Terahertz balanced type six-frequency multiplication structure and terahertz equipment

Abstract

The invention discloses a Hertz balanced six-frequency multiplication structure and terahertz equipment, which are applied to the technical field of terahertz, and comprises an input waveguide directional coupler; the input waveguide directional coupler comprises a first branch and a second branch, the input signal transmitted in the first branch and the input signal transmitted in the second branch are equal in amplitude, and the phase difference is 90 degrees; the microstrip line is connected between the first branch and the second branch; the middle area of the microstrip line is connected with the output waveguide through a current synthesis structure; in the signal transmission direction of the microstrip line, a balanced frequency doubling diode pair, an inter-stage matching network and a frequency tripling diode are sequentially arranged from the first end of the microstrip line to the middle region and from the second end of the microstrip line to the middle region; and the two frequency tripling diodes form a balanced frequency tripling diode pair. The whole structure constructs an idle loop of each idle harmonic wave, and has the capability of high efficiency.

Description

Technical Field

[0001] The present invention relates to the field of terahertz technology, and in particular to a terahertz balanced sextuple frequency structure and a terahertz device. Background Art

[0002] With its unique advantages, terahertz technology has greatly promoted the development of basic frontier sciences such as earth atmosphere observation, planetary observation and space aerospace in the past decades. It also plays a huge role in human security inspection, environmental monitoring, fault detection, archaeology and medical diagnosis. In recent years, the requirements of imaging technology for resolution and imaging speed have promoted the development of terahertz application systems towards array and high frequency, which in turn has put forward an increasingly higher demand for high-power Schottky frequency doubling sources.

[0003] At present, terahertz Schottky frequency doubling sources are usually composed of a series of cascaded doubler and tripler circuits. Even if a single-stage doubler or tripler circuit can achieve a frequency doubling efficiency of more than 40%, the overall frequency doubling efficiency after multi-stage cascading is usually less than one percentage point. In addition, the standing wave effect between different frequency doubling modules will further affect the overall efficiency and in-band performance of the frequency doubling link. Therefore, the demand for single-stage balanced high-order frequency doubling circuits in terahertz applications is extremely urgent, so how to provide a terahertz balanced sextuple frequency doubling structure is an urgent problem that technicians in this field need to solve. Summary of the invention

[0004] An object of the present invention is to provide a terahertz balanced sextuple frequency structure, which can achieve balanced output of the sixth harmonic; another object of the present invention is to provide a terahertz device, which can achieve balanced output of the sixth harmonic.

[0005] In order to solve the above technical problems, the present invention provides a terahertz balanced sextuple frequency structure, comprising:

[0006] An input waveguide directional coupler; the input waveguide directional coupler comprises a first branch and a second branch, the input signal transmitted in the first branch and the input signal transmitted in the second branch have the same amplitude and a phase difference of 90°;

[0007] A microstrip line connected between the first branch and the second branch; a first end of the microstrip line is connected to the first branch, and a second end of the microstrip line is connected to the second branch; a middle area of ​​the microstrip line is connected to an output waveguide via a current synthesis structure;

[0008] Along the signal transmission direction of the microstrip line, a balanced double-frequency diode pair, an interstage matching network, and a triple-frequency diode are sequentially arranged from the first end of the microstrip line to the middle area, and from the second end of the microstrip line to the middle area; the two triple-frequency diodes form a balanced triple-frequency diode pair.

[0009] Optionally, the current synthesis structure includes a three-port differential synthesis probe.

[0010] Optionally, the three-port differential synthesis probe is also connected to a filtering circuit.

[0011] Optionally, the output waveguide extends in a direction away from the input waveguide directional coupler in a lateral direction of the microstrip line; and the filtering circuit is arranged on a side of the microstrip line facing the input waveguide directional coupler.

[0012] Optionally, the diodes in the balanced doubler diode pair have the same direction, one end is connected to the microstrip line and the other end is grounded; one end of the tripler diode is connected to the microstrip line and the other end is grounded.

[0013] Optionally, the balanced frequency doubler diode pair, the interstage matching network, and the frequency tripler diode located on both sides of the microstrip line are symmetrically arranged with the middle area as the center.

[0014] Optionally, the inter-stage matching network includes a low-pass filtering structure.

