A new balanced-unbalanced matching impedance converter device

Abstract

The present invention discloses a novel balanced-unbalanced matching impedance converter device. The device comprises impedance converters with eight impedance conversion ratios, a fixing plate, and a PVC chassis. The impedance converter for each impedance conversion ratio comprises a ferrite core transformer, an input resonant capacitor, an output resonant capacitor, an unbalanced input terminal, a balanced output terminal, a PVC pipe, and a PVC pipe sleeve. The ferrite core transformer is composed of a toroidal core, a primary winding, and a secondary winding. The toroidal core is composed of multiple stacked toroidal manganese-zinc ferrite cores, and the primary and secondary windings are each wound with multiple strands of silver wire. An input resonant capacitor is connected in parallel between the primary windings, and the unbalanced input terminal is an N-type female connector. An output resonant capacitor is connected in parallel between the secondary windings, and the balanced output terminal is a 4mm banana connector. The present invention can achieve eight types of impedance conversion.

Description

Technical Field

[0001] The invention belongs to the technical field of radio electronics measurement, and in particular relates to a novel balanced-unbalanced matching impedance converter device. Background Art

[0002] A balun, short for balanced-to-unbalanced converter, is used to convert balanced signals of equal power and opposite phase into single-ended unbalanced signals for transmission to an unbalanced load. Conversely, it can also convert unbalanced signals into balanced signals. Furthermore, it provides impedance transformation, hence the name balanced feeder. These features have led to its widespread application in microwave technology and antennas, including high-power ultrasonic transducers and laboratory applications for high-power RF impedance matching. Common balun types include high-frequency open-circuit, offset, and transformer. High-frequency open-circuit baluns have a narrow operating bandwidth; offset baluns have a wider frequency bandwidth but are limited by magnetic saturation at high power levels. Transformer baluns primarily achieve balanced-to-unbalance conversion through a high-frequency transformer. Similar to a push-pull output converter, they convert unidirectional unbalanced current into bidirectional balanced current (or vice versa), offering a wide operating frequency band and suitable for high-power operation.

[0003] The impedance converter uses the transformer principle to achieve impedance transformation through the transformer's turns ratio. Since the output impedance of the power amplifier is 50Ω, the desired load impedance transformation can be achieved through the transformer's turns ratio. For example, if the transformer's turns ratio is 1:2, the voltage ratio between the input and output terminals is 1:2, that is, U i / U o =1:2, for maximum power transmission, the power at the balanced and unbalanced ends is equal, that is, P i =P o , so: U i 2 / R i =U o 2 / R o , from this we can get: R i / R o =1 / 4, which is the impedance ratio of 1:4 (the ratio of the square of the turns ratio). When the unbalanced terminal is connected to 50Ω, the impedance at the balanced end is 50×4=200Ω. Therefore, connecting a 200Ω load resistor to the balanced end can achieve impedance matching. At this time: P i is the input power, P o is the output power, U i is the input voltage, U o is the output voltage, R i is the input impedance, R o is the output impedance.

[0004] When calibrating high-frequency electrosurgical analysis, it's necessary to calibrate the power across different load resistors. The JJF1217-2009 High-Frequency Electrosurgical Calibration Specification specifies a range for non-inductive resistance boxes of (10 to 2000) Ω, a high-frequency power meter of (1 to 500) W, and a frequency range of (0.3 to 5.0) MHz. Therefore, when calibrating the load resistor of a high-frequency electrosurgical analyzer, it's necessary to calibrate the high-frequency power across different resistors.

[0005] Currently, the calibration of high-frequency electrosurgical analyzers in China primarily utilizes the electrosurgical analyzer calibration device and the power amplifier method. When using the electrosurgical analyzer calibration device, the technical specifications of current domestic electrosurgical analyzer calibration devices do not fully meet the calibration requirements, and their stability and reliability need to be improved. A major drawback is that they do not cover the frequency range, only measuring high-frequency power at (300-500) kHz and 1 MHz, with a maximum power of 400W, which does not provide sufficient margin. Furthermore, the corresponding load resistance range is limited to (200-500) Ω. The power amplifier method, on the other hand, meets both high-frequency power and frequency calibration requirements because the power amplifier has a 50 Ω output impedance. However, using the power amplifier alone for calibration only calibrates the power across the 50 Ω load resistor of the electrosurgical analyzer. Furthermore, because the power amplifier's output port is an N-type connector and the electrosurgical analyzer's input port is a high-voltage banana plug, a specialized adapter is required to complete the calibration circuit. Power calibration across different load resistors requires the use of a balanced-unbalanced impedance converter.

[0006] Currently, domestic impedance converters or baluns are primarily used in shortwave radio transmission. Their unbalanced ports are UHF, and their balanced ports are copper lugs. They cover a frequency range from 1 MHz to tens of MHz, and can deliver power up to several kilowatts. Applications in the calibration of high-frequency electrosurgical analyzers require interface improvements, and the low-end frequency range must be below 50 kHz. However, impedance accuracy across the entire frequency range is insufficient, resulting in large standing waves. At higher power levels, waveform distortion is significant, and power transmission efficiency is insufficient. Impedance transformers abroad are mainly used in ultrasonic transducers. Usually, there are several impedances to choose from, and the impedance selection is performed through a selection switch. However, the impedance accuracy is low. When the frequency is applied below 3MHz, the impedance accuracy is above 10%, while the frequency of the high-frequency electrosurgical analyzer can reach 5MHz. The accuracy of the load resistance is ±2.5%. Due to the poor impedance matching, the reflected power is large (Tang Wei, Yang Yumei, Zhang Yuxing. Research on transformer balun [J]. Modern Electronic Technology, 2008, 31(15): 3. DOI: 10.3969 / j.issn.1004-373X.2008.15.020.).

[0007] In summary, a new type of impedance conversion device is needed, which uses an N-type interface at the unbalanced end to match the power amplifier and a high-voltage banana plug interface at the balanced end to match the load resistor, especially to improve the impedance accuracy in the entire frequency range, improve impedance matching and power transmission efficiency. Summary of the Invention

[0008] The object of the present invention is to overcome the shortcomings and deficiencies of the above-mentioned prior art and to invent a new balanced-to-unbalanced matching impedance converter device which can achieve a frequency range of 100kHz to 10MHz, an unbalanced end input impedance of 50Ω, and balanced end output impedances of 50Ω, 100Ω, 150Ω, 200Ω, 300Ω, 500Ω, 800Ω, and 1000Ω respectively.

