Terahertz frequency tripler based on four rows of Schottky diode arrays

Abstract

The invention belongs to the technical field of terahertz frequency conversion devices and millimeter wave communication, and particularly provides a terahertz frequency tripler based on a four-row Schottky diode array, which is suitable for an up-conversion device in a frequency band from millimeter waves to terahertz, so as to solve the technical problems of limited power capacity, non-uniform energy distribution and the like of the existing frequency tripler. The invention discloses a multi-channel parallel Schottky diode array power amplifier which comprises an input waveguide, an input height reduction waveguide, an input micro-strip probe, an input matching circuit, a filter circuit, a nonlinear processing unit, an output matching circuit, an output micro-strip probe, an output height reduction waveguide and an output waveguide, and the nonlinear processing unit adopts a four-row parallel Schottky diode array. Through the layout of the four rows of parallel Schottky diode arrays and the collaborative design of an electromagnetic structure, the number of devices is multiplied under the same substrate length, and the power capacity is improved; meanwhile, the power distribution uniformity of each diode unit is improved through multi-row symmetrical reverse configuration.

Description

Technical Field

[0001] This invention belongs to the field of terahertz frequency conversion devices and millimeter-wave communication technology, specifically relating to a high-power terahertz tripler based on a multi-row Schottky diode array, which is particularly suitable for upconversion devices in the millimeter-wave to terahertz frequency band. Background Technology

[0002] Terahertz communication technology, as a core supporting technology for 6G mobile communication systems, has been listed by the International Telecommunication Union (ITU) as a key research direction for next-generation wireless communication. In terahertz signal generation systems, solid-state frequency multipliers based on semiconductor devices have become the preferred alternative to traditional vacuum electronic devices due to their excellent reliability, compact structure, and integrability. Among them, the terahertz third frequency multiplier is a key component, and its performance directly affects the system's output power and frequency stability.

[0003] Currently, most frequency triplers based on Schottky diodes adopt a dual-row anti-parallel structure, but they face significant technical bottlenecks in high-power applications: limited by the maximum withstand power of a single diode, traditional solutions require a linear increase in the number of diodes along the signal transmission direction; this layout leads to many problems: 1) the substrate length increases linearly with the number of devices, causing a cumulative effect of transmission medium loss; 2) the power distribution of the far-end diodes is unbalanced due to the influence of transmission line distribution parameters, resulting in uneven distributed power dissipation; these problems seriously restrict the overall conversion efficiency and long-term stability of the device. Summary of the Invention

[0004] The purpose of this invention is to provide a terahertz tripler based on a four-row Schottky diode array to solve the technical problems of limited power capacity and uneven energy distribution in existing triplers. This invention proposes a novel terahertz tripler, the core innovation of which is to achieve a doubling of device density within a limited substrate length through the layout of the four-row Schottky diode array; at the same time, the use of a multi-row symmetrical reverse polarity configuration strategy effectively improves the uniformity of power distribution.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A terahertz tripler based on a four-row Schottky diode array includes: an input waveguide, an input height reduction waveguide, an input microstrip probe, an input matching circuit, a filter circuit, a nonlinear processing unit, an output matching circuit, an output microstrip probe, an output height reduction waveguide, and an output waveguide; characterized in that the nonlinear processing unit adopts a four-row parallel Schottky diode array, which is composed of two double-row anti-parallel Schottky diode subarrays arranged side by side, and the two are symmetrically arranged.

[0007] Furthermore, in the double-row reverse parallel Schottky diode subarray, each row contains three Schottky diodes arranged in the same direction.

[0008] Furthermore, the Schottky diode uses a gallium arsenide Schottky barrier diode with a die size (anode column diameter) of 4μm.

[0009] Furthermore, the filtering circuit includes two cascaded CMRC filters.

[0010] Furthermore, the input waveguide adopts the WR-12 standard rectangular waveguide, and the output waveguide adopts the WR-4 standard rectangular waveguide.

[0011] Furthermore, the input matching circuit and the output matching circuit adopt a transmission line structure integrated on a gallium arsenide substrate.

