Waveguide-based reconfigurable multi-band terahertz high-efficiency frequency multiplier
By introducing a detachable integrated input matching structure and a multi-stage microstrip matching circuit into the terahertz frequency multiplier, the problem of low output efficiency in multiple frequency bands is solved, achieving high-efficiency frequency band point multiplication, reducing costs and meeting miniaturization requirements.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- UNIV OF ELECTRONICS SCI & TECH OF CHINA
- Filing Date
- 2023-06-13
- Publication Date
- 2026-06-26
AI Technical Summary
Existing terahertz frequency multipliers are inefficient and costly when outputting across multiple frequency bands, and cannot simultaneously achieve efficient output at important atmospheric window frequencies such as 170GHz and 220GHz. Furthermore, existing broadband matching techniques sacrifice efficiency.
Design a waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier. By introducing a detachable integrated input matching structure in the input widened waveguide and output matching structure, combined with multi-stage high and low impedance microstrip matching circuits and DC filter circuits, impedance matching and efficient frequency multiplication for different frequency bands can be achieved.
It achieves high-efficiency frequency doubling output at multiple frequency bands within the 140–220 GHz waveguide bandwidth, reducing chip and cavity costs and meeting the trend of model miniaturization.
Smart Images
Figure CN116722823B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of terahertz technology, specifically relating to a waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier. Background Technology
[0002] Electromagnetic waves with frequencies ranging from 0.1 to 10 THz are called terahertz waves. Their long-wavelength band borders millimeter waves, while their short-wavelength band approaches infrared radiation, placing them at the intersection of electronics and photonics. Compared to lower-frequency microwaves, they possess the following characteristics: 1. A wider usable spectrum and greater information capacity; 2. Easier to implement narrow beams and high-gain antennas, resulting in high resolution and good anti-interference capabilities; 3. Strong plasma penetration ability; 4. Large Doppler shift and high velocity measurement sensitivity. Therefore, terahertz waves have significant implications in communications, radar, guidance, remote sensing, radio astronomy, and spectroscopy.
[0003] Terahertz frequency multipliers have the ability to multiply electromagnetic waves at microwave frequencies to the terahertz band and are widely used in terahertz modules. Among them, terahertz frequency multipliers based on Schottky diodes are the most widely used terahertz solid-state sources.
[0004] In the design of terahertz Schottky diode frequency multipliers, it is generally necessary to pull the optimal embedding impedance of the diode at the required operating frequency to achieve the highest frequency conversion efficiency at that frequency; then, the input and output circuits are matched based on the embedding impedance. Frequency multipliers designed in this way are generally narrow-band and efficient, with a relative bandwidth of about 8 to 12% for a frequency multiplication efficiency of more than 20% (Viegas C, Powell J, Liu H, et al. On-Chip Integrated Backshort for Relaxation of Machining Accuracy Requirements in Frequency Multipliers[J].IEEE Microwave and Wireless Components Letters,2020,PP(99):1-4)(Cooper KB, Rodriguez Monje R, Millan L, et al. Atmospheric Humidity Sounding Using Differential Absorption Radar Near 183GHz[J].IEEE Geoscience and RemoteSensing Letters,2018,PP(2):1-5). These narrowband high-efficiency frequency multipliers only achieve high-efficiency output at a specific frequency, with limited functionality and inability to achieve output across a wide bandwidth. For example, they cannot simultaneously achieve high-efficiency output at both 170GHz and 220GHz (an important atmospheric window frequency in the terahertz band). Therefore, if one wants to achieve multi-band output based on narrowband high-efficiency frequency multipliers, multiple circuits need to be fabricated for different frequency bands, which greatly increases the cost of chips, cavities, and circuits.
