Radio frequency switch circuit board

Abstract

The radio frequency switch circuit board is provided with a control and power supply connection socket, a temperature sensor, a heating circuit, an attenuator, four load calibration units and a switch connection unit. The control and power supply connection socket is used for being connected with a control processing unit of the four-port electronic calibration device through a connection flat cable. The temperature sensor is used for monitoring the working temperature of the load calibration unit. The heating circuit is used for heating the radio frequency switch circuit board. The four load calibration units are electrically connected with four interfaces of the four-port electronic calibration device respectively, and each interface of the four-port electronic calibration device is at least used for being connected with a calibrated port of the vector network analyzer when the vector network analyzer is calibrated. And the switch connection unit is connected with each interface and is used for switching and connecting the two interfaces which are respectively connected with the two calibrated ports. As the radio frequency switch circuit board is provided with the temperature sensor and the heating circuit, the working temperature range of the load calibration unit can be maintained, and the measurement precision of the vector network analyzer is further improved.

Description

Technical Field

[0001] This application relates to the technical field of communication test instruments and meters, and particularly to a radio frequency switch circuit board. Background Art

[0002] As a general-purpose S-parameter test instrument, the vector network analyzer is widely used in various scientific research institutions, laboratories, and production lines for S-parameter measurement, such as in various antenna tests, cavity filter tests, dielectric filter tests, circulator tests, coupler tests, splitter / combiner tests, etc. Before using the network analyzer for measurement, it is necessary to physically connect the test equipment and the equipment to be tested (connect the calibration component or the device under test), and calibration needs to be carried out separately (the main reason is that there are some errors in the vector network analyzer itself, and calibration is required to ensure the measurement accuracy). The measurement errors of the vector network analyzer include directivity error, source matching error, reflection tracking error, load matching error, and transmission tracking error. Among them, the directivity error, source matching error, and reflection tracking error are the single-port errors of the network analyzer, which are determined by directly connecting different types of standard test components (OPEN standard component, SHORTT standard component, and LOAD standard component) respectively. The load matching error and transmission tracking error need to be determined by connecting an external through-line (THRU standard component). Therefore, when calibrating a multi-port vector network analyzer, at least a set of components including OPEN standard component, SHORTT standard component, LOAD standard component, and THRU standard component is required for calibration. At present, when performing through calibration or load calibration on any port of the vector network analyzer, the influence of the working environment factors is not considered. Especially, if the working temperature of the electronic calibration component changes greatly, it will directly cause the measurement error of the vector network analyzer. Summary of the Invention

[0003] This application mainly solves the technical problem that when the working temperature of the electronic calibration component changes, the calibration accuracy of the vector network analyzer decreases.

[0004] According to a first aspect, in one embodiment, a radio frequency switch circuit board is provided. A control and power supply connection socket, a temperature sensor, a heating circuit, four load calibration units, and a switch connection unit are arranged on the radio frequency switch circuit board;

[0005] The control and power supply connection socket is electrically connected to the temperature sensor, the heating circuit, the four load calibration units, and the switch connection unit respectively, and is used to be connected to the control processing unit of the four-port electronic calibration device through a connection cable; the four-port electronic calibration device is used to calibrate the vector network analyzer;

[0006] The temperature sensor is used to monitor the operating temperature of the load calibration unit; the heating circuit is used to raise the temperature of the RF switch circuit board; the four-port electronic calibration device maintains the operating temperature of the load calibration unit within a preset temperature threshold range through the temperature sensor and the heating circuit;

[0007] The four load calibration units are respectively electrically connected to the four interfaces of the four-port electronic calibration device, and each of the interfaces of the four-port electronic calibration device is at least used to connect the port to be calibrated of the vector network analyzer when the vector network analyzer performs calibration;

[0008] The switch connection unit is respectively connected to each of the interfaces; the switch connection unit includes a switch matrix composed of at least six switches, and is used to switch and connect the two interfaces respectively connected to the two ports to be calibrated, so as to perform through calibration on the two ports to be calibrated.

[0009] In one embodiment, an attenuator is further arranged on the RF switch circuit board and is connected in series through the switch connection unit to the path where any two interfaces are connected, so as to attenuate the signal during the through calibration of the two ports to be calibrated; the attenuation amount of the attenuator is 5dB, 10dB, 20dB or 30dB.

[0010] In one embodiment, the switch matrix includes six RF switches electrically connected by microstrip lines.