[0012] Based on the above technical solution, the beneficial effects of the present invention are as follows:

[0013] This invention provides a terahertz tripler based on a four-row Schottky diode array. It innovatively proposes a four-row parallel Schottky diode array as a nonlinear processing unit. Through the coordinated design of the layout and electromagnetic structure of the four-row parallel Schottky diode array, the number of devices is doubled within the same substrate length, thus improving power capacity. Simultaneously, the power distribution uniformity of each diode unit is improved through a multi-row symmetrical reverse configuration. In summary, this invention provides a highly reliable frequency source solution for high-power terahertz communication systems. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the terahertz tripler based on a four-row Schottky diode array in this invention.

[0015] Figure 2 The figure shows the simulation test results of the input efficiency and frequency multiplication efficiency of the terahertz tripler based on a four-row Schottky diode array in this invention. Detailed Implementation

[0016] To make the objectives, technical solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0017] This embodiment provides a terahertz tripler based on a four-row Schottky diode array, such as... Figure 1 As shown, it includes:

[0018] Input waveguide: WR-12 standard rectangular waveguide, operating frequency band 60GHz~90GHz;

[0019] Input and output height reduction waveguides: short-circuit planes are set at the ends of the waveguides;

[0020] Output waveguide: WR-4 standard rectangular waveguide, operating frequency band 170GHz~260GHz;

[0021] Electromagnetic mode conversion structure: The conversion from the TE10 mode of the WR-12 waveguide to the TEM mode of the microstrip line is achieved through a microstrip probe, as well as the inverse conversion from the TEM mode of the microstrip line to the TE10 mode of the WR-4 waveguide.

[0022] The nonlinear processing unit consists of four rows of parallel Schottky diode arrays, including two sets of diode pairs with opposite polarity configurations. Each set contains two rows of three Schottky diodes arranged in the same direction, integrating a total of 12 diode units. Furthermore, the two sets of diode pairs are symmetrically arranged to form a symmetrical and balanced current path. This layout forms an equivalent current balance loop in the lateral dimension, which can effectively improve the uniformity of power distribution. The Schottky diodes are gallium arsenide Schottky barrier diodes with a die size (anode column diameter) of 4μm and a cutoff frequency exceeding 3THz.

[0023] Filtering module: Contains two cascaded CMRC filters, positioned between the input waveguide and the nonlinear processing unit, to suppress the reverse propagation of the third harmonic signal to the input waveguide;

[0024] Input and output matching circuits: The transmission line structure integrated into the gallium arsenide substrate achieves broadband impedance matching; the gallium arsenide substrate is processed to a thickness of 20μm through a back-side thinning process, effectively reducing dielectric loss;

[0025] The input signal (57GHz~85GHz) is fed into a WR-12 standard rectangular waveguide. After passing through the input height reduction waveguide, the mode is converted by a microstrip probe, converting the TE10 mode to the TEM mode. Then, after passing through the input matching circuit and two cascaded CMRC filters, it reaches the nonlinear processing unit, which excites the nonlinear effect of the four-row diode array. The resulting third harmonic signal (171GHz~255GHz) is inversely converted by a microstrip probe after passing through the output matching circuit. After passing through the output height reduction waveguide, it is output through a WR-4 standard rectangular waveguide.

[0026] It should also be noted that: In this embodiment, the waveguide and microstrip structure parameters are optimized using full-wave electromagnetic simulation software. The optimization focuses on the geometric dimensions of the reduced-height waveguide section at the end of the input / output waveguide, the spacing between the short-circuit plane and the gallium arsenide substrate, and the microstrip line dimensions of the matching circuit, to ensure that the fundamental wave energy is efficiently coupled to the diode array. This optimization design process is a common technique in the field and will not be described in detail here.