[0015] Optionally, the microstrip line operates in TEM mode, and the input waveguide connected to the input waveguide directional coupler operates in TE mode.

[0016] Optionally, the microstrip line is a microstrip line processed on the surface of a substrate, and the diodes in the balanced doubler diode pair and the tripler diode are connected to the microstrip line by a conductive adhesive bonding process or a welding process.

[0017] The present invention also provides a terahertz device, comprising the terahertz balanced sextuple frequency structure as described in any one of the above items.

[0018] A terahertz balanced sextuple frequency structure provided by the present invention comprises: an input waveguide directional coupler; the input waveguide directional coupler comprises a first branch and a second branch, the input signal transmitted in the first branch and the input signal transmitted in the second branch have the same amplitude and a phase difference of 90°; a microstrip line connected between the first branch and the second branch; the first end of the microstrip line is connected to the first branch, and the second end of the microstrip line is connected to the second branch; the middle area of ​​the microstrip line is connected to the output waveguide through a current synthesis structure; along the signal transmission direction of the microstrip line, a balanced doubler diode pair, an interstage matching network, and a tripler diode are sequentially arranged from the first end to the middle area of ​​the microstrip line, and from the second end to the middle area of ​​the microstrip line; two tripler diodes form a balanced tripler diode pair.

[0019] The input signal is divided into two signals with equal amplitude and 90° phase difference through the waveguide directional coupler, and then passed through the balanced double-frequency diode pair and the balanced triple-frequency diode pair, and finally transmitted to the output waveguide through the current synthesis structure to achieve the intrinsic suppression of adjacent second, third, fourth, fifth, seventh, eighth, and ninth harmonics. And based on the intrinsic isolation of the waveguide and microstrip line transmission mode, combined with the inter-stage matching network, it can prevent the reverse leakage of each adjacent harmonic to the input waveguide. Therefore, the entire structure itself has constructed an idle loop for each idle harmonic and has high efficiency. And by introducing two different double-frequency Schottky diode pairs, the different tube junction characteristics of the two-stage diodes can be adjusted, so that the first-stage balanced double-frequency diode pair has the characteristics of high power capacity and large junction capacitance, which is suitable for completing the above-mentioned harmonic current conversion. This structure can solve the contradiction between power capacity and frequency doubling efficiency caused by the single-stage diode directly realizing the sixth frequency doubling.

[0020] The present invention also provides a terahertz device, which also has the above-mentioned beneficial effects, which will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic structural diagram of a terahertz balanced sextuple frequency structure provided in an embodiment of the present invention;

[0023] Figure 2 for Figure 1 Schematic diagram of the local structure;

[0024] Figure 3 for Figure 1 Schematic diagram of the relationship between harmonic currents;

[0025] Figure 4 for Figure 1 The simulated frequency doubling efficiency and output power diagram of the structure in the figure.

[0026] In the figure: 1. input waveguide directional coupler, 11. first branch, 12. second branch, 2. balanced doubler diode pair, 3. interstage matching network, 4. tripler diode, 5. current synthesis structure, 51. three-port differential synthesis probe, 6. filtering circuit. DETAILED DESCRIPTION

[0027] The core of the present invention is to provide a terahertz balanced sextuple frequency structure. In the prior art, the terahertz Schottky frequency-doubling source is usually formed by cascading a series of double-frequency and triple-frequency circuits, and the overall frequency-doubling efficiency after multi-stage cascading is usually less than one percentage point.

[0028] The technology of directly realizing the fourth or even higher harmonic frequency doubling through a single type of tube junction faces the contradiction of low high-order harmonic conversion efficiency and insufficient power capacity of the diode. The core is that the higher the output frequency, the smaller the junction capacitance, which in turn leads to lower diode power capacity. However, due to the large series resistance of the low junction capacitance small tube junction, it is difficult to match the optimal impedance range when driven at low frequency, resulting in extremely low frequency doubling efficiency of the corresponding high-order harmonics.

