Ring cascade terahertz source and communication system

Abstract

The present invention relates to the field of communication technology, and in particular to a ring-shaped cascade terahertz source and a communication system, wherein the ring-shaped cascade terahertz source comprises: at least one oscillator primitive, a DC source primitive having the same number as the oscillator primitives, and a coupling network primitive; each oscillator primitive is ring-shaped cascaded, adjacent oscillator primitives are coupled through a coupling network primitive, and each oscillator primitive is also connected to its corresponding DC source primitive; each DC source primitive is used to generate a DC bias voltage, and transmit the DC bias voltage to the oscillator primitive connected to each DC source primitive; each oscillator primitive is used to generate a terahertz signal to radiate to the outside when the amplitude of the DC bias voltage meets a threshold; each coupling network primitive is used to lock the terahertz signal of each oscillator primitive to the same frequency and phase. By controlling the voltage of the DC source primitive corresponding to the oscillator primitive, the phase of each oscillator primitive is regulated, thereby achieving the regulation of the terahertz radiation mode.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a ring-type cascade terahertz source and a communication system. Background Art

[0002] The frequency range of terahertz waves is usually between 0.1THz and 10THz. By utilizing the ultra-wide frequency range characteristics of terahertz, it is expected to solve the increasing problem of data transmission faced by mobile communications and drive the working frequency band of mobile communications to gradually advance to high-frequency terahertz. At present, terahertz sources are mainly divided into two major technologies: electronics and photonics. Since terahertz is between the microwave and optical frequency bands, electronics and photonics technologies face the challenges of breaking through the carrier mobility and energy gap bottlenecks in semiconductor materials, respectively. This results in terahertz sources being less mature than other frequency bands. For example, the radiation power of terahertz sources is low and the radiation mode is single, which cannot temporarily meet the development needs of 6G application scenarios for mobility coverage.

[0003] Terahertz active phased array is a technology path that currently attracts a lot of attention. However, it is difficult to achieve the effect of a phased array by simply arranging terahertz sources in an array. This is mainly because the frequency jitter between array units is large and beam synthesis cannot be achieved. As a result, beam control cannot be achieved, resulting in a single radiation pattern.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The main purpose of the present invention is to provide a ring-shaped cascade terahertz source and a communication system, aiming to solve the technical problem in the prior art that it is difficult to achieve the effect of a phased array by arranging terahertz sources in an array.

[0006] To achieve the above object, the present invention proposes a ring-shaped cascade terahertz source, which comprises: at least one oscillator primitive, a number of direct current source primitives equal to the number of the oscillator primitives, and a coupling network primitive;

[0007] The oscillator primitives are ring-connected in cascade, adjacent oscillator primitives are coupled via the coupling network primitive, and each oscillator primitive is also connected to its corresponding direct current source primitive;

[0008] Each of the DC source primitives is used to generate a DC bias voltage and transmit the DC bias voltage to the oscillator primitive connected to each of the DC source primitives;

[0009] Each of the oscillator primitives is used to generate a terahertz signal to radiate to the outside when the amplitude of the DC bias voltage meets a threshold;

[0010] Each of the coupling network primitives is used to lock the terahertz signals of each of the oscillator primitives to the same frequency and phase.

[0011] Optionally, the annular cascade terahertz source further includes: parasitic oscillation suppression primitives and low-pass filter primitives of the same number as the oscillator primitives;

[0012] The parasitic oscillation suppression primitive and the low-pass filter primitive are arranged between the oscillator primitive and the DC source primitive;

[0013] The parasitic oscillation suppression primitive is used to suppress the low-frequency signal generated by the oscillator primitive;

[0014] The low-pass filter element is used to block the terahertz signal of the oscillator element from being transmitted to the direct current source element.

[0015] Optionally, each of the oscillator primitives comprises: an RTD device and a resonant antenna;

[0016] The RTD device is electrically connected to the resonant antenna;

[0017] The RTD device is used to generate a terahertz signal with reduced resonance loss, and transmit the terahertz signal to the resonant antenna for radiation to the outside.

