CN105391416A - Load impedance matching device and matching method - Google Patents

Abstract

The invention discloses a load impedance matching device and a matching method and belongs to the impedance matching field. The load impedance matching device of the invention includes a surface acoustic wave device adaption seat; one end of the surface acoustic wave device adaption seat is connected with a port A matching circuit unit; the other end of the surface acoustic wave device adaption seat is connected with a port B matching circuit unit; the port A matching circuit unit is connected with a first joint; and the port B matching circuit unit is connected with a second joint. According to the device of the invention, based on the adjustment of the states of four single-pole double-throw switches, non-matching channels and matching channels which are corresponding to a surface acoustic wave device to be tested can be formed, so that the surface acoustic wave device to be tested can further complete load impedance matching. Compared with the prior art, a condition that a plurality of hardware units are disassembled in a whole process can be avoided, and different passive load impedance matching networks are respectively designed for two ports, and flexible processing is realized, so that the two ports can simultaneously achieve at an impedance matching center point, and reflection waves on a transmission line can be reduced, and the transmission efficiency and quality of the surface acoustic wave signals can be improved.

Description

A kind of load impedance coalignment and matching process

Technical field

The invention belongs to impedance-matching art, particularly a kind of load impedance coalignment and matching process.

Background technology

Load impedance coupling and load impedance equal the characteristic impedance of transmission line, are to make high-frequency microwave signal all can with maximum power transfer to a kind of state of POL.Sound surface device exports as high frequency analog signals, the reflected wave on transmission line can be caused comparatively strong thus direct efficiency of transmission and the quality affecting signal when load impedance mismatch.

Carry out the method for load impedance coupling much for SAW (Surface Acoustic Wave) device at present, but all can not solve load matched problem very well:

First, what exist at present can not make its input and output two-port reach coupling about SAW (Surface Acoustic Wave) device load matched scheme mostly simultaneously, and now the connection transmission line place of two-port still exists larger reflected wave;

Secondly, existing SAW (Surface Acoustic Wave) device load matched aspect lacks coalignment and the matching scheme thereof of a system, and conventional method is repeatedly repeatedly dismantled hardware and measured contrast, makes to mate and expends larger time and energy.

Summary of the invention

In order to solve the problem of prior art, first aspect, the invention provides a kind of load impedance coalignment, described load impedance coalignment, comprising:

SAW (Surface Acoustic Wave) device adapted seat, one end of described SAW (Surface Acoustic Wave) device adapted seat is connected with port one match circuit unit, the other end of described SAW (Surface Acoustic Wave) device adapted seat is connected with port two match circuit unit, described port one match circuit unit is connected with the first joint, is connected with the second joint at described port two match circuit unit;

Wherein, described SAW (Surface Acoustic Wave) device adapted seat is connected with described port one match circuit unit by the first single-pole double-throw switch (SPDT), and described SAW (Surface Acoustic Wave) device adapted seat is connected with described port two match circuit unit by the second single-pole double-throw switch (SPDT);

Be provided with the 3rd single-pole double-throw switch (SPDT) between described port one match circuit unit and described first joint, between described port two match circuit unit and described second joint, be provided with the 4th single-pole double-throw switch (SPDT).

Optionally, described SAW (Surface Acoustic Wave) device adapted seat, comprising:

Be provided with the In port be connected with acoustic wave device input pin to be measured in one end of described SAW (Surface Acoustic Wave) device adapted seat, be provided with the Out port be connected with acoustic wave device output pin to be measured at the other end of described SAW (Surface Acoustic Wave) device adapted seat.

Optionally, described port one match circuit unit, comprising:

Electric capacity C11, inductance L 11, inductance L 12;

Wherein, one end of described inductance L 11 is connected with one end of described electric capacity C11, the other end ground connection of described inductance L 11, one end of described inductance L 12 is connected with the other end of described electric capacity C11, the other end ground connection of described inductance L 12, one end of described electric capacity C11 is connected with described first single-pole double-throw switch (SPDT), and the other end of described electric capacity C11 is connected with described 3rd single-pole double-throw switch (SPDT).