[0009] The purpose of the present invention is achieved by at least one of the following technical solutions.

[0010] A novel balanced-unbalanced impedance converter device includes a PVC chassis, a 1:1 impedance converter, a 1:2 impedance converter, a 1:3 impedance converter, a 1:4 impedance converter, a 1:6 impedance converter, a 1:10 impedance converter, a 1:16 impedance converter, and a 1:20 impedance converter.

[0011] Wherein, each of the 1:1 impedance converter, 1:2 impedance converter, 1:3 impedance converter, 1:4 impedance converter, 1:6 impedance converter and 1:10 impedance converter includes a first PVC tube, a first PVC tube, a first PVC tube, a first toroidal magnetic core, a first primary winding, a first secondary winding, an input capacitor, an output capacitor, a first unbalanced input end and a first balanced output end;

[0012] Each of the 1:16 impedance converter and the 1:20 impedance converter includes a second PVC tube, a third PVC tube, a fourth PVC tube, a second toroidal magnetic core, a second primary winding, a second secondary winding, a second unbalanced input terminal, and a second balanced output terminal;

[0013] In the six impedance converters of 1:1 impedance converter, 1:2 impedance converter, 1:3 impedance converter, 1:4 impedance converter, 1:6 impedance converter and 1:10 impedance converter, the first annular magnetic core is composed of a plurality of annular manganese-zinc ferrite cores stacked together and is used as a medium for transmitting power; a first primary winding is formed by winding a plurality of silver wires on the first annular magnetic core, and a first secondary winding is formed by winding a plurality of silver wires on the first annular magnetic core; an input capacitor is connected in parallel at both ends of the first primary winding to form a resonance with the inductance of the first primary winding, and both ends of the input capacitor are connected to the first unbalanced input end, and the first unbalanced The input end is connected to the output port of the power amplifier, and the output end impedance of the power amplifier is 50Ω. An output capacitor is connected in parallel to both ends of the first secondary winding, forming a resonance with the inductance of the first secondary winding. Both ends of the output capacitor are connected to the first balanced output end, and the first balanced output end is connected to both ends of the load resistor of the calibrated high-frequency electrosurgical analyzer. The first toroidal magnetic core, the first primary winding, the first secondary winding, the input capacitor, and the output capacitor are installed in a first PVC tube. A first PVC tube sleeve is installed at one end of the input capacitor of the first PVC tube, and a second PVC tube sleeve is installed at one end of the output capacitor of the first PVC tube.

[0014] In both the 1:16 impedance converter and the 1:20 impedance converter, the second toroidal magnetic core is composed of multiple stacked toroidal manganese-zinc ferrite cores and serves as a medium for transmitting power. A second primary winding is formed by winding multiple strands of silver-plated wire around the second toroidal magnetic core, and a second secondary winding is formed by winding multiple strands of silver-plated wire around the second toroidal magnetic core. Both ends of the second primary winding are connected to a second unbalanced input terminal, which is connected to an output port of a power amplifier, and the output impedance of the power amplifier is 50Ω. Both ends of the second secondary winding are connected to a second balanced output terminal, which is connected to both ends of a load resistor of a calibrated high-frequency electrosurgical analyzer. The second toroidal magnetic core, the second primary winding, and the second secondary winding are installed in a second PVC pipe. A third PVC pipe sleeve is installed at one end of the second primary winding of the second PVC pipe, and a fourth PVC pipe sleeve is installed at one end of the second secondary winding of the second PVC pipe to secure and protect components.

[0015] Furthermore, the first annular magnetic core is composed of 6 identical third annular magnetic cores stacked together and fixed by cable ties. The core material of the third annular magnetic core is manganese-zinc ferrite. The model of a single third annular magnetic core is H36*23*15, with an outer diameter of 36mm, an inner diameter of 23mm, and a thickness of 15mm. The inductance of a single turn is 8~10μH, the magnetic permeability is 2300, and the operating frequency range is 100kHz~10MHz; the power transmitted by a single third annular magnetic core is 120~150W, and the power of 6 third annular magnetic cores stacked together can reach 720~900W.

[0016] Furthermore, the second annular magnetic core is composed of three identical fourth annular magnetic cores stacked together and fixed by cable ties. The core material of the fourth annular magnetic core is manganese-zinc ferrite. The model of a single fourth annular magnetic core is H56*32*18, with an outer diameter of 56mm, an inner diameter of 32mm, and a thickness of 18mm. The inductance of a single turn is 8~10μH, the magnetic permeability is 2500, and the operating frequency range is 100kHz~10MHz; the power transmitted by a single fourth annular magnetic core is 250-300W, and the power of the three fourth annular magnetic cores stacked together can reach 750~900W.

[0017] Furthermore, the interface type of the first unbalanced input terminal and the second unbalanced input terminal is an N-type female connector, which is fully matched and connected to the signal output terminal of the power amplifier.

[0018] Furthermore, the wire used to wind the first primary winding, the first secondary winding, the second primary winding and the second secondary winding is a multi-strand silver-plated wire with a standard cross-sectional area of ​​0.75 square millimeters, 150 strands, a single strand diameter of 0.08 mm, a conductor diameter of 1 mm, a rated current of 4.8 A and a maximum current of 7.5 A.

[0019] Furthermore, the input capacitor and the output capacitor use tan electrolytic capacitors, and the resonant frequency formed by the input capacitor and the inductance of the first primary winding and the resonant frequency formed by the output capacitor and the inductance of the first secondary winding are much lower than the operating frequency of the magnetic core.

[0020] Furthermore, the interfaces of the first balanced output terminal and the second balanced output terminal adopt 4mm banana female connectors, which can be matched and connected to the two ends of the calibrated load resistor through banana connector cables.

[0021] Furthermore, the first PVC tube is a round tube made of PVC, with an outer diameter of 50 mm, a tube wall thickness of 1 mm, and a length of 145 mm.