[0018] Optionally, the RTD device includes: a first resistor and a first capacitor, and the resonant antenna includes: a first inductor, a second capacitor and a second resistor;

[0019] The first resistor is connected in parallel with the first capacitor, and the first inductor, the second capacitor, and the second resistor are connected in parallel.

[0020] Optionally, each of the parasitic oscillation suppression primitives comprises: a third resistor;

[0021] The third resistor is arranged between the positive electrode and the negative electrode of the DC source element.

[0022] Optionally, each of the coupling network primitives includes: a third capacitor, a fourth capacitor and a fifth capacitor;

[0023] The first end of the third capacitor is connected to the positive electrode of one of the oscillator elements and the first end of the fourth capacitor at the same time, the second end of the third capacitor is connected to the first end of the fifth capacitor and is grounded, and the second end of the fourth capacitor is connected to the second end of the fifth capacitor and the positive electrode of another oscillator element at the same time.

[0024] Optionally, the annular cascade terahertz source further includes: a dielectric substrate and a semiconductor conductive layer epitaxially grown on the dielectric substrate, wherein an annular gap exists in the semiconductor conductive layer;

[0025] The positive electrode metal layer and the negative electrode metal layer of each of the DC source elements are both arranged on the semiconductor conductive layer;

[0026] The positive electrode metal layer and the negative electrode metal layer of each of the DC source elements are connected by the semiconductor conductive layer to form each of the parasitic oscillation suppression elements.

[0027] Optionally, the centers of the oscillator primitives are distributed in a ring around the center of the negative electrode metal layer;

[0028] Each of the oscillator primitives comprises: a first air bridge and a junction region layer;

[0029] The junction layer is disposed between the negative electrode metal layer and the first air bridge;

[0030] The first air bridge is formed by the positive electrode metal layer extending through the annular gap toward above the junction layer.

[0031] Optionally, there is an isolation gap between the positive electrode metal layers of each of the DC source elements;

[0032] The negative electrode metal layer extends through the isolation gap toward the top of the positive electrode metal layer;

[0033] The negative electrode metal layer and the positive electrode metal layer above the isolation gap form each coupling network unit through an insulating medium.

[0034] In addition, to achieve the above-mentioned purpose, the present invention further provides a communication system, which includes the ring-shaped cascade terahertz source as described above.

[0035] The present invention provides a ring-type cascade terahertz source, which comprises: at least one oscillator primitive, a DC source primitive with the same number as the oscillator primitive, and a coupling network primitive; each of the oscillator primitives is ring-type cascaded, adjacent oscillator primitives are coupled through the coupling network primitive, and each of the oscillator primitives is also connected to the DC source primitive corresponding to it; each of the DC source primitives is used to generate a DC bias voltage, and transmit the DC bias voltage to the oscillator primitive connected to each of the DC source primitives; each of the oscillator primitives is used to generate a terahertz signal to radiate to the outside when the amplitude of the DC bias voltage meets a threshold; each of the coupling network primitives is used to lock the terahertz signal of each of the oscillator primitives to the same frequency and phase. The frequency and phase locking of multiple oscillator primitives is met by the coupling network primitive, so as to realize high-power coherent terahertz radiation, and the phase of each oscillator primitive is regulated by controlling the voltage of the DC source primitive corresponding to each oscillator primitive, so as to achieve the regulation of the terahertz radiation mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in 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 the structures shown in these drawings without paying creative work.

