Coherent terahertz radiation source and communication system

Abstract

The invention relates to the technical field of communication, in particular to a coherent terahertz radiation source and a communication system.The coherent terahertz radiation source comprises a metal reflecting surface, a terahertz radiation source array composed of diodes and a photonic crystal resonant cavity which are sequentially arranged in a metal cavity; the metal reflecting surface is located at the bottom of the metal cavity, the terahertz radiation source array and the photonic crystal resonant cavity are fixed in a side wall groove of the metal cavity, and the terahertz radiation source array is arranged between the photonic crystal resonant cavity and the metal reflecting surface; and terahertz signals generated by the terahertz radiation source array in the middle are radiated towards the metal reflecting surface at the bottom through the on-chip slot antenna. Terahertz signals except for metal loss are coupled to the photonic crystal resonant cavity at the top through the technical reflecting surface, the frequency and the phase of each diode unit in the terahertz radiation source array are locked, the terahertz signals after coherent power synthesis are radiated to the space, and the miniaturized high-power coherent terahertz radiation source is constructed.

Description

Technical Field

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

[0002] With the promotion and application of innovative services such as the intelligent connection of all things and holographic and full-sensory communication, today's society shows a significant trend of digitalization and intelligent development, which puts forward higher requirements for the peak rate of the sixth generation mobile communication technology (6G). The ultra-wide frequency range characteristics of terahertz are expected to solve the problem of massive data transmission faced by mobile communications. These have driven the working frequency band of mobile communications to gradually advance to high-frequency terahertz. However, compared with other frequency bands, terahertz radiation sources are not mature enough. The frequency stability and radiation power index parameters of terahertz radiation sources are inferior to those of microwave frequency bands, and they cannot temporarily meet the development needs of 6G application scenarios for low power consumption, long distance and wide coverage. Terahertz radiation sources are an effective means to effectively improve the signal-to-noise ratio of the system. Therefore, it is urgent to break through the miniaturization of high-power coherent terahertz radiation sources.

[0003] In the prior art, terahertz radiation sources generally use a metal LC resonator and a resonant tunneling diode (RTD) to form a resonant circuit to generate a terahertz signal. However, due to the large metal ohmic loss of the metal LC resonator in the terahertz frequency band, the quality factor (Q) value of the metal LC resonator is usually in the tens, which easily causes frequency jitter problems, thereby limiting the stability of the terahertz wireless communication system. Therefore, it is particularly important to achieve frequency stability and coherent radiation while meeting the conditions of miniaturization, and to realize the coherent radiation power of the terahertz RTD array radiation source.

[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 coherent terahertz radiation source and a communication system, aiming to solve the technical problems of large frequency jitter and incoherent radiation of traditional terahertz radiation sources in the prior art.

[0006] To achieve the above object, the present invention proposes a coherent terahertz radiation source, which comprises: a metal reflection surface, a terahertz radiation source array composed of diodes, and a photonic crystal resonant cavity, which are sequentially arranged in a metal cavity from bottom to top;

[0007] The metal reflective surface is located at the bottom of the metal cavity, the terahertz radiation source array and the photonic crystal resonant cavity are fixed in the side wall groove of the metal cavity, and the terahertz radiation source array is placed between the photonic crystal resonant cavity and the metal reflective surface;

[0008] The terahertz signal generated by the terahertz radiation source array in the middle is radiated toward the metal reflection surface at the bottom through the on-chip slot antenna, and the metal reflection surface couples the terahertz signal except for metal loss to the photonic crystal resonant cavity at the top;

[0009] The photonic crystal resonant cavity locks the frequency and phase of each diode unit of the terahertz radiation source array, and radiates the terahertz signal after coherent power synthesis into space.

[0010] Optionally, the terahertz radiation source array includes: an RTD device and an antenna;

[0011] The RTD device is electrically connected in series with the antenna;

[0012] The RTD device is used to generate a terahertz signal with reduced resonance loss, and transmit the terahertz signal to the antenna for radiation.