[0022] Furthermore, the first PVC tube sleeve and the second PVC tube sleeve are made of PVC, have an outer diameter of 56.5 mm, a tube wall thickness of 1 mm, and a length of 30 mm.

[0023] Furthermore, the second PVC tube is a round tube made of PVC, with an outer diameter of 75 mm, a tube wall thickness of 1 mm, and a length of 168 mm.

[0024] Furthermore, the third PVC pipe sleeve and the fourth PVC pipe sleeve are made of PVC, have an outer diameter of 82.5 mm, a pipe wall thickness of 1 mm, and a length of 45 mm.

[0025] Furthermore, the 1:1 impedance converter, 1:2 impedance converter, 1:3 impedance converter, 1:4 impedance converter, 1:6 impedance converter, 1:10 impedance converter, 1:16 impedance converter, and 1:20 impedance converter are arranged in two layers in the PVC chassis. The four impedance converters, 1:1 impedance converter, 1:2 impedance converter, 1:3 impedance converter, and 1:4 impedance converter, are located in the lower layer, and the other four impedance converters are located in the upper layer. A fixed plate is provided between the upper and lower layers for separation.

[0026] Furthermore, for a 1:1 impedance converter, the number of turns of the primary winding is 3 turns, the number of turns of the secondary winding is 3 turns, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 50Ω.

[0027] Furthermore, for a 1:2 impedance converter, the number of turns of the primary winding is 5, the number of turns of the secondary winding is 7, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 100Ω.

[0028] Furthermore, for a 1:3 impedance converter, the number of turns of the primary winding is 4, the number of turns of the secondary winding is 7, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 100Ω.

[0029] Furthermore, for a 1:4 impedance converter, the number of turns of the primary winding is 4, the number of turns of the secondary winding is 8, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 100Ω.

[0030] Furthermore, for a 1:6 impedance converter, the number of turns of the primary winding is 7, the number of turns of the secondary winding is 17, the unbalanced end impedance is 50Ω, and the balanced end impedance is 300Ω.

[0031] Furthermore, for a 1:10 impedance converter, the number of turns of the primary winding is 6, the number of turns of the secondary winding is 19, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 500Ω.

[0032] Furthermore, for a 1:16 impedance converter, the number of turns of the primary winding is 4, the number of turns of the secondary winding is 16, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 800Ω.

[0033] Furthermore, for a 1:20 impedance converter, the number of turns of the primary winding is 4, the number of turns of the secondary winding is 18, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 1000Ω.

[0034] When selecting a toroidal core for an impedance converter, the number of turns of the primary and secondary windings, as well as the inner diameter of the toroidal core, must be considered. If the number of turns of the primary and secondary windings cannot be wound together, a toroidal core with a larger inner diameter must be selected when stacking the cores. The basic principles for selecting the number of turns of the primary and secondary windings are as follows:

[0035] Assuming the turns ratio of the primary winding and the secondary winding is: 1:N, the impedance ratio is: 1:N 2 ;

[0036] Conversely, if the impedance ratio is 1:N, then the impedance ratio is:

[0037] Assuming the number of turns of the primary winding is n, the number of turns of the secondary winding is: Where: N = 1, 2, 3, 4, 6, 10, 16, 20; n = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, etc., where n is a natural number;

[0038] Since it is difficult to wind a non-integer number of turns in the actual winding process, The value of is the integer closest to a natural number.

[0039] In addition to the basic principles, the determination of the number of turns of the primary and secondary windings also needs to consider multiple factors such as the inner diameter of the magnetic core, the diameter of the silver-plated wire used in the winding, and the inductance of the winding. These factors should be determined after comprehensive consideration and actual testing.

[0040] Compared with the prior art, the present invention has at least the following beneficial effects:

[0041] (1) The present invention proposes the use of a balanced-unbalanced matching impedance converter for matching the load impedance of a high-frequency electrosurgery analyzer when calibrating the high-frequency electrosurgery analyzer. The nominal range of the load impedance of the high-frequency electrosurgery analyzer is (10-6400) Ω. When calibrating the high-frequency electrosurgery analyzer, it is necessary to measure high-frequency power, high-frequency voltage, and high-frequency current on different loads. The commonly used load impedances of the high-frequency electrosurgery analyzer are 50Ω, 100Ω, 150Ω, 200Ω, 300Ω, 500Ω, 800Ω, and 1000Ω. In this way, when calibrating the high-frequency electrosurgery analyzer, the impedance can be fully matched according to the load impedance used by the customer, meeting the calibration measurement requirements. This overcomes the problem that the load impedance adjustable range of the high-frequency electrosurgery analyzer calibration device cannot cover the commonly used load impedance of the high-frequency electrosurgery analyzer.

[0042] This balun impedance converter device can achieve arbitrarily adjustable output of standard power within the frequency range of 300kHz to 5MHz, as required by JJF1217-2009, "High-Frequency Electrosurgical Calibration Specifications." This device enables traceability of measurement values ​​for high-frequency electrosurgical analyzer instruments, eliminating the need for a wide impedance measurement range for the calibration device. The balun impedance converter can achieve a wide range of impedance variations, theoretically covering the entire electrosurgical analyzer impedance range of 10Ω to 6400Ω, and meeting traceability requirements for current and power under varying impedances.

[0043] (2) The present invention proposes the design of a balanced-unbalanced matching impedance converter using a manganese-zinc ferrite core. The frequency range of manganese-zinc ferrite can cover 100kHz to 10MHz. The commonly used frequency range for calibration of high-frequency electrosurgical analyzers is 300kHz to 1MHz, and its nominal maximum bandwidth is 10MHz. Therefore, the frequency range of the manganese-zinc ferrite core completely covers the frequency bandwidth range of the high-frequency electrosurgical analyzer. Within this frequency range, the power, current, and voltage at any frequency point can be measured, meeting the calibration requirements of the high-frequency electrosurgical analyzer.

[0044] (3) The present invention achieves high-frequency, high-power transmission by stacking multiple manganese-zinc ferrite cores. A single core has a power of 100 to 150 watts, and stacking six cores can achieve a transmission power of 5 milliwatts to 800 watts. The maximum high-frequency power at the load impedance of a high-frequency electrosurgical analyzer is 500 watts. Therefore, calibration can be achieved at any power point at each load impedance of the high-frequency electrosurgical analyzer.