[0037] Figure 1 It is a structural schematic diagram of the first embodiment of the ring-shaped cascade terahertz source of the present invention;

[0038] Figure 2 It is a structural schematic diagram of the second embodiment of the ring-shaped cascade terahertz source of the present invention;

[0039] Figure 3 is an equivalent circuit diagram of the second embodiment of the ring-type cascade terahertz source of the present invention;

[0040] Figure 4 An equivalent circuit diagram of an oscillator element in the second embodiment of the ring-connected terahertz source of the present invention;

[0041] Figure 5 It is a structural schematic diagram of the RTD device in the second embodiment of the ring-type cascade terahertz source of the present invention;

[0042] Figure 6 A DC characteristic curve diagram of the RTD device in the second embodiment of the ring-type cascade terahertz source of the present invention;

[0043] Figure 7 A schematic diagram of the waveform of the radiation power of the ring-type cascade terahertz source in the second embodiment of the ring-type cascade terahertz source of the present invention;

[0044] Figure 8 It is a schematic structural diagram of the third embodiment of the ring-shaped cascade terahertz source of the present invention;

[0045] Fig. 9 It is a structural schematic diagram of a partial enlargement of an oscillator unit in the third embodiment of the ring-type cascade terahertz source of the present invention;

[0046] Fig.10 It is a structural schematic diagram of a partial enlargement of a coupling network element in the third embodiment of the ring-type cascade terahertz source of the present invention;

[0047] Fig.11 It is a schematic diagram of a partially enlarged exploded structure of a coupling network element in the third embodiment of the ring-type cascade terahertz source of the present invention;

[0048] Fig.12The radiation pattern of the first working mode in the third embodiment of the ring-shaped cascade terahertz source of the present invention;

[0049] Fig.13 The radiation pattern of the second working mode of the third embodiment of the ring-shaped cascade terahertz source of the present invention;

[0050] Fig.14 The radiation pattern of the third working mode of the third embodiment of the ring-shaped cascade terahertz source of the present invention;

[0051] Fig.15 The radiation pattern of the fourth working mode of the third embodiment of the ring-shaped cascade terahertz source of the present invention;

[0052] Fig.16 The radiation pattern of the fifth working mode of the third embodiment of the ring-shaped cascade terahertz source of the present invention;

[0053] Fig.17 This is the radiation pattern of the sixth working mode in the third embodiment of the ring-shaped cascade terahertz source of the present invention.

[0054] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0055] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0058] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0059] Reference Figure 1 , Figure 1 FIG. 1 is a schematic diagram of the structure of the first embodiment of the ring-type cascade terahertz source of the present invention. Figure 1 As shown, the main solution of the embodiment of the present invention is: the ring cascade terahertz source includes: at least one oscillator primitive 10, the same number of DC source primitives 20 as the oscillator primitives, and a coupling network primitive 30. Each of the oscillator primitives 10 is ring cascaded, and adjacent oscillator primitives 10 are coupled through the coupling network primitive 30, and each of the oscillator primitives 10 is also connected to the corresponding DC source primitive 20.

[0060] It should be noted that each of the DC source elements 20 can be used to generate a DC bias voltage and transmit the DC bias voltage to the oscillator element connected to each of the DC source elements; each of the oscillator elements 10 can be used to generate a terahertz signal to radiate to the outside when the amplitude of the DC bias voltage meets a threshold; each of the coupling network elements 30 can be used to lock the terahertz signals of each of the oscillator elements to the same frequency and phase.

[0061] Among them, the number of oscillator primitives in the ring cascade terahertz source (refer to Figure 1 In this embodiment, the number of oscillator primitives 10, the number of DC source primitives 20 and the number of coupling network primitives 30 are the same, and the radiation power can be increased by increasing the number n of oscillator primitives 10.

[0062] It should be understood that the oscillator element 10 can use a metal LC resonator and a resonant tunneling diode (RTD) to form a resonant circuit to generate a terahertz signal. Among them, RTD is a high-speed nanodevice that works by using the quantum resonant tunneling effect. After receiving the DC bias voltage provided by the DC source element 20 and exceeding the working threshold, it can excite the antenna connected to the RTD to generate a terahertz signal. Since the metal ohmic loss of the metal LC resonator is large in the terahertz frequency band, the quality factor (Q) value of the metal LC resonator is usually in the tens, which is easy to cause frequency jitter problems, thereby limiting the signal-to-noise ratio. And because multiple oscillator elements are independent of each other and the phase is unstable, it is impossible to achieve the regulation of the terahertz radiation mode.