Optionally, described port two match circuit unit, comprising:

Electric capacity C21, inductance L 21, inductance L 22;

Wherein, one end of described inductance L 21 and one end of described inductance L 22 are connected to one end of described electric capacity C21 jointly, the other end of described inductance L 21 is connected with described second single-pole double-throw switch (SPDT), the other end ground connection of described inductance L 22, the other end of described electric capacity C21 is connected with described 4th single-pole double-throw switch (SPDT).

Second aspect, present invention also offers a kind of load impedance matching process, and described load impedance matching process, comprising:

Step one, is connected to the port of network analyzer by transmission line by load impedance coalignment as described in relation to the first aspect;

Step 2, SAW (Surface Acoustic Wave) device to be measured is placed in the SAW (Surface Acoustic Wave) device adapted seat in described load impedance coalignment, regulate the state of the first single-pole double-throw switch (SPDT), the second single-pole double-throw switch (SPDT), the 3rd single-pole double-throw switch (SPDT), the 4th single-pole double-throw switch (SPDT), make described SAW (Surface Acoustic Wave) device access to be measured not mate passage;

Step 3, measures the impedance of described SAW (Surface Acoustic Wave) device own;

Step 4, in conjunction with matching network structure chart, builds passive impedance matching network;

Step 5, determines passive impedance matching network value;

Step 6, determines all passive load matching network values being positioned at described load impedance coalignment middle port one and port two, builds the load matching circuit associated with port two with described port one;

Step 7, regulates the state of described first single-pole double-throw switch (SPDT), the second single-pole double-throw switch (SPDT), the 3rd single-pole double-throw switch (SPDT), the 4th single-pole double-throw switch (SPDT), by described SAW (Surface Acoustic Wave) device access coupling passage to be measured, completes load matched.

Optionally, describedly determine passive impedance matching network value, comprising:

According to formula one and formula two, in conjunction with Smith's matching track figure determination passive impedance matching network value;

$L_{match}=\frac{1}{h\×Y_0\×\mathrm{\ω}}=\frac{1}{h\×Y_0\×2\mathrm{\π}f},$ Formula one

$C_{match}=\frac{1}{h\×Z_0\×\mathrm{\ω}}=\frac{1}{h\×Z_0\×2\mathrm{\π}f},$ Formula two

Wherein, h is arc locus length to be matched, and Z0 is vector network analyzer line characteristic impedance, f is center frequency of acoustic surface wave device, L _matchfor coupling inductance value, C _matchfor matching capacitance value.

The beneficial effect that technical scheme provided by the invention is brought is:

By the adjustment of four single-pole double-throw switch (SPDT) states in this device, form do not mate passage and mate passage corresponding with SAW (Surface Acoustic Wave) device to be measured respectively, thus make SAW (Surface Acoustic Wave) device one step to be measured complete load impedance coupling.Relative to prior art, avoid the generation of multiple hardware being dismantled to this situation in whole process, and different passive load impedance matching networks can be designed respectively for two ports, sweetly disposition makes two-port reach impedance matching central point simultaneously, reduce the reflected wave on transmission line, improve efficiency of transmission and the quality of surface acoustic wave signal.

Accompanying drawing explanation

In order to be illustrated more clearly in technical scheme of the present invention, below the accompanying drawing used required in describing embodiment is briefly described, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is the overall structure schematic diagram of a kind of load impedance coalignment provided by the invention;

Fig. 2 is the electrical block diagram of a kind of load impedance coalignment provided by the invention;

Fig. 3 is the structural representation of a kind of load impedance coalignment middle port one match circuit provided by the invention;

Fig. 4 is the structural representation of a kind of load impedance coalignment middle port two match circuit provided by the invention;

Fig. 5 is the schematic flow sheet of a kind of load impedance matching process provided by the invention;

Fig. 6 is Smith's matching track figure of a kind of load impedance matching process provided by the invention;

Fig. 7 is the matching network structure chart of a kind of load impedance matching process provided by the invention;

Fig. 8 is the S11 impedance chart after the coupling of a kind of load impedance matching process provided by the invention;

Fig. 9 is the S22 impedance chart after the coupling of a kind of load impedance matching process provided by the invention.

Embodiment

For making structure of the present invention and advantage clearly, below in conjunction with accompanying drawing, structure of the present invention is further described.