[0011] In one embodiment, the six RF switches of the switch matrix are respectively a first RF switch, a second RF switch, a third RF switch, a fourth RF switch, a fifth RF switch, and a sixth RF switch; the four interfaces of the four-port electronic calibration device are respectively a first interface, a second interface, a third interface, and a fourth interface; the first RF switch is electrically connected to the first interface, the fifth RF switch, the sixth RF switch, and the third RF switch respectively, and the first RF switch is used to connect or disconnect the third RF switch from the fifth RF switch, the sixth RF switch, and the first interface respectively; the second RF switch is connected to the third interface, the fourth RF switch, the fifth RF switch, and the sixth RF switch respectively, and the second RF switch is used to connect or disconnect the fourth RF switch from the third interface, the fifth RF switch, and the sixth RF switch respectively; the third RF switch is connected to the first RF switch, the fourth RF switch, and the attenuator respectively, the fourth RF switch is connected to the third RF switch, the second RF switch, and the attenuator respectively, and the third RF switch and the fourth RF switch are used to connect the attenuator between the first RF switch and the second RF switch, or electrically isolate the attenuator; the fifth RF switch is connected to the second interface, the first RF switch, and the second RF switch respectively, and the fifth RF switch is used to connect or disconnect the second interface from the first RF switch and the second RF switch respectively; the sixth RF switch is connected to the fourth interface, the second RF switch, and the first RF switch respectively, and the sixth RF switch is used to connect or disconnect the fourth interface from the second RF switch and the first RF switch respectively.

[0012] In one embodiment, the first RF switch and the second RF switch are single-pole multi-throw RF switches; the third RF switch, the fourth RF switch, the fifth RF switch, and the sixth RF switch are single-pole double-throw RF switches.

[0013] In one embodiment, an even number of the temperature sensors are arranged on the RF switch circuit board and are centrosymmetric; the average value of the temperature monitoring values obtained by the multiple temperature sensors is taken as the current working temperature value of the load calibration unit.

[0014] In one embodiment, the heating circuit includes a plurality of heating resistors, which are arranged in a uniform and flat manner on the RF switch circuit board to synchronously heat the RF switch circuit board.

[0015] In one embodiment, the load calibration unit is electrically connected to one of the interfaces of the four-port electronic calibration device through a microstrip line; at least one DC-blocking capacitor is connected in series on the microstrip line connecting the load calibration unit and the interface.

[0016] In one embodiment, the load calibration unit includes at least one of a test SHORT circuit, a test OPEN circuit, and a test LOAD circuit.

[0017] In one embodiment, the test OPEN circuit realizes an OPEN load by leaving the pin floating; the test LOAD circuit uses two 0201 package resistors connected in parallel at the end of the RF trace as the load; the test SHORT circuit realizes a short load by connecting the pin to the ground via a GND via.

[0018] According to the RF switch circuit board of the above embodiment, since a temperature sensor and a heating circuit are provided thereon, by keeping the load calibration unit working within a preset operating temperature range, the calibration error of the load calibration unit caused by temperature changes is reduced, thereby improving the measurement accuracy of the vector network analyzer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural block diagram of an electronic calibration component in one embodiment;

[0020] Figure 2 It is a schematic structural connection diagram of a load calibration unit in one embodiment;

[0021] Figure 3 It is a schematic flow diagram of a port calibration method in one embodiment;

[0022] Figure 4 It is a schematic structural connection diagram of a four-port electronic calibration device in one embodiment;

[0023] Figure 5 It is a schematic structural connection diagram of a switch connection unit in one embodiment;

[0024] Figure 6 It is a schematic circuit connection diagram of a switch connection unit in one embodiment;

[0025] Figure 7 It is a schematic diagram of the electronic device arrangement of an RF switch circuit board in one embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] The present application will be further described in detail below in conjunction with the accompanying drawings through specific embodiments. Similar elements in different embodiments are denoted by related similar element numbers. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification, which is to avoid overwhelming the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0027] In addition, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in an obvious manner by those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0028] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the described objects and do not have any sequential or technical meaning. The "connection" and "coupling" mentioned in the present application, unless otherwise specified, both include direct and indirect connection (coupling).

[0029] Embodiment 1:

[0030] Please refer to Figure 1, which is a structural block diagram of an electronic calibration component in an embodiment. The electronic calibration component 1 is used to calibrate a vector network analyzer 2, and includes at least three interfaces 11, load calibration units 12 with the same number as the interfaces 11, a control processing unit 13, a switch connection unit 14, and a data communication unit 15. Each interface 11 is at least used to connect to the port to be calibrated of the vector network analyzer 2 during calibration. The load calibration unit 12 is used to perform load calibration on the port to be calibrated. The control processing unit 13 is used to output corresponding control instructions in response to the port to be calibrated and calibration mode specified by the user. The calibration modes include a load calibration mode and a through calibration mode. The switch connection unit 14 includes a switch matrix composed of at least four switches. The switch connection unit responds to the control instruction to control the corresponding switch to switch. When the control instruction is the first instruction for performing load calibration on the port to be calibrated specified by the user, the interface 11 connected to the port to be calibrated specified by the user and the load calibration unit 12 corresponding to this interface 11 are connected to perform load calibration on the port to be calibrated specified by the user. When the control instruction is the second instruction for performing through calibration on two ports to be calibrated specified by the user, the two interfaces 11 connected to the two ports to be calibrated specified by the user are connected to perform through calibration on the two ports to be calibrated specified by the user. The data communication unit 15 is used to be electrically connected to the vector network analyzer 2 to be calibrated. The data communication unit 15 is also electrically connected to the control processing unit 13 and is used to perform data transmission between the vector network analyzer 2 to be calibrated and the control processing unit 13.