[0063] It should be noted that each DC source unit 20 corresponds to an oscillator unit 10, generates a DC bias voltage, and transmits the DC bias voltage to the oscillator unit 10 connected to each DC source unit 20. Therefore, by controlling each DC source unit 20 to generate different DC bias voltages, the phase of the terahertz signal generated by each oscillator unit can be independently regulated, thereby adjusting the terahertz radiation mode. The amplitude threshold of the DC bias voltage of the terahertz signal generated by the oscillator unit can be selected according to actual use requirements, and no specific restrictions are made here. The coupling efficiency can be regulated by adjusting the impedance matching between the coupling network unit 30 and the oscillator unit 10, and then the mutual injection locking of each oscillator unit 10 is achieved by the size of the coupling efficiency, so that the frequency and phase of each oscillator unit 10 reach the same stable value.

[0064] It should be understood that the connection between the elements can be in the form of metal transmission lines, including but not limited to microstrip lines, strip lines, coplanar waveguides, and metal waveguides.

[0065] In this embodiment, the ring-cascaded terahertz source includes: at least one oscillator primitive, the same number of DC source primitives as the oscillator primitives, and a coupling network primitive; each of the oscillator primitives is ring-cascaded, and the adjacent oscillator primitives are coupled through the coupling network primitive, and each of the oscillator primitives is also connected to the corresponding DC source primitive; each of the DC source primitives is used to generate a DC bias voltage and transmit the DC bias voltage to the oscillator primitive connected to each of the DC source primitives; each of the oscillator primitives is used to generate a terahertz signal to radiate to the outside when the amplitude of the DC bias voltage meets the threshold; each of the coupling network primitives is used to lock the terahertz signal of each of the oscillator primitives to the same frequency and phase. The frequency and phase locking of multiple oscillator primitives is achieved through the coupling network primitive, so as to achieve high-power coherent terahertz radiation, and by controlling the voltage of the DC source primitive corresponding to each oscillator primitive, the phase of each oscillator primitive is regulated to achieve the regulation of the terahertz radiation mode.

[0066] Based on the first embodiment of the present application, in the second embodiment of the present application, the same or similar contents as those in the above-mentioned embodiment 1 can be referred to the above introduction, and will not be described in detail later. Figure 2 , Figure 2 It is a schematic structural diagram of the second embodiment of the ring-type cascade terahertz source of the present invention.

[0067] In this embodiment, the annular cascade terahertz source further includes: parasitic oscillation suppression elements 40 and low-pass filter elements 50, the same number as the oscillator elements. The parasitic oscillation suppression elements 40 and the low-pass filter elements 50 are arranged between the oscillator element 10 and the DC source element 20.

[0068] It should be noted that the parasitic oscillation suppression unit 40 can be used to suppress the low-frequency signal generated by the oscillator unit 10; and the low-pass filter unit 50 can be used to block the terahertz signal of the oscillator unit from being transmitted to the DC source unit.

[0069] It should be understood that the oscillator element 10 will generate a low-frequency interference signal when working normally, which will interfere with the generation of the terahertz signal. The interference signal is suppressed by the parasitic oscillation suppression element 40, and the terahertz signal path between the oscillator element 10 and the DC source element 20 is blocked by the low-pass filter element 50. The low-pass filter element 50 can completely reflect the terahertz signal and play the role of passing the DC working voltage signal.

[0070] Reference Figure 3 , Figure 3 : is an equivalent circuit diagram of the second embodiment of the ring cascade terahertz source of the present invention. Each of the oscillator primitives may include: a negative resistance diode Dn and a resonant antenna An. Figure 4 , Figure 4 This is an equivalent circuit diagram of the oscillator element in the second embodiment of the ring-type cascade terahertz source of the present invention. The negative resistance diode Dn can be an RTD device; the RTD device is electrically connected to the resonant antenna; the RTD device can be used to generate a terahertz signal with reduced resonance loss, and transmit the terahertz signal to the resonant antenna for radiation to the outside world.

