Non-reciprocal high-shielding ultra-wideband X-band energy selection surface unit and system

Abstract

The invention discloses a non-reciprocal high-shielding ultra-wideband X-band energy selection surface unit and system. The system comprises the design of an X-band energy selection surface, and a coupler, a power detection circuit, a quick response switch and a biasing circuit which are designed for realizing non-reciprocal transmission. The X-band energy selection surface comprises a three-layer unit structure in array periodic arrangement, straight microstrip lines are arranged at the upper and lower ends of a top layer and a bottom layer to serve as bias circuits, the coupler comprises a straight microstrip and an arc-shaped microstrip which are bilaterally symmetrical, and the power detection circuit is a diode detection circuit. The non-reciprocal high-shielding ultra-wideband X-band energy selection surface unit system has very low insertion loss for low-power signals with different incident angles in a transceiving link, so that lossless transmission of useful signals is facilitated; high-power signals in a transmitting link are transmitted normally, and high-power signals in a receiving link are shielded and protected, so that the self-adaptive protection array for non-reciprocal transmission of receiving and transmitting signals in a radio frequency front-end transceiving link is designed.

Description

Technical Field

[0001] The invention relates to the field of high-power electromagnetic pulse protection, and in particular to a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit and system. Background Art

[0002] Electronic devices have always been facing the problem of strong electromagnetic threats. Protecting electronic devices from strong electromagnetic interference and damage is a vital task. In order to resist the potential damage to electronic devices caused by strong electromagnetic threats such as strong electromagnetic pulses (EMP) or high-power microwaves (HPM), some protective measures need to be taken. Some traditional protection measures such as limiters and frequency selective surfaces can be used to limit the transmission of pulses. However, since limiters not only affect the transmission of incident high-power signals, but also affect the passage of normal signals, they are increasingly unsuitable for the protection of high-power microwaves. Although frequency selective surfaces are a reliable signal transmission method, the electromagnetic wave energy size in its passband is not selective, and it cannot block the interference signal in the passband, so it cannot effectively block the transmission of high-power pulses. To overcome the above problems, a self-driven protection structure directly triggered by a high-power signal, namely an energy selective surface, is proposed. The energy selective surface can ensure that the device can normally transmit low-power working signals, and on the other hand, it can prevent useless high-power incident signals from entering the subsequent equipment, preventing damage to the subsequent equipment, and playing a protective role.

[0003] In addition, based on the working principle of the transceiver component, not only low-power signals need to be transmitted normally and high-power signals need to be shielded, but at the same time, when high-power useful signals need to be transmitted, the ordinary energy selection surface loses its effect and will also shield the transmission of useful high-power working signals. The non-reciprocal X-band energy selective surface unit improves the protection capability against high-power electromagnetic pulses, overcomes the limitations of traditional protection methods, and expands the practicality of non-reciprocal transmission of high-power signals. It provides a new solution for the stable operation of electronic equipment and systems. However, the current solution cannot work in the entire X-band and has low shielding effectiveness. The energy selective surface in the patent with the announcement number "CN 114824812B" works at 6-10GHz, with a shielding effectiveness greater than 20dB, the energy selective unit and surface in the patent with the announcement number "CN 113131221 B" works at 8-10GHz, with a shielding effectiveness greater than 10dB, and the energy selective surface in the patent with the announcement number "CN 115566437 B" works at 8.55-12.95GHz, with a shielding effectiveness greater than 15dB. These patents do not fully work in the entire X-band, and the shielding effectiveness is low in the entire frequency band. Therefore, it is of great significance to strengthen the research on non-reciprocal, high-shielding, dual-polarization, and ultra-wideband energy selective surfaces in the X-band.

[0004] Therefore, this paper proposes a non-reciprocal energy selective surface unit system. Through the bias circuit, a reverse bias voltage is applied to both ends of the PIN diode in the energy selective surface, so that the PIN tube is in a reverse bias cut-off state. At this time, the low-power electromagnetic waves in the transceiver link are allowed to be transmitted normally and the high-power useful electromagnetic waves in the transmission link are allowed to be transmitted normally. When an external high-power signal is incident in the receiving link, the signal is coupled to the power detection circuit through the coupler and exceeds the set protection threshold voltage, the output DC signal will quickly respond to the switch to short-circuit the bias circuit, and the PIN diode in the energy selective surface will work normally, shielding the high-power signal from entering, and realizing the non-reciprocal transmission of the guided electromagnetic wave in the transceiver link system. Finally, a non-reciprocal protection array that can be placed in the RF front end to protect the downstream equipment is obtained. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention proposes a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit and system, which has the functions of low insertion loss transmission of low-power signals in the full frequency band, shielding protection of useless high-power signals, and normal low insertion loss transmission of useful high-power signals. At the same time, it can quickly respond and process different power signals at the same time, and the transmission performance changes with the change of the incident field strength.

