal frequency equivalent impedance parameter of each working frequency point of the second node is a second Q value;
the correction network is a matching correction network, and the matching correction network enables the Q value of the equivalent impedance parameter of each working frequency point at the third node behind the filter network to be a third Q value;
the first Q value and the third Q value are low-frequency Q values of working frequency, and the second Q value is a high-frequency Q value of interference signals.
In the above technical solution of the present invention, the Q value is a ratio (Q ═ X/R) of an imaginary part and a real part of the operating frequency point impedance value (R + jX).
In a second aspect of the present invention, a matching design method is provided for performing parameter design on the antenna matching network of the first aspect.
More specifically, the design method comprises designing a matching network from an antenna terminal to a circuit output/input terminal, and is specifically embodied in that:
measuring or calculating to obtain equivalent impedance parameters of the antennas at the multiple working frequency points;
designing the pre-adjusting network according to the acquired real frequency data of the antennas of the working frequency points, so that the equivalent impedance parameters of the working frequency points of the first node can meet the requirement of a low Q value to the maximum extent;
designing the filter network according to the frequency of an interference signal, wherein the filter network adopts a parallel resonance network to block the interference signal;
designing the matching correction network to enable equivalent impedance parameters of the working frequency points at the third node to meet the requirement of a low Q value to the maximum extent;
the low Q value is in the range of [ -1,1 ].
More specifically, the design method further comprises:
designing an antenna pre-tuning network according to the acquired real frequency data of each working frequency point antenna, and connecting the pre-tuning network in parallel (or in series) at an antenna feed point, so that the impedance (R + jX) of each working frequency point of a network node (a first node) behind the antenna pre-tuning network meets the requirement of a low Q value (Q is X/R) to the maximum extent, and the Q values of equivalent impedance parameters of the working frequency points as many as possible are in the range of-1 to + 1;
an impedance matching filter network is designed according to the frequency of an interference signal, the filter network can use a parallel resonance network to block the interference signal, and when the frequency of the interference signal is not clear, a specific filter network is not considered to be added (no matter whether the specific filter network is added or not, the antenna matching network with the matching correction network has a band-pass filtering function);
the matching correction network is designed to enable the equivalent impedance parameter (R + jX) of the working frequency point at the third node to meet the requirement of a low Q value (Q is X/R), the Q values of the equivalent impedance parameters of the working frequency points are enabled to be in the range of-1 to +1 as much as possible, and the impedance imaginary part value of the high-frequency working frequency point is larger than the impedance imaginary part value of the low-frequency point.
The match correction preconditioning, filtering, correction and impedance matching networks are comprised of reactive elements or reactive networks.
Meanwhile, when the antenna works in a single working frequency band, the pre-adjusting network can realize the low Q value by a single reactance element generally; when the antenna operates in a multi-frequency sharing mode, the pre-tuning network is usually designed as a composite network to achieve low Q values of each operating frequency band.
The antenna matching network and the design method thereof can improve the flatness index and the bandwidth index of the working frequency band, improve the technical index of anti-interference, and can also design a matching network which meets the technical index requirement and can work with more frequencies sharing the antenna.
Further advantages of the invention will be apparent in the detailed description section in conjunction with the drawings attached hereto.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a sub-network structure diagram of an antenna matching network structure according to an embodiment of the present invention
FIG. 2 is a diagram of an embodiment of an antenna matching network as described in FIG. 1
FIG. 3 is a schematic diagram of a matching design method of the antenna matching network shown in FIG. 1 or FIG. 2
FIG. 4 is a schematic diagram of an antenna matching network operating in a single frequency band
FIG. 5 is a schematic diagram of an antenna matching network operating in a composite frequency band
FIGS. 6-9 are schematic diagrams of portions of the design principles of antenna matching network structures
FIGS. 10-16 are partial parameter table diagrams for verifying the performance of the antenna matching network described in FIG. 4 or FIG. 5
Detailed Description
The invention is further described with reference to the following drawings and detailed description.
It should be noted that the description of the drawings given in the various embodiments of the present invention is merely schematic and does not represent all of the specific circuit configurations;
the present invention is not limited to the specific module structure described in the prior art. The prior art mentioned in the background section can be used as part of the invention to understand the meaning of some technical features or parameters. The scope of the present invention is defined by the claims.