[0071] It should be noted that in the equivalent circuit, the RTD device includes: a first resistor R1 and a first capacitor C1, and the resonant antenna includes: a first inductor L1, a second capacitor C2 and a second resistor R2; the first resistor R1 is connected in parallel with the first capacitor C1, and the first inductor L1, the second capacitor C2 and the second resistor R2 are connected in parallel.

[0072] It should be understood that the negative resistance diode Dn has a negative resistance phenomenon that can decrease as the DC bias voltage increases, so it can offset the loss in the resonant antenna under working conditions and realize the generation and radiation of terahertz signals. Among them, the negative resistance diode can be selected from RTD devices, or other diode devices with negative resistance characteristics, including but not limited to Gunn diode oscillators, Impact Ionization Avalanche Transit Time (IMPATT) diodes, etc., or other types of silicon-based transistors, compound transistors, etc. The negative resistance diode Dn in the embodiment of this scheme is mainly described for the terahertz source integrated with the terahertz RTD and the resonant antenna.

[0073] Reference Figure 5 , Figure 5 The schematic diagram of the structure of the RTD device in the second embodiment of the ring cascade terahertz source of the present invention. RTD generally adopts a quantum well structure composed of AlAs / InGaAs / AlAs, in which AlAs and InGaAs constitute barriers and quantum wells respectively. The emitter and collector are emitters and collectors respectively. QW1 and E QW2 are the first and second energy levels of the quantum well, E F and E C are the Fermi level of the emitter and the bottom energy level of the conduction band. Vbias represents the DC bias voltage variable loaded on both ends of the RTD. Vb represents the voltage Vbias loaded on both ends of the RTD just so that the first ground state energy level E in the quantum well QW1 and the emitter Fermi level E FAt this time, the electrons start to tunnel from the emitter to the collector by resonance. Since the electrons in the quantum well structure work in the ballistic transport mode and have a small intrinsic capacitance value, RTD is more likely to generate terahertz signals than other negative resistance diode devices.

[0074] After the bias signal provided by the external voltage control circuit reaches a certain voltage, the first ground state energy level E in the lower quantum well QW1 and the Fermi level E of the emitter F When the alignment is achieved, electron resonant tunneling begins, accompanied by a rapid increase in current. As the DC bias voltage Vbias increases further, when the first ground state energy level E QW1 Below the bottom energy level of the emitter conduction band E C When the electrons cannot reach the collector in the form of resonant tunneling, the current decreases and negative resistance is generated. At this time, the RTD can offset the loss of the resonant circuit to achieve the emission of terahertz signals. Figure 6 As shown, Figure 6 This is a DC characteristic curve diagram of the RTD device in the second embodiment of the ring-type cascade terahertz source of the present invention. In the gray area (negative resistance area) of the figure, the current Current of the RTD device decreases as the voltage Voltage increases.

[0075] It should be noted that the working condition of the negative resistance diode oscillator element composed of the RTD device is that the absolute value of the negative resistance of the first resistor R1 in the RTD is less than the absolute value of the second resistor in the resonant antenna. That is, under working conditions, the RTD can offset the loss in the resonant antenna. The operating frequency of the oscillator element is:

[0076] 1 / (2*pi*sqrt(L1*(C2+ C1)))

[0077] Furthermore, each of the parasitic oscillation suppression primitives includes: a third resistor R3; the third resistor R3 is arranged between the positive electrode and the negative electrode of the DC source primitive. Each of the coupling network primitives includes: a third capacitor C3, a fourth capacitor C4 and a fifth capacitor C5; the first end of the third capacitor C3 is simultaneously connected to the positive electrode of one of the oscillator primitives 10 and the first end of the fourth capacitor C4, the second end of the third capacitor C3 is connected to the first end of the fifth capacitor C5 and grounded, and the second end of the fourth capacitor C4 is simultaneously connected to the second end of the fifth capacitor C5 and the positive electrode of another oscillator primitive.