[0005] One feasible solution is to design a frequency multiplier using broadband matching technology, which can generally achieve the full waveguide bandwidth, thereby enabling cross-band output, such as a full waveguide bandwidth frequency multiplier for 140–220 GHz (Deng J, Yang Y, Zhu Z, et al. A 140-220-GHz Balanced Doubler With 8.7%–12.7% Efficiency[J]. IEEE Microwave and Wireless Components Letters, 2018, PP(99):1-3)(Wu C, Zhang Y, Li Y, et al. A Balanced Frequency Doubler Covering 140–220 GHz With an Efficiency of 6.8%–11.6%[J]. IEEE microwave and wireless components letters: A publication of the IEEE Microwave Theory and Techniques Society, 2022(8):32). However, this broadband matched frequency multiplier comes at the cost of efficiency, with typical multiplication efficiencies ranging from 6% to 13%. Compared to narrowband, high-efficiency frequency multipliers, its efficiency is too low to effectively utilize the power of the preceding driver stage. Achieving higher power output would necessitate indirectly increasing the cost of the driver. However, current technology lacks a high-efficiency terahertz frequency multiplier capable of multi-band output. Summary of the Invention
[0006] To address the problems in the prior art, this invention provides a waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier, achieving high-efficiency frequency multiplication output across multiple important terahertz frequency bands.
[0007] The technical solution adopted in this invention is as follows:
[0008] A high-efficiency multi-band terahertz frequency multiplier based on waveguide reconfigurability is characterized by comprising, in sequence, a first input narrowing waveguide, a microstrip circuit, an output narrowing waveguide, and an output rectangular waveguide; it also includes multiple detachable and reconfigurable integrated input matching structures connected to the first input narrowing waveguide, and a flange choke ring disposed around the first input narrowing waveguide; by disassembling and replacing the integrated input matching structures, frequency multiplication output at multiple frequency bands within the target waveguide bandwidth can be achieved;
[0009] The microstrip circuit includes a diode package structure, a multi-stage high and low impedance microstrip matching circuit, an output matching probe, and a DC filter circuit, arranged sequentially. The output width-reducing waveguide is connected to the microstrip circuit through the output matching probe. The integrated input matching structure includes an input matching waveguide and a second input width-reducing waveguide at the corresponding frequency band. The second input width-reducing waveguide is connected to the first input width-reducing waveguide and has the same width.
[0010] Furthermore, the design method of the multi-band terahertz frequency multiplier includes the following steps:
[0011] Step 1: Select multiple frequency bands within a target waveguide bandwidth as needed, select the intrinsic parameters of the diode based on the frequency bands, and design the diode package structure in the electromagnetic simulation software; take the intermediate frequency value of the multiple frequency bands, perform structural parameter scanning on the diode package structure at the intermediate frequency value, and obtain the impedance pulling result under the optimal efficiency of the diode. At this time, the distance between the diode package structure and the short-circuit surface of the first input widening waveguide is L.
[0012] Step 2: Assume that the distance between the interface of the output widened waveguide / output rectangular waveguide and the microstrip circuit is L1, the length of the low-impedance microstrip line in the multi-stage high and low impedance microstrip matching circuit is L2, and the length of the high-impedance microstrip line is L3. Based on the target waveguide bandwidth, design the multi-stage high and low impedance microstrip matching circuit, the output matching probe and the DC filter circuit, and perform structural parameter scanning to obtain the output impedance variation trajectory under different L1, L2 and L3.
[0013] Step 3: By performing imaginary part analysis on the output impedance variation trajectory under different L1, L2, and L3, select L1, L2, and L3 that can simultaneously form imaginary part troughs between frequency band points, corresponding to the optimal output matching; where there are frequency band points in the target waveguide bandwidth sideband, first select L1, L2, and L3 that can simultaneously form imaginary part troughs between other non-sideband frequency band points, and then optimize the selected L1, L2, and L3 with the same weight for the sideband frequency band points to obtain the L1, L2, and L3 corresponding to the optimal output matching;
[0014] Step 4: Based on the L corresponding to the diode's optimal efficiency, and L1, L2, and L3 corresponding to the optimal output matching, the input fundamental impedance is adjusted to obtain the input fundamental impedance at different frequency bands. The first and second input narrowing waveguides are used together as the input narrowing waveguide. The structural parameters of the input narrowing waveguide are scanned based on the input fundamental impedance to obtain the length of the input narrowing waveguide at different frequency bands. Half of the minimum length of the obtained input narrowing waveguide is taken as the length L4 of the first input narrowing waveguide. The length of the input narrowing waveguide at different frequency bands is subtracted from the length of the first input narrowing waveguide to obtain the length L5 of the second input narrowing waveguide at the corresponding frequency band.
