Balanced frequency tripling structure and terahertz equipment

Abstract

The invention discloses a balanced frequency tripling structure and terahertz equipment, which are applied to the technical field of terahertz, and comprise an odd-mode excitation structure connected with an input waveguide, a waveguide mode excitation structure connected with an output waveguide, and two coupling lines connected with the odd-mode excitation structure and the waveguide mode excitation structure, the two coupling lines are arranged in parallel to transmit differential signals; one coupling line is connected with a frequency doubling diode, the other coupling line is connected with another frequency doubling diode, and the two frequency doubling diodes form a balanced frequency doubling diode pair. Through the odd-mode excitation structure, electromagnetic waves can be converted into coupling line odd-mode work, so that radio frequency reverse excitation is carried out on the two frequency doubling diodes, and basic conditions for realizing idle harmonic suppression are constructed. And meanwhile, the odd mode excitation structure and the waveguide mode excitation structure can lock even harmonics generated by the frequency doubling diode in a nonlinear manner in the coupling line to form a high-integration-level idle harmonic loop, so that high efficiency of third harmonics can be ensured.

Description

Technical Field

[0001] The present invention relates to the field of terahertz technology, and in particular to a balanced triple 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 few 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 increasing demand for high-power Schottky frequency doubling sources. At present, terahertz Schottky frequency doubling sources are usually composed of a series of double and triple frequency doubling circuits cascaded, among which the balanced triple frequency doubling circuit is widely used due to its simple circuit structure, high frequency conversion efficiency and high frequency conversion times.

[0003] However, for terahertz Schottky frequency tripling circuits, the contradiction between the harmonic suppression of the circuit and the DC loop is the fundamental limitation of most structures. Therefore, how to provide a balanced frequency tripling structure that can construct an idle harmonic loop of the frequency tripling circuit and achieve corresponding harmonic intrinsic suppression without using on-chip bypass capacitors and redundant peripheral circuits is an urgent problem that technicians in this field need to solve. Summary of the invention

[0004] The object of the present invention is to provide a balanced triple frequency structure, which can construct an idle harmonic loop of a triple frequency circuit and achieve corresponding harmonic intrinsic suppression without using on-chip bypass capacitors and redundant peripheral circuits; another object of the present invention is to provide a terahertz device, which can construct an idle harmonic loop of a triple frequency circuit and achieve corresponding harmonic intrinsic suppression without using on-chip bypass capacitors and redundant peripheral circuits.

[0005] In order to solve the above technical problems, the present invention provides a balanced triple frequency structure, comprising an odd mode excitation structure connected to an input waveguide, a waveguide mode excitation structure connected to an output waveguide, and two coupling lines connecting the odd mode excitation structure and the waveguide mode excitation structure, wherein the two coupling lines are arranged in parallel to transmit differential signals;

[0006] One of the coupling lines is connected to a frequency doubling diode, and the other coupling line is connected to another frequency doubling diode, and the two frequency doubling diodes form a balanced frequency doubling diode pair.

[0007] Optionally, the odd mode excitation structure includes a single-ended to differential structure, the waveguide mode excitation structure includes a differential to single-ended structure, and the two coupling lines form a differential signal line connecting the single-ended to differential structure and the differential to single-ended structure.

[0008] Optionally, the single-ended to differential structure includes a first coupling line segment and a second coupling line segment, wherein an extension direction of the first coupling line segment and an extension direction of the second coupling line segment are both perpendicular to a signal transmission direction of the coupling line, the first coupling line segment extends from one end of one of the coupling lines toward a first direction, and the second coupling line segment extends from one end of the other coupling line toward a second direction, and the first direction is opposite to the second direction.

[0009] Optionally, the differential-to-single-ended structure includes a third coupling line segment and a fourth coupling line segment, and the extension direction of the third coupling line segment and the extension direction of the fourth coupling line segment are both perpendicular to the signal transmission direction of the coupling line, the third coupling line segment extends from one end of one of the coupling lines to a first direction, and the fourth coupling line segment extends from one end of the other coupling line to a second direction, and the first direction is opposite to the second direction.