Embodiment one

The invention provides a kind of load impedance coalignment, described load impedance coalignment, comprising:

SAW (Surface Acoustic Wave) device adapted seat, one end of described SAW (Surface Acoustic Wave) device adapted seat is connected with port one match circuit unit, the other end of described SAW (Surface Acoustic Wave) device adapted seat is connected with port two match circuit unit, described port one match circuit unit is connected with the first joint, is connected with the second joint at described port two match circuit unit;

Wherein, described SAW (Surface Acoustic Wave) device adapted seat is connected with described port one match circuit unit by the first single-pole double-throw switch (SPDT), and described SAW (Surface Acoustic Wave) device adapted seat is connected with described port two match circuit unit by the second single-pole double-throw switch (SPDT);

Be provided with the 3rd single-pole double-throw switch (SPDT) between described port one match circuit unit and described first joint, between described port two match circuit unit and described second joint, be provided with the 4th single-pole double-throw switch (SPDT).

In force, can not reach the defect of matching status to solve the SAW (Surface Acoustic Wave) device input port that exists in prior art and output port, propose a kind of load impedance coalignment in the present invention, as shown in Figure 1, the detailed construction of this device is as follows simultaneously:

The main body of this load impedance coalignment is SAW (Surface Acoustic Wave) device adapted seat, be connected to port one match circuit unit and port two match circuit unit at these adapted seat two ends, and port one match circuit unit is connected with the second joint with the first joint respectively with port two match circuit unit.

Wherein, between port one match circuit unit and SAW (Surface Acoustic Wave) device adapted seat, be provided with the first single-pole double-throw switch (SPDT) S1, between port two match circuit unit and SAW (Surface Acoustic Wave) device adapted seat, be provided with the second single-pole double-throw switch (SPDT) S2.Between port one match circuit unit and described first joint, be provided with the 3rd single-pole double-throw switch (SPDT) S3, between port two match circuit unit and described second joint, be provided with the 4th single-pole double-throw switch (SPDT) S4.

Concrete, in fig. 2, when single-pole double-throw switch (SPDT) S1 be positioned at S11 end, single-pole double-throw switch (SPDT) S2 be positioned at S21 end, single-pole double-throw switch (SPDT) S3 be positioned at S31 and single-pole double-throw switch (SPDT) S4 be positioned at S41 end time, the first joint, SAW (Surface Acoustic Wave) device are formed with the second joint interface channel does not mate passage;

When single-pole double-throw switch (SPDT) S1 be positioned at S12 end, single-pole double-throw switch (SPDT) S2 is positioned at S22 end, single-pole double-throw switch (SPDT) S3 be positioned at S32 and single-pole double-throw switch (SPDT) S4 be positioned at S42 end time, the first joint, port one match circuit unit, SAW (Surface Acoustic Wave) device, port two match circuit unit form with the second joint interface channel and mate passage.

Owing to devising four single-pole double-throw switch (SPDT)s in whole load impedance coalignment, by adjusting the concrete connection status of four single-pole double-throw switch (SPDT)s, can make when carrying out load impedance coupling, the order SAW (Surface Acoustic Wave) device to be measured be arranged in SAW (Surface Acoustic Wave) device adapted seat accesses respectively does not mate passage and coupling passage, different passive impedance matching networks can also be built for port one and port two, finally make port one and port two reach load impedance match point, on the transmission line of minimizing two ends, information source is to the reflected wave of Load transportation signal simultaneously.

The invention provides a kind of load impedance coalignment, comprise SAW (Surface Acoustic Wave) device adapted seat, and the port one match circuit unit be attached thereto and port two match circuit unit, by the adjustment of four single-pole double-throw switch (SPDT) states in this device, form do not mate passage and mate passage corresponding with SAW (Surface Acoustic Wave) device to be measured respectively, thus make SAW (Surface Acoustic Wave) device one step to be measured complete load impedance coupling.Relative to prior art, avoid the generation of multiple hardware being dismantled to this situation in whole process, and different passive load impedance matching networks can be designed respectively for two ports, sweetly disposition makes two-port reach impedance matching central point simultaneously, reduce the reflected wave on transmission line, improve efficiency of transmission and the quality of surface acoustic wave signal.

Optionally, described SAW (Surface Acoustic Wave) device adapted seat, comprising:

Be provided with the In port be connected with acoustic wave device input pin to be measured in one end of described SAW (Surface Acoustic Wave) device adapted seat, be provided with the Out port be connected with acoustic wave device output pin to be measured at the other end of described SAW (Surface Acoustic Wave) device adapted seat.

In force, SAW (Surface Acoustic Wave) device adapted seat In port accesses SAW (Surface Acoustic Wave) device input pin to be measured, and SAW (Surface Acoustic Wave) device adapted seat Out port accesses SAW (Surface Acoustic Wave) device output pin to be measured.

By above-mentioned connection, SAW (Surface Acoustic Wave) device to be measured is accessed whole load impedance coalignment by SAW (Surface Acoustic Wave) device adapted seat.

Optionally, described port one match circuit unit, comprising:

Electric capacity C11, inductance L 11, inductance L 12;

Wherein, one end of described inductance L 11 is connected with one end of described electric capacity C11, the other end ground connection of described inductance L 11, one end of described inductance L 12 is connected with the other end of described electric capacity C11, the other end ground connection of described inductance L 12, one end of described electric capacity C11 is connected with described first single-pole double-throw switch (SPDT), and the other end of described electric capacity C11 is connected with described 3rd single-pole double-throw switch (SPDT).

In force, the details of port one match circuit unit as shown in Figure 3, one end of electric capacity C11 is connected to the S32 end in the 3rd single-pole double-throw switch (SPDT) S3, the other end of electric capacity C11 is connected to the S12 end in the first single-pole double-throw switch (SPDT) S1, and one end of inductance L 11 is connected with one end of described electric capacity C11, the other end ground connection of inductance L 11, inductance L 12 is similar with it, its one end is connected with the other end of described electric capacity C11, the other end ground connection of inductance L 12.

The said structure of port one match circuit unit is also called pi-network.

Optionally, described port two match circuit unit, comprising:

Electric capacity C21, inductance L 21, inductance L 22;

Wherein, one end of described inductance L 21 and one end of described inductance L 22 are connected to one end of described electric capacity C21 jointly, the other end of described inductance L 21 is connected with described second single-pole double-throw switch (SPDT), the other end ground connection of described inductance L 22, the other end of described electric capacity C21 is connected with described 4th single-pole double-throw switch (SPDT).

In force, the details of port two match circuit unit as shown in Figure 4, one end of inductance L 21 and one end of inductance L 22 are connected to one end of electric capacity C21 jointly, the other end of inductance L 21 is then connected to the S22 end in the second single-pole double-throw switch (SPDT) S2, the other end ground connection of inductance L 21, the other end of electric capacity C21 is connected to the S42 end in the 4th single-pole double-throw switch (SPDT) S4.

The said structure of port two match circuit unit is also called T-shaped circuit.

The invention provides a kind of load impedance coalignment, comprise SAW (Surface Acoustic Wave) device adapted seat, and the port one match circuit unit be attached thereto and port two match circuit unit, by the adjustment of four single-pole double-throw switch (SPDT) states in this device, form do not mate passage and mate passage corresponding with SAW (Surface Acoustic Wave) device to be measured respectively, thus make SAW (Surface Acoustic Wave) device one step to be measured complete load impedance coupling.Relative to prior art, avoid the generation of multiple hardware being dismantled to this situation in whole process, and different passive load impedance matching networks can be designed respectively for two ports, sweetly disposition makes two-port reach impedance matching central point simultaneously, reduce the reflected wave on transmission line, improve efficiency of transmission and the quality of surface acoustic wave signal.

Embodiment two

The invention provides a kind of load impedance matching process, as shown in Figure 5, described load impedance matching process is specific as follows:

Step one, is connected to the port of network analyzer by transmission line by load impedance coalignment;

Step 2, SAW (Surface Acoustic Wave) device to be measured is placed in the SAW (Surface Acoustic Wave) device adapted seat in described load impedance coalignment, regulate the state of the first single-pole double-throw switch (SPDT), the second single-pole double-throw switch (SPDT), the 3rd single-pole double-throw switch (SPDT), the 4th single-pole double-throw switch (SPDT), make described SAW (Surface Acoustic Wave) device access to be measured not mate passage;

Step 3, measures the impedance of described SAW (Surface Acoustic Wave) device own;

Step 4, in conjunction with matching network structure chart, builds passive impedance matching network;

Step 5, determines passive impedance matching network value;

Step 6, determines all passive load matching network values being positioned at described load impedance coalignment middle port one and port two, builds the load matching circuit associated with port two with described port one;

Step 7, regulates the state of described first single-pole double-throw switch (SPDT), the second single-pole double-throw switch (SPDT), the 3rd single-pole double-throw switch (SPDT), the 4th single-pole double-throw switch (SPDT), by described SAW (Surface Acoustic Wave) device access coupling passage to be measured, completes load matched.

In force, based on the load impedance coalignment recorded in embodiment one, a kind of load impedance matching process is proposed in the present embodiment.For convenience of explanation, the present embodiment adopts centre frequency to be 101.764MHz, and bandwidth is the SAW (Surface Acoustic Wave) device of 30MHz, and surface acoustic wave adapted seat is 24 leg bases.

First, the first joint in load impedance coalignment is connected to the Port1 port of network analyzer by transmission line, the second joint in load impedance coalignment is connected to the Port2 port of network analyzer by transmission line.

Then, SAW (Surface Acoustic Wave) device to be measured is placed in the SAW (Surface Acoustic Wave) device adapted seat in load impedance coalignment, single-pole double-throw switch (SPDT) S1 is positioned at S11 end, single-pole double-throw switch (SPDT) S2 is positioned at S21 end, single-pole double-throw switch (SPDT) S3 is positioned at S31 and single-pole double-throw switch (SPDT) S4 when being positioned at S41 end, thus by SAW (Surface Acoustic Wave) device to be measured access by the first joint, SAW (Surface Acoustic Wave) device and the second joint interface channel overall form do not mate in passage.

Then, measuring SAW (Surface Acoustic Wave) device S11 and S22 impedance own, is be measure the impedance of the input reflection coefficient S11 of SAW (Surface Acoustic Wave) device to be measured and output reflection coefficient S22 in center frequency points itself respectively with Smith chart as shown in Figure 6 on network analyzer in fact.S11 and S22 that it should be noted that herein is input and the output reflection coefficient of surface acoustic wave to be measured, is the particular measurement parameter for network analyzer, different from the meaning of parameters of representation switch in accompanying drawing.

Exemplary, two resistance values got are S11=11.43 Ω-j10.87 Ω, S22=54.19 Ω+j38.49 Ω.

Again, according to matching network structure chart as shown in Figure 7, respectively passive impedance matching network is built to port one and the second port according to after the adjustment of impedance location-appropriate.According to the previous step position that S11 with S22 is different at center frequency points place in Smith chart, the matching network structure chart shown in composition graphs 7, builds different passive impedance matching networks to port one and port two respectively.

In the matching network structure chart shown in Fig. 7,1 to the 6 match circuit structure that totally six positions are corresponding different respectively, impedance position all can be made to arrive impedance matching centre point place by these six kinds different match circuit structures, according to the particular location be in Fig. 7, choose the circuit structure that this position is corresponding.

Exemplary, port one match circuit unit adopts the pi-network of position 3 in Fig. 7, and port two match circuit unit adopts T-shaped circuit, adopts the T-shaped circuit of position 5 in Fig. 7 after adjustment.

Then, according to the dissimilar circuit after above-mentioned selection, passive impedance matching network value is determined.In matching track figure existence wait resistance circle, etc. conductance circle etc., all belong to Smith chart, when accessing the passive devices such as inductance capacitance to SAW (Surface Acoustic Wave) device to be measured in mode that is in parallel or series connection, the position of center frequency points place impedance in Smith chart now can change.

Concrete, be increase inductance value in time giving SAW (Surface Acoustic Wave) device series inductance, now edge, impedance position waits the smoother hour hands of resistance to move, and shunt inductance then inductance value reduces, and the conductance circles such as edge are mobile counterclockwise.According to above-mentioned Changing Pattern, constantly by adjustment, make impedance position movement could reach impedance matching centre point step by step, concrete mobile how many and corresponding much resistance capacitance values of needs are obtained by formulae discovery.Network values in this step is just the inductance capacitance value in the T-shaped or pi-network be mentioned in previous step.

Now, the type of adopted match circuit has been determined according to abovementioned steps, the arc length of movement as required in Smith chart, the inductance value, the capacitance that need to regulate can be determined, namely determine all passive load matching network values of load impedance coalignment middle port one and port two.Further, for " centre frequency is 101.764MHz; bandwidth is the SAW (Surface Acoustic Wave) device of 30MHz; surface acoustic wave adapted seat is 24 leg bases " of middle proposition above, built pi-network at its port one, port two has built T-shaped circuit, makes it to reach impedance matching centre point, for mating different SAW (Surface Acoustic Wave) device, different network can be built.

Finally, when mating for a certain SAW (Surface Acoustic Wave) device, different SAW (Surface Acoustic Wave) device itself has different impedances, so first need first passage not to be mated in its access, then measure above the impedance S11 own and impedance S22 own that are mentioned to, then complete matching network according to step 3 to step 6, after determining network values whole in matching network, again by the mode of by-pass cock, SAW (Surface Acoustic Wave) device is made to access coupling passage, so that checking matching result.Therefore only need a coalignment, the load impedance coupling flow process for different SAW (Surface Acoustic Wave) device can be completed.

Wherein, determine all passive load matching network values of port one and port two, build port one and port two load matching circuit.Now in counting circuit, the design parameter of each element is as follows:

$L_{11}=\frac{1}{h\×Y_0\×2\mathrm{\π}f}=\frac{1}{0.0029\×0.02\×2\mathrm{\π}\×101.764\×{10}^6}\≈266.1\mathrm{\μ}H,$ Get 270 μ H herein. $C_{11}=\frac{1}{h\×Z_0\×2\mathrm{\π}f}=\frac{1}{13.54\×50\×2\mathrm{\π}\×101.764\×{10}^6}\≈22.8pF,$ Get 22pF.

$L_{12}=\frac{1}{h\×Y_0\×2\mathrm{\π}f}=\frac{1}{0.0000144\×0.02\×2\mathrm{\π}\×101.764\×{10}^6}\≈53.6mH,$ Get 50mH.

$L_{21}=\frac{1}{h\×Y_0\×2\mathrm{\π}f}=\frac{1}{0.000178\×0.02\×2\mathrm{\π}\×101.764\×{10}^6}\≈43.4nH,$ Get 40nH.

$L_{22}=\frac{1}{h\×Y_0\×2\mathrm{\π}f}=\frac{1}{0.0032\×0.02\×2\mathrm{\π}\×101.764\×{10}^6}\≈241.2\mathrm{\μ}H,$ Get 270 μ H.

$C_{21}=\frac{1}{h\×Z_0\×2\mathrm{\π}f}=\frac{1}{6.27\×50\×2\mathrm{\π}\×101.764\×{10}^6}\≈49.2pF,$ Get 47pF.

Adjustment single-pole double-throw switch (SPDT) S1 is positioned at S12, single-pole double-throw switch (SPDT) S2 is positioned at S22, single-pole double-throw switch (SPDT) S3 is positioned at S32, single-pole double-throw switch (SPDT) S4 is positioned at S42, by SAW (Surface Acoustic Wave) device access coupling passage to be measured, complete load matched, measure S11 and the S22 impedance chart after coupling as shown in Figure 8 and Figure 9.

Fig. 8 has been the Smith impedance coupling circle diagram of input reflection coefficient S11 after coupling, it is measurement parameter immediately below in figure, measuring center frequency (Center) is 101.764MHz, intermediate-frequency bandwidth (IFBW) is set to 30KHz, and scan power scope (Span) is 40MHz.The center frequency points place that 1 position is SAW (Surface Acoustic Wave) device to be measured is marked in Fig. 8, as shown in the display of upper left side, marking 1 place's frequency is 101.764MHz, impedance real part is 50.763 Ω, imaginary part is-3.4120 Ω, namely mating rear center Frequency point place S11 impedance is: S11=50.763 Ω-j3.4120 Ω, after port one match circuit unit, S11 shows part capacitive, and size is 458.36pF.

Fig. 9 has been the Smith impedance coupling circle diagram of input reflection coefficient S22 after coupling, it is measurement parameter immediately below in figure, measuring center frequency (Center) is 101.764MHz, intermediate-frequency bandwidth (IFBW) is set to 30KHz, and scan power scope (Span) is 40MHz.The center frequency points place that 1 position is SAW (Surface Acoustic Wave) device to be measured is marked in Fig. 9, as shown in the display of upper left side, marking 1 place's frequency is 101.764MHz, impedance real part is 49.937 Ω, imaginary part is-2.9931 Ω, namely mating rear center Frequency point place S22 impedance is: S22=49.937 Ω-2.9931 Ω, after port two match circuit unit, S22 shows part capacitive, and size is 522.51pF.

Optionally, describedly determine passive impedance matching network value, comprising:

According to formula one and formula two, in conjunction with Smith's matching track figure determination passive impedance matching network value;

$L_{match}=\frac{1}{h\×Y_0\×\mathrm{\ω}}=\frac{1}{h\×Y_0\×2\mathrm{\π}f},$ Formula one

$C_{match}=\frac{1}{h\×Z_0\×\mathrm{\ω}}=\frac{1}{h\×Z_0\×2\mathrm{\π}f},$ Formula two

Wherein, h is arc locus length to be matched, and Z0 is vector network analyzer line characteristic impedance, f is center frequency of acoustic surface wave device, and Lmatch is coupling inductance value, and Cmatch is matching capacitance value.

In force, in conjunction with Smith's matching track figure determination passive impedance matching network value, specific formula for calculation is as follows:

$L_{match}=\frac{1}{h\×Y_0\×\mathrm{\ω}}=\frac{1}{h\×Y_0\×2\mathrm{\π}f}$

$C_{match}=\frac{1}{h\×Z_0\×\mathrm{\ω}}=\frac{1}{h\×Z_0\×2\mathrm{\π}f}$

Wherein: h is arc locus length to be matched, and Z0 is vector network analyzer line characteristic impedance, f is center frequency of acoustic surface wave device, and Lmatch is coupling inductance value, and Cmatch is matching capacitance value.

The invention provides a kind of load impedance matching process, comprise and use connecting line that load impedance coalignment is connected to network analyzer by transmission line, then SAW (Surface Acoustic Wave) device to be measured is placed in the SAW (Surface Acoustic Wave) device adapted seat in described load impedance coalignment, make the state of adjustment four single-pole double-throw switch (SPDT)s, make SAW (Surface Acoustic Wave) device to be measured access and do not mate passage, then the own impedance be mentioned to is measured above, then matching network is completed according to step 3 to step 6, after determining network values whole in matching network, again by the mode of by-pass cock, SAW (Surface Acoustic Wave) device is made to access coupling passage, so that checking matching result.Therefore only need a coalignment, the load impedance coupling flow process for different SAW (Surface Acoustic Wave) device can be completed.Relative to prior art, avoid the generation of multiple hardware being dismantled to this situation in whole process, and different passive load impedance matching networks can be designed respectively for two ports, sweetly disposition makes two-port reach impedance matching central point simultaneously, reduce the reflected wave on transmission line, improve efficiency of transmission and the quality of surface acoustic wave signal.

It should be noted that: a kind of load impedance coalignment that above-described embodiment provides and matching process carry out the embodiment of load impedance coupling, only as this coalignment and matching process explanation in actual applications, can also use in other application scenarioss according to actual needs and by above-mentioned coalignment and matching process, its specific implementation process is similar to above-described embodiment, repeats no more here.

Each sequence number in above-described embodiment, just to describing, does not represent the sequencing in the assembling of each parts or use procedure.

The foregoing is only embodiments of the invention, not in order to limit the present invention, within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (6)

1. a load impedance coalignment, is characterized in that, described load impedance coalignment, comprising:

SAW (Surface Acoustic Wave) device adapted seat, one end of described SAW (Surface Acoustic Wave) device adapted seat is connected with port one match circuit unit, the other end of described SAW (Surface Acoustic Wave) device adapted seat is connected with port two match circuit unit, described port one match circuit unit is connected with the first joint, is connected with the second joint at described port two match circuit unit;

Wherein, described SAW (Surface Acoustic Wave) device adapted seat is connected with described port one match circuit unit by the first single-pole double-throw switch (SPDT), and described SAW (Surface Acoustic Wave) device adapted seat is connected with described port two match circuit unit by the second single-pole double-throw switch (SPDT);

Be provided with the 3rd single-pole double-throw switch (SPDT) between described port one match circuit unit and described first joint, between described port two match circuit unit and described second joint, be provided with the 4th single-pole double-throw switch (SPDT).

2. load impedance coalignment according to claim 1, is characterized in that, described SAW (Surface Acoustic Wave) device adapted seat, comprising:

Be provided with the In port be connected with acoustic wave device input pin to be measured in one end of described SAW (Surface Acoustic Wave) device adapted seat, be provided with the Out port be connected with acoustic wave device output pin to be measured at the other end of described SAW (Surface Acoustic Wave) device adapted seat.

3. load impedance coalignment according to claim 1, is characterized in that, described port one match circuit unit, comprising:

Electric capacity C11, inductance L 11, inductance L 12;

Wherein, one end of described inductance L 11 is connected with one end of described electric capacity C11, the other end ground connection of described inductance L 11, one end of described inductance L 12 is connected with the other end of described electric capacity C11, the other end ground connection of described inductance L 12, one end of described electric capacity C11 is connected with described first single-pole double-throw switch (SPDT), and the other end of described electric capacity C11 is connected with described 3rd single-pole double-throw switch (SPDT).

4. load impedance coalignment according to claim 1, is characterized in that, described port two match circuit unit, comprising:

Electric capacity C21, inductance L 21, inductance L 22;

Wherein, one end of described inductance L 21 and one end of described inductance L 22 are connected to one end of described electric capacity C21 jointly, the other end of described inductance L 21 is connected with described second single-pole double-throw switch (SPDT), the other end ground connection of described inductance L 22, the other end of described electric capacity C21 is connected with described 4th single-pole double-throw switch (SPDT).

5. a load impedance matching process, is characterized in that, described load impedance matching process, comprising:

Step one, is connected to the port of network analyzer by transmission line by the load impedance coalignment described in claim 1;

Step 2, SAW (Surface Acoustic Wave) device to be measured is placed in the SAW (Surface Acoustic Wave) device adapted seat in described load impedance coalignment, regulate the state of the first single-pole double-throw switch (SPDT), the second single-pole double-throw switch (SPDT), the 3rd single-pole double-throw switch (SPDT), the 4th single-pole double-throw switch (SPDT), make described SAW (Surface Acoustic Wave) device access to be measured not mate passage;

Step 3, measures the impedance of described SAW (Surface Acoustic Wave) device own;

Step 4, in conjunction with matching network structure chart, builds passive impedance matching network;

Step 5, determines passive impedance matching network value;

Step 6, determines all passive load matching network values being positioned at described load impedance coalignment middle port one and port two, builds the load matching circuit associated with port two with described port one;

Step 7, regulates the state of described first single-pole double-throw switch (SPDT), the second single-pole double-throw switch (SPDT), the 3rd single-pole double-throw switch (SPDT), the 4th single-pole double-throw switch (SPDT), by described SAW (Surface Acoustic Wave) device access coupling passage to be measured, completes load matched.

6. load impedance matching process according to claim 5, is characterized in that, describedly determines passive impedance matching network value, comprising:

According to formula one and formula two, in conjunction with Smith's matching track figure determination passive impedance matching network value;

$L_{match}=\frac{1}{h\×Y_0\×\mathrm{\ω}}=\frac{1}{h\×Y_0\×2\mathrm{\π}f},$ Formula one

$C_{match}=\frac{1}{h\×Z_0\×\mathrm{\ω}}=\frac{1}{h\×Z_0\×2\mathrm{\π}f},$ Formula two

Wherein, h is arc locus length to be matched, Z ₀for vector network analyzer line characteristic impedance, f is center frequency of acoustic surface wave device, L _matchfor coupling inductance value, C _matchfor matching capacitance value.