Test system and method for intrinsic radiation characteristics of an antenna under test

Abstract

The application provides a kind of to be measured antenna intrinsic radiation characteristic test system and method, including probe;To be measured antenna is obtained by probe self-radiation from embedding to be measured antenna intrinsic radiation characteristic;Or, to be measured antenna is obtained by probe radiation calibration to be measured antenna intrinsic radiation characteristic.The application can effectively separate the self-radiation of radio frequency probe and the intrinsic radiation of to be measured antenna, which is conducive to accurately obtaining the self-radiation characteristic of radio frequency probe and improving the accuracy of to be measured antenna intrinsic radiation characteristic test.

Description

Technical Field

[0001] This invention relates to the technical field of antenna testing, specifically to a testing system and method for the intrinsic radiation characteristics of an antenna under test. More particularly, it preferably relates to an accurate calibration method and radiation calibration kit for the intrinsic radiation characteristics of an antenna under test. Background Technology

[0002] Since the 1990s, the emergence of highly integrated wireless systems has greatly promoted the development of industries such as wireless communication, detection, imaging, and sensing. Antennas, as key components of these wireless systems, have also evolved accordingly, giving rise to various types, including antenna-in-package (AiP) based on packaging materials and processes, antenna-on-chip (AoC) based on semiconductor materials and processes, and antenna-on-display (AoD) based on transparent materials and processes. All of these antennas possess a degree of integration, and in the 5G and future post-5G mobile world, integrated antennas will be the mainstream. They will be embedded in your mobile phone, providing you with a brand-new, exceptional high-quality user experience; they will be installed in your car, ensuring your safety, stability, and smooth driving; and they will appear in the Internet of Things and the Industrial Internet to improve productivity. However, the emergence of integrated antennas also brings significant challenges to testing during the research and development and production stages.

[0003] Probes are the primary feeding method for conducted testing of integrated antennas. We know that probes were developed for testing integrated circuits. Circuit testing does not involve radiation, so open probes, even after circuit de-embedding (calibration), can accurately test circuit characteristics (especially impedance parameters). However, the antenna under test (DUT) needs to have its radiation characteristics tested. Open probes themselves radiate, thus affecting the radiation test of the DUT. Therefore, when using probes to feed and test antenna radiation, the probe's own radiation should be as low as possible. In other words, if the probe can be considered as an antenna, its antenna gain should be as low as possible. Thus, when selecting the probe, it is necessary to first calibrate its radiation characteristics as an antenna.

[0004] Currently, there is no standardized procedure in the industry for calibrating the self-emission characteristics of probes. Directly using a traditional impedance standard substrate (ISS) designed for probe circuit de-embedding to calibrate the probe's radiation de-embedding and radiation characteristics is inaccurate. Traditional impedance standard substrates integrate multiple sets of short circuits (S=Short), open circuits (O=Open), through circuits (T=Through), and matched loads (L=Load). Because each calibration circuit is located in a different position on the substrate, when a probe is mounted on a circuit with the same circuit properties but in a different location, it will generate different self-emissions, resulting in different calibrated probe radiation characteristics.

[0005] In addition to the self-radiation of the probe itself, the probe housing and many other test equipment in the test environment will produce electromagnetic interference effects such as reflection / scattering / diffraction on the intrinsic radiation of the antenna under test. These will pose a great challenge to the accurate testing of the radiation characteristics of the antenna under test. The industry has not yet made progress on how to obtain accurate intrinsic radiation characteristics of the antenna under test.

[0006] Chinese invention patent document CN110741264A discloses a method and system for testing an antenna comprising multiple radiating elements, wherein an array of one or more probes is placed in front of the antenna to be tested, and wherein the following steps are performed: acquiring an RF signal emitted by the antenna to be tested or the array of one or more probes through the array of one or more probes or through the radiating elements of the antenna to be tested; performing backpropagation reconstruction of the emitted signal by calculating the signals received by each probe of the array of one or more probes or the radiating elements of the antenna to be tested; and testing the reconstructed signal or its parameters to detect potential defects in the antenna.

[0007] Regarding the aforementioned technologies, the inventors believe that the methods described above are prone to causing electromagnetic interference to the intrinsic radiation of the antenna under test, resulting in low accuracy in testing the radiation characteristics of the antenna under test. Summary of the Invention

[0008] In view of the deficiencies in the prior art, the purpose of this invention is to provide a testing system and method for the intrinsic radiation characteristics of the antenna under test.

[0009] A testing system for the intrinsic radiation characteristics of an antenna under test, according to the present invention, includes a probe;

[0010] The intrinsic radiation characteristics of the antenna under test are obtained by de-embedding the probe through self-radiation.

[0011] or,

[0012] The intrinsic radiation characteristics of the antenna under test are obtained by probe radiation calibration.

[0013] Preferably, the system also includes a negatively radiating antenna under test;

[0014] The negative-phase radiating antenna under test is an auxiliary antenna that reverses the radiation phase of the antenna under test's radiation field.

[0015] The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test;

[0016] The probe feeds the negatively radiating antenna under test, and the radiation characteristic data of the negatively radiating antenna under test are obtained.

[0017] The intrinsic radiation characteristics of the antenna under test are obtained by subtracting the radiation characteristic data of the negatively radiating antenna under test and then dividing by two.

[0018] Preferably, the system further includes a radiation standard kit, which includes a radiation standard antenna and a negative radiation standard antenna;

[0019] The radiation standard antenna is an antenna that forms an impedance match with the probe;

[0020] The negative phase radiating standard antenna is an auxiliary antenna that reverses the radiating phase of the radiating standard antenna.