[0013] Optionally, the RTD device includes: a negative conductance and a first capacitor, and the antenna includes: a first inductance, a second capacitor and a second conductance;

[0014] The negative conductance is connected in parallel with the first capacitor, and the first inductance, the second capacitor, and the second conductance are connected in parallel.

[0015] Optionally, the coherent terahertz radiation source comprises: metal bonding;

[0016] The metal bonding is used to form an ohmic connection between an external voltage control circuit and the terahertz radiation source array to supply power to the terahertz radiation source array.

[0017] Optionally, the coherent terahertz radiation source further includes: a low-pass filter;

[0018] The low-pass filter is arranged between the external voltage control circuit and the terahertz radiation source array.

[0019] Optionally, the photonic crystal resonant cavity comprises: a dielectric substrate into which point defects are introduced;

[0020] Air holes are periodically arranged on the dielectric substrate.

[0021] Optionally, the coherent terahertz radiation source further includes: a coupling capacitor;

[0022] The coupling capacitor is electrically connected between the terahertz radiation source array and the photonic crystal resonant cavity.

[0023] Optionally, the terahertz radiation source array includes: a first resistor, a second inductor and a third capacitor;

[0024] The first end of the first resistor is connected to the first end of the diode unit, the second end of the first resistor is connected to the first end of the coupling capacitor, the first end of the second inductor is connected to the second end of the diode and is grounded, the second end of the second inductor is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the coupling capacitor.

[0025] Optionally, the photonic crystal resonant cavity comprises: a second resistor, a third inductor and a fourth capacitor;

[0026] The first end of the second resistor is connected to the first end of the coupling capacitor, the first end of the third inductor is connected to the second end of the coupling capacitor, the second end of the third inductor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is connected to the second end of the second resistor.

[0027] In addition, to achieve the above-mentioned object, the present invention further provides a communication system, which includes the coherent terahertz radiation source as described above.

[0028] The present invention provides a coherent terahertz radiation source, which comprises: a metal reflection surface, a terahertz radiation source array composed of diodes, and a photonic crystal resonant cavity, which are sequentially arranged in a metal cavity from bottom to top; the metal reflection surface is located at the bottom of the metal cavity, the terahertz radiation source array and the photonic crystal resonant cavity are fixed in the side wall groove of the metal cavity, and the terahertz radiation source array is placed between the photonic crystal resonant cavity and the metal reflection surface; the terahertz signal generated by the terahertz radiation source array in the middle is radiated toward the metal reflection surface at the bottom through an on-chip slot antenna, and the metal reflection surface couples the terahertz signal except for metal loss to the photonic crystal resonant cavity at the top; the photonic crystal resonant cavity locks the frequency and phase of each diode unit of the terahertz radiation source array, and radiates the terahertz signal after coherent power synthesis into space. By coupling the terahertz radiation source array with the photonic crystal resonant cavity, the effect of locking the terahertz radiation frequency is achieved, and then a miniaturized high-power coherent terahertz radiation source is realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] 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.

[0030] Figure 1It is a schematic structural diagram of a first embodiment of a coherent terahertz radiation source of the present invention;

[0031] Figure 2 It is a schematic diagram of the resonator signal frequency in the prior art;

[0032] Figure 3 It is a schematic diagram of the radiation source signal frequency in the prior art;

[0033] Figure 4 It is a schematic structural diagram of a terahertz radiation source array in the first embodiment of a coherent terahertz radiation source of the present invention;

[0034] Figure 5 It is a schematic diagram of the structure of the photonic crystal resonant cavity in the first embodiment of the coherent terahertz radiation source of the present invention;

[0035] Figure 6 It is a structural schematic diagram of the RTD device in the second embodiment of the coherent terahertz radiation source of the present invention;

[0036] Figure 7 It is a DC characteristic curve diagram of the RTD device in the second embodiment of the coherent terahertz radiation source of the present invention;

[0037] Figure 8 is an equivalent circuit diagram of a terahertz radiation source array in the second embodiment of a coherent terahertz radiation source of the present invention;

[0038] Fig. 9 FIG. 4 is an equivalent circuit diagram of the RTD device in the third embodiment of the coherent terahertz radiation source of the present invention.