[0045] (4) The present invention uses multiple strands of silver wire to wind the magnetic core. When the high-frequency current is sufficient, the multiple strands of silver wire have better high-frequency characteristics than the existing copper enameled wire. It can achieve higher frequencies with less waveform distortion and less power loss.

[0046] (5) The present invention uses an N-type female connector at the unbalanced end and a 4mm banana connector at the balanced end, distinguished by red and black, with red representing the positive polarity or signal end and black representing the negative polarity or ground end. The N-type female connector can ensure matching connection with the power amplifier or directional coupler, reducing high-frequency signal reflection. The 4mm banana connector is directly connected to the load port of the calibrated high-frequency electric knife analyzer via a 4mm banana connector test cable, without the need for adapters, thereby improving power transfer efficiency.

[0047] (6) The present invention uses PVC tubes to fix multiple stacked manganese-zinc ferrite cores, solving the problem of core movement and possible wear caused by multiple connections and plugging and unplugging of test lines.

[0048] (7) The high-frequency electrosurgery analyzer calibration device composed of the balanced-unbalanced matching impedance converter, power amplifier, microwave signal generator, current and voltage measurement standards provides a new measurement standard and measurement method for the calibration of the high-frequency electrosurgery analyzer, which can completely replace the existing measurement standard of the high-frequency electrosurgery analyzer.

[0049] (8) Each impedance transformation adopts an independent magnetic core superposition winding method, which is more accurate and has lower loss than the impedance transformation performed by the large-size magnetic core tapping method using a switching switch, and there is no need to consider the impact of the switching switch.

[0050] (9) Impedance tests were conducted on the balun provided by the present invention and an existing imported impedance converter. The results showed that the 200Ω balun provided by the present invention had higher accuracy than the balun. This indicates that the present invention can achieve better impedance matching and improve power transmission efficiency in practical applications. This demonstrates the effectiveness of the present invention.

[0051] (10) Impedance tests were conducted on the balun provided by the present invention and an existing imported impedance converter. The results showed that the 50Ω balun provided by the present invention had higher accuracy than the balun. This can achieve better impedance matching and improve power transmission efficiency in practical applications, demonstrating the effectiveness of the present invention.

[0052] (11) Impedance tests were conducted on the balun provided by the present invention and an existing imported impedance converter. The results showed that the 50Ω balun provided by the present invention had higher accuracy than the balun. This indicates that the present invention can achieve better impedance matching and improve power transmission efficiency in practical applications. This demonstrates the effectiveness of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 A schematic diagram of the structure of a 1:4 impedance converter provided by an embodiment of the present invention;

[0054] Figure 2 Schematic diagram of the structures of a 1:16 impedance converter and a 1:20 impedance converter provided in an embodiment of the present invention;

[0055] Figure 3 Schematic diagram of the structure of a novel balanced-to-unbalanced impedance converter device according to an embodiment of the present invention;

[0056] Figure 4 Schematic diagram of calibrating a high-frequency electrosurgical analyzer using a 1:1 impedance converter, a 1:4 impedance converter, and a 1:6 impedance converter in a balanced-to-unbalanced impedance converter device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0058] Example:

[0059] A novel balanced-unbalanced impedance converter device, such as Figure 1 、 Figure 2 、 Figure 3 and Figure 4 As shown, it includes a PVC chassis 1, a 1:1 impedance converter 3, a 1:2 impedance converter 4, a 1:3 impedance converter 5, a 1:4 impedance converter 6, a 1:6 impedance converter 7, a 1:10 impedance converter 8, a 1:16 impedance converter 9 and a 1:20 impedance converter 10;

[0060] like Figure 1 As shown, each of the 1:1 impedance converter 3, the 1:2 impedance converter 4, the 1:3 impedance converter 5, the 1:4 impedance converter 6, the 1:6 impedance converter 7 and the 1:10 impedance converter 8 includes a first PVC tube 11, a first PVC tube 12, a first PVC tube 13, a first annular magnetic core 14, a first primary winding 15, a first secondary winding 16, an input capacitor 17, an output capacitor 18, a first unbalanced input terminal 19 and a first balanced output terminal 20;

[0061] like Figure 2 As shown, each of the 1:16 impedance converter 9 and the 1:20 impedance converter 10 includes a second PVC tube 21, a third PVC tube 22, a fourth PVC tube 23, a second annular magnetic core 24, a second primary winding 25, a second secondary winding 26, a second unbalanced input terminal 27, and a second balanced output terminal 28;

[0062] like Figure 1As shown, in the six impedance converters, namely, the 1:1 impedance converter 3, the 1:2 impedance converter 4, the 1:3 impedance converter 5, the 1:4 impedance converter 6, the 1:6 impedance converter 7 and the 1:10 impedance converter 8, the first annular magnetic core 14 is composed of a plurality of stacked annular manganese-zinc ferrite cores and is used as a medium for transmitting power; a first primary winding 15 is formed by winding a plurality of silver wires on the first annular magnetic core 14, and a first secondary winding 16 is formed by winding a plurality of silver wires on the first annular magnetic core 14; an input capacitor 17 is connected in parallel at both ends of the first primary winding 15 to form a resonance with the inductance of the first primary winding 15, and both ends of the input capacitor 17 are connected to a first unbalanced input terminal 19, and the first unbalanced input terminal 19 is connected to the first unbalanced input terminal 19. 9 is connected to the output port of the power amplifier, and the output impedance of the power amplifier is 50Ω; an output capacitor 18 is connected in parallel to both ends of the first secondary winding 16, forming a resonance with the inductance of the first secondary winding 16, and both ends of the output capacitor 18 are connected to the first balanced output end 20, and the first balanced output end 20 is connected to both ends of the load resistor of the high-frequency electrosurgical analyzer being calibrated; the first toroidal magnetic core 14, the first primary winding 15, the first secondary winding 16, the input capacitor 17, and the output capacitor 18 are installed in the first PVC tube 11; a first PVC tube sleeve 12 is installed at one end of the input capacitor 17 of the first PVC tube 11, and a second PVC tube sleeve 13 is installed at one end of the output capacitor 18 of the first PVC tube 11;