[0021] A probe-fed radiating standard antenna is used to obtain its radiation characteristics data.

[0022] The negative-radiating standard antenna is fed by a probe to obtain its radiation characteristics data.

[0023] The self-radiation characteristics of the probe are obtained by adding the radiation characteristic data of the radiating standard antenna and the radiation characteristic data of the negative radiating standard antenna and then dividing by two.

[0024] The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test;

[0025] The intrinsic radiation characteristics of the antenna under test are obtained by removing the self-radiation characteristics of the probe from the radiation characteristic data of the probe antenna.

[0026] Preferably, the system also includes an impedance calibration kit;

[0027] The probe is fed to the matched load element of the impedance calibration kit to obtain the self-radiation characteristics of the probe;

[0028] The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test;

[0029] The intrinsic radiation characteristics of the antenna under test are obtained by removing the self-radiation characteristics of the probe from the radiation characteristic data of the probe antenna.

[0030] Preferably, the radiator on the antenna under test and the radiator on the negative phase radiating antenna under test are rotatable.

[0031] Preferably, the radiators on the radiation standard antenna and the radiators on the negative phase radiation standard antenna are rotatable.

[0032] According to the present invention, a method for testing the intrinsic radiation characteristics of an antenna under test, using a testing system for the intrinsic radiation characteristics of the antenna under test, includes the following steps:

[0033] The first step in obtaining intrinsic radiation characteristics is to obtain the intrinsic radiation characteristics of the antenna under test by de-embedding the probe through self-radiation.

[0034] or,

[0035] The second step in obtaining intrinsic radiation characteristics is to obtain the intrinsic radiation characteristics of the antenna under test by means of probe radiation calibration.

[0036] Preferably, the first step of obtaining the intrinsic radiation characteristics includes the following steps:

[0037] Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test;

[0038] Steps for acquiring data from a negatively radiating antenna under test: The probe feeds the negatively radiating antenna under test to obtain the radiation characteristic data of the negatively radiating antenna under test;

[0039] The first step in calculating the intrinsic radiation characteristics is to subtract the radiation characteristic data of the antenna under test from the radiation characteristic data of the negatively radiating antenna under test, and then divide by two to obtain the intrinsic radiation characteristics of the antenna under test.

[0040] Preferably, the second step of obtaining the intrinsic radiation characteristics includes the following steps:

[0041] Steps for acquiring radiation standard antenna data: Feed the radiation standard antenna with a probe to obtain the radiation characteristic data of the radiation standard antenna;

[0042] Negative radiation standard antenna data acquisition steps: The probe feeds the negative radiation standard antenna to obtain the radiation characteristic data of the negative radiation standard antenna;

[0043] The first step in obtaining the self-radiation characteristics is to add the radiation characteristic data of the radiating standard antenna and the radiation characteristic data of the negative radiating standard antenna together and then divide by two to obtain the self-radiation characteristics of the probe.

[0044] Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test;

[0045] The second step in calculating the intrinsic radiation characteristics is to remove the self-radiation characteristics of the probe from the radiation characteristic data of the detection antenna to obtain the intrinsic radiation characteristics of the antenna under test.

[0046] Preferably, the second step of obtaining the intrinsic radiation characteristics includes the following steps:

[0047] The second step in obtaining the self-radiation characteristics is to feed the probe to the matched load element of the impedance calibration kit to obtain the self-radiation characteristics of the probe.

[0048] Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test;

[0049] The second step in calculating the intrinsic radiation characteristics is to remove the self-radiation characteristics of the probe from the radiation characteristic data of the detection antenna to obtain the intrinsic radiation characteristics of the antenna under test.

[0050] Compared with the prior art, the present invention has the following beneficial effects:

[0051] 1. This invention optimizes probe impedance calibration and proposes a novel probe radiation de-embedding method, radiation calibration method, and calibration kit based on the concept of "radiation field," which is beneficial to improving the accuracy of testing the radiation characteristics of the antenna under test.

[0052] 2. This invention provides a design method for an auxiliary antenna and an auxiliary radiation standard kit that are compatible with the probe radiation effect removal method. The method is simple, easy to implement, and can achieve the desired effect well.

[0053] 3. This invention improves upon the traditional method of calibrating probe radiation using impedance calibration substrates, fills technical gaps, and enhances and promotes the progress of the antenna testing industry. Attached Figure Description

[0054] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0055] Figure 1 This is a conceptual diagram of a short circuit according to an embodiment of the present invention;

[0056] Figure 2 This is a conceptual diagram of an open circuit according to an embodiment of the present invention;

[0057] Figure 3 This is a conceptual diagram of a pathway according to an embodiment of the present invention;

[0058] Figure 4This is a conceptual diagram of a matching load circuit according to an embodiment of the present invention;

[0059] Figure 5 This is a conceptual diagram of an antenna under test (used as a radiation standard antenna in the radiation calibration method) according to an embodiment of the present invention;

[0060] Figure 6 This is a conceptual diagram of a negative phase antenna under test (used as a negative phase radiation standard antenna in the radiation calibration method) according to an embodiment of the present invention;

[0061] Figure 7 This is a conceptual diagram of a rotating radiator antenna according to an embodiment of the present invention;

[0062] Figure 8 This is a conceptual diagram of a negative-phase antenna under test with a rotating radiator according to an embodiment of the present invention;

[0063] Figure 9 This is the E-plane co-polarization pattern of the probeless radiating standard antenna and the negative phase radiating standard antenna of the present invention;

[0064] Figure 10 This is the cross-polarization pattern of the E-plane of the radiating standard antenna and the negative phase radiating standard antenna without a probe in this invention;

[0065] Figure 11 This is the H-plane co-polarization pattern of the radiating standard antenna and the negative phase radiating standard antenna without a probe in this invention;

[0066] Figure 12 This is the H-plane cross-polarization pattern of the radiating standard antenna and the negative phase radiating standard antenna without a probe according to the present invention;

[0067] Figure 13 This invention includes the E-plane co-polarization radiation pattern of the probe-emitting standard antenna and the negative phase radiating standard antenna, as well as the calibration value of the probe's E-plane co-polarization radiation characteristics.