[0039] 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

[0040] 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.

[0041] 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.

[0042] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) 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.

[0043] 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.

[0044] Reference Figure 1 , Figure 1 FIG. 1 is a schematic structural diagram of a first embodiment of a coherent terahertz radiation source according to the present invention. Figure 1 As shown, in this embodiment, the coherent terahertz radiation source includes: a metal reflection surface 10, a terahertz radiation source array 20 composed of diodes, and a photonic crystal resonant cavity 30, which are sequentially arranged in the metal cavity 40 from bottom to top.

[0045] The metal cavity 40 can be divided into two parts, namely, a side wall with a groove and an upper radiation opening. The metal reflective surface 10 is located at the bottom of the metal cavity 40, the terahertz radiation source array 20 and the photonic crystal resonant cavity 30 are fixed in the side wall groove of the metal cavity 40, and the terahertz radiation source array 20 is placed between the photonic crystal resonant cavity 30 and the metal reflective surface 10.

[0046] Since the terahertz RTD radiation source generally uses a metal LC resonator and RTD to form a resonant circuit to generate a terahertz signal, and the metal LC resonator has a large metal ohmic loss in the terahertz frequency band, the quality factor (Q) value of the metal LC resonator is usually in the tens, which easily causes frequency jitter problems, thereby limiting the stability of the terahertz wireless communication system. The frequency jitter of the terahertz RTD radiation source unit will cause incoherent radiation problems, with multiple radiation frequencies, affecting the synthesis efficiency of the radiation power, thereby limiting the room for improvement in coherent radiation power, and then affecting the air interface transmission distance of the terahertz wireless communication system. Figure 2 and Figure 3 As shown, Figure 2 It is a schematic diagram of the resonator signal frequency in the prior art; Figure 3 It is a schematic diagram of the radiation source signal frequency in the prior art. Figure 2The output power of the metal LC resonator is 3MHz in resolution bandwidth (RBW), 10kHz in video bandwidth (VBW), 50ms in sweep time, and oscillation frequency (f osc ) changes with the signal frequency (Intermediate frequency) when ) is 0.55THz. Figure 3 The middle is the curve of the radiation source signal intensity (Intensity) changing with the signal frequency (Frequency) using a low-Q LC metal resonator.

[0047] In this solution, the terahertz signal generated by the terahertz radiation source array 20 in the middle is radiated toward the metal reflection surface 10 at the bottom through the on-chip slot antenna. Since the metal reflection surface 10 has a total reflection characteristic, the terahertz signal except for the metal loss can be coupled to the photonic crystal resonant cavity 30 at the top. The photonic crystal resonant cavity 30 is used to lock the frequency and phase of each diode unit of the terahertz radiation source array 20, and the terahertz signal after the coherent power synthesis is radiated into space (the radiation area refers to Figure 1 of 60).

[0048] It should be noted that the terahertz radiation source array includes a plurality of structures composed of diodes and antennas 201. The diodes may be RTD devices, or other diodes with negative resistance characteristics, including but not limited to Gunn diodes, Impact Ionization Avalanche Transit Time (IMPATT) diodes, etc., or other types of diodes such as Schottky diodes, Fermi level controllable barrier diodes, etc. Figure 4 As shown, Figure 4 Schematic diagram of the structure of the terahertz radiation source array in the first embodiment of the coherent terahertz radiation source of the present invention.

[0049] It should be understood that a negative resistance diode has a negative resistance phenomenon that can decrease as the DC bias voltage increases, so under working conditions it can offset the loss in the resonant circuit and achieve the emission of terahertz signals.

[0050] Furthermore, the photonic crystal resonant cavity comprises: a dielectric substrate 301 with point defects introduced; and air holes 302 are periodically arranged on the dielectric substrate. Figure 5 As shown, Figure 5 Schematic diagram of the structure of the photonic crystal resonant cavity in the first embodiment of the coherent terahertz radiation source of the present invention.