[0078] It should be noted that the DC source primitive can be composed of a DC voltage source DC. The low-pass filter primitive can be equivalently composed of the third resistor R3 in the parasitic oscillation suppression primitive and the third capacitor C3, the fourth capacitor C4 and the fifth capacitor C5 connected in a triangle in the coupling network primitive.

[0079] It should be understood that the low-pass filter primitive, the parasitic oscillation suppression primitive and the coupling network primitive can be composed of discrete devices such as capacitors, resistors or inductors, or can be composed of capacitors, resistors or inductors equivalent to metal transmission lines, and the connection between the discrete devices or elements can be in series, parallel, triangle or star connection. The ring cascade terahertz source provided in this embodiment can be used in the terahertz frequency band as well as other frequency bands, such as microwaves and millimeter waves.

[0080] Furthermore, circuit simulation modeling calculation can be performed based on the equivalent circuit of the above-mentioned ring cascade terahertz source, referring to Figure 7 , Figure 7 Schematic diagram of the waveform of the radiation power of the ring-shaped cascade terahertz source in the second embodiment of the ring-shaped cascade terahertz source of the present invention. Figure 7 The waveforms in are the theoretical results of the radiation power and oscillation frequency of the oscillator primitives at different numbers n. The calculation parameters used by all primitives are the same. For example, the peak-to-valley voltage and current of the terahertz RTD used in the nth oscillator primitive in the negative resistance region are 400mV and 8mA respectively, the loss resistance R2 of the resonant antenna is 200Ω, the inductance L1 is 6pH and the capacitance Cn is 5fF, the capacitances C3, C4 and C5 of the coupling network primitives between the oscillator primitives are 10fF, 50fF and 10fF respectively, and the DC bias voltage of the terahertz RTD is the center voltage of the negative resistance region. The calculation results show that at this time, multiple terahertz RTD oscillator primitives can achieve mutual injection locking, not only the oscillation frequency is a single frequency, but also the radiation power increases with the increase in number, achieving the effect of high-power coherent terahertz radiation.

[0081] Based on the first embodiment and / or the second embodiment of the present application, in the third embodiment of the present application, the same or similar contents as those of the above-mentioned first and second embodiments can be referred to the above introduction, and will not be described in detail later. Figure 8 , Figure 8 It is a schematic structural diagram of the third embodiment of the ring-shaped cascade terahertz source of the present invention.

[0082] In this embodiment, the ring-shaped cascade terahertz source is provided with four oscillator primitives for explanation, and accordingly, the number of resonant antennas An, the number of negative resistance diodes Dn, the number of coupling network primitives, and the number of DC source primitives are all 4. The ring-shaped cascade terahertz source further includes: a dielectric substrate 101 and a semiconductor conductive layer 102 epitaxially grown on the dielectric substrate, wherein a ring-shaped gap 103 exists in the semiconductor conductive layer. The material of the dielectric substrate 101 includes, but is not limited to, semiconductor materials such as silicon, gallium arsenide, and indium phosphide. The material of the semiconductor conductive layer 102 is a conductive semiconductor material doped with a heavy metal.

[0083] It should be noted that the positive electrode metal layer 201 and the negative electrode metal layer 202 of each of the DC source elements are arranged on the semiconductor conductive layer 102. The center of each of the oscillator elements is distributed in a ring around the center of the negative electrode metal layer. The shape of the ring can be but is not limited to a circle, an ellipse, a polygon, etc. The negative resistance diode Dn is integrated at any position of the slot in the resonant antenna An composed of Metal-Insulator-Metal (MIM) at both ends, and the slot resonant antenna is a traditional half-wavelength antenna. The negative resistance diode element is considered to be a terahertz RTD element, and the terahertz RTD element is distributed in a ring around the center of the central DC source negative electrode circular surface.