[0068] Figure 14 This invention includes the cross-polarization pattern of the E-plane of the probe-emitting standard antenna and the negative-phase radiating standard antenna, as well as the calibration value of the cross-polarization radiation characteristics of the probe's E-plane.

[0069] Figure 15 This invention includes the H-plane co-polarization radiation pattern of the probe-emitting standard antenna and the negative phase radiating standard antenna, as well as the calibration value of the probe's H-plane co-polarization radiation characteristics.

[0070] Figure 16 This invention includes the H-plane cross-polarization pattern of the probe-emitting standard antenna and the negative phase radiating standard antenna, as well as the calibration value of the probe's H-plane cross-polarization radiation characteristics.

[0071] Figure 17This invention describes the E-plane common polarization pattern of the antenna under test after removing the influence of the probe using the probe radiation de-embedding method.

[0072] Figure 18 This invention describes the cross-polarization pattern of the E-plane of the antenna under test after removing the influence of the probe using the probe radiation de-embedding method.

[0073] Figure 19 This invention describes the H-plane common polarization pattern of the antenna under test after removing the influence of the probe using the probe radiation de-embedding method.

[0074] Figure 20 This invention presents the H-plane cross-polarization pattern of the antenna under test after removing the influence of the probe using the probe radiation de-embedding method. Detailed Implementation

[0075] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0076] This invention discloses a testing system for the intrinsic radiation characteristics of an antenna under test, such as... Figure 5 and Figure 6 As shown, it includes a probe; the intrinsic radiation characteristics of the antenna under test are obtained by self-radiation de-embedding of the probe. Alternatively, the intrinsic radiation characteristics of the antenna under test are obtained by radiation calibration of the probe.

[0077] The process of obtaining the intrinsic radiation characteristics of the antenna under test (UTT) through probe self-radiation de-embedding involves the following steps: The system also includes a negative-radiating UDT antenna; the negative-phase radiating UDT antenna is an auxiliary antenna that reverses the radiation phase of the UDT antenna's radiation field; the probe feeds the UDT antenna to obtain its radiation characteristic data; the probe feeds the negative-radiating UDT antenna to obtain its radiation characteristic data; the UDT antenna's radiation characteristic data and the negative-radiating UDT antenna's radiation characteristic data are subtracted, and then divided by two to obtain the intrinsic radiation characteristics of the UDT antenna. Figure 7 As shown, the radiator on the antenna under test and the negative phase radiator on the antenna under test can rotate.

[0078] The first scenario for obtaining the intrinsic radiation characteristics of the antenna under test (UTT) through probe radiation calibration: The system also includes a radiation standard kit, which includes a radiating standard antenna and a negative radiating standard antenna. The radiating standard antenna is an antenna that forms an impedance match with the probe. The negative radiating standard antenna is an auxiliary antenna that reverses the radiation phase of the radiating standard antenna. The probe feeds the radiating standard antenna to obtain its radiation characteristic data. The probe feeds the negative radiating standard antenna to obtain its radiation characteristic data. The radiation characteristic data of the radiating standard antenna and the negative radiating standard antenna are added together and divided by two to obtain the probe's self-radiation characteristic. The probe feeds the UDT to obtain its radiation characteristic data. The self-radiation characteristic of the probe is removed from the radiation characteristic data of the probe antenna to obtain the intrinsic radiation characteristics of the UDT. Figure 8 As shown, the radiators on the standard radiating antenna and the negative phase radiating antenna can rotate.

[0079] In the second scenario where the intrinsic radiation characteristics of the antenna under test (UTT) are obtained through probe radiation calibration, the system also includes an impedance calibration kit. The probe feeds the matched load element (matched load circuit) of the impedance calibration kit to obtain the probe's self-radiation characteristics; the probe feeds the UDT to obtain the radiation characteristic data of the UDT; the radiation characteristic data of the probe is used to remove the probe's self-radiation characteristics to obtain the intrinsic radiation characteristics of the UDT.

[0080] This invention also discloses a method for testing the intrinsic radiation characteristics of an antenna under test, such as... Figure 5 and Figure 6 As shown, the test system for obtaining the intrinsic radiation characteristics of the antenna under test includes the following steps: First step of obtaining intrinsic radiation characteristics: The intrinsic radiation characteristics of the antenna under test are obtained by self-radiation de-embedding of the probe. Alternatively, second step of obtaining intrinsic radiation characteristics: The intrinsic radiation characteristics of the antenna under test are obtained by radiation calibration of the probe.

[0081] The first step in obtaining intrinsic radiation characteristics includes the following steps: Antenna under test data acquisition step: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test.

[0082] Steps for acquiring data from a negatively radiating antenna under test: The probe feeds the negatively radiating antenna under test to obtain the radiation characteristic data of the negatively radiating antenna under test.