[0063] like Figure 2 As shown, in the two impedance converters, the 1:16 impedance converter 9 and the 1:20 impedance converter 10, the second annular magnetic core 24 is composed of a plurality of annular manganese-zinc ferrite cores stacked together and is used as a medium for transmitting power; a second primary winding 25 is formed by winding a plurality of strands of silver-plated wire on the second annular magnetic core 24, and a second secondary winding 26 is formed by winding a plurality of strands of silver-plated wire on the second annular magnetic core 24; both ends of the second primary winding 25 are connected to a second unbalanced input terminal 27, and the second unbalanced input terminal 27 is connected to the output port of the power amplifier. The output impedance of the oscillator is 50Ω; both ends of the second secondary winding 26 are connected to the second balanced output terminal 28, which is connected to both ends of the load resistor of the calibrated high-frequency electrosurgical analyzer; the second annular magnetic core 24, the second primary winding 25, and the second secondary winding 26 are installed in the second PVC tube 21; a third PVC tube sleeve 22 is installed at one end of the second primary winding 25 of the second PVC tube 21, and a fourth PVC tube sleeve 23 is installed at one end of the second secondary winding 26 of the second PVC tube 21 to secure and protect the components.

[0064] In one embodiment of the present invention, the first annular magnetic core 14 in the 1:4 impedance converter 6 is composed of 6 identical third annular magnetic cores stacked together and fixed by cable ties. The core material of the third annular magnetic core is manganese-zinc ferrite. The model of a single third annular magnetic core is H36*23*15, with an outer diameter of 36mm, an inner diameter of 23mm, and a thickness of 15mm. The inductance of a single turn is 8~10μH, the magnetic permeability is 2300, and the operating frequency range is 100kHz~10MHz; the power transmitted by a single third annular magnetic core is 120~150W, and the power of 6 third annular magnetic cores stacked together can reach 720~900W.

[0065] In one embodiment of the present invention, the second annular magnetic core 24 in the 1:16 impedance converter 9 is composed of three identical fourth annular magnetic cores stacked together and fixed by cable ties. The core material of the fourth annular magnetic core is manganese-zinc ferrite. The model of a single fourth annular magnetic core is H56*32*18, with an outer diameter of 56mm, an inner diameter of 32mm, and a thickness of 18mm. The inductance of a single turn is 8~10μH, the magnetic permeability is 2500, and the operating frequency range is 100kHz~10MHz; the power transmitted by a single fourth annular magnetic core is 250-300W, and the power of the three fourth annular magnetic cores stacked together can reach 750~900W.

[0066] In one embodiment of the present invention, the interface type of the first unbalanced input terminal 19 and the second unbalanced input terminal 27 is an N-type female interface, which is fully matched with the signal output terminal of the power amplifier.

[0067] In one embodiment of the present invention, the wire used to wind the first primary winding 15, the first secondary winding 16, the second primary winding 25, and the second secondary winding 26 is a multi-strand silver-plated wire. The standard cross-sectional area of ​​the silver-plated wire is 0.75 square millimeters, the number of strands is 150, the diameter of each strand is 0.08 mm, the conductor diameter is 1 mm, the rated current is 4.8 A, and the maximum current is 7.5 A.

[0068] In one embodiment of the present invention, the input capacitor 17 and the output capacitor 18 use tan electrolytic capacitors, and the resonant frequency formed by the input capacitor 17 and the inductance of the first primary winding 15 and the resonant frequency formed by the output capacitor 18 and the inductance of the first secondary winding 16 are much lower than the operating frequency of the magnetic core.

[0069] In one embodiment of the present invention, the interfaces of the first balanced output terminal 20 and the second balanced output terminal 28 adopt 4mm banana female connectors, which can be matched and connected to the two ends of the calibrated load resistor through banana connector cables.

[0070] In one embodiment of the present invention, the first PVC tube 11 is a round tube made of PVC, with an outer diameter of 50 mm, a wall thickness of 1 mm, and a length of 145 mm.

[0071] In one embodiment of the present invention, the first PVC tube sleeve 12 and the second PVC tube sleeve 13 are made of PVC, have an outer diameter of 56.5 mm, a tube wall thickness of 1 mm, and a length of 30 mm.

[0072] In one embodiment of the present invention, the second PVC tube 21 is a round tube made of PVC, with an outer diameter of 75 mm, a wall thickness of 1 mm, and a length of 168 mm.

[0073] In one embodiment of the present invention, the third PVC tube sleeve 22 and the fourth PVC tube sleeve 23 are made of PVC, have an outer diameter of 82.5 mm, a tube wall thickness of 1 mm, and a length of 45 mm.

[0074] In one embodiment of the present invention, the 1:1 impedance converter 3, the 1:2 impedance converter 4, the 1:3 impedance converter 5, the 1:4 impedance converter 6, the 1:6 impedance converter 7, the 1:10 impedance converter 8, the 1:16 impedance converter 9, and the 1:20 impedance converter 10 are arranged in two layers in the PVC chassis 1. The four impedance converters, namely the 1:1 impedance converter 3, the 1:2 impedance converter 4, the 1:3 impedance converter 5, and the 1:4 impedance converter 6, are located in the lower layer, and the other four impedance converters are located in the upper layer. A fixed plate 2 is provided between the upper and lower layers for separation.

[0075] In one embodiment of the present invention, for the 1:1 impedance converter 3 , the number of turns of the primary winding is 3, the number of turns of the secondary winding is 3, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 50Ω.

[0076] In one embodiment of the present invention, for the 1:2 impedance converter 4 , the number of turns of the primary winding is 5, the number of turns of the secondary winding is 7, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 100Ω.

[0077] In one embodiment of the present invention, for the 1:3 impedance converter 5 , the number of turns of the primary winding is 4, the number of turns of the secondary winding is 7, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 100Ω.

[0078] In one embodiment of the present invention, for the 1:4 impedance converter 6 , the number of turns of the primary winding is 4, the number of turns of the secondary winding is 8, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 100Ω.