[0031] In one embodiment, the load calibration mode includes not only performing single-port calibration on the external port (port to be calibrated) of the vector network analyzer 2, but also performing single-port calibration on the interface 11 when the interface 11 of the electronic calibration component 1 is used as the extended external interface (port to be calibrated) of the vector network analyzer 2. In one embodiment, the through calibration mode is to directly connect the external ports of the vector network analyzer 2 through the electronic calibration component 1 to perform through calibration on the two directly connected external ports.

[0032] In one embodiment, the control processing unit 13 is further used to calculate the vector characteristic parameters of the specified port in the specified calibration mode. The data communication unit 15 also transmits the vector characteristic parameters of the specified port calculated by the control processing unit 13 to the vector network analyzer 2 to be calibrated, so that the vector network analyzer 2 to be calibrated can update its own parameters when performing vector characteristic measurement on the network under test.

[0033] In one embodiment, the electronic calibration component 1 further includes a storage unit 16, and the control and processing unit 13 stores the calculated vector characteristic parameters of the specified port (used as the external connection port for vector network analysis) in the storage unit 16. In one embodiment, the switch connection unit 14 includes a switch matrix composed of at least six switches. The electronic calibration component 1 further includes an attenuator 17, and the attenuator 17 is configured to be connected in series through the switch connection unit 14 into the path where any two interfaces 11 are connected. The control and processing unit 13 calculates the vector characteristic parameters of the specified port in the through calibration mode with attenuation, and compares the vector characteristic parameters in the through calibration mode with attenuation and the vector characteristic parameters in the through calibration mode without attenuation, and determines whether the electronic calibration component has completed the calibration of the vector network analyzer 2 according to the comparison result.

[0034] In one embodiment, the data communication unit 15 is a USB module. When the USB module is electrically connected to the vector network analyzer 2 to be calibrated, it also provides electrical energy for the electronic calibration component 1. In one embodiment, the USB module includes a type interface. In one embodiment, the electronic calibration component 1 further includes a temperature control unit for adjusting the operating temperature of the load calibration unit 12 to be maintained within a preset temperature threshold range. In one embodiment, the switches of the switch connection unit 14 are RF switches.

[0035] In one embodiment, different interfaces of the electronic calibration component are also used to connect the device under test and the vector network analyzer respectively, to establish a direct connection between the external connection port of the vector network analyzer and the device under test, so as to expand the number of external connection ports of the vector network analyzer.

[0036] Please refer to Figure 2 , which is a schematic structural connection diagram of the load calibration unit in one embodiment. The load calibration unit 12 includes at least one of a test SHORT circuit 21, a test OPEN circuit 22, and a test LOAD circuit 23. The test SHORT circuit 21, the test OPEN circuit 22, and the test LOAD circuit 23 are electrically connected to the interface 11 through a connection switch circuit 24. In the load calibration mode, the connection switch circuit 24 responds to the control electrical signal sent by the control and processing unit 13 to connect one of the test SHORT circuit 21, the test OPEN circuit 22, and the test LOAD circuit 23 to the interface 11, so as to connect the test SHORT circuit 21, the test OPEN circuit 22, or the test LOAD circuit 23 to the interface to perform calibration for the interface 11.

[0037] Please refer to Figure 3 , which is a schematic flowchart of the port calibration method in one embodiment, used to calibrate the vector network analyzer through the electronic calibration component. Among them, the electronic calibration component includes at least three interfaces, a load calibration unit with the same number as the number of interfaces, a control and processing unit, and a switch connection unit. The port calibration method includes:

[0038] Step 101, preset a connection interface and a calibration mode.

[0039] The electronic calibration component receives instructions of a port to be calibrated and a calibration mode specified by a user through a calibration display interface of a vector network analyzer. Among them, the calibration mode includes a load calibration mode and a through calibration mode.

[0040] Step 102, check the interface and obtain calibration information.

[0041] Judge whether the interface of the electronic calibration component is connected to the specified port to be calibrated. If so, send the calibration information to the control processing unit of the electronic calibration component. Among them, the calibration information includes the port to be calibrated and the calibration mode specified by the user.

[0042] Step 103, output a control instruction.

[0043] The control processing unit outputs a corresponding control instruction in response to the port to be calibrated and the calibration mode specified by the user.

[0044] Step 104, execute the control instruction.

[0045] The switch connection unit controls the corresponding switch to switch in response to the control instruction, so that when the control instruction is the first instruction for load calibration of the port to be calibrated specified by the user, connect the interface connected to the port to be calibrated specified by the user and the load calibration unit corresponding to the interface, so as to perform load calibration on the port to be calibrated specified by the user. When the control instruction is the second instruction for through calibration of two ports to be calibrated specified by the user, connect the two interfaces connected to the two ports to be calibrated specified by the user, so as to perform through calibration on the two ports to be calibrated specified by the user.