[0083] The first step in calculating the intrinsic radiation characteristics is to subtract the radiation characteristic data of the antenna under test from the radiation characteristic data of the negatively radiating antenna under test, and then divide by two to obtain the intrinsic radiation characteristics of the antenna under test.

[0084] The second step in obtaining intrinsic radiation characteristics includes the following steps (Case 1): Radiation standard antenna data acquisition step: The probe feeds the radiation standard antenna to obtain the radiation characteristic data of the radiation standard antenna.

[0085] Steps for acquiring data from a negatively radiating standard antenna: Feed the negatively radiating standard antenna with a probe to obtain the radiation characteristic data of the negatively radiating standard antenna.

[0086] The first step in obtaining the self-radiation characteristics is to add the radiation characteristic data of the radiating standard antenna and the radiation characteristic data of the negative radiating standard antenna together and then divide by two to obtain the self-radiation characteristics of the probe.

[0087] Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test.

[0088] The second step in calculating intrinsic radiation characteristics is to remove the self-radiation characteristics of the probe from the radiation characteristic data of the probe antenna to obtain the intrinsic radiation characteristics of the antenna under test.

[0089] The second step for obtaining intrinsic radiation characteristics includes the following steps (Case 2): Second step for obtaining self-radiation characteristics: The probe is fed to the matched load element of the impedance calibration kit to obtain the self-radiation characteristics of the probe.

[0090] Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test.

[0091] The second step in calculating intrinsic radiation characteristics is to remove the self-radiation characteristics of the probe from the radiation characteristic data of the probe antenna to obtain the intrinsic radiation characteristics of the antenna under test.

[0092] This invention also discloses an accurate calibration method and radiation calibration kit for the intrinsic radiation characteristics of an antenna under test, such as... Figure 5 and Figure 6 The figure shows the data processing method for radiation characteristics and the radiation calibration kit.

[0093] The data processing methods for radiation characteristics include the following two operation modes: Data subtraction principle (data subtraction operation): Subtracting the first set of radiation characteristic data and then dividing by 2 can achieve the first goal.

[0094] The first set of radiation characteristic data refers to the radiation characteristic data of the probe-fed antenna under test and the radiation characteristic data of the probe-fed negative-phase radiating antenna under test. The primary objective is to determine the intrinsic radiation characteristics of the probe-fed antenna under test after eliminating probe self-radiation.

[0095] A negative-phase radiating antenna under test is designed using an auxiliary antenna that reverses the phase of the radiated field of the antenna under test through some means. For example, a typical one can be considered as... Figure 5The image shown is a microstrip patch antenna operating at 28 GHz. Figure 6 The image shows the corresponding negative-phase radiating antenna under test. Through proper design, the two antennas have a phase difference of approximately 180 degrees only in the transmission line between the feed port and the radiating element. This results in the following: when the probe feeds this antenna, if the probe tip is considered as the phase reference point of the transmission line, the two antennas under test will exhibit radiating far-field radiation with the same amplitude but opposite phase. Thus, the probe's radiation is constant, while the radiation from the antenna under test and the negative-phase radiating antenna under test is out of phase. Subtracting the two radiation characteristic data obtained from the test directly cancels out the probe radiation, leaving twice the intrinsic radiation of the antenna under test. Dividing this by 2 yields the radiation characteristic of the antenna under test after removing the probe's self-radiation. This method of achieving the first objective through pure data post-processing is called the probe radiation de-embedding method. The complete process is called probe self-radiation de-embedding.

[0096] Data addition principle (data addition operation): Adding the second set of radiation characteristic data and then dividing by 2 achieves the second objective. The second set of radiation characteristic data refers to the radiation characteristic data of the probe-fed radiating standard antenna and the radiation characteristic data of the probe-fed negative-phase radiating standard antenna. The second objective is to determine the self-radiation characteristics of the probe. A negative-phase radiating standard antenna is an auxiliary antenna that uses some means to reverse the phase of the radiation field of the radiating standard antenna. A radiating standard antenna is any type of antenna that can establish good impedance matching with the probe.

[0097] A radiating standard antenna can theoretically be used as any type of antenna. Figure 5 The image shows a typical example of a radiating standard antenna. A negative-phase radiating standard antenna is designed using a method to create an auxiliary antenna whose radiation field is phase-reversed compared to that of the radiating standard antenna. For example... Figure 6 The negative-phase radiating standard antenna shown has a 180-degree phase difference between its microstrip transmission line and the radiating standard antenna. If the probe tip is considered as the phase reference point of the transmission line, the two radiating standard antennas will exhibit radiating far-fields with the same amplitude but opposite phase, which perfectly matches the design principle. When the radiation characteristics of the two radiating standard antennas are added together, the probe's radiation field is superimposed to twice its own size, while the radiation fields of the standard antennas cancel each other out. Therefore, dividing by 2 after the addition operation calibrates the probe's radiation.

[0098] The second objective can be further implemented to achieve the first objective.

[0099] The collection of several sets of standard radiating antennas and negative phase radiating antennas used is called a radiation calibration kit.

[0100] Radiation calibration refers to the technique of removing the probe's self-radiation characteristics from the radiation characteristic data of the antenna under test by using prepared probe self-radiation data.

[0101] After determining the probe radiation, further operations can be performed to obtain the intrinsic radiation of the antenna under test. The complete process is called radiation calibration. By performing a probe-feed test on the antenna under test to obtain radiation characteristic data, and subtracting the determined probe self-radiation data, the probe self-radiation can be removed from the radiation characteristic data of the antenna under test.