[0015] Furthermore, based on the determined L, L1, L2, L3, L4, and L5, a multi-band terahertz high-efficiency frequency multiplier with input-output impedance matching can be realized.
[0016] Furthermore, the target waveguide bandwidth is 140–220 GHz, and the selected frequency bands are 170 GHz, 183 GHz, and 220 GHz.
[0017] Furthermore, in step 1, L is selected as 1 / 4 of the waveguide wavelength at the intermediate frequency value.
[0018] The beneficial effects of this invention are as follows:
[0019] This invention proposes a waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier. It can achieve high-efficiency frequency multiplication output at multiple frequency bands within the target waveguide bandwidth by using only a microstrip circuit chip, a main cavity, an output matching structure, and multiple detachable and reconfigurable integrated input matching structures. This not only meets the trend of model miniaturization but also greatly reduces chip cost. Attached Figure Description
[0020] Figure 1 This is a schematic diagram of the overall structure of the waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier proposed in Example 1;
[0021] Figure 2 This is a schematic diagram of the split structure of the waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier proposed in Example 1;
[0022] Figure 3 This is a schematic diagram of the design process of the waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier in Example 1;
[0023] Figure 4 The output impedance variation trajectory under different L1 values in Example 1 is shown; where (a) represents the effect on the imaginary part of the output impedance from 160 to 200 GHz; (b) represents the effect on the real part of the output impedance from 210 to 230 GHz; and (c) represents the effect on the imaginary part of the output impedance from 210 to 230 GHz.
[0024] Figure 5 The output impedance variation trajectory under different L2 values in Example 1 is shown; where (a) is the effect on the imaginary part of the output impedance from 160 to 200 GHz; (b) is the effect on the real part of the output impedance from 210 to 230 GHz; and (c) is the effect on the imaginary part of the output impedance from 210 to 230 GHz.
[0025] Figure 6The output impedance variation trajectory under different L3 values in Example 1 is shown; where (a) represents the effect on the imaginary part of the output impedance from 160 to 200 GHz; (b) represents the effect on the real part of the output impedance from 210 to 230 GHz; and (c) represents the effect on the imaginary part of the output impedance from 210 to 230 GHz.
[0026] Figure 7 This refers to the final output impedance result of the output matching structure in the corresponding frequency band in Example 1;
[0027] Figure 8 The three-dimensional electromagnetic structure (a) and impedance results (b) of the integrated input matching structure corresponding to 170GHz in Example 1 are shown.
[0028] Figure 9 The three-dimensional electromagnetic structure (a) and impedance results (b) of the integrated input matching structure corresponding to 183GHz in Example 1 are shown.
[0029] Figure 10 The three-dimensional electromagnetic structure (a) and impedance results (b) of the integrated input matching structure corresponding to 220GHz in Example 1 are shown.
[0030] Figure 11 The curves showing the input matching impedance variation of the 170GHz input matching waveguide in Example 1 under the condition of having a flangeless choke are shown.
[0031] Figure 12 This is a schematic diagram of the waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier proposed in Example 1; wherein, (a) is a schematic diagram of the overall cavity; and (b) is a schematic diagram of the partitioned cavity.
[0032] The explanations of the markings in the attached diagram are as follows:
[0033] 1. First input narrowing waveguide; 2. Microstrip circuit; 3. Output narrowing waveguide; 4. Output rectangular waveguide; 5. Integrated input matching structure; 6. Flange choke ring; 7. Diode package structure; 8. Low-impedance microstrip line; 9. High-impedance microstrip line; 10. Output matching probe; 11. DC filter circuit; 12. Input matching waveguide; 13. Second input narrowing waveguide; 14. Cavity assembly gap. Detailed Implementation
[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.
[0035] Example 1
[0036] For a target waveguide bandwidth of 140–220 GHz, this embodiment provides a waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier, specifically a monolithic frequency multiplier that is adjustable at three frequency bands: 170 GHz, 183 GHz, and 220 GHz.
[0037] Structure as Figure 1 and Figure 2 As shown, it includes a first input narrowing waveguide 1, a microstrip circuit 2, an output narrowing waveguide 3, and an output rectangular waveguide 4 in sequence; it also includes multiple detachable and reconfigurable integrated input matching structures 5, and a flange choke ring 6 disposed around the first input narrowing waveguide 1; the integrated input matching structure 5 is connected to the first input narrowing waveguide 1 through a cavity assembly gap 14 (due to actual processing), and by disassembling and replacing the integrated input matching structure 5, frequency doubling output at multiple frequency bands within the target waveguide bandwidth can be achieved.