[0084] Reference Fig. 9 , Fig. 9 The schematic diagram of the structure of the oscillator unit in the third embodiment of the ring-type cascade terahertz source of the present invention is a partially enlarged schematic diagram. Each of the oscillator units includes: a first air bridge 301 and a junction layer 302; the junction layer 302 is arranged between the negative electrode metal layer 202 and the first air bridge 301. The first air bridge 301 is formed by the positive electrode metal layer 201 extending to the top of the junction layer 302 through the annular gap 103. The first air bridge 301 is located below the annular gap 103 section without the junction layer 302 and the semiconductor conductive layer 102. Among them, the junction layer is the terahertz RTD.

[0085] Furthermore, each of the parasitic oscillation suppression elements 40 is formed between the positive electrode metal layer 201 and the negative electrode metal layer 202 of each of the DC source elements through the semiconductor conductive layer. An isolation gap 104 exists between the positive electrode metal layers 201 of each of the DC source elements, which is used to achieve isolation between the positive electrode metal layers of adjacent DC source elements. The negative electrode metal layer 202 extends above the positive electrode metal layer 201 through the isolation gap 104. Each of the coupling network elements 30 is formed between the negative electrode metal layer 202 and the positive electrode metal layer 201 above the isolation gap 104 through an insulating medium 303, and the coupling network element 30 is also a MIM structure. The coupling network element 30 is connected to the negative electrode metal layer 202 via a second air bridge 304. Refer to Fig.10 and Fig.11 , Fig.10 It is a schematic diagram of the structure of a partial enlargement of a coupling network element in the third embodiment of the ring-type cascade terahertz source of the present invention. Fig.11 This is a schematic diagram of a partially enlarged exploded structure of a coupling network element in the third embodiment of the ring-type cascade terahertz source of the present invention.

[0086] It should be noted that the ring-type cascade terahertz source with four oscillator primitives includes six working modes: in the first working mode, one oscillator primitive works; in the second working mode, two adjacent oscillator primitives work simultaneously (with the same phase); in the third working mode, two diagonal oscillator primitives work simultaneously (with the same phase); in the fourth working mode, three adjacent oscillator primitives work simultaneously (with the same phase); in the fifth working mode, four oscillator primitives work simultaneously (with the same phase); in the sixth working mode, four oscillator primitives work simultaneously (with a phase difference of 90 degrees). The calculation results of the radiation pattern at the frequency of 0.3THz are used for illustration. Figures 12 to 17 , Fig.12 This is the radiation pattern of the first working mode in the third embodiment of the ring-shaped cascade terahertz source of the present invention. Fig.13 This is the radiation pattern of the second working mode in the third embodiment of the ring-shaped cascade terahertz source of the present invention. Fig.14 This is the radiation pattern of the third working mode in the third embodiment of the ring-shaped cascade terahertz source of the present invention. Fig.15 This is the radiation pattern of the fourth working mode in the third embodiment of the ring-shaped cascade terahertz source of the present invention. Fig.16 This is the radiation pattern of the fifth working mode in the third embodiment of the ring-shaped cascade terahertz source of the present invention. Fig.17 This is the radiation pattern of the sixth working mode in the third embodiment of the ring-connected terahertz source of the present invention. By controlling the working mode of the terahertz oscillator primitive, different radiation modes can be regulated, and by increasing the number of terahertz oscillator primitives, more radiation modes can be regulated.

[0087] In addition, to achieve the above purpose, an embodiment of the present invention further proposes a communication system. Since the communication system includes the above-mentioned ring cascade terahertz source, it at least has all the beneficial effects brought by the technical solutions of the above-mentioned embodiments, which will not be described one by one here.