[0010] Optionally, the frequency doubling diodes have the same direction, with one end connected to the coupling line and the other end grounded.

[0011] Optionally, an impedance matching network is provided in the coupling line between the odd-mode excitation structure and the frequency doubling diode.

[0012] Optionally, the impedance matching network is formed with a low-pass filtering structure.

[0013] Optionally, the coupling line is a coupling line processed on the surface of the substrate, and the frequency doubling diode is connected to the coupling line through a conductive adhesive bonding process or a welding process.

[0014] Optionally, the input waveguide and the output waveguide operate in TE mode.

[0015] The present invention also provides a terahertz device, comprising the balanced triple frequency structure as described in any one of the above items.

[0016] A balanced triple frequency structure provided by the present invention comprises an odd mode excitation structure connected to an input waveguide, a waveguide mode excitation structure connected to an output waveguide, and two coupling lines connecting the odd mode excitation structure and the waveguide mode excitation structure, wherein the two coupling lines are arranged in parallel to transmit differential signals; one coupling line is connected to a frequency doubling diode, and the other coupling line is connected to another frequency doubling diode, and the two frequency doubling diodes form a balanced frequency doubling diode pair.

[0017] Electromagnetic waves usually work in the TE mode in the input waveguide. After passing through the odd-mode excitation structure, they can be converted into the odd-mode operation of the coupled line, thereby realizing RF reverse excitation of the two frequency-doubling diodes, and constructing the basic conditions for realizing idle harmonic suppression. At the same time, since the odd-mode excitation structure and the waveguide mode excitation structure can achieve a high degree of mode isolation between the waveguide main mode and the coupled line even mode, the even harmonics generated by the nonlinearity of the frequency-doubling diode can be locked inside the coupled line, forming a highly integrated idle harmonic loop, which can ensure the high efficiency of the third harmonic. Therefore, the above-mentioned balanced triple frequency structure can achieve idle harmonic suppression, and essentially has higher triple frequency efficiency and working bandwidth.

[0018] 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

[0019] 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.

[0020] Figure 1 A structural schematic diagram of a balanced triple frequency structure provided by an embodiment of the present invention;

[0021] Figure 2 for Figure 1 Schematic diagram.

[0022] In the figure: 1. odd mode excitation structure, 11. first coupling line segment, 12. second coupling line segment, 2. waveguide mode excitation structure, 21. third coupling line segment, 22. fourth coupling line segment, 3. balanced frequency doubling diode pair, 4. impedance matching network. DETAILED DESCRIPTION

[0023] The core of the present invention is to provide a balanced frequency tripling structure. In the prior art, there are two types of terahertz high-efficiency frequency tripling circuits that can achieve DC bias: the first is the most reported unbalanced frequency tripling circuit. Because it adopts an unbalanced circuit structure, the entire circuit contains fundamental signals, secondary, tertiary, quaternary and other harmonic signals after the nonlinear action of the diode, and a high-Q frequency selection network needs to be loaded in the planar circuit. While the frequency selection network causes high insertion loss, the frequency selection network will cause the impedance of the second harmonic to shift from the optimal impedance point of the pure imaginary number, resulting in a decrease in circuit efficiency and a sharp decrease in circuit bandwidth. Therefore, the traditional frequency tripling circuit based on thin film technology has the disadvantages of narrow bandwidth and low efficiency, and there is no solution in the current circuit form.