[0051] It should be noted that photonic crystal is an artificial structure with periodic changes in the refractive index of the material. It has the important physical characteristics of the photonic band gap. Electromagnetic waves within a specific frequency range cannot propagate in the photonic crystal. Because electromagnetic waves within a specific frequency range within the photonic band gap cannot propagate in the photonic crystal, point defects are introduced to make the electromagnetic waves reflect back and forth around the point defects, thereby confining the electromagnetic waves to this point defect, and then realizing the photonic crystal resonant cavity. Introducing point defects in the dielectric substrate of periodically arranged air holes can realize a resonant cavity with high quality Q value. The dielectric substrate of the terahertz photonic crystal resonant cavity can be, but is not limited to, high-resistance silicon, metal, etc.

[0052] It should be understood that the distance between the terahertz radiation source array 20 and the metal reflective surface 10 can be set to 1 / 4 of the terahertz radiation wavelength to further enhance the terahertz radiation effect. The processing technology of the metal cavity 40 adopts but is not limited to precision machining, 3D printing, etc.

[0053] Furthermore, the coherent terahertz radiation source may further include: a metal bond 50. The metal bond may be used to form an ohmic connection between an external voltage control circuit (i.e., a DC power supply) and the terahertz radiation source array 20 to power the terahertz radiation source array 20.

[0054] In this embodiment, the coherent terahertz radiation source may include: a metal reflective surface, a terahertz radiation source array composed of diodes, and a photonic crystal resonant cavity, which are sequentially arranged in the metal cavity from bottom to top; the metal reflective surface is located at the bottom of the metal cavity, the terahertz radiation source array and the photonic crystal resonant cavity are fixed in the side wall groove of the metal cavity, and the terahertz radiation source array is placed between the photonic crystal resonant cavity and the metal reflective surface; the terahertz signal generated by the terahertz radiation source array in the middle is radiated toward the metal reflective surface at the bottom through the on-chip slot antenna, and the metal reflective surface couples the terahertz signal except for the metal loss to the photonic crystal resonant cavity at the top; the photonic crystal resonant cavity locks the frequency and phase of each diode unit of the terahertz radiation source array, and radiates the terahertz signal after the coherent power synthesis into space. By coupling the terahertz radiation source array with the photonic crystal resonant cavity, the effect of locking the terahertz radiation frequency is achieved, and then a miniaturized high-power coherent terahertz radiation source is realized.

[0055] 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 6 , Figure 6The schematic diagram of the structure of the RTD device in the second embodiment of the coherent terahertz radiation source of the present invention. In this embodiment, the RTD device is used as an example in the terahertz radiation source array. The RTD can be a high-speed nano device that works by using the quantum resonance tunneling effect. RTD generally adopts a quantum well structure composed of AlAs / InGaAs / AlAs, in which AlAs and InGaAs constitute barriers and quantum wells, respectively. Among them, the emitter and collector are emitters and collectors, respectively. QW1 and E QW2 are the first energy level and the second energy level of the quantum well, EF and EC are the Fermi level of the emitter and the bottom energy level of the conduction band, respectively. bias Represents the DC bias voltage variable loaded across the RTD. V b Represents the voltage V loaded across the RTD bias Just make the first ground state energy level E in the quantum well QW1 and the emitter Fermi level E F At 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.

[0056] It should be understood that 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 7 As shown, Figure 7 This is a DC characteristic curve diagram of the RTD device in the second embodiment of the coherent terahertz radiation source of the present invention. In the figure, the current Current in the gray area decreases as the voltage Voltage increases.

[0057] Further, refer to Figure 8 , Figure 8 The equivalent circuit diagram of the terahertz radiation source array in the second embodiment of the coherent terahertz radiation source of the present invention is shown in FIG. RTD ) and the first capacitor (C RTD), the antenna includes: a first inductor (L ANT )、Second capacitor (C ANT ) and the second conductance (G ANT ); the negative conductance is connected in parallel with the first capacitor, and the first inductance, the second capacitor and the second conductance are connected in parallel.

[0058] It should be noted that the working condition of the terahertz radiation source array composed of RTD devices is that the absolute value of the negative conductance of the RTD is greater than the absolute value of the second conductance in the antenna, that is, under working conditions, the loss in the resonant circuit can be offset.