[0079] In one embodiment of the present invention, for the 1:6 impedance converter 7 , the number of turns of the primary winding is 7, the number of turns of the secondary winding is 17, the unbalanced end impedance is 50Ω, and the balanced end impedance is 300Ω.

[0080] In one embodiment of the present invention, for the 1:10 impedance converter 8 , the number of turns of the primary winding is 6, the number of turns of the secondary winding is 19, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 500Ω.

[0081] In one embodiment of the present invention, for the 1:16 impedance converter 9 , the number of turns of the primary winding is 4, the number of turns of the secondary winding is 16, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 800Ω.

[0082] In one embodiment of the present invention, for the 1:20 impedance converter 10 , the number of turns of the primary winding is 4, the number of turns of the secondary winding is 18, the impedance of the unbalanced input end is 50Ω, and the impedance of the balanced output end is 1000Ω.

[0083] In one embodiment of the present invention, impedance tests were conducted on the balun provided by the present invention and an existing imported impedance converter. As shown in Table 1, the maximum impedance error of the 1:4 impedance converter 6, at 200Ω, within the 5MHz frequency range is 2.49%, and the maximum impedance error within the 100kHz to 1MHz frequency range is 0.78%. In contrast, the maximum impedance error of the imported IT1003, at 200Ω, within the 100kHz to 1MHz frequency range is 4.17%. Compared to these two, the 200Ω balun provided by the present invention has higher accuracy, enabling better impedance matching and improved power transmission efficiency in practical applications. This demonstrates the effectiveness of the present invention.

[0084] Table 1 1:4 Impedance converter 6 200Ω impedance accuracy

[0085]

[0086]

[0087] In one embodiment of the present invention, impedance tests were conducted on the balun provided by the present invention and an existing imported impedance converter. As shown in Table 2, the maximum impedance error of the 50Ω impedance of the 1:1 impedance converter 3 within the frequency range of 100kHz to 1MHz was 0.56%, and the minimum error was 0.06%. In contrast, the maximum impedance error of the 50Ω impedance of the imported IT1003 within the frequency range of 100kHz to 1MHz was -0.78%, and the minimum error was -0.30%. Compared to the two, the 50Ω impedance of the 1:1 impedance converter 3 of the present invention has higher accuracy, which can achieve better impedance matching in practical applications and improve power transmission efficiency. This demonstrates the effectiveness of the present invention.

[0088] Table 2 50Ω impedance accuracy of 1:1 impedance converter 3

[0089]

[0090] In one embodiment of the present invention, impedance tests were conducted on the balun provided by the present invention and an existing imported impedance converter. As shown in Table 3, the maximum error in the 100Ω impedance of the 1:2 impedance converter 4 within the frequency range of 100kHz to 1MHz was 5.08%, and the minimum error was 0.56%. In contrast, the maximum error in the 100Ω impedance of the imported IT1003 within the frequency range of 100kHz to 1MHz was -5.84%, and the minimum error was -4.05%. Compared to the two, the 100Ω impedance of the 1:2 impedance converter 4 of the present invention has higher accuracy, enabling better impedance matching and improved power transmission efficiency in practical applications. This demonstrates the effectiveness of the present invention.

[0091] Table 3 100Ω impedance accuracy of 1:2 impedance converter 4

[0092]

[0093] In one embodiment of the present invention, a 1:1 impedance converter (3) is used to calibrate the high frequency power of a high frequency electrosurgical analyzer 32 of model ESU-2400, factory serial number 73781996, and the impedance of the high frequency electrosurgical analyzer 32 is set to 50Ω. The calibration connection is as follows: Figure 4As shown, the output port of the signal generator / microwave signal source 29 is connected to the input port of the power amplifier 30 via an N-type cable. The output port of the power amplifier 30 is also connected to the unbalanced input of the impedance converter 31 via an N-type cable. The "+" and "-" ports of the balanced output of the impedance converter 31 are connected to the "+" and "-" ports of the calibrated high-frequency electrosurgical analyzer 32, respectively, using 4mm banana-plug cables. The power calibration data at frequencies of 500kHz and 1000kHz are shown in Table 4.

[0094] Table 4 ESU-2400 high-frequency electrosurgical analyzer 50 ohm power calibration data

[0095]

[0096]

[0097] The calibration data shows that the maximum error of the power calibration value at a frequency of 500kHz is 2.50%, the minimum error is 0.30%, and the measurement uncertainty is k = 2.0%. The maximum error of the power calibration value at a frequency of 1000kHz is 2.38%, the minimum error is 0.55%, and the measurement uncertainty is k = 2.0%. The maximum allowable error of power in the instrument's technical specification is ±5%. Considering the uncertainty factor, the calibration values ​​of all power calibration points meet the requirements of the instrument's technical specification, and the calibration results are valid. This proves that the 50Ω impedance matching of the 1:1 impedance converter 3 is good, the performance meets the actual calibration requirements, and it can solve the problem of high-frequency power value traceability, demonstrating the effectiveness of the present invention.

[0098] In one embodiment of the present invention, a 1:4 impedance converter 6 is used to calibrate the power of a high-frequency electrosurgical analyzer 32, model QA-ESIII, with a factory serial number of 5915003. The impedance of the high-frequency electrosurgical analyzer 32 is set to 200Ω. The calibration connection is as follows: Figure 4 As shown, the output port of the signal generator / microwave signal source 29 is connected to the input port of the power amplifier 30 via an N-type cable. The output port of the power amplifier 30 is also connected to the unbalanced input port of the impedance converter 31 via an N-type cable. The balanced output ports of the impedance converter 31 are connected to the + and - ports of the high-frequency electrosurgical analyzer 32 being calibrated, respectively, using 4mm banana-plug cables. Table 5 shows the power calibration data at frequencies of 300kHz and 500kHz.