[0046] Step 105, perform verification.

[0047] Calculate the first vector characteristic parameter measured by the vector network analyzer on the specified port to be calibrated in the specified calibration mode through the electronic calibration component.

[0048] Step 106, update the interface parameters.

[0049] Update the self-parameters of the vector network analyzer recorded corresponding to the parameter type of the first vector parameter by using the first vector characteristic parameter. The self-parameters are the parameters related to the self-characteristics of the vector network analyzer used when the vector network analyzer measures the vector characteristics of the network under test.

[0050] In an embodiment, the electronic calibration component further includes an attenuator, and the attenuator is configured to be connected in series to the path where any two interfaces are connected through the switch connection unit. The port calibration method further includes:

[0051] Step 107, connect an attenuator.

[0052] After calibrating the specified port to be calibrated in the specified calibration mode, the control processing unit outputs a calibration confirmation instruction. In response to the calibration confirmation instruction, the switch connection unit serially connects the attenuator into the path that is connected to the two interfaces connected to the two ports to be calibrated specified by the user.

[0053] Step 108, obtain through calibration parameters.

[0054] Calculate the vector characteristic parameters of the specified port in the through calibration mode with attenuation, compare the vector characteristic parameters in the through calibration mode with attenuation and the vector characteristic parameters in the through calibration mode without attenuation, and determine whether the electronic calibration component has completed the calibration of the vector network analyzer according to the comparison result.

[0055] The electronic calibration component disclosed in this embodiment includes at least three interfaces connected to the ports to be calibrated of the vector network analyzer, a load calibration unit, a control processing unit, a switch connection unit, and a data communication unit. The load calibration unit performs load calibration on the ports to be calibrated. The control processing unit outputs corresponding control instructions in response to the ports to be calibrated and the calibration mode specified by the user. The switch connection unit connects the load calibration unit and the interfaces or connects any two interfaces in response to the control instructions. The data communication unit is used for data transmission between the vector network analyzer and the control processing unit. By calibrating the external ports of the network analyzer through multiple interfaces of the electronic calibration component, not only can multiple calibration ports of the vector network analyzer be verified in a time-sharing asynchronous manner, but also the interfaces of the electronic calibration component can be used as the calibration ports of the vector network analyzer to expand the number of its external ports.

[0056] Embodiment 2:

[0057] Please refer to Figure 4, which is a schematic structural connection diagram of a four-port electronic calibration device in an embodiment. The four-port electronic calibration device 100 is used as an electronic calibration component to calibrate the vector network analyzer 2, and includes a housing and four interfaces (a first interface 31, a second interface 32, a third interface 33, and a fourth interface 34), four load calibration units (a first load calibration unit 35, a second load calibration unit 36, a third load calibration unit 37, and a fourth load calibration unit 38), a control processing unit 13, a switch connection unit 14, and a data communication unit 15 arranged in the housing. In one embodiment, the four load calibration units and the switch connection unit 14 are arranged on a radio frequency switch circuit board 200. Among them, each interface is connected to a load calibration unit, that is, the first interface 31 is connected to the first load calibration unit 35, the second interface 32 is connected to the second load calibration unit 36, the third interface 33 is connected to the third load calibration unit 37, and the fourth interface 34 is connected to the fourth load calibration unit 38. Each interface is at least used to connect the port to be calibrated of the vector network analyzer 2 during calibration. Each load calibration unit is used to perform load calibration on the port to be calibrated. The control processing unit 13 is used to output corresponding control instructions in response to the port to be calibrated and the calibration mode specified by the user. The calibration mode includes a load calibration mode and a through calibration mode. The switch connection unit 14 responds to the control instruction to control the switching of the corresponding switch. When the control instruction is the first instruction to perform load calibration on the port to be calibrated specified by the user, the interface connected to the port to be calibrated specified by the user and the load calibration unit corresponding to this interface are connected to perform load calibration on the port to be calibrated specified by the user. When the control instruction is the second instruction to perform through calibration on two ports to be calibrated specified by the user, the two interfaces connected to the two ports to be calibrated specified by the user are connected to perform through calibration on the two ports to be calibrated specified by the user. The data communication unit 15 is used to be electrically connected to the vector network analyzer 2 to be calibrated. The data communication unit 15 is also electrically connected to the control processing unit 13 and is used to perform data transmission between the vector network analyzer 2 to be calibrated and the control processing unit 13. In one embodiment, the four-port electronic calibration device is also used to be respectively connected to the vector network analyzer 2 and the device under test through at least two interfaces for the vector network analyzer 2 to monitor the device under test. In one embodiment, the control processing unit 15 is a single-chip microcomputer (MCU). In one embodiment, the data communication unit 15 is a USB interface. In one embodiment, the four-port electronic calibration device obtains the working power supply through the USB interface.