[0038] The microstrip circuit 2 includes, in sequence, a diode package structure 7, a multi-stage high and low impedance microstrip matching circuit, an output matching probe 10, and a DC filter circuit 11; the multi-stage high and low impedance microstrip matching circuit includes a high-impedance microstrip line 9 and a low-impedance microstrip line 8; the output width-reducing waveguide 3 is connected to the microstrip circuit 2 through the output matching probe 10; the integrated input matching structure 5 includes an input matching waveguide 12 and a second input width-reducing waveguide 13 corresponding to the frequency band point, the second input width-reducing waveguide 13 is connected to the first input width-reducing waveguide 1, and they have the same width; the multi-stage high and low impedance microstrip matching circuit, the output matching probe 10, the DC filter circuit 11, and the output width-reducing waveguide 3 together constitute the output matching structure.
[0039] Except for the detachable and reconfigurable integrated input matching structure 5, all other structures are located inside the main cavity.
[0040] The design flow of the waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier proposed in this embodiment is as follows: Figure 3 As shown, it includes the following steps:
[0041] Step 1: Select the intrinsic parameters of the diode based on the frequency band and design the diode package structure 7 in the electromagnetic simulation software. Assuming the distance between the diode package structure 7 and the short-circuit surface of the first input widening waveguide 1 is L, the diode package structure 7 with different values of L is pulled at three frequency bands: 170GHz, 183GHz, and 220GHz, resulting in the impedance pulling results shown in Table 1. Considering the feasibility of matching, the real and imaginary parts of the impedance are set in the range of (-300, 300). It should be noted that the relative bandwidth and peak frequency doubling efficiency here are results of ideal impedance and do not take into account the losses caused by actual circuit design and the degree of matching between input and output impedances. Therefore, the final circuit design result will be lower than this theoretical expectation.
[0042] Table 1. Impedance results of diode package structures with different L values (100mW input).
[0043]
[0044] Based on the impedance pulling results above, due to performance degradation caused by resonance at L = 225μm, only the optimal output impedance in the L = 275–425μm region is considered. The imaginary part of the optimal impedance at 170GHz and 183GHz shows a linear decreasing relationship, with a basic difference of j40Ω. This is because the frequencies are close, and the optimal output impedance characteristics are consistent, showing a linear decreasing trend as the frequency increases. However, at 220GHz, which is in the sideband, the optimal output impedance is more divergent. Therefore, the matching selection of the output circuit is particularly important. It needs to satisfy one of the aforementioned divergent output impedances at 220GHz, while exhibiting an imaginary part trough (difference of j40Ω) at 170GHz and 183GHz.
[0045] To determine the final L, this embodiment takes the midpoint frequency value of 195GHz from multiple frequency bands and performs a structural parameter sweep on the diode package structure 7 at the midpoint frequency value to obtain the impedance pulling result under the optimal efficiency of the diode. At this time, the distance between the diode package structure 7 and the short-circuit surface of the first input widening waveguide 1 is L = 325μm.
[0046] Step 2: Assuming the distance between the interface of the output widened waveguide 3 / output rectangular waveguide 4 and the microstrip circuit 2 is L1, the length of the low-impedance microstrip line 8 is L2, and the length of the high-impedance microstrip line 9 is L3, based on the target waveguide bandwidth, design a multi-stage high and low impedance microstrip matching circuit, an output matching probe 10, and a DC filter circuit 11, and perform structural parameter scanning to obtain the output impedance variation trajectory under different L1, L2, and L3, respectively corresponding to... Figures 4-6 .