[0102] The probe can also directly power and test the matched load element of the impedance calibration kit, achieving a second objective. Figure 4 An example of a matching load element suitable for a probe is shown, wherein a pair of 100Ω thin-film resistors in parallel are fabricated at the transmission line termination. By feeding the matching load element to the probe, the self-radiation characteristics of the probe can be approximately simulated when the probe termination is close to the input impedance of the antenna under test, but without radiation from a radiator.

[0103] The radiators on the antenna under test (DUT) and the negative-phase DUT in the data subtraction principle, and the radiating standard antenna and the negative-phase radiating standard antenna in the data addition principle, can be rotated appropriately to reduce the influence of probe reflection and the asymmetry of the radiator's position on the substrate. Figure 7 The rotating radiator shown is a standard antenna for radiation and Figure 8 The following example illustrates a negative-phase radiating standard antenna with a rotating radiator: Because the microstrip patch antenna in this case is not centered on the substrate, its radiation characteristics are distorted. Furthermore, when radiating a scan onto the plane facing the probe's metal casing, it suffers from severe reflections from the probe casing. To address this, the microstrip patch antenna is rotated 90 degrees around the feed metal pillar beneath it, significantly reducing the impact of these problems. Subsequent operations are identical to those in the data subtraction and addition principles. In practical applications, the antenna design may differ from this example, but the underlying principles can be applied to solve similar problems.

[0104] A comparison of the advantages and disadvantages of probe radiation de-embedding methods and radiation calibration methods in obtaining the intrinsic radiation of the antenna under test: Probe radiation de-embedding methods require the fabrication of a separate negative-phase antenna for each type of antenna under test, resulting in higher complexity and cost, but this method offers better reliability. Radiation calibration methods only require calibrating the probe's self-radiation characteristics once using a radiation standard kit. This data can then be used to calibrate radiation data when testing any type and number of antennas under test with the same probe. The disadvantage is that its reliability is lower than that of the direct probe radiation de-embedding method.

[0105] A comparison of the advantages and disadvantages of the data addition principle and the direct testing of matched load elements in calibrating probe self-radiation: The probe-fed matched load element method is very simple and easy to operate, but its reliability is poor. For example, the impedance error of thin-film resistors based on LTCC is very high, and the radiation characteristics of the probe vary greatly when fed with elements of different input impedances. Therefore, the probe radiation calibrated by this method has a large error. The data addition method for calibrating probe self-radiation is highly reliable because the radiation standard antennas used are easier to ensure the accuracy and consistency of the input impedance compared to thin-film resistors. The disadvantage is that at least two radiation standard antennas need to be fed by the probe, which increases the complexity of operation.

[0106] The method employs a probe impedance calibration kit and a radiation calibration kit, comprising the following hardware: The probe impedance calibration kit includes short-circuit, open-circuit, closed-circuit, and matched-load circuits. The radiation calibration kit includes a radiation standard antenna, a negative-phase radiation standard antenna, preferably a rotating radiator radiation standard antenna, and a rotating radiator negative-phase radiation standard antenna.

[0107] The probe impedance calibration kit includes four types of probe circuit calibration elements: short-circuit, open-circuit, closed-circuit, and matched-load circuits. The only difference between these elements is their input impedance characteristics; other hardware characteristics, such as substrate material, manufacturing process, and power supply circuit structure, are essentially the same. Minor errors are acceptable.

[0108] The features of the probe radiation de-embedding element include the following: the four probe radiation de-embedding elements represented by the radiation standard antenna, the negative phase radiation standard antenna, the antenna under test with the preferred rotating radiator, and the negative phase antenna under test with the rotating radiator should have basically the same hardware characteristics such as substrate material, processing technology, and power supply circuit structure. Figures 1 to 8 This refers to the appearance of the kit shown. For example... Figure 1 The diagram shown illustrates the concept of a short circuit. Figure 2 As shown, this is a conceptual diagram of an open circuit. Figure 3 The diagram shows a conceptual representation of the pathway. Figure 4 The diagram shown is a conceptual diagram of a matching load circuit. Figure 5 The diagram shown is a conceptual representation of a standard radiating antenna. Figure 6 The diagram shown is a conceptual representation of a negative-phase radiating standard antenna. Figure 7 The diagram shows a conceptual illustration of a standard radiating antenna with a rotating radiator (the probe structure is for illustrative purposes only and is not included in the kit). Figure 8The diagram shows a conceptual representation of a negative-phase radiating standard antenna with a rotating radiator (the probe structure is for illustrative purposes only and is not included in the kit). The positional relationship between the feed port and the patch antenna is the same for both the rotating radiating standard antenna and the negative-phase radiating standard antenna. The difference lies in the electrical length of the transmission line between the feed port and the patch antenna. This ensures that the antenna's gain, radiation efficiency, and other parameters are essentially the same. The difference is that the radiation amplitude of the rotating radiating standard antenna and the negative-phase radiating standard antenna are the same, but their phases are opposite. The radiation from the original radiating standard antenna and the rotating radiating standard antenna has rotated a certain angle around the axis formed by the patch antenna feed post.

[0109] For example, this example uses a microstrip patch antenna; other antenna types can also be used to design radiation standard kits. This example uses a radio frequency probe with a "ground-signal-ground" tip configuration; other probe types such as "ground-signal," "ground-signal-ground-signal-ground," etc., can also be used with this invention. This invention uses a strip transmission line as an example to achieve radiation phase inversion; other types of transmission lines can also be used. Furthermore, any circuit that can provide the required radiation phase shift, whether active or passive, can be used to design radiation standard kits. Similar solutions described above are essentially the same as the examples given in this invention.