[0058] Please refer to Figure 5, which is a schematic structural connection diagram of a switch connection unit in an embodiment. In one embodiment, the switch connection unit is a switch matrix composed of a first radio frequency switch 41, a second radio frequency switch 42, a third radio frequency switch 43, a fourth radio frequency switch 44, a fifth radio frequency switch 45, and a sixth radio frequency switch 46. The first load calibration unit 35 is connected to the first interface 31, the second load calibration unit 36 is connected to the second interface 32, the third load calibration unit 37 is connected to the third interface 33, and the fourth load calibration unit 38 is connected to the fourth interface 34. In one embodiment, the four-port electronic calibration device further includes an attenuator 17, and the attenuator 17 is configured to be connected in series through the switch connection unit 14 to the path where any two interfaces are connected. The control processing unit 13 calculates the vector characteristic parameters of the specified port in the through calibration mode with attenuation, and compares the vector characteristic parameters in the through calibration mode with attenuation and the vector characteristic parameters in the through calibration mode without attenuation, and determines whether the electronic calibration component has completed the calibration of the vector network analyzer according to the comparison result.

[0059] In one embodiment, the first radio frequency switch 41 is respectively connected to the first interface 31, the fifth radio frequency switch 45, the sixth radio frequency switch 46, and the third radio frequency switch 43. The first radio frequency switch 41 is used to connect or disconnect the third radio frequency switch 43 from the fifth radio frequency switch 45, the sixth radio frequency switch 46, and the first interface 31. The second radio frequency switch 42 is respectively connected to the third interface 33, the fourth radio frequency switch 44, the fifth radio frequency switch 45, and the sixth radio frequency switch 46. The second radio frequency switch 42 is used to connect or disconnect the fourth radio frequency switch 44 from the third interface 33, the fifth radio frequency switch 45, and the sixth radio frequency switch 46. The third radio frequency switch 43 is respectively connected to the first radio frequency switch 41, the fourth radio frequency switch 44, and the attenuator. The fourth radio frequency switch 44 is respectively connected to the third radio frequency switch 43, the second radio frequency switch 42, and the attenuator 17. The third radio frequency switch 43 and the fourth radio frequency switch 44 are used to connect the attenuator 17 between the first radio frequency switch 41 and the second radio frequency switch 42, or to electrically isolate the attenuator. The fifth radio frequency switch 45 is respectively connected to the second interface 32, the first radio frequency switch 41, and the second radio frequency switch 42. The fifth radio frequency switch 45 is used to connect or disconnect the second interface 32 from the first radio frequency switch 41 and the second radio frequency switch 42. The sixth radio frequency switch 46 is respectively connected to the fourth interface 34, the second radio frequency switch 42, and the first radio frequency switch 41. The sixth radio frequency switch 46 is used to connect or disconnect the fourth interface 34 from the second radio frequency switch 42 and the first radio frequency switch 41.

[0060] Please refer to Figure 6, which is a schematic circuit connection diagram of the switch connection unit in an embodiment. In one embodiment, the first RF switch 41 and the second RF switch 42 are single-pole multi-throw RF switches (SP4T), each including a moving terminal connection end and three fixed terminal connection ends. The third RF switch 43, the fourth RF switch 44, the fifth RF switch 45, and the sixth RF switch 46 are single-pole double-throw RF switches (SPDT), each including a moving terminal connection end and two fixed terminal connection ends. SP4T is a one-to-four switch, which includes a common port (moving terminal connection end) and four conducting ports (fixed terminal connection ends). The common port can conduct with any one of the conducting ports, and the four conducting ports cannot conduct with each other. SPDT is a one-to-two switch, which includes a common port (moving terminal connection end) and two conducting ports (fixed terminal connection ends). The common port can conduct with any one of the conducting ports, and the two conducting ports cannot conduct with each other.

[0061] The moving terminal connection end of the first RF switch 41 is connected to the moving terminal connection end of the third RF switch 43. The three fixed terminal connection ends of the first RF switch 41 are respectively connected to the first interface, one fixed terminal connection end of the fifth RF switch 45, and one fixed terminal connection end of the sixth RF switch 46. The moving terminal connection end of the second RF switch 42 is connected to the moving terminal connection end of the fourth RF switch 44. The three fixed terminal connection ends of the second RF switch 42 are respectively connected to the third interface, one fixed terminal connection end of the fifth RF switch 45, and one fixed terminal connection end of the sixth RF switch 46. One fixed terminal of the third RF switch 43 is connected to one fixed terminal of the fourth RF switch 44. The moving terminal connection end of the fifth RF switch 45 is connected to the second interface. The two fixed terminals of the fifth RF switch 45 are respectively connected to one fixed terminal connection end of the first RF switch 41 and one fixed terminal connection end of the second RF switch 42. The moving terminal connection end of the sixth RF switch 46 is connected to the fourth interface. The two fixed terminals of the sixth RF switch 46 are respectively connected to one fixed terminal connection end of the first RF switch 41 and one fixed terminal connection end of the second RF switch 42.

[0062] In one embodiment, the attenuator 17 (ATT) is respectively connected to one fixed terminal of the third RF switch 43 and one fixed terminal of the fourth RF switch 44. In one embodiment, the attenuation amount of the attenuator 17 is 5dB, 10dB, 20dB, or 30dB.