[0029] The present invention provides a terahertz balanced sextuple frequency structure, comprising: an input waveguide directional coupler; the input waveguide directional coupler comprises a first branch and a second branch, the input signal transmitted in the first branch and the input signal transmitted in the second branch have the same amplitude and a phase difference of 90°; a microstrip line connected between the first branch and the second branch; the first end of the microstrip line is connected to the first branch, and the second end of the microstrip line is connected to the second branch; the middle area of ​​the microstrip line is connected to the output waveguide through a current synthesis structure; along the signal transmission direction of the microstrip line, a balanced doubler diode pair, an interstage matching network, and a tripler diode are sequentially arranged from the first end to the middle area of ​​the microstrip line, and from the second end to the middle area of ​​the microstrip line; two tripler diodes form a balanced tripler diode pair.

[0030] The input signal is divided into two signals with equal amplitude and 90° phase difference through the waveguide directional coupler, and then passed through the balanced double-frequency diode pair and the balanced triple-frequency diode pair, and finally transmitted to the output waveguide through the current synthesis structure to achieve the intrinsic suppression of adjacent second, third, fourth, fifth, seventh, eighth, and ninth harmonics. And based on the intrinsic isolation of the waveguide and microstrip line transmission mode, combined with the inter-stage matching network, it can prevent the reverse leakage of each adjacent harmonic to the input waveguide. Therefore, the entire structure itself has constructed an idle loop for each idle harmonic and has high efficiency. And by introducing two different double-frequency Schottky diode pairs, the different tube junction characteristics of the two-stage diodes can be adjusted, so that the first-stage balanced double-frequency diode pair has the characteristics of high power capacity and large junction capacitance, which is suitable for completing the above-mentioned harmonic current conversion. This structure can solve the contradiction between power capacity and frequency doubling efficiency caused by the single-stage diode directly realizing the sixth frequency doubling. Two diode pairs with different junction capacitances are used to achieve the generation of different harmonics, which can ensure both sufficient power capacity and efficient conversion and generation of the sixth harmonic.

[0031] In order to enable those skilled in the art to better understand the scheme of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than 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 work are within the scope of protection of the present invention.

[0032] Embodiment 1

[0033] Please refer to Figures 1 to 4 , Figure 1 A schematic structural diagram of a terahertz balanced sextuple frequency structure provided in an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram of the local structure; Figure 3 for Figure 1 Schematic diagram of the relationship between harmonic currents; Figure 4 for Figure 1 The simulated frequency doubling efficiency and output power diagram of the structure in the figure.

[0034] See also Figure 1In an embodiment of the present invention, a terahertz balanced sextuple frequency structure includes: an input waveguide directional coupler; the input waveguide directional coupler includes a first branch and a second branch, the input signal transmitted in the first branch and the input signal transmitted in the second branch have equal amplitude and a phase difference of 90°; a microstrip line connected between the first branch and the second branch; the first end of the microstrip line is connected to the first branch, and the second end of the microstrip line is connected to the second branch; the middle area of ​​the microstrip line is connected to the output waveguide through a current synthesis structure; along the signal transmission direction of the microstrip line, a balanced doubler diode pair, an interstage matching network, and a tripler diode are sequentially arranged from the first end of the microstrip line to the middle area, and from the second end of the microstrip line to the middle area; two tripler diodes form a balanced tripler diode pair.

[0035] The above-mentioned input waveguide directional coupler needs to be connected to the input waveguide. The input waveguide directional coupler is used to receive the signal transmitted from the input waveguide and divide the input signal into two signals with equal signal amplitude and a phase difference of 90°, and the two signals will propagate independently in the first branch and the second branch. The input waveguide directional coupler is mainly used to generate two signals with a phase difference of 90°, and has generated a sextuple frequency signal in the subsequent propagation process of the two signals. The above-mentioned input waveguide directional coupler can be a metal directional coupler made of metals such as aluminum and copper. The specific material of the input waveguide directional coupler can be set according to the actual situation and is not specifically limited here.

[0036] In this embodiment, the first branch and the second branch are usually symmetrically arranged, and the tail of the first branch and the tail of the second branch are arranged relative to each other, so as to facilitate the subsequent arrangement of the microstrip line. The microstrip line is usually arranged between the tail of the first branch and the tail of the second branch, and the two signals with a phase difference of 90° are propagated from the two ends of the microstrip line to the middle area thereof. Specifically, in this embodiment, the two ends of the microstrip line are the first end and the second end, respectively, wherein the first end of the microstrip line is connected to the first branch, and the second end of the microstrip line is connected to the second branch, and a current synthesis structure is specifically arranged in the middle area of ​​the microstrip line, and the current synthesis structure is usually arranged at the midpoint of the microstrip line, and its two input ends are correspondingly connected to the half microstrip lines on the left and right sides to receive the signals transmitted from the two ends of the microstrip line, and its output end is usually connected to the output waveguide. The current synthesis structure can realize the same phase synthesis of the dual-port current, and the signals transmitted from the two ends of the microstrip line are synthesized in the current synthesis structure, and the synthesized six-fold frequency signal is transmitted to the output waveguide.