Referring to fig. 1, a sub-network structure diagram of an antenna matching network structure according to an embodiment of the present invention is shown.
In fig. 1, the antenna matching network structure includes a pre-tuning network, a filter network, a correction network, and an impedance matching network.
The preset network is connected with the filter network through a first node 1; the filtering network is connected to the correction network via a second node 2; the correction network is connected to the impedance matching network through a third node 3; the impedance node of the impedance matching network is the fourth node 4.
It should be noted that the filter network is optional depending on the actual scenario.
In particular, in practical design, the filter network needs to be designed according to the frequency of the interference signal or the state of the working frequency band.
Preferably, if the interference signal frequency cannot be acquired temporarily, the filter network is not designed temporarily; i.e. if the interfering signal frequency is ambiguous, the antenna matching network structure temporarily does not add the filter network.
Correspondingly, when the antenna matching network is debugged, after determining that the interference signal cannot be effectively filtered, the filter network is redesigned and added according to the frequency band of the interference signal, and the matching correction network is redesigned. Preferably, the antenna matching network comprises a band-pass filter, the filtering frequency of the band-pass filter corresponding to a plurality of possible frequencies of the interference signal.
In addition, if the antenna matching network operates in a single frequency band, the filter network may not be needed, which will be specifically mentioned in the following embodiments.
Thus, in fig. 1, the filter network is represented in the form of a dashed box.
On the basis of fig. 1, further reference is made to fig. 2.
In fig. 2, the preset network is an antenna impedance preset network, and the antenna impedance preset network adjusts real frequency data of antenna impedances at multiple working frequency points, so that a Q value of an equivalent impedance parameter of the multiple working frequency points at the first node is a first Q value;
specifically, the antenna impedance pre-adjusting network adjusts the antenna impedance real frequency data of each working frequency point, and the equivalent impedance parameter (R + jX) of each working frequency point at the node 1 after adjustment and transformation can meet the requirement of a low Q value (X/R);
the filter network is a high-Q-value impedance matching filter network, and the high-Q-value impedance matching filter network performs blocking filtering on interference frequencies outside the plurality of working frequency points, so that the Q value of an interference signal frequency equivalent impedance parameter of each working frequency point of the second node is a second Q value;
the correction network is a matching correction network, and the matching correction network enables the Q value of the equivalent impedance parameter of each working frequency point at the third node behind the filter network to be a third Q value.
Specifically, in fig. 2, the matching correction network makes the real frequency data of the equivalent impedance of each working frequency point at the node 3 after the filter network meet the requirement of low Q value.
Further, the impedance matching network is a matching conjugate network, and the matching conjugate network transforms the equivalent antenna impedance matching at the third node to a first predetermined impedance value and cancels out reactance components of the plurality of working frequency points.
Specifically, in fig. 2, the matching conjugate network transforms the equivalent antenna impedance at the node 3 to an impedance value (e.g., 50 ohms) required by the circuit, and cancels out reactance components at each operating frequency as much as possible.
In the embodiments described in fig. 1 to 2, the Q value refers to a ratio of an imaginary part to a real part of the operating frequency point impedance value (R + jX) (Q ═ X/R).
In the above embodiment, the first Q value and the third Q value range from [ -1,1 ].
The plurality of working frequency points comprise high-frequency working frequency points and low-frequency working frequency points;
and the impedance imaginary part value of the high-frequency working frequency point is greater than that of the low-frequency working frequency point.
The match correction network is made up of reactive elements or reactive networks.
Fig. 3 further shows the specific design steps of the antenna matching network.
In fig. 3, the designing step mainly includes designing a pre-tuning network, designing a filter network, and designing a matching correction network after measuring or calculating the equivalent impedance parameters of the antenna for obtaining the plurality of working frequency points;
wherein the design filter network is optional and is therefore indicated by a dashed box.
Specifically, in practical design, whether to design the filter network needs to be considered according to the frequency of the interference signal or the state of the operating frequency band.
Preferably, if the interference signal frequency cannot be acquired temporarily, the filter network is not designed temporarily; i.e. if the interfering signal frequency is ambiguous, the antenna matching network structure temporarily does not add the filter network.
In addition, as mentioned above, if the antenna matching network operates in a single frequency band, the filter network may not be needed.