[0024] The second type is a balanced frequency multiplication circuit based on on-chip bypass capacitors, which specifically constructs a locking loop for even harmonics through a pair of reverse-parallel diodes to achieve balanced output of odd harmonics. The most critical core component is the on-chip MIM (Metal-Insulator-Metal) bypass capacitor based on monolithic process technology, which can realize DC power supply while realizing equivalent grounding of RF signals. The capacitor medium is usually SiN or SiO2 material (thickness of tens of nanometers). This circuit can only be implemented through a monolithic process, and the process compatibility is low. In addition, the Q value of the on-chip capacitor is usually 2~7, which means that the equivalent impedance of the capacitor has a real impedance of 3.7Ω~20Ω. Therefore, this real impedance component will cause additional work loss, which will lead to the fundamental wave, second harmonic and third harmonic components not being perfectly grounded. In this way, the amplitude consistency and phase difference of the diodes on the upper and lower sides of the balanced frequency multiplication circuit will deviate from the predetermined value, resulting in amplitude and phase imbalance, causing the circuit performance to deteriorate.

[0025] The present invention provides a balanced triple frequency structure, including an odd-mode excitation structure connected to an input waveguide, a waveguide mode excitation structure connected to an output waveguide, and two coupling lines connecting the odd-mode excitation structure and the waveguide mode excitation structure, wherein the two coupling lines are arranged in parallel to transmit differential signals; one coupling line is connected to a frequency doubling diode, and the other coupling line is connected to another frequency doubling diode, and the two frequency doubling diodes form a balanced frequency doubling diode pair.

[0026] Electromagnetic waves usually work in the TE mode in the input waveguide. After passing through the odd-mode excitation structure, they can be converted into the odd-mode operation of the coupled line, thereby realizing RF reverse excitation of the two frequency-doubling diodes, and constructing the basic conditions for realizing idle harmonic suppression. At the same time, since the odd-mode excitation structure and the waveguide mode excitation structure can achieve a high degree of mode isolation between the waveguide main mode and the coupled line even mode, the even harmonics generated by the nonlinearity of the frequency-doubling diode can be locked inside the coupled line, forming a highly integrated idle harmonic loop, which can ensure the high efficiency of the third harmonic. Therefore, the above-mentioned balanced triple frequency structure can achieve idle harmonic suppression, and essentially has higher triple frequency efficiency and working bandwidth.

[0027] 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.

[0028] Embodiment 1

[0029] Please refer to Figure 1 as well as Figure 2 , Figure 1 A structural schematic diagram of a balanced triple frequency structure provided by an embodiment of the present invention; Figure 2 for Figure 1 Schematic diagram.

[0030] See also Figure 1 In an embodiment of the present invention, a balanced triple frequency structure includes an odd mode excitation structure 1 connected to an input waveguide, a waveguide mode excitation structure 2 connected to an output waveguide, and two coupling lines connecting the odd mode excitation structure 1 and the waveguide mode excitation structure 2, wherein the two coupling lines are arranged in parallel to transmit differential signals; one of the coupling lines is connected to a frequency doubling diode, and the other coupling line is connected to another frequency doubling diode, and the two frequency doubling diodes form a balanced frequency doubling diode pair 3.

[0031] The above-mentioned odd-mode excitation structure 1 needs to be coupled to the input waveguide. When working, the signal in the input waveguide is usually a TE mode. For example, when the input waveguide is a rectangular waveguide, the signal transmitted is a TE mode. 10 Mode. In this embodiment, the input waveguide and the output waveguide usually work in TE mode. The above-mentioned odd mode excitation structure 1 is used to convert the TE mode signal of the input waveguide into the odd mode signal of the coupling line for transmission. In this embodiment, the signal input from the input waveguide will pass through the odd mode excitation structure 1, the coupling line and the waveguide mode excitation structure 2 in sequence, and finally be transmitted to the output waveguide, and the coupling line connecting the odd mode excitation structure 1 and the waveguide mode excitation structure 2 is specifically two parallel coupling lines to form a differential line. The above-mentioned odd mode signal converted by the odd mode excitation structure 1 is specifically a differential signal, and the two signals of the differential signal are specifically transmitted in the corresponding coupling lines.