[0047] Step 3: By performing imaginary part analysis on the output impedance variation trajectory under different L1, L2, and L3 values, it can be seen that: L1 affects the frequency of the imaginary part impedance trough; as L1 increases, the frequency of the trough decreases, and when L1 = 900 μm, the trough appears around 170 GHz; L2 affects the absolute impedance difference of the imaginary part trough; as L2 increases, the absolute difference of this imaginary part trough decreases, and it also affects the frequency of the trough; L3 affects the absolute impedance difference of the imaginary part trough and the maximum value of this imaginary part; as L3 increases, the maximum value of this imaginary part impedance continuously increases. By adjusting L1, L2, and L3, the imaginary part impedance difference is made approximately j40 Ω between 170 and 183 GHz. For the 220GHz sideband frequency, the influence of L1, L2, and L3 on the output impedance in the 210–230GHz range is not clearly defined and is highly divergent. Therefore, the selected L1, L2, and L3 are optimized with equal weights, yielding optimal output matching values of L1 = 890μm, L2 = 460μm, and L3 = 130μm. The optimal output impedances at 170GHz, 183GHz, and 220GHz are 34+j*66Ω, 30+j*22Ω, and 226+j*110Ω, respectively, with output matching structure impedances of 33.4+j*71Ω, 43+j*21Ω, and 256+j*157Ω. Figure 7 As shown.
[0048] Step 4: Based on the optimal efficiency of the diode corresponding to L = 325μm, and the optimal output matching corresponding to L1 = 890μm, L2 = 460μm, and L3 = 130μm, the input fundamental impedance is adjusted to obtain the corresponding input fundamental impedances at 85GHz, 91.5GHz, and 110GHz as 330+j*22Ω, 170+j*98Ω, and 53-j*118Ω, respectively.
[0049] The closer to the diode package structure 7, the greater the impact on input matching. Therefore, the first input widening waveguide 1, which is directly connected, has the greatest impact. The first input widening waveguide 1 and the second input widening waveguide 13 are used together as the input widening waveguide. Based on the input fundamental impedance, the structural parameters of the input widening waveguide are scanned, and the lengths of the input widening waveguide at 170GHz, 183GHz, and 220GHz are 2.32mm, 1.64mm, and 1.97mm, respectively. Half of the minimum length of the obtained input widening waveguide is taken as the length of the first input widening waveguide 1, L4≈1mm. The length of the first input widening waveguide is subtracted from the length of the input widening waveguide at different frequency bands to obtain the length of the second input widening waveguide L5 at the corresponding frequency bands, which are 1.32mm, 0.64mm, and 0.97mm, respectively.
[0050] Furthermore, based on the determined L, L1, L2, L3, L4 and L5, a multi-band terahertz frequency multiplier with input-output impedance matching can be realized.
[0051] The three-dimensional electromagnetic structures (including the connected first input broadening waveguide 1 and flange choke ring 6) and impedance results of the integrated input matching structure 5 corresponding to 170GHz, 183GHz, and 220GHz are shown below. Figures 8-10 As shown.
[0052] In this embodiment, a flange choke ring 6 is added at the first input widening waveguide 1 adjacent to the cavity assembly gap 14, which can reduce losses and participate in input impedance matching.
[0053] Figure 11 The input matching impedance curves for the 170GHz input matching waveguide 12 are shown in the cases with and without the flange choke 6. It can be seen that the input matching impedance is more concentrated after adding the flange choke 6, while the input matching impedance without the flange choke 6 is very diffuse and cannot achieve the required impedance design.
[0054] The overall circuit simulation of the waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier obtained in this embodiment was performed. With a 100mW input, three different input matching integrated structures 5 were connected to the circuit simulation, and the frequency multiplication efficiency of the frequency multiplier was as follows:
[0055] When assembling the 170GHz input matching integrated structure 5, the peak efficiency is 41%, and the efficiency is >20% in the 165-178GHz range;
[0056] When assembling the 183GHz input matching integrated structure 5, the peak efficiency is 42%, and the efficiency is >20% in the 173-189GHz range;
[0057] When assembling the 220GHz input matching integrated structure 5, the peak efficiency is 35%, and the efficiency is >20% in the 216-227GHz range;
[0058] Simulation results show that this embodiment achieves high-efficiency output in different frequency bands.
[0059] Figure 12 (a) is a schematic diagram of the overall cavity of the waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier obtained in this embodiment. By dividing the E-plane of the overall cavity into upper and lower halves, we obtain... Figure 12 (b) shows a breakdown diagram and assembly details. After the microstrip circuit 2 is bonded to the main cavity with conductive adhesive, high-efficiency outputs of 170GHz, 183GHz and 220GHz are achieved by assembling different input matching integrated structures 5.