[0037] In this embodiment, along the signal transmission direction of the microstrip line, a balanced double-frequency diode pair, an interstage matching network, and a triple-frequency diode are sequentially arranged from the first end of the microstrip line to the middle area, and from the second end of the microstrip line to the middle area. The signal transmission direction of the above-mentioned microstrip line is from the two ends to the middle direction, that is, the entire microstrip line is provided with two groups of balanced double-frequency diode pairs, two interstage matching networks and two triple-frequency diodes, wherein the two triple-frequency diodes will form a balanced triple-frequency diode pair for frequency doubling. The above-mentioned balanced double-frequency diode pair is a first-level structure, and the balanced triple-frequency diode pair is a second-level structure. This embodiment uses two diode pairs with different junction capacitances to achieve the generation of different harmonics, which can not only ensure sufficient power capacity, but also ensure the efficient conversion and generation of the sixth harmonic.

[0038] See also Figure 2 , usually, the diodes in the above-mentioned balanced double-frequency diode pair need to be in the same direction, one end of which is connected to the microstrip line and the other end is grounded; one end of the above-mentioned triple-frequency diode usually needs to be connected to the microstrip line and the other end needs to be grounded to achieve its corresponding function. In order to ensure that the final signal can be synthesized in the current synthesis structure, the balanced double-frequency diode pair, the interstage matching network, and the triple-frequency diode located on both sides of the microstrip line usually need to be symmetrically arranged with the middle area as the center, and the two pairs of balanced double-frequency diode pairs are equivalent to reverse parallel connection.

[0039] The diodes used in the above-mentioned balanced double frequency diode pair are usually Schottky diodes, thus forming a balanced double frequency Schottky diode pair. The above-mentioned triple frequency diodes are usually Schottky diodes, thus forming a balanced triple frequency Schottky diode pair. The balanced double frequency diode pair can convert the second harmonic under the drive of the input fundamental wave, and intrinsically suppress the adjacent odd harmonic components. The above-mentioned interstage matching network usually needs to include a low-pass filter structure, for example, a microstrip line structure with "narrow→wide→narrow" along the signal transmission direction to form a low-pass filter structure. The interstage matching network is mainly used to suppress high-order harmonics to prevent them from leaking to the input end, and at the same time achieve impedance matching between the two-stage structures. The above-mentioned second-stage balanced triple frequency Schottky diode pair realizes the frequency doubling of the second harmonic to the sixth harmonic.

[0040] The above-mentioned current synthesis structure can use a three-port differential synthesis probe, which can realize the in-phase synthesis of the respective harmonic currents by the balanced triple frequency diode and achieve the corresponding harmonic suppression. Of course, in this embodiment, other structures that can realize two-port in-phase synthesis can also be selected as replacements, including hybrid structures based on waveguides and microstrip lines, which are not specifically limited here.

[0041] See also Figure 3Specifically, the microstrip line usually works in TEM mode, and the input waveguide connected to the input waveguide directional coupler usually works in TE mode. Taking a rectangular waveguide as an example, the input electromagnetic wave works in TE mode in the waveguide. 10 mode, after passing through the input waveguide directional coupler, it is divided into signal S1 and signal S2 with the same amplitude and a phase difference of 90°. Signal S1 and signal S2 drive two pairs of balanced double-frequency diodes connected in reverse parallel, and stimulate different harmonic currents respectively. For the balanced double-frequency diode pair stimulated by signal S1, it is assumed that its relative phase is 0°, so the two tube junctions of the balanced double-frequency diode pair will be forward excited and reverse excited respectively, and the corresponding currents are I1(0°) and I2(0°), respectively, and the expression is:

[0042] ;

[0043] ;