[0032] See also Figure 2 ,exist Figure 2 The frequency of the signal in the odd-mode excitation structure 1 is ω0, and the frequency of the signal transmitted to the output waveguide is 3ω0. In the present embodiment, each coupling line is connected to a corresponding frequency doubling diode, and the two frequency doubling diodes form a balanced frequency doubling diode pair 3. The above-mentioned frequency doubling diodes are usually triple-frequency Schottky diodes. In the present embodiment, the directions of the frequency doubling diodes are usually the same, one end is connected to the coupling line and the other end is grounded to form two diodes with the same polarity relative to the ground. The above-mentioned odd-mode signal can realize reverse RF signal excitation for the above-mentioned two diodes with the same polarity relative to the ground, and respectively excite the harmonic current I1 and the harmonic current I2, and the expressions are as follows:

[0033]

[0034]

[0035] The above harmonic current I1 and harmonic current I2 are the basic conditions for constructing an idle harmonic suppression loop, that is, an idle even harmonic loop in the figure. At the same time, the odd-mode excitation structure 1 has an intrinsic suppression on the even-mode signal of the coupled line, which can prevent the even harmonics generated by the diode nonlinearity from leaking back to the input waveguide and causing power loss.

[0036] The waveguide mode excitation structure 2 is used to synthesize the two paths of the differential signal, and convert the transmission mode of the synthesized signal into the mode required by the output waveguide transmission signal for transmission in the output waveguide. That is, the waveguide mode excitation structure 2 can realize the superposition synthesis of the harmonic current I1 and the harmonic current I2 in the coupling line, and convert them into the main mode TE mode of the output waveguide, and the expression of the total current I is shown as follows:

[0037]

[0038] The physical meaning of this expression is that the even harmonics operating in the even mode of the coupled line are locked in the coupled line loop by the odd mode excitation structure 1 and the waveguide mode excitation structure 2, and cannot leak into the input waveguide and the output waveguide. In this way, the optimal conversion efficiency of the fundamental signal power to the third harmonic signal can be guaranteed.

[0039] In the present embodiment, an impedance matching network 4 is provided in the coupling line between the odd-mode excitation structure 1 and the frequency doubling diode. One of the main functions of the impedance matching network 4 is to ensure that the signal can be well transmitted backward in the coupling line. Furthermore, in the present embodiment, the impedance matching network 4 can form a low-pass filter structure, for example, a coupling line structure of "narrow→wide→narrow" exists along the signal transmission direction in the coupling line, forming a low-pass filter structure to filter the signal. In the present embodiment, the impedance matching network 4 of the above structure can prevent the required third harmonic from leaking back to the input waveguide while achieving impedance matching for the balanced frequency doubling diode pair 3, thereby maximizing the conversion efficiency of the fundamental signal to the third harmonic. Figure 2 As shown, the even harmonics excited by the balanced frequency doubling diode pair 3 work in the even mode of the coupled line, and the odd harmonics work in its odd mode.

[0040] In this embodiment, the odd mode excitation structure 1 includes a single-ended to differential structure, and the waveguide mode excitation structure 2 includes a differential to single-ended structure, and the two coupling lines form a differential signal line connecting the single-ended to differential structure and the differential to single-ended structure. The above-mentioned single-ended to differential structure is used to generate a signal working in an odd mode, and the signal will be transmitted in the two coupling lines in a differential form. Correspondingly, the differential to single-ended structure is used to synthesize the differential signal into a signal that conforms to the waveguide transmission mode, and transmit the signal to the output waveguide. In this embodiment, the odd mode excitation structure 1 can be replaced by other structures that can realize the conversion of a single port to a differential port, and the waveguide mode excitation structure 2 can be replaced by other structures that can realize the conversion of a differential port to a single port, including hybrid structures based on waveguides, coplanar waveguides, slot lines or microstrip lines, etc., which are not specifically limited here.