[0027] In terms of working principle: For a frequency multiplier, the nonlinear effect of the current and voltage across a diode is used to multiply the input signal; the nonlinear IV characteristic curve is expanded into a Taylor series at a fixed bias point, and the output current i o Represented as:

[0028] i o =f(v)=a0+a1v+a2v 2 +a3v 3 +...+a n v n

[0029] Where v represents voltage, a0 represents the DC component of the output, a1 represents the fundamental component of the output, and a n Represents the nth harmonic component;

[0030] Assume the input signal is a sinusoidal signal: v in =V0 cosω0t, where V0 represents the signal amplitude, ω0 represents the signal frequency, and t represents time; then the output current i out Represented as:

[0031]

[0032] As shown in the above equation, due to the nonlinear effect of diodes, a large number of harmonic components are generated after a sinusoidal signal is input, and the power of each component is different. In the traditional design of multi-die tripler, an even number of dies are generally selected and arranged in a double-row anti-parallel configuration as diode pairs. At this time, the output current i out Represented as:

[0033] i out =f(v in )-f(-v in )=2(a1V+a3V 3 +...)

[0034] Analysis shows that the output signal of the tripler only contains the fundamental frequency and odd harmonic components;

[0035] Based on this principle, this invention creatively proposes a nonlinear processing unit based on a four-row parallel Schottky diode structure. Four rows of 12 Schottky diode units are arranged along the microstrip line transmission direction on a gallium arsenide substrate, with three diodes in the same direction integrated in each row. The two rows of diodes at the edge of the substrate and the two rows in the middle adopt an anti-polarity configuration to form a symmetrical and balanced current path. Compared with the traditional double-row anti-parallel structure, this invention achieves a doubling of the number of devices and a significant improvement in power capacity under the same substrate length. At the same time, the multi-row symmetrical anti-polarity configuration strategy effectively improves the uniformity of power distribution.

[0036] like Figure 2 The figure shows the simulation test results of the input efficiency and frequency doubling efficiency of the terahertz third frequency multiplier based on a four-row Schottky diode array in this embodiment. As can be seen from the figure, this embodiment achieves an input efficiency of over 88% in the input frequency band of 57 GHz to 85 GHz and a frequency doubling efficiency of over 6% in the output frequency band of 171 GHz to 255 GHz (covering 93% of the bandwidth of the WR-4 standard waveguide). The results show that the four-row parallel structure reduces transmission loss by shortening the substrate length and uses a symmetrical layout to uniformly load the fundamental energy onto each diode, ultimately achieving synergistic optimization of device power capacity, conversion efficiency, and stability. This design breaks through the limitations of traditional structures and provides a high-performance frequency doubling source solution for terahertz communication systems.

[0037] The above description is merely a specific embodiment of the present invention. Any feature disclosed in this specification may be replaced by other equivalent or similar features unless otherwise specified. All disclosed features, or steps in all methods or processes, may be combined in any way except for mutually exclusive features and / or steps.

Claims

1. A terahertz tripler based on a four-row Schottky diode array, comprising: The system comprises an input waveguide, an input height reduction waveguide, an input microstrip probe, an input matching circuit, a filter circuit, a nonlinear processing unit, an output matching circuit, an output microstrip probe, an output height reduction waveguide, and an output waveguide; characterized in that the nonlinear processing unit adopts a four-row parallel Schottky diode array, which is composed of two double-row anti-parallel Schottky diode subarrays arranged side by side, and the two are symmetrically arranged.

2. The terahertz tripler based on a four-row Schottky diode array according to claim 1, characterized in that, In a double-row reverse parallel Schottky diode subarray, each row contains three Schottky diodes arranged in the same direction.

3. The terahertz third multiplier based on a four-row Schottky diode array according to claim 1, characterized in that, The Schottky diode is a gallium arsenide Schottky barrier diode with a die size (anode column diameter) of 4μm.

4. The terahertz third multiplier based on a four-row Schottky diode array according to claim 1, characterized in that, The filtering circuit consists of two cascaded CMRC filters.

5. The terahertz third multiplier based on a four-row Schottky diode array according to claim 1, characterized in that, The input waveguide uses the WR-12 standard rectangular waveguide, and the output waveguide uses the WR-4 standard rectangular waveguide.

6. The terahertz third multiplier based on a four-row Schottky diode array according to claim 1, characterized in that, The input matching circuit and the output matching circuit adopt a transmission line structure integrated on a gallium arsenide substrate.

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