In any case, however, the match correction network may filter out some of the possible frequencies of the interfering signal.
Preferably, the antenna matching network comprises a band-pass filter, and the filtering frequency of the band-pass filter corresponds to multiple possible frequencies of the interference signal.
Without loss of generality, the design principles of all sub-networks are described separately below in various aspects.
Namely measuring or calculating to obtain equivalent impedance parameters of the antennas of the plurality of working frequency points;
designing the pre-adjusting network according to the acquired real frequency data of the antennas of the working frequency points, so that the equivalent impedance parameters of the working frequency points of the first node can meet the requirement of a low Q value to the maximum extent;
designing the filter network according to the frequency of an interference signal, wherein the filter network adopts a parallel resonance network to block the interference signal;
designing the matching correction network to enable equivalent impedance parameters of the working frequency points at the third node to meet the requirement of a low Q value to the maximum extent;
the low Q value is in the range of [ -1,1 ].
More specifically, in conjunction with the aforementioned fig. 2, the main theoretical principles of various embodiments of the present invention can be summarized as follows:
designing an antenna matching network, adjusting the equivalent impedance parameters of working frequency points of a node 1 and a node 3 in 3 key nodes of the matching network to a low Q value, adjusting the interference frequency of a node 2 to a high Q value, and improving the technical indexes (bandwidth, standing-wave ratio index and anti-interference signal index) of the antenna matching network;
an antenna impedance pre-adjusting network is designed, antenna impedance real-frequency data of each working frequency point are adjusted, and the equivalent impedance parameter (R + jX) of each working frequency point at the node 1 after adjustment and transformation can meet the requirement of a low Q value (X/R);
designing a high Q-value impedance matching filter network to carry out blocking filtering on interference frequency outside the working frequency;
designing a matching correction network to enable the equivalent impedance real-frequency data of each working frequency point at a node 3 behind the filter network to meet the requirement of a low Q value;
and designing a matching conjugate network, matching and converting the equivalent antenna impedance at the node 3 to an impedance value (such as 50 ohms) required by a circuit, and offsetting reactance components of each working frequency point as much as possible.
In combination with the foregoing embodiments, more specific aspects include:
measuring or calculating to obtain equivalent impedance parameters of each working frequency point antenna;
designing an antenna pre-tuning network according to the obtained real frequency data of each working frequency point antenna, and connecting the pre-tuning network in parallel (or in series) at an antenna feed point, so that the impedance (R + jX) of each working frequency point of a network node (node 1) behind the antenna pre-tuning network meets the requirement of a low Q value (Q is X/R) to the maximum extent, and the Q values of equivalent impedance parameters of the working frequency points as many as possible are in the range of-1 to + 1;
an impedance matching filter network is designed according to the frequency of an interference signal, the filter network can use a parallel resonance network to block the interference signal, and when the frequency of the interference signal is not clear, a specific filter network is not considered to be added (no matter whether the specific filter network is added or not, the antenna matching network with the matching correction network has a band-pass filtering function);
the matching correction network is designed to ensure that the equivalent impedance parameter (R + jX) of each working frequency point at the node 3 meets the requirement of a low Q value (Q is X/R), the Q values of the equivalent impedance parameters of the working frequency points are in the range of-1 to +1 as much as possible, and the impedance imaginary part value of the high-frequency working frequency point is larger than the impedance imaginary part value of the low-frequency point (the condition that the impedance imaginary part value of an individual high-frequency working frequency point cannot be adjusted to meet the requirement of the impedance imaginary part value larger than the low-frequency working frequency point is possible, but the technical index for improving the antenna matching network is not influenced). The matching correction network is composed of reactive elements or reactive networks;
reference is next made to fig. 4-5.
The antenna matching network structure works in a single frequency band or a multi-frequency band;
when the antenna matching network structure works in a single frequency band, a single reactance element forms the pre-tuning network, as shown in fig. 4;
in fig. 4, a schematic diagram of a 612KHZ single-frequency antenna matching network is shown, wherein the matching network is composed of a matching conjugate network, a correction network and a pre-modulation network;
when the antenna matching network structure works in a multi-frequency band, the pre-adjusting network is designed to be a composite network; as shown in fig. 5.