[0110] Calibration of Probe Radiation Characteristics: Open probes radiate radiation, so they can be considered antennas. How to calibrate antenna radiation characteristics remains unresolved. Some methods calibrate radiation characteristics with the probe in an open-circuit state, while others calibrate with the probe connected to a matching load on a traditional impedance standard substrate. The open-circuit state differs significantly from the actual usage state of the probe. Testing with a matching load is closer to reality and more reasonable, but the closely spaced matching loads on a traditional impedance standard substrate create electromagnetic coupling with the probe, leading to significant errors in the calibrated probe radiation. Furthermore, the radiation produced by matching circuits at different locations on the substrate where the probe is connected also varies, making the self-radiation calibration of the probe unreliable.

[0111] The calibration of the probe's self-radiation characteristics in this invention is performed with the probe connected to a matched load. However, instead of using the matched load on the traditional impedance standard substrate used for probe circuit calibration, this invention utilizes either the impedance calibration kit or the radiation calibration kit to calibrate the probe's self-radiation characteristics. The specific measurement and calibration process is as follows: Scheme 1: Using the impedance calibration kit of this invention: The probe is fed to the matched load circuit in the impedance calibration kit, and a radiation characteristic test is performed to obtain test data. This data can be considered as the probe's self-radiation characteristics. Generally, this scheme can sufficiently accurately characterize the probe's self-radiation characteristics and can very quickly select probes with excellent radiation characteristics. When it is desired to calibrate the probe's radiation characteristics in a way that most closely approximates the actual use of the probe in certain application scenarios, Scheme 2 should be followed. Scheme 2: Using our invented radiation calibration kit in conjunction with the data addition principle: First, the probe is fed to a radiating standard antenna, and a radiation characteristic test is performed to obtain a set of data. Then, the probe is fed to a negative-phase radiating standard antenna, and another radiation characteristic test is performed to obtain another set of data. Since the standard radiating antenna in the radiation calibration kit has the exact same radiator as the negative-phase standard radiating antenna, the only difference is that the antennas' radiation phases differ by 180° (proof as follows). Figure 9 , Figure 10 , Figure 11 and Figure 12 As shown). Figure 9 As shown in the figure, the E-plane co-polarization patterns of the microstrip patch antennas for the radiating standard antenna and the negative-phase radiating standard antenna are displayed without a probe. Figure 10 As shown in the figure, the cross-polarization pattern of the E-plane of the microstrip patch antenna is displayed when there is no probe and when the antenna is a negative-phase radiating standard antenna. Figure 11 As shown in the figure, the H-plane co-polarization patterns of the microstrip patch antennas for the radiating standard antenna and the negative-phase radiating standard antenna are displayed without a probe. Figure 12 As shown in the figure, the cross-polarization patterns of the H-plane of the microstrip patch antennas with radiating and negative-phase radiating standard antennas are displayed without a probe. It can be verified that the radiation fields of the radiating and negative-phase radiating standard antennas are essentially equal in magnitude and opposite in direction, because the combined value obtained after adding the two sets of data is essentially zero. The E-plane and H-plane are determined by the characteristics of the patch antenna itself in this case. The E-plane of the patch antenna refers to the cross-section passing through the antenna's maximum radiation direction and parallel to the electric field vector. Similarly, the H-plane is the cross-section passing through the antenna's maximum radiation direction and parallel to the magnetic field vector.

[0112] Subsequently, the probe is loaded onto a radiation standard kit for testing or simulation. The radiation characteristic data is then analyzed using the principle of data addition; that is, by adding the two sets of data and dividing by 2, the self-radiation characteristics of the probe when the antenna under test is received at the probe tip are obtained. The contribution of the antenna's intrinsic radiation has already been canceled out at the data end. For example... Figure 13 As shown in the figure, the radiation E-plane co-polarization pattern and effectiveness of the probe-fed radiating standard antenna and the negative-phase radiating standard antenna processed by the data addition principle are illustrated. Figure 14 As shown in the figure, the radiation E-plane cross-pattern of the probe-fed radiating standard antenna and the negative-phase radiating standard antenna processed by the data addition principle is displayed, along with the results. Figure 15 As shown in the figure, the radiation H-plane co-polarization pattern and effectiveness of the probe-fed radiating standard antenna and the negative-phase radiating standard antenna processed by the data addition principle are illustrated. Figure 16 As shown in the figure, the radiation H-plane cross-polarization patterns and effectiveness of the probe-fed radiating standard antenna and the negative-phase radiating standard antenna processed by the data addition principle are illustrated. The probe radiation pattern calibration results are as follows: Figure 13 , Figure 14 , Figure 15 and Figure 16 The solid lines marked with circles in the figure are shown. The solid lines marked with pentagrams in the figure are theoretical reference values ​​for the probe's radiation characteristics. They match the solid lines marked with circles very well, indicating that the radiation calibration kit and subsequent data processing method of this invention can effectively measure and calibrate the probe's radiation and provide correct results.

[0113] Intrinsic radiation acquisition of the antenna under test: The intrinsic radiation characteristics of the antenna under test can be obtained in two ways. The first method is the radiation calibration method. Based on the probe radiation characteristics obtained using the data addition principle, the measured values ​​of the antenna under test's radiation characteristics are further processed. The radiation calibration method only requires calibrating the probe's self-radiation characteristics once using a radiation standard kit. This data can then be used to calibrate radiation data when testing any type and number of antennas under test with the same probe. Specifically, the antenna under test's radiation characteristics are tested with the probe to obtain a set of data. Then, the pre-calibrated and stored probe radiation data is subtracted from the data. This method is very simple and efficient, but its reliability is lower than the second method described below.