[0063] As Figure 2As shown, the first load calibration unit, the second load calibration unit, the third load calibration unit, and the fourth load calibration unit respectively include a connection switch circuit 24 and a test SHORT circuit 21, a test OPEN circuit 22, and a test LOAD circuit 23. The test SHORT circuit 21, the test OPEN circuit 22, and the test LOAD circuit 23 are respectively connected to the connection switch circuit 24. Among them, OPEN is an open circuit of the RF microstrip line directly (test OPEN circuit), SHORT (test SHORT circuit) is a direct short circuit of the RF microstrip line to the ground, and LOAD (test LOAD circuit) is composed of a 50Ω load. In one embodiment, as Figure 6 As shown, the connection switch circuit 24 is a single-pole multi-throw RF switch (SP4T), including a moving terminal connection end and four fixed terminal connection ends. The moving terminal connection end of the single-pole multi-throw RF switch of the switch circuit 24 is connected to an interface of the four-port electronic calibration device, and the four fixed terminal connection ends are respectively connected to the test SHORT circuit 21, the test OPEN circuit 22, the test LOAD circuit 23, and the switch connection unit. In one embodiment, the test LOAD circuit is a 50Ω load. In one embodiment, the test SHORT circuit is a direct short circuit of the RF microstrip line to the ground. In one embodiment, the test OPEN circuit is an open circuit of the RF microstrip line directly.

[0064] In one embodiment, the four-port electronic calibration device can realize the connection of the test SHORT circuit, the test OPEN circuit, or the test LOAD circuit to any interface connected to the vector network analyzer, so as to realize the pre-test calibration of the vector network analyzer. The four-port electronic calibration device can also realize the physical through connection of any two interfaces, so that in addition to individually calibrating the interface to be measured (external interface) by the vector network analyzer, it can also perform a direct connection calibration on two interfaces to be measured. In addition, the interfaces of the four-port electronic calibration device can also be used as external interfaces for vector network analysis to expand the number of external interfaces for vector network analysis. In one embodiment, at least two interfaces of the four-port electronic calibration device are respectively connected to the external interface of the vector network analyzer and the device under test, so as to realize the free conversion between calibration and measurement under the condition that the physical connection method does not change. In one embodiment, the attenuator with a preset attenuation amount can be freely loaded and isolated according to the test requirements by setting the conduction of the third RF switch and the fourth RF switch.

[0065] As Figure 4 shown, in one embodiment, the four-port electronic calibration device further includes a temperature control unit 18 connected to the control processing unit 13. The temperature control unit 18 includes a heating circuit and a temperature sensor, and is used to keep the working temperature of the four load calibration units in the four-port electronic calibration device stable.

[0066] In one embodiment, the four-port electronic calibration device further includes a storage unit connected to the control processing unit 10. The parameter storage unit is used to store the electrical parameter data related to the test and calibration of the vector network analyzer 2. Among them, the electrical parameter data includes the S-parameter and attenuation parameter data of the OPEN calibration, SHORT calibration, LOAD calibration, and / or THRU calibration of each interface.

[0067] The four-port electronic calibration device disclosed in this embodiment is used for calibrating the externally connected ports of the vector network analyzer, and includes a housing, four interfaces, four load calibration units, a control processing unit, a switch connection unit, and a data communication unit. Each interface is at least used to connect the port to be calibrated of the vector network analyzer. Each interface is connected to a load calibration unit for performing load calibration on the port to be calibrated. The control processing unit is used to output corresponding control instructions in response to the port to be calibrated and the calibration mode specified by the user. The switch connection unit performs load calibration or through calibration on the port to be calibrated specified by the user in response to the control instruction. The data communication unit is used for data transmission between the vector network analyzer and the control processing unit. By calibrating the externally connected ports of the network analyzer through multiple interfaces of the electronic calibration component, not only can the multiple calibration ports of the vector network analyzer be calibrated in a time-sharing asynchronous manner, but also the interfaces of the electronic calibration component can be used as the calibration ports of the vector network analyzer to expand the number of its externally connected ports. Further, when used as an externally connected port for expanding the vector network analyzer, since there is no plugging and unplugging operation during the calibration and testing process, the physical connection method between the test interface of the vector network analyzer and the device under test will not change, thereby greatly reducing the calibration error caused by the difference during the plugging and unplugging of the ports of the vector network analyzer.

[0068] Embodiment Three:

[0069] Please refer to Figure 7 , which is a schematic diagram of electronic components of a radio frequency switch circuit board in an embodiment. A control and power supply connection socket 50, at least one temperature sensor 51, multiple heating circuits 52, an attenuator 17, four load calibration units, and a switch connection unit as described in Embodiment Two are provided on the radio frequency switch circuit board 200. The control and power supply connection socket 50 is used to be connected to the control processing unit of the four-port electronic calibration device through a connection cable. The four load calibration units are arranged axially symmetrically on the radio frequency switch circuit board 200, and the four load calibration units are respectively electrically connected to the interfaces of the four-port electronic calibration device through microstrip lines.