Fig. 5 shows a schematic diagram of a quad-band (612, 900, 1170, 1503KHZ) antenna matching network. The system comprises a matching conjugate network, a correction network, a filter network and a composite preset network;
the antenna impedance parameters are transformed by connecting an antenna pre-adjusting network (usually a reactive element or a composite network) in parallel or in series with the antenna, so that the antenna impedance parameter values of all the working frequency points are transformed to low Q values. The equivalent impedance parameters (R + jX) of each working frequency point at the node 1 after the antenna pre-adjusting network is adjusted meet the requirement of low Q value (X/R) to the maximum extent, and the Q values of the equivalent impedance parameters of the working frequency points are in the range of-1 to +1 as many as possible;
when the antenna operates in a single operating band, the pre-tuning network can achieve the low Q value by a single reactive element (see fig. 4 for example).
When the antenna operates in a multi-frequency sharing mode, the pre-tuning network is usually designed as a composite network (see fig. 5 for example) to achieve low Q values in each operating frequency band.
In the above embodiment, the impedance real-frequency data of the antenna end and each node of the antenna matching network is obtained by measurement or calculation.
At key nodes (a node 1 after the antenna matching network is preset, a node 3 after the antenna matching network is matched with the correction network and before the antenna matching network is matched with the conjugate network), the impedance value of each working frequency point is adjusted to be a low Q value, so that the working frequency band of the antenna matching network has better flatness; the interference signal frequency is designed into a high Q value filter, so that the interference signal can be well inhibited.
According to the principle, when an antenna matching network is designed, the Q values of the working frequency point equivalent impedance real-frequency data obtained by measuring or calculating two nodes (node 1 and node 3) of the matching network are enabled to be as small as possible by designing the antenna matching pre-adjusting network and the matching correction network, and the Q values of the equivalent impedance parameters of the working frequency points are enabled to be in the range of-1 to +1 as many as possible.
For the suppression of the interference signal frequency, a filter can be designed according to a theoretical principle and a high Q value principle. When a plurality of strong interference signal frequencies exist, a plurality of high-Q filters can be designed and used together so as to meet the strong suppression requirements on various interference signal frequencies. The filter network is generally a network resonant in parallel to the frequency of the interference signal, and may also extend a branch, and a bypass network is used to filter the interference signal, and the bypass network is generally a network resonant in series to the frequency of the interference signal.
Designing a filter network:
the design of the filter network only needs to block or bypass various strong interference signal frequencies outside the working frequency band, each blocking (bypass) network can block (bypass) the frequency of a specific frequency band of the interference signal, and the Q value of the blocking (bypass) network is designed according to the strength of the interference signal to be blocked.
Designing an antenna matching correction network:
impedance parameters of each frequency point after passing through the antenna pre-adjusting network and the filter network do not necessarily meet the requirement of low Q value, a matching correction network is required to be designed and connected in series for the purpose, and the impedance parameters at the node 2 are balanced and adjusted, so that the impedance values of all working frequency points at the node 3 after the matching correction network meet the requirement of the low Q value again.
In addition, when the node impedance parameter after the matching correction network is implemented with a low Q value, the impedance imaginary part value of the high-frequency point of the working frequency band is required to be larger than the impedance imaginary part value of the low-frequency point, which is beneficial to reducing the deviation degree of the impedance data of each working frequency point participating in the matching transformation, and improving the bandwidth index and the flatness index of the antenna matching network (the following contents can simply analyze the reason.
Designing matching conjugate networks
The matching conjugate network is used for matching and transforming the impedance of the central working frequency to an impedance value (such as 50 ohms) required by the circuit and offsetting reactive components of other working frequency points as much as possible.
The principle of transforming the antenna impedance parameters can be seen in the schematic diagrams of fig. 6-9.
Fig. 6-9 illustrate that the impedance R1+ JX1 is transformed to R3+ JX3 through the reactance JX22, and the formula for calculating R3 and X3 is derived as follows:
the impedance value of each frequency point of the node 3 adjusted by the matching correction network is substituted into R1+ jX1, the impedance value R3+ jX3 of each frequency point is obtained through matching transformation of jX22, and after conjugate offset, the result finally matched with the requirement of an output/input circuit is obtained at the node 4.