[0044] Similarly, the phase of signal S2 is 90°, so the harmonic currents excited are I1(90°) and I2(90°), respectively, and the expressions are:

[0045] ;

[0046] ;

[0047] Therefore, the balanced double-frequency diode pairs excited by the signals S1 and S2 can obtain their respective combined currents I(0°) and I(90°) after differential output, respectively:

[0048] ;

[0049] ;

[0050] Furthermore, after the inter-stage matching network is matched, the current I(0°) and the current I(90°) pass through different triple frequency diodes, and the expressions of the formed current I3(0°) and the current I3(90°) are respectively:

[0051] ;

[0052] ;

[0053] After the three-port differential synthesis probe is synthesized, the total current I(RL) finally reflected in the output waveguide is expressed as follows:

[0054] ;

[0055] Among them, due to the isolation between the microstrip line working mode and the output waveguide working mode, the second harmonic in the total current is directly suppressed by the output waveguide, and the entire circuit realizes the intrinsic suppression of the second to ninth harmonics adjacent to the output port, constructs the corresponding idle harmonic loop and realizes the balanced output of the sixth harmonic. Therefore, the terahertz balanced sextuple frequency structure provided in this embodiment can realize the efficient generation of the sixth harmonic while regulating the phase relationship of different diode pairs, constructing an idle loop of adjacent harmonics, and realizing the intrinsic suppression of idle harmonics. This intrinsic suppression capability enables the sextuple frequency circuit to realize the required sixth harmonic output in an extremely simplified structure without using any filtering network, so as to maximize the frequency doubling efficiency.

[0056] In this embodiment, the three-port differential synthesis probe is also connected to a filter circuit, which can be used as a structure to realize the feeding function, and each diode is DC-fed through the three-port differential synthesis probe. Specifically, in this embodiment, the output waveguide usually extends in the lateral direction of the microstrip line in a direction away from the input waveguide directional coupler; the filter circuit is usually arranged on the side of the microstrip line facing the input waveguide directional coupler. In this embodiment, in order to facilitate the setting of the microstrip line, the first branch and the second branch are usually arranged in a clamp-like shape, and the microstrip line is specifically arranged at the ends of the first branch and the second branch, so that space is left between the first branch and the second branch. In order to make full use of the space in the device without affecting the outward extension of the output waveguide, it is possible to set the output waveguide to usually extend in the lateral direction of the microstrip line in a direction away from the input waveguide directional coupler, and set the filter circuit to usually be arranged on the side of the microstrip line facing the input waveguide directional coupler, that is, to set the above-mentioned filter circuit in the above-mentioned reserved space.

[0057] See also Figure 2 In this embodiment, the three-port differential synthesis probe can be used as a DC feeding port to provide a DC feeding channel for each diode, and provide a DC feeding voltage V to each diode during operation. b , and realize the coupled output of the total synthetic current from the suspended microstrip to the output waveguide. An impedance matching structure can also be provided in the output waveguide to realize the impedance matching between the three-port differential synthetic probe and the output waveguide. In this embodiment, the microstrip line can be a microstrip line processed on the surface of the substrate, and the diodes in the balanced double-frequency diode pair and the triple-frequency diode can be connected to the microstrip line by a conductive adhesive bonding process or a welding process. That is, the microstrip line in this embodiment is specifically a suspended microstrip structure, which can be processed by a thin film substrate such as quartz, alumina ceramic, aluminum nitride ceramic, etc., and the thinner the substrate thickness, the better. The installation of each of the above-mentioned diodes, including the diodes in the balanced double-frequency diode pair and the triple-frequency diode, can be achieved by a traditional conductive adhesive bonding process or a welding process.

[0058] The sextuple frequency structure proposed in this embodiment has an ultra-high circuit integration. The core frequency multiplication unit can be integrated into a 5mm×0.38mm thin film substrate circuit. This high integration also further improves the sextuple frequency multiplication efficiency. Figure 4 It can be seen that the terahertz balanced sextuple frequency structure proposed in this embodiment can provide a frequency doubling efficiency of more than 5% and an output power of 25 mW.