[0114] The second method is the probe radiation de-embedding method. Based on the data subtraction principle, the probe self-radiation characteristics are directly removed from the radiation test results of the antenna under test. The specific process is as follows: First, the antenna under test is fed with a probe, and its radiation characteristics are measured to obtain a set of data. Then, the antenna under test is fed with a negative phase using the probe, and its radiation characteristics are tested again to obtain another set of data. Finally, using the data subtraction principle, that is, subtracting the two sets of data and dividing by 2, the intrinsic radiation characteristics of the antenna under test after removing the probe radiation are obtained. Figure 17As shown in the figure, the common polarization pattern of the E-plane of the antenna under test is displayed after removing the influence of probe radiation. Figure 18 As shown in the figure, the cross-polarization pattern of the E-plane of the antenna under test is displayed after removing the influence of probe radiation. Figure 19 As shown in the figure, the H-plane common polarization pattern of the antenna under test is displayed after removing the influence of probe radiation. Figure 20 As shown in the figure, the H-plane cross-polarization pattern of the antenna under test is displayed after removing the influence of probe radiation. The results of the data addition principle are as follows: Figure 17 , Figure 18 , Figure 19 and Figure 20 The solid lines marked with circles in the figure are shown. The solid lines marked with pentagrams in the figure represent the theoretical reference values ​​for the intrinsic radiation of the antenna under test. They match the solid lines marked with circles very well, indicating that the data subtraction principle based on this invention can effectively remove the probe radiation component from the radiation pattern measurement results of the antenna under test. However, from... Figure 17 and Figure 19 The comparison reveals that the E-plane radiation pattern is severely distorted, while the H-plane radiation pattern is distorted. Figure 10 The difference is perfect. This is because the E-plane is directly opposite the probe's metal casing and experiences strong electromagnetic interference such as reflections, while the H-plane, being orthogonal to the E-plane, experiences very weak interference from probe reflections. Based on this understanding, the following method was developed to further eliminate interference from the probe casing.

[0115] The basic method involves using a rotating radiator antenna under test (UTT) and a rotating negative-phase UDT antenna. The fundamental design principle is to adjust the radiating surface of the UDT antenna of interest to be parallel to the main reflector surface of the probe's metal casing. In this example, the radiating E-plane of the UDT antenna of interest is severely affected by probe reflection. Therefore, the microstrip patch radiator can be rotated 90° around the feed post below the antenna to obtain a rotating radiator antenna under test and a rotating negative-phase UDT antenna. In this way, the radiating E-plane of the UDT antenna and the negative-phase UDT antenna, which were originally subject to severe electromagnetic interference, are rotated to a plane with minimal interference from the probe casing. The subsequent probe radiation de-embedding operation is performed in exactly the same way.

[0116] In summary, the intrinsic radiation characteristics of the microstrip patch antenna under test in this example, after eliminating both probe radiation and electromagnetic interference from the probe housing, can now be obtained.

[0117] Similar to the operation of de-embedding and calibrating probes to the probe tip using short circuits, open circuits, and matched loads on a traditional impedance standard substrate, we have designed a set of impedance calibration kits, such as... Figures 1 to 4This is indicated by [the description of the method]. The advantage is that the components of the probe impedance calibration kit have the same or similar hardware characteristics as the substrate material, fabrication process, and feed circuit of the antenna under test, and the cost is lower than using traditional impedance standard substrates. The probe's circuit characteristics can be calibrated using the probe impedance calibration kit.

[0118] This invention optimizes probe impedance calibration and proposes a novel probe radiation de-embedding method based on the concept of "radiation field," going beyond the traditional "path"-based de-embedding approach. The new methods included in this invention include: a more reliable probe impedance calibration method, a precise probe radiation characteristic calibration method, and a method for measuring the true intrinsic radiation characteristics of the antenna under test (eliminating effects such as reflection / scattering / diffraction caused by equipment in the test environment). This invention relates to antenna testing based on probe feeding. The invention includes a probe impedance calibration and radiation calibration kit, and a precise testing method for the probe's own radiation characteristics and the intrinsic radiation characteristics of the probe-fed antenna under test. Using the newly invented calibration kit and data post-processing method, the influence of the test environment and the probe on the antenna test results can be completely eliminated, thereby obtaining the true radiation characteristics of the probe and the antenna under test.

[0119] This invention provides a radiation calibration kit and a method for testing the intrinsic radiation characteristics of an antenna under test (ATT), including a probe radiation de-embedding method or a radiation calibration method: The probe radiation de-embedding method involves using a probe to feed the ATT and an auxiliary antenna in a probe-like manner and testing them. The intrinsic radiation characteristics of the ATT are determined based on the test data. The radiation calibration method involves using a probe to feed the radiation calibration kit in a probe-like manner and testing it to obtain the probe's self-radiation characteristic test data. The intrinsic radiation characteristics of the ATT are then processed based on the test data of the ATT's radiation. This invention can effectively separate the self-radiation of the RF probe from the intrinsic radiation of the ATT, which is beneficial for accurately obtaining the RF probe's self-radiation characteristics and improving the accuracy of testing the intrinsic radiation characteristics of the ATT. This invention provides a precise testing method for probe impedance calibration and radiation calibration kits, as well as for the probe's self-radiation characteristics and the intrinsic radiation characteristics of an ATT with probe-like feeding.