[0099] Table 5 QA-ESIII high frequency electrosurgical analyzer 200 ohm power calibration data

[0100] Frequency (kHz) Indication value (W) Measured value (W) error(%) <![CDATA[Uncertainty U rel (%)]]> Inclusion factor k 300 1 1.013 -1.30 2.0 2 300 2 2.025 -1.25 2.0 2 300 5 5.085 -1.70 2.0 2 300 10 10.14 -1.40 2.0 2 300 20 20.11 -0.55 2.0 2 300 50 50.21 -0.42 2.0 2 300 75 74.96 0.05 2.0 2 300 100 99.75 0.25 2.0 2 300 150 149.8 0.13 2.0 2 300 200 199.5 0.25 2.0 2 300 250 248.8 0.48 2.0 2 300 302 301.8 0.07 2.0 2 300 353 353.6 -0.17 2.0 2 300 390 393.4 -0.87 2.0 2 500 1 1.023 -2.30 2.0 2 500 2 2.025 -1.25 2.0 2 500 5 5.091 -1.82 2.0 2 500 10 10.29 -2.90 2.0 2 500 20 20.14 -0.70 2.0 2 500 50 50.56 -1.12 2.0 2 500 75 75.03 -0.04 2.0 2 500 100 100.3 -0.30 2.0 2 500 150 151.2 -0.80 2.0 2 500 200 200.1 -0.05 2.0 2 500 250 250.6 -0.24 2.0 2 500 303 305.3 -0.76 2.0 2 500 350 351.4 -0.40 2.0 2 500 393 395.1 -0.53 2.0 2

[0101] From the calibration data, we can see that the maximum error of the power calibration value at 300kHz is -1.70%, the minimum error is 0.05%, and the measurement uncertainty is U rel = 2.0%; the maximum error of the power calibration value at a frequency of 500kHz is -2.90%, the minimum error is -0.04%, and the measurement uncertainty is U rel = 2.0%; the maximum allowable error for power in the instrument's technical specification is ±5%. Taking uncertainty into account, the calibration values ​​at all power calibration points meet the instrument's technical specification requirements, and the calibration results are valid. This demonstrates that the 200Ω impedance matching of the 1:4 impedance converter 6 is excellent, its performance meets the actual calibration requirements, and it can solve the problem of high-frequency power traceability, demonstrating the effectiveness of the present invention.

[0102] In one embodiment of the present invention, a 1:6 impedance converter 7 is used to calibrate the power of a high-frequency electrosurgical analyzer 32 of model RG802 and factory serial number 330020XX0004. The impedance of the high-frequency electrosurgical analyzer 32 is set to 300Ω. The calibration connection is as follows: Figure 4 As shown, the output port of the signal generator / microwave signal source 29 is connected to the input port of the power amplifier 30 via an N-type cable. The output port of the power amplifier 30 is also connected to the unbalanced input of the impedance converter 31 via an N-type cable. The "+" and "-" ports of the balanced output of the impedance converter 31 are connected to the "+" and "-" ports of the calibrated high-frequency electrosurgical analyzer 32, respectively, using 4mm banana-plug cables. The power calibration data at frequencies of 300kHz and 500kHz are shown in Table 6.

[0103] Table 6 RG802 High Frequency Electrosurgical Knife Analyzer 300 Ohm Power Calibration Data

[0104] Frequency (kHz) Indication value (W) Measured value (W) error(%) <![CDATA[Uncertainty U rel (%)]]> Inclusion factor k 410 2 1.91 4.50 2.0 2 410 10 9.57 4.30 2.0 2 410 50 47.88 4.24 2.0 2 410 100 95.91 4.09 2.0 2 410 150 146.2 2.53 2.0 2 410 300 292.6 2.47 2.0 2 512 2 1.93 3.50 2.0 2 512 10 9.61 3.90 2.0 2 512 50 47.60 4.80 2.0 2 512 100 96.32 3.87 2.0 2 512 152 145.6 4.46 2.0 2 512 300 292.2 2.66 2.0 2

[0105] From the calibration data, we can see that the maximum error of the power calibration value at 410kHz is 4.50%, the minimum error is 2.47%, and the measurement uncertainty is U rel = 2.0%; the maximum error of the power calibration value at 512kHz is 4.80%, the minimum error is 2.66%, and the measurement uncertainty is U rel =2.0%; the maximum allowable error for power (≤50W) in the instrument's technical specification is ±3.5W, and the maximum allowable error for power (>50W) is ±5%. The calibration values ​​of all power calibration points meet the requirements of the instrument's technical specification, and the calibration results are valid. This demonstrates that the 300Ω impedance matching of the impedance converter 1:6, 7, is good, and its performance meets the actual calibration requirements. It can solve the problem of high-frequency power traceability, demonstrating the effectiveness of the present invention.

[0106] As mentioned above, the present invention proposes to stack a plurality of manganese-zinc ferrite cores of the same model as a medium for power transmission, thereby improving the frequency range (greater than or equal to 5MHz) and power range of the transmission signal. Conventional impedance converters use a single core, and the frequency range coverage is insufficient or the power is relatively small. The present invention innovatively proposes to use an impedance converter to achieve a good match with the load impedance of a high-frequency electrosurgical analyzer, and to use an N-type interface at the unbalanced input end of the impedance converter to achieve a good connection with the power amplifier, and a 4mm banana head is used for connection at the balanced end. When using an impedance converter for calibration, the power transfer efficiency is high, the transmission loss is small, and the frequency range used is wide, which meets the traceability requirements of high-frequency power.

[0107] The implementation methods of the present invention are not limited to the above-mentioned embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principles of the present invention shall be considered as equivalent replacement methods and shall be included in the scope of protection of the present invention.