[0059] Furthermore, the coherent terahertz radiation source further includes: a low pass filter (LPF); the low pass filter is arranged between the external voltage control circuit and the terahertz radiation source array. The diffusion of the terahertz wave can be suppressed by introducing the low pass filter between the external voltage control circuit and the terahertz radiation source array, that is, the high-speed baseband signal can pass through the low pass filter. The operating frequency of the terahertz radiation source array is 1 / (2*pi*sqrt(L ANT (C ANT +C RTD )).

[0060] In this embodiment, the terahertz radiation source array includes: an RTD device and an antenna; the RTD device is electrically connected in series with the antenna; the RTD device is used to generate a terahertz signal with reduced resonance loss, and transmit the terahertz signal to the antenna for radiation. The RTD device includes: a negative conductance and a first capacitor, and the antenna includes: a first inductor, a second capacitor, and a second conductance; the negative conductance is connected in parallel with the first capacitor, and the first inductor, the second capacitor, and the second conductance are connected in parallel. The loss of the resonant circuit is offset by the negative resistance phenomenon of the RTD device, and the RTD has a smaller intrinsic capacitance value, which makes it easier to achieve the emission of terahertz signals.

[0061] 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. Fig. 9 , Fig. 9 FIG. 1 is an equivalent circuit diagram of the RTD device in the third embodiment of the coherent terahertz radiation source of the present invention. In this embodiment, the coherent terahertz radiation source further includes: a coupling capacitor C0; the coupling capacitor C0 is electrically connected and arranged between the terahertz radiation source array 20 and the photonic crystal resonant cavity 30.

[0062] It should be noted that the terahertz radiation source array includes: a first resistor, a second inductor and a third capacitor (refer to R1, L1 and C1 in the figure, the values ​​in the subsequent calculation formula also correspond to R1, L1 and C1); the first end of the first resistor is connected to the first end of the diode unit, the second end of the first resistor is connected to the first end of the coupling capacitor, the first end of the second inductor is connected to the second end of the diode and grounded, the second end of the second inductor is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the coupling capacitor.

[0063] Furthermore, the photonic crystal resonant cavity includes: a second resistor, a third inductor and a fourth capacitor (refer to R2, L2 and C2 in the figure, the values ​​in the subsequent calculation formula also correspond to R2, L2 and C2); the first end of the second resistor is connected to the first end of the coupling capacitor, the first end of the third inductor is connected to the second end of the coupling capacitor, the second end of the third inductor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is connected to the second end of the second resistor.

[0064] It should be noted that the RTD device, together with R1, L1 and C1, can form a terahertz radiation source of a traditional low-Q metal LC resonator, and can form a high-Q Fano resonant cavity by coupling with a high-Q photonic crystal resonant cavity through a coupling capacitor C0.

[0065] It should be understood that assuming the negative resistance of the RTD |R RTD |≥R1+R2, which means the oscillation condition of the radiation source is met. According to Kirchhoff's voltage law, the differential equation of the equivalent circuit of the RTD radiation source is obtained:

[0066]

[0067] Among them, C e1 and C e2 is the sum of the series capacitances of the coupling capacitor C0, C1 and C2, respectively, and we have:

[0068]

[0069] Substituting the above two equations into the solution, we can get the radiation power of the RTD terahertz radiation source array:

[0070]

[0071] Where V is the voltage v(t) amplitude of the RTD radiation source, is the angular frequency of the RTD radiation source.

[0072] It should be understood that according to the solved radiation power The radiation frequency of a coherent terahertz radiation source can be changed by coupling a terahertz radiation source array composed of RTDs to a photonic crystal resonant cavity, that is, coupling the terahertz radiation source array with a high-Q photonic crystal resonant cavity can achieve the effect of locking the terahertz radiation frequency.