[0120] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0121] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A testing system for the intrinsic radiation characteristics of an antenna under test, characterized in that, Includes probes; The intrinsic radiation characteristics of the antenna under test are obtained by probe self-radiation de-embedding; this also includes antennas under test with negative phase radiation. The negative-phase radiating antenna under test is an auxiliary antenna that reverses the radiation phase of the antenna under test's radiation field. The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test; The probe feeds the negative phase radiating antenna under test, and the radiation characteristic data of the negative phase radiating antenna under test are obtained. The intrinsic radiation characteristics of the antenna under test are obtained by subtracting the radiation characteristic data of the negative phase radiating antenna under test and dividing by two. This process is called probe self-radiation de-embedding.

2. The testing system for the intrinsic radiation characteristics of the antenna under test according to claim 1, characterized in that, The radiator on the antenna under test and the radiator on the negative phase radiating antenna under test can rotate.

3. A testing system for the intrinsic radiation characteristics of an antenna under test, characterized in that, Includes probes; The intrinsic radiation characteristics of the antenna under test are obtained through probe radiation calibration; a radiation standard kit is also included. The radiation standard kit includes a radiation standard antenna and a negative phase radiation standard antenna; The radiation standard antenna is an antenna that forms an impedance match with the probe; The negative phase radiating standard antenna is an auxiliary antenna that reverses the radiating phase of the radiating standard antenna. A probe-fed radiating standard antenna is used to obtain its radiation characteristics data. A probe-fed negative-phase radiating standard antenna was used to obtain its radiation characteristic data. The self-radiation characteristics of the probe are obtained by adding the radiation characteristic data of the standard radiating antenna and the radiation characteristic data of the negative phase radiating antenna and then dividing by two. The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test; The intrinsic radiation characteristics of the antenna under test are obtained by removing the self-radiation characteristics of the probe from the radiation characteristic data of the antenna under test.

4. The testing system for the intrinsic radiation characteristics of the antenna under test according to claim 3, characterized in that, The radiators on the standard radiating antenna and the radiators on the negative phase radiating antenna are rotatable.

5. A testing system for the intrinsic radiation characteristics of an antenna under test, characterized in that, Includes probes; The intrinsic radiation characteristics of the antenna under test are obtained through probe radiation calibration; an impedance calibration kit is also included. The impedance calibration kit is as follows: The probe is fed to the matched load element of the impedance calibration kit to obtain the self-radiation characteristics of the probe; The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test; The intrinsic radiation characteristics of the antenna under test are obtained by removing the self-radiation characteristics of the probe from the radiation characteristic data of the antenna under test.

6. A method for testing the intrinsic radiation characteristics of an antenna under test, characterized in that, The test system for the intrinsic radiation characteristics of the antenna under test as described in claim 1 includes the following steps: The first step in obtaining intrinsic radiation characteristics is to obtain the intrinsic radiation characteristics of the antenna under test by de-embedding it through probe self-radiation.

7. The method for testing the intrinsic radiation characteristics of the antenna under test according to claim 6, characterized in that, The first step in obtaining the intrinsic radiation characteristics includes the following steps: Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test; Steps for acquiring data from a negative-phase radiating antenna under test: Feed the negative-phase radiating antenna under test with a probe to obtain the radiation characteristic data of the negative-phase radiating antenna under test; The first step in calculating the intrinsic radiation characteristics is to subtract the radiation characteristic data of the antenna under test from the radiation characteristic data of the negative phase radiating antenna under test, and then divide by two to obtain the intrinsic radiation characteristics of the antenna under test.

8. A method for testing the intrinsic radiation characteristics of an antenna under test, characterized in that, The test system for the intrinsic radiation characteristics of the antenna under test as described in claim 3 or 4 includes the following steps: The second step in obtaining intrinsic radiation characteristics is to obtain the intrinsic radiation characteristics of the antenna under test by means of probe radiation calibration.

9. The method for testing the intrinsic radiation characteristics of the antenna under test according to claim 8, characterized in that, The second step of obtaining the intrinsic radiation characteristics includes the following steps: Steps for acquiring radiation standard antenna data: Feed the radiation standard antenna with a probe to obtain the radiation characteristic data of the radiation standard antenna; Steps for acquiring data from a negative phase radiating standard antenna: Feed the negative phase radiating standard antenna with a probe to obtain the radiation characteristic data of the negative phase radiating standard antenna; The first step in obtaining the self-radiation characteristics is to add the radiation characteristic data of the radiation standard antenna and the radiation characteristic data of the negative phase radiation standard antenna together and then divide by two to obtain the self-radiation characteristics of the probe. Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test; The second step in calculating the intrinsic radiation characteristics is to remove the self-radiation characteristics of the probe from the radiation characteristic data of the antenna under test to obtain the intrinsic radiation characteristics of the antenna under test.

10. The method for testing the intrinsic radiation characteristics of the antenna under test according to claim 8, characterized in that, The second step of obtaining the intrinsic radiation characteristics includes the following steps: The second step in obtaining the self-radiation characteristics is to feed the probe to the matched load element of the impedance calibration kit to obtain the self-radiation characteristics of the probe. Steps for acquiring data from the antenna under test: The probe feeds the antenna under test to obtain the radiation characteristic data of the antenna under test; The second step in calculating the intrinsic radiation characteristics is to remove the self-radiation characteristics of the probe from the radiation characteristic data of the antenna under test to obtain the intrinsic radiation characteristics of the antenna under test.

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