[0041] Specifically, in this embodiment, the single-ended to differential structure includes a first coupling line segment 11 and a second coupling line segment 12, the extension direction of the first coupling line segment 11 and the extension direction of the second coupling line segment 12 are both perpendicular to the signal transmission direction of the coupling line, the first coupling line segment 11 extends from one end of one of the coupling lines to the first direction, the second coupling line segment 12 extends from one end of the other coupling line to the second direction, and the first direction is opposite to the second direction. Correspondingly, the differential to single-ended structure includes a third coupling line segment 21 and a fourth coupling line segment 22, the extension direction of the third coupling line segment 21 and the extension direction of the fourth coupling line segment 22 are both perpendicular to the signal transmission direction of the coupling line, the third coupling line segment 21 extends from one end of one of the coupling lines to the first direction, the fourth coupling line segment 22 extends from one end of the other coupling line to the second direction, and the first direction is opposite to the second direction.

[0042] The first direction and the second direction are both perpendicular to the signal transmission direction of the coupling line, and the transmission direction of the coupling line is usually equal to the length direction of the coupling line, so the first direction and the second direction are both the width direction of the coupling line, which is perpendicular to the length direction of the coupling line. The difference between the first direction and the second direction is that they point to different sides of the coupling line, for example, the first direction points to the upper side in the figure, and the second direction points to the lower side in the figure.

[0043] At this time, the first coupling line segment 11 and the second coupling line segment 12 will form a dipole-like antenna structure, which is used to convert the TE mode signal in the input waveguide into an odd-mode differential signal. Correspondingly, the third coupling line segment 21 and the fourth coupling line segment 22 will also form a dipole-like antenna structure, which is used to transmit the TE mode signal of the output waveguide of the differential signal conversion layer to the output waveguide. In this embodiment, one coupling line will connect the first coupling line segment 11 and the third coupling line segment 21, and the other coupling line will connect the second coupling line segment 12 and the fourth coupling line segment 22. In this embodiment, the DC bias of each of the two frequency doubling diodes can be loaded through the dipole antenna terminal of the odd mode excitation structure 1 and the waveguide mode excitation structure 2 in a dipole-like antenna structure through a low-pass filter to form a DC feeding channel.

[0044] In this embodiment, the cavity of the balanced triple frequency structure can be processed by materials such as aluminum and copper, and the surface is gold-plated. The coupling line can be a coupling line processed on the surface of the substrate, and the frequency doubling diode is connected to the coupling line by a conductive adhesive bonding process or a welding process. The above-mentioned substrate can be a thin film of quartz, alumina ceramic, aluminum nitride ceramic and the like, that is, the above-mentioned coupling line can be processed on a thin film substrate of quartz, alumina ceramic, aluminum nitride ceramic and the like, and the thickness of the substrate is generally the thinner the better. The frequency doubling diode can be connected to the coupling line by a conductive adhesive bonding process or a welding process, that is, its installation can be achieved by a conventional conductive adhesive bonding process or a welding process.

[0045] A balanced triple frequency structure provided in this embodiment solves the conflicting problem between the reverse excitation requirement of the two internal junctions of the balanced frequency doubling diode and the RF and DC grounding of the diode, and abandons the low-integration E-plane split T / Y-type junction to construct a highly integrated single-ended to differential hybrid integrated balun-like structure.

[0046] Electromagnetic waves usually work in TE in the input waveguide 10mode, which can be converted into a coupled line odd-mode signal after passing through the odd-mode excitation structure 1, thereby realizing RF reverse excitation of two frequency-doubling diodes with the same DC polarity, and constructing the basic conditions for realizing idle harmonic suppression. At the same time, since the odd-mode excitation structure 1 and the waveguide mode excitation structure 2 can realize a high degree of mode isolation between the waveguide main mode and the coupled line even mode, the even harmonics generated by the nonlinearity of the balanced frequency-doubling diode pair 3 can be locked inside the coupled line, forming a highly integrated idle even harmonic loop, which can ensure the high efficiency of the third harmonic. Therefore, compared with the unbalanced triple frequency structure, the balanced triple frequency structure of this embodiment can realize idle harmonic suppression, and essentially has higher triple frequency efficiency and working bandwidth. At the same time, since the balanced triple frequency structure of this embodiment has an independent RF circuit and DC feeding channel, has the ability to apply an external bias voltage, has the ability to regulate the working bias voltage of the diode, and has higher triple frequency efficiency potential.