[0073] In this embodiment, by setting a coupling capacitor, an electrical connection is set between the terahertz radiation source array and the photonic crystal resonant cavity. The terahertz radiation source array may include: a first resistor, a second inductor and a third capacitor; and the photonic crystal resonant cavity includes: a second resistor, a third inductor and a fourth capacitor. The above equivalent circuit can prove that the coupling of the terahertz radiation source array and the high-Q photonic crystal resonant cavity can achieve the effect of locking the terahertz radiation frequency, thereby realizing a miniaturized high-power coherent terahertz radiation source.

[0074] In addition, in order to achieve the above purpose, an embodiment of the present invention further proposes a communication system. Since the communication system includes the above coherent terahertz radiation source, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be described one by one here.

[0075] 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.

[0076] Obviously, the described embodiments are only some embodiments of the present invention, not all 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.

[0077] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) 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.

[0078] 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.

Claims

1. A coherent terahertz radiation source, characterized in that: The coherent terahertz radiation source comprises: a metal reflection surface, a terahertz radiation source array composed of diodes and a photonic crystal resonant cavity, which are sequentially arranged in the metal cavity from bottom to top; The metal reflective surface is located at the bottom of the metal cavity, the terahertz radiation source array and the photonic crystal resonant cavity are fixed in the side wall groove of the metal cavity, and the terahertz radiation source array is placed between the photonic crystal resonant cavity and the metal reflective surface; The terahertz signal generated by the terahertz radiation source array in the middle is radiated toward the metal reflection surface at the bottom through the on-chip slot antenna, and the metal reflection surface couples the terahertz signal except for metal loss to the photonic crystal resonant cavity at the top; The photonic crystal resonant cavity locks the frequency and phase of each diode unit of the terahertz radiation source array, and radiates the terahertz signal after coherent power synthesis into space.

2. The coherent terahertz radiation source according to claim 1, characterized in that: The terahertz radiation source array includes: an RTD device and an antenna; The RTD device is electrically connected in series with the antenna; The RTD device is used to generate a terahertz signal with reduced resonance loss, and transmit the terahertz signal to the antenna for radiation.

3. The coherent terahertz radiation source according to claim 2, characterized in that: The RTD device includes: a negative conductance and a first capacitor, and the antenna includes: a first inductance, a second capacitor and a second conductance; The negative conductance is connected in parallel with the first capacitor, and the first inductance, the second capacitor, and the second conductance are connected in parallel.

4. The coherent terahertz radiation source according to claim 1, characterized in that: The coherent terahertz radiation source includes: metal bonding; The metal bonding is used to form an ohmic connection between an external voltage control circuit and the terahertz radiation source array to supply power to the terahertz radiation source array.

5. The coherent terahertz radiation source according to claim 4, characterized in that: The coherent terahertz radiation source further includes: a low-pass filter; The low-pass filter is arranged between the external voltage control circuit and the terahertz radiation source array.

6. The coherent terahertz radiation source according to claim 1, characterized in that: The photonic crystal resonant cavity comprises: a dielectric substrate into which point defects are introduced; Air holes are periodically arranged on the dielectric substrate.

7. The coherent terahertz radiation source according to claim 1, characterized in that: The coherent terahertz radiation source further includes: a coupling capacitor; The coupling capacitor is electrically connected between the terahertz radiation source array and the photonic crystal resonant cavity.

8. The coherent terahertz radiation source according to claim 7, characterized in that: The terahertz radiation source array comprises: a first resistor, a second inductor and a third capacitor; The first end of the first resistor is connected to the first end of the diode unit, the second end of the first resistor is connected to the first end of the coupling capacitor, the first end of the second inductor is connected to the second end of the diode and is grounded, the second end of the second inductor is connected to the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the coupling capacitor.

9. The coherent terahertz radiation source according to claim 8, characterized in that: The photonic crystal resonant cavity comprises: a second resistor, a third inductor and a fourth capacitor; The first end of the second resistor is connected to the first end of the coupling capacitor, the first end of the third inductor is connected to the second end of the coupling capacitor, the second end of the third inductor is connected to the first end of the fourth capacitor, and the second end of the fourth capacitor is connected to the second end of the second resistor.

10. A communication system, characterized in that: The communication system comprises the coherent terahertz radiation source according to any one of claims 1 to 9.

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