And matching transformation, namely adjusting the value of jX22, so that the R3 value of the transformed central working frequency point is equal to the impedance value required by the circuit. The jX22 can be realized by an inductive element or an inductive network, or by a capacitive element or a capacitive network, and a matching transformation network with relatively good flatness index can be selected from the inductive matching network and the capacitive matching network in simple design.
It can also be seen from the above derived formula that, in addition to the final matching result adjusted by jX22, the distribution situation of jX1 values at each frequency point at the node 3 adjusted by the antenna matching correction network affects the final matching impedance at each working frequency point. Further, the change relation of the X3 affected by the X1 is analyzed by a formula, and it can be seen that after the impedance parameter of the node 3 meets two requirements of a low Q value and a working frequency band high frequency point impedance imaginary part value larger than a low frequency point impedance imaginary part value, the deviation degree of impedance data of each working frequency point after matching transformation can be reduced, and the bandwidth index and the flatness index of the antenna matching network are improved.
The performance of the antenna matching network described in fig. 4 or fig. 5 is verified by partly and specifically testing the parameter values of the network elements identified in fig. 4 and fig. 5, and in particular, see fig. 10-fig. 16.
Fig. 10 is the measured antenna impedance data for 11 operating frequency points (30 KHZ bandwidth) centered at 612KHZ and 900KHZ, the antenna being a vertical ground antenna with a height of 142.5 meters. Under the influence of interference signals during testing, the data of individual frequency points are not accurate, and no correction is made in order to keep the authenticity of the data. Besides actual measurement of antenna data, the data of the components of the matching network in fig. 4 and 5 is calculated after being designed by the method provided by the invention, so that calculation and verification are facilitated. In implementation, the element parameters can be adjusted within a certain range without violating the design principle.
For the embodiment of fig. 4, a design with a center frequency of 612KHZ and a bandwidth of 30KHZ is provided. In the scheme, the pre-regulation network is realized by connecting a capacitor 1040PF in parallel. Fig. 11 shows the antenna impedance data of 11 frequency points at node 1 after being pre-adjusted by the pre-adjusting network, which conforms to the principle of "low Q value".
The matching correction network is designed to be composed of two parallel networks, and real-frequency data of each working frequency point at a node 3 regulated by the matching correction network not only meets a low Q value, but also meets the condition that an impedance imaginary part value of a high-frequency point is larger than an impedance imaginary part value of a low-frequency point. Impedance data for 11 frequency bins at node 3 is shown in fig. 12.
The design does not design a filter network aiming at specific interference frequency, and if necessary, the matching correction network is redesigned after the filter network is added according to a design method.
The final matching technical index after passing through the matching conjugate network reaches the standing-wave ratio better than 1.2 in the bandwidth of 30KHZ, which is shown in figure 13.
In the example of fig. 5, four frequencies 612KHZ, 900KHZ, 1170KHZ, 1503KHZ co-antenna transmission are achieved.
When the four-frequency common antenna works, the situation that the antenna pre-adjusting network part works more complicated than that of single-frequency work is complicated, and the reason for the complication is that frequency bands of the four common antennas work meet the principle of low Q value at the same time. The operating frequency points of two frequencies of the four-frequency co-antenna shown in fig. 14 are adjusted by the antenna pre-adjusting network shown in fig. 5 to obtain the impedance values.
When the four-frequency co-antenna works, a matching circuit of each working frequency needs to be designed to realize parallel blocking filtering on the working frequencies of other 3 co-antennas, and therefore a plurality of parallel networks which resonate at specific frequencies are designed for blocking filtering. For simple and convenient measurement, the inductance of the parallel blocking network uniformly takes 50 uH.
Each frequency of the co-antenna operation is subjected to adjustment of the matching correction network after blocking and filtering, fig. 5 shows parameters of matching correction network elements at two frequencies of 612KHZ and 900KHZ, and fig. 15 shows impedance data of frequency points at a node after adjustment of the matching correction network.
The final matching technical indexes of the two frequencies of 612KHZ and 900KHZ after passing through the matching conjugate network are shown in figure 16, so that the standing-wave ratio in the bandwidth of 20KHZ is better than 1.2, and the standing-wave ratio in the bandwidth of 30KHZ is better than 1.3.