[0047] In addition, in terms of the basic conditions for constructing idle harmonic suppression, the circuit of this embodiment can use a highly integrated odd-mode excitation structure 1 to replace the redundant on-chip MIM bypass capacitors in the existing triple frequency circuit, solving the problems of large parasitic resistance of the MIM bypass capacitors and unbalanced RF grounding. At the same time, it also realizes the replacement of the waveguide E-plane T / Y-type junction, achieving high integration of the circuit and ensuring scalability of higher power capacity. In short, the triple frequency circuit of this embodiment has high amplitude and phase balance, high integration, and the characteristics of high efficiency and broadband, and is suitable for the design of frequency doublers in the entire terahertz frequency band.

[0048] Embodiment 2

[0049] A terahertz device provided by an embodiment of the present invention is introduced below. The terahertz device described below and the balanced triple frequency structure described above can be referred to each other.

[0050] In this embodiment, the terahertz device includes a balanced triple frequency structure provided by any of the above-mentioned invention embodiments. The specific structure of the balanced triple 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.

[0051] Since the terahertz device provided in this embodiment specifically uses the balanced triple frequency structure provided in the above embodiments, the terahertz device can generate high-quality third harmonics, thereby having more excellent performance.

[0052] 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.

[0053] 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.

[0054] The above is a detailed introduction to a balanced triple frequency structure and 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 balanced triple frequency structure, characterized in that: It includes an odd mode excitation structure connected to the input waveguide, a waveguide mode excitation structure connected to the output waveguide, and two coupling lines connecting the odd mode excitation structure and the waveguide mode excitation structure, wherein the two coupling lines are arranged in parallel to transmit differential signals; One of the coupling lines is connected to a frequency doubling diode, and the other coupling line is connected to another frequency doubling diode, and the two frequency doubling diodes form a balanced frequency doubling diode pair.

2. The balanced triple frequency structure according to claim 1, characterized in that: The odd mode excitation structure includes a single-ended to differential structure, the waveguide mode excitation structure includes a differential to single-ended structure, and the two coupling lines form a differential signal line connecting the single-ended to differential structure and the differential to single-ended structure.

3. The balanced triple frequency structure according to claim 2, characterized in that: The single-ended to differential structure includes a first coupling line segment and a second coupling line segment, wherein the extension direction of the first coupling line segment and the extension direction of the second coupling line segment are both perpendicular to the signal transmission direction of the coupling line, the first coupling line segment extends from one end of one of the coupling lines to a first direction, and the second coupling line segment extends from one end of the other coupling line to a second direction, and the first direction is opposite to the second direction.

4. The balanced triple frequency structure according to claim 2, characterized in that: The differential-to-single-ended structure includes a third coupling line segment and a fourth coupling line segment, wherein the extension direction of the third coupling line segment and the extension direction of the fourth coupling line segment are both perpendicular to the signal transmission direction of the coupling line, the third coupling line segment extends from one end of one of the coupling lines to a first direction, and the fourth coupling line segment extends from one end of the other coupling line to a second direction, and the first direction is opposite to the second direction.

5. The balanced triple frequency structure according to claim 1, characterized in that: The frequency doubling diodes have the same direction, one end of which is connected to the coupling line and the other end is grounded.

6. The balanced triple frequency structure according to claim 1, characterized in that: An impedance matching network is arranged in the coupling line between the odd-mode excitation structure and the frequency doubling diode.

7. The balanced triple frequency structure according to claim 6, characterized in that: The impedance matching network forms a low-pass filtering structure.

8. The balanced triple frequency structure according to claim 1, characterized in that: The coupling line is a coupling line processed on the surface of the substrate, and the frequency doubling diode is connected to the coupling line through a conductive adhesive bonding process or a welding process.

9. The balanced triple frequency structure according to claim 1, characterized in that: The input waveguide and the output waveguide operate in TE mode.

10. A terahertz device, characterized in that: The invention comprises a balanced triple frequency structure as claimed in any one of claims 1 to 9.

Images