[0070] In one embodiment, the heating circuit 52 is heated by a heating resistor. In one embodiment, an even number of temperature sensors 51 are provided on the RF switch circuit board 200 and are symmetrically arranged at the center of the RF switch circuit board 200. In one embodiment, the heating resistor is composed of 0402 resistors with a resistance of 619 Ω, the supply voltage is 5V, and the heating power is 1.7W. When the power supply of the switch connection unit is provided by the USB interface of the vector network analyzer, its power supply capacity is 5V and 500mA, totaling 2.5W (general USB interface), and the remaining 0.8W is consumed by power-consuming devices such as the control processing unit (MCU) and the switch circuit. The supply voltage of the heating resistor is controlled by the MCU to be turned off. The MCU reads the temperature at any time through the temperature sensor 51 and sets a temperature range (for example, 33 °C to 35 °C) as the operating temperature of the electronic calibration component (testing the SHORT circuit, testing the OPEN circuit, and testing the LOAD circuit). Under this temperature condition, the electronic calibration component has the highest accuracy. When the MCU reads that the operating temperature of the switch connection unit is less than 33 °C, heating is enabled. When it reads that the operating temperature of the switch connection unit is between 33 °C and 35 °C, heating stops.

[0071] In one embodiment, the heating circuit 52 includes a plurality of heating resistors, which are arranged in a uniform and tiled manner on the RF switch circuit board to achieve synchronous heating of the entire RF switch circuit board, making the heating effect more balanced and capable of reaching the temperature stable state in the shortest time.

[0072] In one embodiment, the MCU identifies the temperature through red and green indicator lights. When the MCU reads that the temperature of the RF switch circuit board is less than 33 °C, the MCU controls the red light to light up and the green light to go out; when it reads that the temperature of the RF switch circuit board is between 33 °C and 35 °C, the green light lights up and the red light goes out.

[0073] In one embodiment, a DC-blocking capacitor 53 is provided on the microstrip line connecting the load calibration unit and the interface to protect the RF chip.

[0074] In one embodiment, the test OPEN circuit in the load calibration unit realizes the OPEN load by leaving the pin floating. In one embodiment, the test LOAD circuit in the load calibration unit uses two 100 Ω 0201 packages connected in parallel at the end of the RF trace to form a 50 Ω load. The test SHORT circuit realizes the short load by connecting the pin to the ground via a GND via.

[0075] In one embodiment, the six switches of the switch connection unit are electrically connected through microstrip lines. In one embodiment, the control processing unit of the four-port electronic calibration device is a single-chip microcomputer (MCU). In one embodiment, the data communication unit 11 of the four-port electronic calibration device is a USB interface.

[0076] In one embodiment, the attenuator is respectively connected to the third RF switch 43 and the fourth RF switch 44 of the switch connection unit. In one embodiment, the attenuation amount of the attenuator is 5 dB, 10 dB, 20 dB or 30 dB. In one embodiment, the fixed attenuator is a verification piece, which is similar to the through state between ports. The difference is that the third RF switch 43 and the fourth RF switch 44 conduct the path of the attenuator at the same time, and any two interfaces in the four-port electronic calibration device can be switched to the path of the conducting attenuator. In one embodiment, when writing the parameter data of the calibration piece, the S21 parameter of the conducting attenuator path is also written into the memory of the storage unit. After calibrating the network analyzer using the electronic calibration piece, the S21 parameter of the attenuation path is re-measured and compared with the S21 parameter stored in the memory, which can be used to evaluate whether the four-port electronic calibration device has completed the calibration of the network analyzer and can judge whether the calibration is correct.

[0077] In one embodiment, the switch connection unit includes the first RF switch circuit 41, the second RF switch circuit 42, the third RF switch 43, the fourth RF switch 44, the fifth RF switch 45 and the sixth RF switch 46 which are electrically connected through microstrip lines.

[0078] In one embodiment, the housing 100 is a shielding case. In one embodiment, the attenuation circuit 17 is arranged in the middle of the RF switch circuit board 200.

[0079] A disclosed RF switch circuit board in the present embodiment is provided with a control and power supply connection socket, a temperature sensor, a heating circuit, an attenuator, four load calibration units and a switch connection unit. The control and power supply connection socket is used to be connected to the control processing unit of the four-port electronic calibration device through a connection cable. The temperature sensor is used to monitor the working temperature of the load calibration unit. The heating circuit is used to raise the temperature of the RF switch circuit board. The four load calibration units are respectively electrically connected to the four interfaces of the four-port electronic calibration device. Each interface of the four-port electronic calibration device is at least used to connect the port to be calibrated of the vector network analyzer when calibrating the vector network analyzer. The switch connection unit is connected to each interface and is used to switch and connect two interfaces respectively connected to two ports to be calibrated. Since the temperature sensor and the heating circuit are arranged on the RF switch circuit board, the working temperature range of the load calibration unit can be maintained, thereby improving the measurement accuracy of the vector network analyzer.