It can be seen that the advantages of the present invention include at least:
1. when the antenna matching network is designed or debugged, the equivalent impedance real-frequency data (the measured or calculated impedance value R + jX, the same below) of each working frequency point can be adjusted to be a low Q value (the absolute value of Q is shown, and Q is X/R), so that the technical index of the matching network can be improved;
2. the equivalent impedance parameter values of all frequency points of 4 nodes (node 1, node 2, node 3 and node 4) marked in the antenna matching network structure can respectively meet the requirements of low Q value, interference signal filtering and circuit matching through specific network adjustment;
3. an antenna pre-adjusting network is designed according to real-frequency data of the working frequency point antenna impedance and the working mode of the antenna (the working mode of the antenna refers to that the antenna works in a single-frequency or multi-frequency sharing mode), so that the equivalent impedance parameter value of each working frequency point at a node 1 meets a 'low Q value';
4. designing a filter network according to the frequency of the interference signal to keep the frequency of the interference signal at the node 2 at a high Q value;
5. designing a matching correction network to readjust the equivalent impedance value of each working frequency point at the node 3 to be a low Q value, and keeping the imaginary part of the impedance value of the high-frequency point of the working frequency point higher than the imaginary part of the impedance value of the low-frequency point as much as possible;
6. and designing a matching conjugate network to realize the matching impedance required by the circuit.
7. When a matching network for multi-frequency co-antenna work is designed, a high-Q-value parallel blocking network can be designed to isolate each frequency of the co-antenna work, and crosstalk among the frequencies is completely eliminated;
8. the antenna matching network for the multi-frequency co-antenna work is designed, so that the crosstalk among various frequencies is eliminated, and better bandwidth indexes and antenna standing-wave ratio indexes can be obtained.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (8)
1. An antenna matching network structure, the antenna matching network structure comprising a preconditioning network, a filter network, a correction network, and an impedance matching network;
the preset network is connected with the filter network through a first node;
the filter network is connected to the correction network through a second node;
the correction network is connected to the impedance matching network through a third node;
the method is characterized in that:
the pre-adjusting network is an antenna impedance pre-adjusting network, and the antenna impedance pre-adjusting network adjusts real frequency data of antenna impedance of a plurality of working frequency points, so that equivalent impedance parameters of the plurality of working frequency points at the first node are first Q values;
the filter network is a high-Q-value impedance matching filter network, and the high-Q-value impedance matching filter network performs blocking filtering on interference frequencies outside the working frequency points, so that the equivalent impedance parameter of each working frequency point of the second node is a second Q value;
the correction network is a matching correction network, and the matching correction network enables equivalent impedance parameters of all working frequency points at the third node behind the filter network to be third Q values;
the first Q value and the third Q value are low-frequency Q values of working frequency, and the second Q value is a high-frequency Q value of an interference signal;
the first and third Q values range from [ -1,1 ];
the Q value is the ratio of the imaginary part to the real part of the impedance value of the working frequency point;
the plurality of working frequency points comprise high-frequency working frequency points and low-frequency working frequency points;
and the impedance imaginary part value of the high-frequency working frequency point is greater than that of the low-frequency working frequency point.
2. An antenna matching network structure as claimed in claim 1, characterized in that:
the impedance matching network is a matching conjugate network, and the matching conjugate network transforms the equivalent antenna impedance at the third node to a preset impedance value and offsets reactance components of the plurality of working frequency points.
3. An antenna matching network structure as claimed in claim 1, characterized in that:
the match correction network is made up of reactive elements or reactive networks.
4. A matching design method of an antenna matching network structure according to any of claims 1-3, characterized in that the matching design method comprises:
measuring or calculating to obtain equivalent impedance parameters of the antennas at the multiple working frequency points;
designing the pre-adjusting network according to the acquired real frequency data of the antennas of the working frequency points, so that the equivalent impedance parameters of the working frequency points of the first node can meet the requirement of a low Q value to the maximum extent;
designing the filter network according to the frequency of an interference signal, wherein the filter network adopts a parallel resonance network to block the interference signal;
designing the matching correction network to enable equivalent impedance parameters of the working frequency points at the third node to meet the requirement of a low Q value to the maximum extent;
the low Q value is in the range of [ -1,1 ].
5. A matching design method according to claim 4, characterized in that:
if the interfering signal frequency is ambiguous, the antenna matching network structure temporarily does not add the filter network.