Claims

1. A novel balanced-unbalanced impedance converter device, characterized in that: It includes a PVC chassis (1), a 1:1 impedance converter (3), a 1:2 impedance converter (4), a 1:3 impedance converter (5), a 1:4 impedance converter (6), a 1:6 impedance converter (7), a 1:10 impedance converter (8), a 1:16 impedance converter (9), and a 1:20 impedance converter (10); Each of the 1:1 impedance converter (3), 1:2 impedance converter (4), 1:3 impedance converter (5), 1:4 impedance converter (6), 1:6 impedance converter (7) and 1:10 impedance converter (8) comprises a first PVC tube (11), a first PVC tube sleeve (12), a second PVC tube sleeve (13), a first annular magnetic core (14), a first primary winding (15), a first secondary winding (16), an input capacitor (17), an output capacitor (18), a first unbalanced input terminal (19) and a first balanced output terminal (20); Each of the 1:16 impedance converter (9) and the 1:20 impedance converter (10) comprises a second PVC tube (21), a third PVC tube sleeve (22), a fourth PVC tube sleeve (23), a second annular magnetic core (24), a second primary winding (25), a second secondary winding (26), a second unbalanced input terminal (27), and a second balanced output terminal (28); In the six impedance converters, namely, the 1:1 impedance converter (3), the 1:2 impedance converter (4), the 1:3 impedance converter (5), the 1:4 impedance converter (6), the 1:6 impedance converter (7) and the 1:10 impedance converter (8), the first annular magnetic core (14) is composed of a plurality of annular manganese-zinc ferrite cores stacked together and used as a medium for transmitting power; a first primary winding (15) is formed by winding a plurality of silver wires on the first annular magnetic core (14); a first secondary winding (16) is formed by winding a plurality of silver wires on the first annular magnetic core (14); an input capacitor (17) is connected in parallel to both ends of the first primary winding (15), resonating with the inductance of the first primary winding (15); both ends of the input capacitor (17) are connected to a first unbalanced input end (19), and the first unbalanced input end (19) is connected to the power supply. The first secondary winding (16) is connected to the output port of the power amplifier, and the output impedance of the power amplifier is 50Ω; an output capacitor (18) is connected in parallel at both ends of the first secondary winding (16), forming resonance with the inductance of the first secondary winding (16), and both ends of the output capacitor (18) are connected to the first balanced output end (20), and the first balanced output end (20) is connected to both ends of the load resistor of the calibrated high-frequency electric knife analyzer; the first annular magnetic core (14), the first primary winding (15), the first secondary winding (16), the input capacitor (17) and the output capacitor (18) are installed in the first PVC tube (11); a first PVC tube sleeve (12) is installed at one end of the input capacitor (17) of the first PVC tube (11), and a second PVC tube sleeve (13) is installed at one end of the output capacitor (18) of the first PVC tube (11); In the two impedance converters, the 1:16 impedance converter (9) and the 1:20 impedance converter (10), the second annular magnetic core (24) is composed of a plurality of annular manganese-zinc ferrite cores stacked together and is used as a medium for transmitting power; a second primary winding (25) is formed by winding a plurality of strands of silver-plated wire on the second annular magnetic core (24); a second secondary winding (26) is formed by winding a plurality of strands of silver-plated wire on the second annular magnetic core (24); both ends of the second primary winding (25) are connected to a second unbalanced input terminal (27), the second unbalanced input terminal (27) is connected to an output port of a power amplifier, and the output of the power amplifier is connected to the second primary winding (25). The terminal impedance is 50Ω; both ends of the second secondary winding (26) are connected to the second balanced output end (28), and the second balanced output end (28) is connected to both ends of the load resistor of the calibrated high-frequency electric knife analyzer; the second annular magnetic core (24), the second primary winding (25), and the second secondary winding (26) are installed in the second PVC tube (21); a third PVC tube sleeve (22) is installed at one end of the second primary winding (25) of the second PVC tube (21), and a fourth PVC tube sleeve (23) is installed at one end of the second secondary winding (26) of the second PVC tube (21), which serves to fix and protect components.

2. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The first annular magnetic core (14) is composed of six identical third annular magnetic cores stacked together and fixed by a cable tie. The core material of the third annular magnetic core is manganese-zinc ferrite, the inductance of a single turn is 8μH~10μH, and the operating frequency range is 100kHz~10MHz; the power transmitted by a single third annular magnetic core is 120W~150W, and the power used by the stacking of six third annular magnetic cores reaches 720W~900W.

3. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The second annular magnetic core (24) is composed of three identical fourth annular magnetic cores stacked together and fixed by a cable tie. The core material of the fourth annular magnetic core is manganese-zinc ferrite, the inductance of a single turn is 8μH~10μH, and the operating frequency range is 100kHz~10MHz; the power transmitted by a single fourth annular magnetic core is 250W-300W, and the power used by the three fourth annular magnetic cores stacked together is 750W~900W.

4. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The interface type of the first unbalanced input terminal (19) and the second unbalanced input terminal (27) is an N-type female connector, which is fully matched and connected with the signal output terminal of the power amplifier.

5. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The wires used to wind the first primary winding (15), the first secondary winding (16), the second primary winding (25) and the second secondary winding (26) are multiple strands of silver-plated wire.

6. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The input capacitor (17) and the output capacitor (18) use electrolytic capacitors. The resonant frequency formed by the input capacitor (17) and the inductance of the first primary winding (15) and the resonant frequency formed by the output capacitor (18) and the inductance of the first secondary winding (16) are much lower than the operating frequency of the magnetic core.

7. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The interfaces of the first balanced output end (20) and the second balanced output end (28) adopt banana female connectors, which are matched and connected to the two ends of the load resistor to be calibrated via banana connector cables.

8. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The first PVC tube (11) is a round tube made of PVC, with an outer diameter of 50 mm, a wall thickness of 1 mm, and a length of 145 mm; The second PVC tube (21) is a round tube made of PVC, with an outer diameter of 75 mm, a wall thickness of 1 mm, and a length of 168 mm.

9. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The first PVC tube sleeve (12) and the second PVC tube sleeve (13) are made of PVC, have an outer diameter of 56.5 mm, a tube wall thickness of 1 mm, and a length of 30 mm; The third PVC tube sleeve (22) and the fourth PVC tube sleeve (23) are made of PVC, have an outer diameter of 82.5 mm, a tube wall thickness of 1 mm, and a length of 45 mm.

10. The novel balanced-to-unbalanced impedance converter device according to claim 1, characterized in that: The 1:1 impedance converter (3), 1:2 impedance converter (4), 1:3 impedance converter (5), 1:4 impedance converter (6), 1:6 impedance converter (7), 1:10 impedance converter (8), 1:16 impedance converter (9), and 1:20 impedance converter (10) are arranged in two layers in the PVC chassis (1). The four impedance converters, 1:1 impedance converter (3), 1:2 impedance converter (4), 1:3 impedance converter (5), and 1:4 impedance converter (6), are located in the lower layer, and the other four impedance converters are located in the upper layer. A fixed plate (2) is provided between the upper and lower layers for spacing.

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