[0080] The above uses specific examples to elaborate on the present application, which is only used to help understand the present application and is not intended to limit the present application. For those skilled in the technical field to which the present invention belongs, according to the idea of the present application, several simple deductions, deformations or substitutions can also be made.

Claims

1. A radio frequency switch circuit board, characterized in that: The radio frequency switch circuit board is provided with a control and power supply connection socket, a temperature sensor, a heating circuit, four load calibration units and a switch connection unit; The control and power supply connection socket is electrically connected to the temperature sensor, the heating circuit, the four load calibration units and the switch connection unit respectively, and is used to connect to the control processing unit of the four-port electronic calibration device through a connecting cable; the four-port electronic calibration device is used to calibrate the vector network analyzer; The temperature sensor is used to monitor the working temperature of the load calibration unit; the heating circuit is used to heat the RF switch circuit board; the four-port electronic calibration device maintains the working temperature of the load calibration unit within a preset temperature threshold range through the temperature sensor and the heating circuit; The four load calibration units are electrically connected to the four interfaces of the four-port electronic calibration device respectively, and each interface of the four-port electronic calibration device is at least used to connect to the calibrated port of the vector network analyzer when the vector network analyzer is calibrated; The switch connection unit is connected to each of the interfaces respectively; the switch connection unit comprises a switch matrix composed of at least six switches, which is used for switching the two interfaces respectively connected to the two calibrated ports to perform through calibration on the two calibrated ports.

2. The radio frequency switch circuit board according to claim 1, characterized in that: An attenuator is also provided on the RF switch circuit board, which is connected in series to any two paths connected by the interfaces through the switch connection unit to attenuate the signals of the two calibrated ports during through-calibration; the attenuation of the attenuator is 5dB, 10dB, 20dB or 30dB.

3. The radio frequency switch circuit board according to claim 2, characterized in that: The switch matrix includes six radio frequency switches electrically connected via microstrip lines.

4. The radio frequency switch circuit board according to claim 3, characterized in that: The six RF switches of the switch matrix are respectively the first RF switch, the second RF switch, the third RF switch, the fourth RF switch, the fifth RF switch and the sixth RF switch; the four interfaces of the four-port electronic calibration device are respectively the first interface, the second interface, the third interface and the fourth interface; the first RF switch is electrically connected to the first interface, the fifth RF switch, the sixth RF switch and the third RF switch respectively, and the first RF switch is used for connecting or disconnecting the third RF switch with the fifth RF switch, the sixth RF switch and the first interface respectively; the second RF switch is connected to the third interface, the fourth RF switch, the fifth RF switch and the sixth RF switch respectively, and the second RF switch is used for connecting or disconnecting the fourth RF switch with the third interface, the fifth RF switch and the sixth RF switch ; The third RF switch is respectively connected to the first RF switch, the fourth RF switch and the attenuator, the fourth RF switch is respectively connected to the third RF switch, the second RF switch and the attenuator, the third RF switch and the fourth RF switch are used to connect the attenuator between the first RF switch and the second RF switch, or to electrically isolate the attenuator; the fifth RF switch is respectively connected to the second interface, the first RF switch and the second RF switch, the fifth RF switch is used to connect or disconnect the second interface with the first RF switch and the second RF switch; the sixth RF switch is respectively connected to the fourth interface, the second RF switch and the first RF switch, the sixth RF switch is used to connect or disconnect the fourth interface with the second RF switch and the first RF switch.

5. The radio frequency switch circuit board according to claim 4, characterized in that: The first RF switch and the second RF switch are single-pole multi-throw RF switches; the third RF switch, the fourth RF switch, the fifth RF switch and the sixth RF switch are single-pole double-throw RF switches.

6. The radio frequency switch circuit board according to claim 1, characterized in that: An even number of the temperature sensors are arranged on the radio frequency switch circuit board and are centrally symmetrical; an average of the temperature monitoring values ​​obtained by the multiple temperature sensors is taken as the current operating temperature value of the load calibration unit.

7. The radio frequency switch circuit board according to claim 1, characterized in that: The heating circuit includes a plurality of heating resistors which are evenly arranged on a radio frequency switch circuit board to heat the radio frequency switch circuit board synchronously.

8. The radio frequency switch circuit board according to claim 1, characterized in that: The load calibration unit is electrically connected to one of the interfaces of the four-port electronic calibration device via a microstrip line; and at least one DC blocking capacitor is connected in series on the microstrip line connecting the load calibration unit and the interface.

9. The radio frequency switch circuit board according to claim 1, characterized in that: The load calibration unit includes at least one of a test SHORT circuit, a test OPEN circuit, and a test LOAD circuit.

10. The radio frequency switch circuit board according to claim 9, characterized in that: The test OPEN circuit realizes OPEN load by leaving the pin floating; the test LOAD circuit connects two 0201 package resistors in parallel as load at the end of the RF trace; the test SHORT circuit realizes SHORT load by drilling GND vias to the ground through the pin.

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