[0060] The above embodiments are only for illustrating the principles and advantages of the present invention, and are not intended to limit the present invention. They are only for helping to understand the principles of the present invention. The scope of protection of the present invention is not limited to the above configurations and embodiments. Those skilled in the art can make various other specific modifications and combinations based on the disclosed technology without departing from the essence of the present invention, but they are still within the scope of protection of the present invention.
Claims
1. A waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier, characterized in that, It includes a first input narrowing waveguide, a microstrip circuit, an output narrowing waveguide, and an output rectangular waveguide connected in sequence; it also includes multiple detachable and reconfigurable integrated input matching structures connected to the first input narrowing waveguide, and a flange choke ring disposed around the first input narrowing waveguide; by disassembling and replacing the integrated input matching structure, frequency doubling output at multiple frequency bands within the target waveguide bandwidth can be achieved; The microstrip circuit includes a diode package structure, a multi-stage high and low impedance microstrip matching circuit, an output matching probe, and a DC filter circuit in sequence; the output width reduction waveguide is connected to the microstrip circuit through the output matching probe; the integrated input matching structure includes an input matching waveguide and a second input width reduction waveguide at the corresponding frequency band point, the second input width reduction waveguide is connected to the first input width reduction waveguide, and the two have the same width. The design method of the multi-band terahertz frequency multiplier includes the following steps: Step 1: Select multiple frequency bands within a target waveguide bandwidth as needed, select the intrinsic parameters of the diode based on the frequency bands, and design the diode package structure in the electromagnetic simulation software; take the intermediate frequency value of the multiple frequency bands, perform structural parameter scanning on the diode package structure at the intermediate frequency value, and obtain the impedance pulling result under the optimal efficiency of the diode. At this time, the distance between the diode package structure and the short-circuit surface of the first input widening waveguide is L. Step 2: Assume that the distance between the interface of the output widened waveguide / output rectangular waveguide and the microstrip circuit is L1, the length of the low-impedance microstrip line in the multi-stage high and low impedance microstrip matching circuit is L2, and the length of the high-impedance microstrip line is L3. Based on the target waveguide bandwidth, design the multi-stage high and low impedance microstrip matching circuit, the output matching probe and the DC filter circuit, and perform structural parameter scanning to obtain the output impedance variation trajectory under different L1, L2 and L3. Step 3: By performing imaginary part analysis on the output impedance variation trajectory under different L1, L2, and L3, select L1, L2, and L3 that can simultaneously form imaginary part troughs between frequency band points, corresponding to the optimal output matching; where there are frequency band points in the target waveguide bandwidth sideband, first select L1, L2, and L3 that can simultaneously form imaginary part troughs between other non-sideband frequency band points, and then optimize the selected L1, L2, and L3 with the same weight for the sideband frequency band points to obtain the L1, L2, and L3 corresponding to the optimal output matching; Step 4: Based on the L corresponding to the diode's optimal efficiency, and L1, L2, and L3 corresponding to the optimal output matching, the input fundamental impedance is adjusted to obtain the input fundamental impedance at different frequency bands. The first and second input narrowing waveguides are used together as the input narrowing waveguide. The structural parameters of the input narrowing waveguide are scanned based on the input fundamental impedance to obtain the length of the input narrowing waveguide at different frequency bands. Half of the minimum length of the obtained input narrowing waveguide is taken as the length L4 of the first input narrowing waveguide. The length of the input narrowing waveguide at different frequency bands is subtracted from the length of the first input narrowing waveguide to obtain the length L5 of the second input narrowing waveguide at the corresponding frequency band. Furthermore, based on the determined L, L1, L2, L3, L4, and L5, a multi-band terahertz high-efficiency frequency multiplier with input-output impedance matching can be realized.
2. The waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier according to claim 1, characterized in that, In step 1, L is selected as 1 / 4 of the waveguide wavelength at the intermediate frequency value.
3. The waveguide-reconfigurable multi-band terahertz high-efficiency frequency multiplier according to claim 1 or 2, characterized in that, The target waveguide bandwidth is 140~220 GHz, and the selected frequency bands are 170 GHz, 183 GHz and 220 GHz.