[0059] A terahertz balanced sextuple frequency structure provided by an embodiment of the present invention can achieve intrinsic suppression of adjacent second, third, fourth, fifth, seventh, eighth, and ninth harmonics. And at the input end, due to the intrinsic isolation of the waveguide TE mode and the microstrip line TEM mode, combined with the inter-stage matching network, it is possible to prevent each adjacent harmonic from leaking back to the input waveguide. Therefore, the entire circuit itself has already constructed an idle loop for each idle harmonic, and has the ability of high efficiency; by introducing two stages of different frequency-doubling Schottky diode pairs, the different junction characteristics of the two-stage diodes can be regulated, so that the first-stage diode characteristics have the characteristics of high power capacity and large junction capacitance, which is suitable for completing the harmonic current conversion described in the above formula. This structure can solve the contradiction between power capacity and frequency doubling efficiency caused by a single-stage diode directly realizing the sixth frequency doubling, thereby ensuring efficient generation of the sixth harmonic.

[0060] Embodiment 2

[0061] A terahertz device provided by an embodiment of the present invention is introduced below. The terahertz device described below and the terahertz balanced sextuple frequency structure described above can refer to each other.

[0062] In this embodiment, the terahertz device includes a terahertz balanced sextup frequency structure provided by any of the above-mentioned invention embodiments. The specific structure of the terahertz balanced sextup frequency structure has been described in detail in the above-mentioned invention embodiments, and will not be described in detail here. The remaining structures of the terahertz device, such as the antenna, the housing, etc., can refer to the prior art, and will not be described in detail here.

[0063] Since the terahertz device provided in this embodiment specifically uses the terahertz balanced sextuple frequency structure provided in the above embodiments, the terahertz device can realize a highly efficient sextuple frequency signal, thereby having more excellent performance.

[0064] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0065] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0066] The above is a detailed introduction to a terahertz balanced sextupling structure and a terahertz device provided by the present invention. This article uses specific examples to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A terahertz balanced sextupling structure, characterized in that: include: An input waveguide directional coupler; the input waveguide directional coupler comprises a first branch and a second branch, the input signal transmitted in the first branch and the input signal transmitted in the second branch have the same amplitude and a phase difference of 90°; A microstrip line connected between the first branch and the second branch; a first end of the microstrip line is connected to the first branch, and a second end of the microstrip line is connected to the second branch; a middle area of ​​the microstrip line is connected to an output waveguide via a current synthesis structure; Along the signal transmission direction of the microstrip line, a balanced double-frequency diode pair, an interstage matching network, and a triple-frequency diode are sequentially arranged from the first end of the microstrip line to the middle area, and from the second end of the microstrip line to the middle area; the two triple-frequency diodes form a balanced triple-frequency diode pair.

2. The terahertz balanced sextupling structure according to claim 1, characterized in that: The current synthesis structure includes a three-port differential synthesis probe.

3. The terahertz balanced sextupling structure according to claim 2, characterized in that: The three-port differential synthesis probe is also connected to a filtering circuit.

4. The terahertz balanced sextupling structure according to claim 3, characterized in that: The output waveguide extends in a direction away from the input waveguide directional coupler in the lateral direction of the microstrip line; and the filter circuit is arranged on a side of the microstrip line facing the input waveguide directional coupler.

5. The terahertz balanced sextupling structure according to claim 1, characterized in that: The diodes in the balanced doubler diode pair have the same direction, one end of which is connected to the microstrip line and the other end is grounded; one end of the tripler diode is connected to the microstrip line and the other end is grounded.

6. The terahertz balanced sextupling structure according to claim 1, characterized in that: The balanced frequency doubling diode pair, the interstage matching network, and the frequency tripling diode located on both sides of the microstrip line are symmetrically arranged with the middle area as the center.

7. The terahertz balanced sextupling structure according to claim 1, characterized in that: The inter-stage matching network includes a low-pass filtering structure.

8. The terahertz balanced sextupling structure according to claim 1, characterized in that: The microstrip line operates in TEM mode, and the input waveguide connected to the input waveguide directional coupler operates in TE mode.

9. The terahertz balanced sextupling structure according to claim 1, characterized in that: The microstrip line is a microstrip line processed on the surface of the substrate, and the diodes in the balanced doubler diode pair and the tripler diode are connected to the microstrip line through a conductive adhesive bonding process or a welding process.

10. A terahertz device, characterized in that: It comprises the terahertz balanced sextuple frequency structure as claimed in any one of claims 1 to 9.

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