[0088] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A ring cascade terahertz source, characterized in that: The ring-shaped cascade terahertz source comprises: a plurality of oscillator primitives, a DC source primitive having the same number as the oscillator primitives, and a coupling network primitive; The oscillator primitives are ring-connected in cascade, adjacent oscillator primitives are coupled via the coupling network primitive, and each oscillator primitive is also connected to its corresponding direct current source primitive; Each of the DC source primitives is used to generate a DC bias voltage and transmit the DC bias voltage to the oscillator primitive connected to each of the DC source primitives; Each of the oscillator primitives is used to generate a terahertz signal to radiate to the outside when the amplitude of the DC bias voltage meets a threshold; Each of the coupling network primitives is used to satisfy the mutual injection locking condition of each of the oscillator primitives, so that the terahertz signals generated by each of the oscillator primitives are locked to the same frequency and phase; Wherein, each of the coupling network primitives comprises: a third capacitor, a fourth capacitor and a fifth capacitor; The first end of the third capacitor is connected to the positive electrode of one of the oscillator elements and the first end of the fourth capacitor at the same time, the second end of the third capacitor is connected to the first end of the fifth capacitor and is grounded, and the second end of the fourth capacitor is connected to the second end of the fifth capacitor and the positive electrode of another oscillator element at the same time.

2. The ring-shaped cascade terahertz source according to claim 1, characterized in that: The ring-shaped cascade terahertz source further includes: parasitic oscillation suppression primitives and low-pass filter primitives having the same number as the oscillator primitives; The parasitic oscillation suppression primitive and the low-pass filter primitive are arranged between the oscillator primitive and the DC source primitive; The parasitic oscillation suppression primitive is used to suppress the low-frequency signal generated by the oscillator primitive; The low-pass filter element is used to block the terahertz signal of the oscillator element from being transmitted to the direct current source element.

3. The ring-shaped cascade terahertz source according to claim 2, characterized in that: Each of the oscillator primitives comprises: an RTD device and a resonant antenna; The RTD device is electrically connected to the resonant antenna; The RTD device is used to generate a terahertz signal with reduced resonance loss, and transmit the terahertz signal to the resonant antenna for radiation to the outside.

4. The ring-shaped cascade terahertz source according to claim 3, characterized in that: The RTD device includes: a first resistor and a first capacitor, and the resonant antenna includes: a first inductor, a second capacitor and a second resistor; The first resistor is connected in parallel with the first capacitor, and the first inductor, the second capacitor, and the second resistor are connected in parallel.

5. The ring-shaped cascade terahertz source according to claim 2, characterized in that: Each of the parasitic oscillation suppression primitives comprises: a third resistor; The third resistor is arranged between the positive electrode and the negative electrode of the DC source element.

6. The ring-shaped cascade terahertz source according to claim 2, characterized in that: The annular cascade terahertz source further includes: a dielectric substrate and a semiconductor conductive layer epitaxially grown on the dielectric substrate, wherein an annular gap exists in the semiconductor conductive layer; The positive electrode metal layer and the negative electrode metal layer of each of the DC source elements are both arranged on the semiconductor conductive layer; The positive electrode metal layer and the negative electrode metal layer of each of the DC source elements are connected by the semiconductor conductive layer to form each of the parasitic oscillation suppression elements.

7. The ring-shaped cascade terahertz source according to claim 6, characterized in that: The centers of the oscillator primitives are distributed in a ring around the center of the negative electrode metal layer; Each of the oscillator primitives comprises: a first air bridge and a junction region layer; The junction layer is disposed between the negative electrode metal layer and the first air bridge; The first air bridge is formed by the positive electrode metal layer extending through the annular gap toward above the junction layer.

8. The ring-shaped cascade terahertz source according to claim 7, characterized in that: There are isolation gaps between the positive electrode metal layers of each of the DC source primitives; The negative electrode metal layer extends through the isolation gap toward the top of the positive electrode metal layer; The negative electrode metal layer and the positive electrode metal layer above the isolation gap form each coupling network unit through an insulating medium.

9. A communication system, characterized in that: The communication system comprises the ring-shaped cascade terahertz source according to any one of claims 1 to 8.

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