6. A matching design method according to claim 5, characterized in that:
the match correction network is directly connected to the first node and the third node without adding a filter network.
7. A matching design method according to any of claims 4-6, characterized by:
the equivalent impedance parameters of the working frequency points meet the requirement of a low Q value to the maximum extent, namely the equivalent impedance parameters of the working frequency points meet the range of the low Q value as much as possible.
8. A matching design method according to any of claims 4-6, characterized by:
designing the matching correction network to enable the impedance imaginary part value of the high-frequency working frequency point at the third node to be larger than the impedance imaginary part value of the low-frequency working frequency point;
the antenna matching network structure works in a single frequency band or a multi-frequency band;
when the antenna matching network structure works in a single frequency band, the pre-adjusting network is formed by a single reactance element;
when the antenna matching network structure works in a multi-frequency band, the pre-adjusting network is designed to be a composite network.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110772327.0A CN113489469B (en) | 2021-07-08 | 2021-07-08 | Antenna matching network and matching design method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110772327.0A CN113489469B (en) | 2021-07-08 | 2021-07-08 | Antenna matching network and matching design method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113489469A CN113489469A (en) | 2021-10-08 |
| CN113489469B true CN113489469B (en) | 2022-03-15 |
Family
ID=77937483
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110772327.0A Active CN113489469B (en) | 2021-07-08 | 2021-07-08 | Antenna matching network and matching design method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113489469B (en) |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1728567A (en) * | 2005-07-25 | 2006-02-01 | 胡昭培 | Bandwidth widen method and system-correction of standing-wave ratio of transmission system in medium wave |
| CN101488732B (en) * | 2009-02-17 | 2011-01-05 | 何连成 | Lumped parameter rectangular band pass filter |
| CN211045742U (en) * | 2020-01-17 | 2020-07-17 | 成都凌风天线设备有限公司 | Deployment network for superposition broadening of medium wave |
| CN112152729B (en) * | 2020-09-25 | 2022-03-01 | 上海埃威航空电子有限公司 | Bandwidth-extensible medium wave antenna feed system |
-
2021
- 2021-07-08 CN CN202110772327.0A patent/CN113489469B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN113489469A (en) | 2021-10-08 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103490733A (en) | Double-frequency-band Doherty power amplifier with frequency ratio of 1.25-2.85 | |
| JP2008005182A (en) | Band-pass filter circuit | |
| CN108292928A (en) | Multiple-harmonic matching network | |
| CN109450484A (en) | Circuit and method are eliminated in a kind of signal reflex | |
| CN104821792A (en) | Mixer and method capable of outputting local oscillation harmonic amplitude through cancellation and suppression | |
| CN105978522A (en) | Absorption-type band pass filter assembly | |
| JP4910586B2 (en) | Transmission / reception device and electronic apparatus using the same | |
| CN210780743U (en) | Radio frequency circuit for solving 2.4G interference 5G wireless performance | |
| CN111917424B (en) | Low-emission broadband noise no-load short-wave radio station and implementation method thereof | |
| CN104242980B (en) | The design of a kind of Sub-1G RF front-end circuit based on RF energy measuring and parameter regulation means | |
| CN105656436A (en) | CMOS power amplifier matching circuit | |
| CN113489469B (en) | Antenna matching network and matching design method thereof | |
| CN106797064A (en) | Micro-strip multiplexer | |
| KR101443963B1 (en) | Electronic component | |
| CN110535449B (en) | Constant-resistance short-wave multiplexer | |
| CN112713904B (en) | Composite tuning network and antenna tuner | |
| CN211046890U (en) | Impedance matching circuit | |
| Stiri et al. | Realization of a low-cost impedance matching circuit for stable power line communications: From testbeds to practical implementation | |
| CN220401726U (en) | Multiplexer and communication equipment | |
| CN106170925B (en) | High-frequency front-end circuit | |
| CN217607784U (en) | Stray suppression device suitable for frequency mixing circuit | |
| CN213754520U (en) | Long-distance optical dispersion compensation device | |
| CN216356688U (en) | Matching circuit and wireless communication device | |
| CN219740334U (en) | Novel miniaturized frequency hopping filter | |
| RU2800642C1 (en) | Device and method for coordination of radio-transmitting antenna-feeder track with antenna of various types |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |