TW201405136A - Radio frequency scattering parameter measurement structure with two correctors and correction method thereof - Google Patents

Abstract

A radio frequency scattering parameter measurement structure with two correctors and a correction method thereof are disclosed. The present invention comprises an offset series element corrector, an offset parallel element corrector and a measurement device for an object under test. Length of Transmission lines of the offset series element corrector and the offset parallel element corrector is the same with the length of transmission line of the measurement device for the object under test, such that the offset series element corrector, the offset parallel element corrector and the measurement device for the object under test have the same error box. After the correction method calculates a scattering parameter matrix of the error box, the measurement device for the object under test can be connected to an electronic component under test, and the invention performs calculation to uncorrected measurement data, so as to derive a radio frequency scattering parameter of the object under test.

Description

Radio frequency scattering parameter measuring structure with two correctors and correction method thereof

The invention relates to a radio frequency scattering parameter measuring structure with two correctors and a calibration method thereof, in particular to a one-tier semiconductor wafer component or other substrate component capable of analyzing a characteristic impedance of a transmission line. The influence of the object is measured, and the measurement structure of the RF scattering parameter measurement and the embedded measurement method and the correction method thereof are performed.

When the general signal is in the RF microwave frequency band, it is difficult to measure its voltage and current directly. Therefore, in this frequency band, it should be discussed in the form of fluctuations, which are used for incidence, reflection and absorption to measure the scattering parameters. Since the entire measurement system needs to go through a series of complicated processes, it is necessary to use the measurement correction to improve the measurement accuracy. The measurement error can be characterized by the mathematical method of the error matrix, and the measurement error is divided into random, drift, And systemic three major errors, wherein the systematic error can be measured by the network analyzer in a stable measurement environment, and the error amount can be further determined, which is the measurement correction.

In practice, the calibration procedure is implemented to adjust the initial state of the instrument from the initial state after booting to the actual measurement environment defined by the user to remove errors other than the object to be tested. The Scattering parameter measurement is traditionally a two-stage method. The steps are as follows: 1. Correct the system before the measurement to remove the effects caused by the measuring instrument and the environment. Therefore, the probe is used with the standard. The Impedance Standard Substrate (ISS) is corrected, and the correction method may be SOLT (Short-Open-Load-Thru) or LRM (Line-Reflect-Match); The reference plane is moved to the probe tip, but the probe pad has a small connecting line with the device under test in the wafer, and the large-area probe contact capacitance effect cannot be calibrated; 2. The additional dummy structure (Dummy structure, such as Short, Open, Thru, etc.) is measured to remove the joint and connection line effects, which is the de-embedding program, so the main de-embedding process The purpose is to remove the test fixture effect from the measured data from the original test results to obtain the most primitive characteristics of the component.

However, this two-stage measurement method has the following disadvantages: 1. The high frequency characteristics of the additional virtual structure on the wafer are not easy to know. If it is assumed to be an ideal characteristic, the de-embedding result will introduce a large error at high frequency; 2. Two-stage measurement costing wafer probe Test time, so it becomes very important when applied to a large number of tests; 3. Because the Impedance Standard Substrate (ISS) is expensive, the contact is degraded by the scratch characteristics of the probe every time it is tested. Therefore, it needs to be replaced after a certain number of times, thus also increasing the test cost.

In view of the above shortcomings, some documents have mentioned solutions, and their contents are as follows:

1. IEEE Trans . Electron Devices , vol. 54, no. 10, pp. 2706-2714, Oct. 2007 , which refers to the use of one-stage measurement for de-embedding, but the disadvantage is that five The virtual structure (Open, Short, Thru, Left, Right), so its accuracy will be sacrificed compared to the two-stage approach.

2. IEEE Trans . Microwave Theory Tech ., vol. 51, pp. 2391-2401, Dec. 2003 , which refers to the development of Multiline Thru-Reflect-Line (TRL) by NIST (National Institute of Standards and Technology). The calibration method can complete the calibration and de-embedding procedures in one stage, but the disadvantage is that a multi-segment transmission line is required, which is very expensive.

In addition, the National Institute of Standards and Technology has developed a standard line length and line width of 50Ω. All designed transmission lines can be compared according to this standard transmission line, and then mathematical operations can be used. Finding its characteristic impedance, this method solves the limitation that the substrate needs low loss, but also because each design has to go to the US National Bureau of Standards for comparison, which also causes many inconveniences.

Therefore, if a radio frequency scattering parameter measuring structure with two correctors and a correction method thereof can be provided, the RF scattering parameter measurement de-embedding program of the one-stage semiconductor wafer component or other substrate components can be performed, in addition to being capable of self In addition to the characteristic impedance of the transmission line, and without using a standard impedance plate, only three variables are needed to solve the operation, which should be an optimal solution.

The object of the present invention is to provide a radio frequency scattering parameter measuring structure with two correctors and a calibration method thereof, in order to improve the accuracy of scattering parameter measurement, and to use a one-stage measurement to perform de-embedding procedures. In addition, it is also possible to self-determine the characteristic impedance of the transmission line.

Another object of the present invention is to provide a radio frequency scattering parameter measuring structure with two correctors and a calibration method thereof, which can achieve wide frequency measurement by using only two correctors, and can be provided by a corrector. Known conditions to solve for the same or a greater number of unknowns in order to achieve self-correction.

Radio frequency scattering parameter measuring structure with two correctors for achieving the above object And a calibration method thereof, wherein a microwave probe is used as a contact interface for transmitting a microwave signal, the microwave probe includes at least a ground end and a signal end, and the RF scattering parameter measuring structure system with two correctors Included in the offset series component corrector, the microwave probe is in contact with the offset series component corrector, and the offset series component corrector comprises two transmission lines, an offset transmission line and a series resistor, wherein the offset transmission line and The series resistor is connected between the two transmission lines, and the transmission line is connected to the signal end of the microwave probe for measuring the component characteristics of the series resistor; and the complementary parallel component corrector is performed by the microwave probe The pin is in contact with the offset parallel component corrector, and the offset parallel component corrector comprises two transmission lines, an offset transmission line and a parallel resistance, wherein the offset transmission line and the parallel resistance are connected between the two transmission lines, and the a transmission line is connected to the signal end of the microwave probe for measuring component characteristics of the parallel resistor; and a test is to be tested The measuring device is connected to the object to be tested by the microwave probe, and the measuring object of the object to be tested comprises two transmission lines and a device to be tested, wherein the device to be tested is connected to the two The middle of the transmission line is connected to the signal end of the microwave probe for measuring the component characteristics of the component to be tested.

More specifically, the transmission line of the offset series element corrector and the transmission line of the offset parallel element corrector are the same as the transmission line length of the object to be tested.

More specifically, the offset series element corrector, the offset parallel element corrector, and the object to be tested can be used for a germanium substrate, a compound semiconductor substrate (GaAs, GaN, InP, etc.), a ceramic substrate/FR -4 on the substrate or epoxy fiberglass board substrate.

More specifically, the offset series element corrector, the offset parallel element corrector, and the object to be tested can use a Coplanar waveguide or a microstrip as a connection transmission line.

More specifically, the microwave probe is a high frequency probe, and the probe type can be G-S-G-S-G, G-S-S-G, G-S-G or G-S.

In addition, the present invention has two corrector radio frequency scattering parameter measurement and correction methods, which use two correctors, a test object measuring instrument and an arithmetic expression having three variables, wherein the two correctors and the standby The measuring instrument has the same error box, and the scattering parameter matrix of the error box can be obtained by the calibration method, so that the measuring object to be tested can be connected to an electronic component to be tested, and the uncorrected measurement can be performed. The data is calculated to find the RF scattering parameters of the object to be tested.

More specifically, the radio frequency scattering parameter correction method can perform self-correction, and the correction system is configured to be able to deduct the error added during the measurement, and the characteristics of the error quantities are represented by a mathematical model, and the transmission line segment corrector After the parallel component corrector is measured and measured, the mathematical model can be input to calculate all the error parameters. Therefore, after repeated calculation, the error value of the required calibration can be obtained, and the actual value can be further obtained. The parameter value of the object to be tested.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Please refer to FIG. 1A, FIG. 1B and FIG. 2 for a coplanar waveguide layout structure diagram, a microstrip line layout structure diagram, a corrector, etc. of a radio frequency scattering parameter measurement structure with two correctors and a correction method thereof. As shown in the figure, the RF scattering parameter measuring structure is a microwave probe as a contact interface for transmitting a microwave signal, wherein the microwave probe includes at least a ground terminal 11 and a signal terminal 12, and the RF The scattering parameter measuring structure comprises: an offset series element corrector 2, wherein the microwave probe (the ground end 11 and the signal end 12) is in contact with the offset series element corrector 2, and the offset series element corrector 2 Department contains two passes The transmission line 21, an offset transmission line 22 and a series resistor 23, wherein the offset transmission line 22 is the same width as the transmission line 21, and the offset transmission line 22 is connected to the series resistor 23, and the offset transmission line 22 is connected to the series resistor 23 Between the two transmission lines 21, the transmission line 21 is connected to the signal terminal 12 of the microwave probe for measuring the component characteristics of the series resistor 23; and the complementary parallel component corrector 3 is used for the microwave probe. The pin (ground terminal 11 and signal terminal 12) is in contact with the offset parallel component corrector 3, and the offset parallel component corrector 3 includes two transmission lines 31, an offset transmission line 32 and a parallel resistor 33, wherein the offset transmission line 32 The transmission line 31 is the same width as the transmission line 31, and the offset transmission line 32 is connected to the parallel resistor 33, and the offset transmission line 32 and the parallel resistor 33 are connected between the two transmission lines 31, and the transmission line 31 is connected to the microwave probe. The signal terminal 12 is connected to measure the component characteristics of the parallel resistor 33; a DUT 4 is in contact with the amount of the object to be tested by the microwave probe (the ground terminal 11 and the signal terminal 12) The measuring device 4 includes two transmission lines 41 and a device under test 42, wherein the device under test 42 is connected between the two transmission lines 41, and the transmission line 41 is connected to the microwave probe The signal terminal 12 of the pin is connected to measure the component characteristics of the device under test 42 (as shown in FIG. 1A and FIG. 1B, the device to be tested is a FET component).

It is worth mentioning that, as shown in FIG. 2, the equivalent circuit operation formula ( y _sp is a high frequency parasitic element) that compensates for the series element corrector 2 includes:

It is worth mentioning that, as shown in FIG. 2, the equivalent circuit expression ( z _tp is a high frequency parasitic element) of the complementary parallel element corrector 3 includes:

It is worth mentioning that the transmission line 21 of the offset serial component corrector 2 and the transmission line 31 of the complementary parallel component corrector 3 are the same length as the transmission line 41 of the analyte measuring device 4, so that the transmission line segment corrector 2. The offset parallel component corrector 3 has the same error box as the analyte detector 4.

It is worth mentioning that the offset transmission line 22 of the offset series element corrector 2 and the offset transmission line 32 of the offset parallel element corrector 3 are not the same length.

It is worth mentioning that the offset series element corrector 2, the offset parallel element corrector 3 and the object to be tested 4 can be used for a germanium substrate, a compound semiconductor (GaAs, GaN, InP, etc.) substrate or Ceramic/FR-4 (epoxy fiberglass board) substrate.

It is worth mentioning that the offset series element corrector 2, the offset parallel element corrector 3 and the object to be tested 4 can be connected by a Coplanar waveguide or a microstrip line. a transmission line, as shown in FIG. 1A, wherein the corrector (the offset series element corrector 2, the offset parallel element corrector 3) and the object to be tested 4 use a coplanar waveguide as a connection transmission line, and As shown in FIG. 1B, the corrector (the offset series element corrector 2, the offset parallel element corrector 3) and the object to be tested 4 use a microstrip line as a connection transmission line.

It is worth mentioning that the microwave probe is a high frequency probe, and the probe type can be G-S-G-S-G, G-S-S-G, G-S-G (Ground-Signal-Ground) or G-S (Ground-Signal).

Please refer to FIG. 3, which is a flowchart of the calibration operation of a radio frequency scattering parameter measuring structure with two correctors and a calibration method thereof. It can be seen from the figure that the known conditions provided by the two correctors can be used to solve the same problem. Or a greater number of unknowns, and the calibration procedure of the RF scattering parameter measurement correction method with two correctors is: 1. First set the measurement reference impedance of the transmission line to Z _C and set a self-correction with several variables Equation 301, and the variable is , z , y , z _tp , y _sp ( γ is the propagation constant of the transmission line, Δ l _S is the length of the offset transmission line segment of the offset series element corrector, Δ l _{T is} the length of the offset transmission line segment of the offset parallel element corrector, w = △ l _T / Δ l _S , z is the normalized impedance of the series element corrector, y is the normalized admittance of the parallel element corrector, z _tp , y _sp is the high frequency parasitic element), and the self-correcting equation is as follows: Set the self-correction equation to y _sp , z _tp to 0, and then use the self-correcting equations (1) to (3) to use the Newton-Raphson method to make the measurement results of the offset series element corrector and the offset parallel element corrector. the equation can converge to obtain γ, y, z value of 302; 3 determined using gamma] y _sp, z _tp value of 303, wherein the y _sp, z _tp equation _{is:. y sp = γ △ l} S / 2 (4)

z _tp = γ Δ l _T /2 (5) 4. Combine the measurement results of the offset series element corrector and the offset parallel element corrector, and substitute y _sp , z _tp obtained in the third process into the self Correct the equations (1) to (3) to find the value of γ' , z' , y' 304; 5. Then find the value of y' _sp , z ' _tp by γ ' and calculate the amount of error 305, and the error amount ε =| y' _sp - y _sp |/| y _sp |+| z' _tp - z _tp |/| z _tp |; 6. If the judgment error amount ε is smaller than the required error amount 306, then Start to obtain the error box, and start to perform the de-embedding program 308 (de-embedding can obtain the scattering parameter of the object to be tested, and the characteristic impedance of the transmission line is used as the reference impedance). Conversely, if the error amount ε is still greater than the requirement The error amount is returned to the third process in the third step (and the γ' is replaced by the original γ, the z' is replaced by the original z , and the y' is replaced by the original y ) 307 until the error amount ε is smaller than the required error amount; 7. Finally, Z _{C is} calculated using γ' , and transmission line reference impedance conversion is performed from Z _C to Z ₀ (typically 50 Ω), and a scattering parameter 309 of the real object to be tested with Z ₀ as a reference impedance reference is obtained.

It is worth mentioning that, please refer to Figure 4, for the overall measurement of the dual-turn network architecture, where the characteristic impedance of the transmission line in the network is Z _C , and the characteristic impedance of the signal generated by the network analyzer is Z ₀ , which can be converted. The relational equation converts the characteristic impedance from Z _C to Z ₀ , thus finding the scattering parameter of the actual object to be tested, and the conversion relation equation is: among them[ ]and[ ] respectively, the transmission matrix before and after the conversion, which is defined as:

It is worth mentioning that the [ M ] in the self-correction equation is the transmission matrix of the measurement, in which the foot f and r represent the forward and reverse transmission matrices.

It is worth mentioning that in the process of the calibration step 7, if the reference impedance needs to be converted to the conventional 50 Ω, the characteristic impedance of the transmission line is required, so that the DC resistance measurement value of the offset series component corrector can be utilized. The reference impedance of the transmission line is obtained, and finally the scattering parameter of the real object to be tested with a reference impedance of 50 Ω is obtained.

Z _C = γ /( j 2π fC ) (8)

It can be seen from the above that the DC resistance measurement value of the offset series element corrector can be used to obtain the transmission line characteristic impedance; after the measurement result is substituted into the mathematical matrix operation, the needle, the metal contact and the internal metal signal transmission line can be deducted. The non-ideal effect is to achieve broadband correction measurement.

The invention provides a radio frequency scattering parameter measuring structure with two correctors and a calibration method thereof, and has the following advantages when compared with other conventional technologies:

1. The invention can improve the accuracy of the scattering parameter measurement, and can use the measurement and de-embedding procedure of the one-stage semiconductor wafer component or other substrate component RF scattering parameters, and can also self-determine the characteristic impedance of the transmission line.

2. The present invention requires only two correctors to achieve wide-band measurement, and can use the known conditions provided by the corrector to solve the same or a larger number of unknowns in order to reach To the purpose of self-correction.

3. The calibration method used in the present invention has the characteristics of being convenient and simple to manufacture, so that it is not necessary to use an expensive material for fabrication, and it is possible to calibrate to a good bandwidth range by using the characteristics of the resistor series and parallel connection, and all the characteristics. Parameters can be obtained through a self-calibration procedure.

The features and spirit of the present invention will be more apparent from the detailed description of the preferred embodiments. On the contrary, the intention is to cover various modifications and equivalents within the scope of the invention as claimed.

11‧‧‧ Grounding

12‧‧‧ Signal end

2‧‧‧Compensated series element corrector

21‧‧‧ transmission line

22‧‧‧Receiving transmission line

23‧‧‧ series resistor

3‧‧‧Compensated parallel component corrector

31‧‧‧ transmission line

32‧‧‧Receiving transmission line

33‧‧‧Parallel resistance

4‧‧‧Measurement object measuring device

41‧‧‧ transmission line

42‧‧‧Device under test

FIG. 1A is a schematic diagram of a coplanar waveguide layout structure of a radio frequency scattering parameter measuring structure with two correctors and a calibration method thereof; FIG. 1B is a radio frequency scattering parameter measuring structure with two correctors according to the present invention; The microstrip line layout structure diagram of the calibration method thereof; FIG. 2 is an equivalent circuit diagram of the radio frequency scattering parameter measuring structure with two correctors and the correcting method of the correcting method thereof; FIG. 3 is a second correction of the present invention Radio frequency scattering parameter measurement structure and correction method thereof; and FIG. 4 is a double-turn network architecture diagram of a radio frequency scattering parameter measurement structure with two correctors and an overall measurement method thereof .

11‧‧‧ Grounding

12‧‧‧ Signal end

2‧‧‧Compensated series element corrector

21‧‧‧ transmission line

22‧‧‧Receiving transmission line

23‧‧‧ series resistor

3‧‧‧Compensated parallel component corrector

31‧‧‧ transmission line

32‧‧‧Receiving transmission line

33‧‧‧Parallel resistance

4‧‧‧Measurement object measuring device

41‧‧‧ transmission line

42‧‧‧Device under test

Claims (7)

A radio frequency scattering parameter measuring structure with two correctors is a microwave probe as a contact interface for transmitting microwave signals, and the microwave probe includes at least one ground terminal and one signal terminal, and the two calibrations are provided. The RF scattering parameter measuring structure comprises: an offset series element corrector, wherein the microwave series probe contacts the offset series element corrector, and the offset series element corrector comprises two transmission lines and an offset transmission line And a series resistor, wherein the offset transmission line and the series resistor are connected between the two transmission lines, and the transmission line is connected to the signal end of the microwave probe for measuring component characteristics of the series resistor; The component corrector is in contact with the offset parallel component corrector by the microwave probe, and the complementary parallel component corrector comprises two transmission lines, an offset transmission line and a parallel resistance, wherein the offset transmission line and the parallel resistance system Connected to the middle of the two transmission lines, and the transmission line is connected to the signal end of the microwave probe for measuring the The component characteristic of the combined resistance; and a test object measuring device, wherein the microwave probe is in contact with the object to be tested, and the object to be tested comprises two transmission lines and a device to be tested The device to be tested is connected to the middle of the two transmission lines, and the transmission line is connected to the signal end of the microwave probe for measuring the component characteristics of the device to be tested. The radio frequency scattering parameter measuring structure with two correctors as described in claim 1, wherein the transmission line of the complementary series element corrector, the transmission line of the complementary parallel element corrector, and the measuring object of the object to be tested The length of the transmission line is the same. RF scattering parameter measurement with two correctors as described in claim 1 The offset series element corrector, the offset parallel element corrector, and the object to be tested can be used for a germanium substrate, a compound semiconductor substrate, a ceramic substrate, or an epoxy fiberglass board substrate. The radio frequency scattering parameter measuring structure with two correctors as described in claim 1, wherein the offset series element corrector, the offset parallel element corrector, and the object to be tested are capable of using a coplanar waveguide Or a microstrip line as a connection transmission line. The radio frequency scattering parameter measuring structure with two correctors as described in claim 1, wherein the microwave probe is a high frequency probe, and the probe type can be GGSSG, GSSG, GSG or GS. A method for correcting radio frequency scattering parameter measurement with two correctors, using two correctors, a test object and an arithmetic expression having three variables, wherein the two correctors and the amount of the object to be tested The detector has the same error box, and the scattering parameter matrix of the error box can be obtained by the calibration method, so that the unmeasured measurement data can be calculated after the object to be tested is connected to an electronic component to be tested. To find the RF scattering parameters of the analyte. The radio frequency scattering parameter measurement correction method with two correctors as described in claim 6 of the patent application can perform self-correction, and the correction system is characterized in that the error is added in order to be able to deduct the error added during the measurement. According to the mathematical model, after the offset series element corrector and the offset parallel element corrector are measured, the mathematical model can be input to calculate all the error parameters, so that the error of the required calibration can be obtained after the operation. Value, and can further determine the parameter value of the actual test object.