[0006] The technical solution to achieve the purpose of the present invention is:

[0007] A non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit comprises a first dielectric substrate, a second dielectric substrate and a third dielectric substrate, wherein the three dielectric substrates are all square and are provided with metal units, wherein every two dielectric substrates are separated by an equidistant air gap layer, wherein:

[0008] The metal unit on the front side of the first dielectric substrate at the top layer and the metal unit on the back side of the third dielectric substrate at the bottom layer are both symmetrical structures, including a plurality of metal small units, the plurality of metal small units are connected to each other through a first rectangular patch and a PIN tube, and the metal small unit close to the edge of the dielectric substrate is connected to the edge of the dielectric substrate through the first rectangular patch, the PIN tube and the second rectangular patch;

[0009] The metal unit located on the front side of the second dielectric substrate of the middle layer includes two rectangular metal patches which are arranged vertically and cross-shaped and have equal length and width.

[0010] Preferably, each metal unit includes a square metal patch and four trapezoidal metal patches, the four trapezoidal metal patches are distributed around the square metal patch, the long bottom side of the trapezoidal metal patch is equal to the side length of the square metal patch, and the trapezoidal metal patch is connected to the square metal patch.

[0011] Preferably, the metal unit on the front side of the first dielectric substrate includes nine evenly distributed metal small units, and the metal unit on the back side of the third dielectric substrate includes four evenly distributed metal small units.

[0012] Preferably, the left and right edges of the first dielectric substrate and the third dielectric substrate are connected to the closest metal small unit through the second rectangular patch, the PIN tube and the first rectangular patch connected in sequence, and the upper and lower edges of the first dielectric substrate and the third dielectric substrate are connected to the closest metal small unit through the second rectangular patch, the first rectangular patch and the PIN tube connected in sequence.

[0013] Preferably, the side length p of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate is between 4-6 mm, all of them are made of F4BK225, the dielectric constant is 2.25, the thickness h is set to 0.25 mm, and the interval between adjacent dielectric substrates is set to 1.5 mm.

[0014] Preferably, the length of the first rectangular metal patch and the width c of the second rectangular metal patch are between 0.1-0.2 mm, the width b of the first rectangular metal patch is between 0.1-0.2 mm, the length of the second rectangular metal patch 103 is a, between 0.15-0.4 mm, and the length of the PIN tube is between 0.1-0.4 mm.

[0015] Preferably, the short bottom side of the trapezoidal metal patch on the first dielectric substrate is equal to the length of the first rectangular metal patch, between 0.1-0.2 mm, the height is between 0.15-0.4 mm, and the side length of the square metal patch is between 0.4-1 mm.

[0016] Preferably, the short bottom side of the trapezoidal metal patch on the second dielectric substrate is between 0.3-0.6 mm, the height is between 0.3-0.5 mm, and the side length of the square metal patch is between 0.5-1.5 mm.

[0017] Preferably, the two rectangular metal patches on the second dielectric substrate have the same width, which is between 0.05-0.25 mm.

[0018] A non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system comprises a plurality of periodically arranged X-band energy selective surface units, a coupler, a power detection circuit, a fast response switch and a bias circuit.

[0019] The coupler circuit is located after the phased array antenna in the receiving link, and couples the detection signal from the input end to the power detection circuit, wherein the input end and the through end are connected by a fifth rectangular metal patch, and the coupling end and the isolation end are connected by a sixth rectangular metal patch and an arc-shaped metal patch;

[0020] The power detection circuit is located after the coupler circuit and outputs the coupled power signal as a DC voltage signal for subsequent MOS tube switch conduction voltage;

[0021] The fast response switch is a MOS tube, which is controlled by the DC voltage output by the power detection circuit. When the DC voltage output is greater than the conduction voltage, the MOS tube is turned on, short-circuiting the bias circuit, so that the energy selection surface works normally and the high-power signal is shielded from transmission;

[0022] The bias circuit is located at the upper and lower edges of the dielectric substrate of the top and bottom layers of the X-band energy selective surface unit, and is respectively connected to the positive and negative electrodes of the PIN tubes in each column. When a reverse bias voltage is applied, all PIN tubes are reverse biased and cut off, the energy selective surface is in a closed state, low-power signals are transmitted normally, and high-power signals in the transmission link are transmitted normally.

[0023] Compared with the prior art, the technical effects of the present invention are:

[0024] (1) The present invention has a symmetrical structure and is easy to process. It has very low insertion loss and ultra-high shielding effectiveness in the X-band and meets the TE and TM dual-polarization angle stability of 0°-60°.

[0025] (2) The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit of the present invention can control the on and off states of the PIN tube to cause the resonance point of the overall equivalent circuit to undergo a frequency shift; when a low-power electromagnetic wave is incident, the equivalent circuit is a bandpass filter in the X-band, and the low-power electromagnetic wave can be transmitted with low insertion loss; when a high-power electromagnetic wave is incident, the resonance point of the equivalent circuit undergoes a frequency shift, and it is a bandstop filter in the X-band, so that high-power electromagnetic waves are highly shielded when incident; when a useful high-power electromagnetic wave is emitted, a reverse bias voltage is applied to the PIN tube through a bias circuit, so that the PIN tube is forced to reverse bias and cut off, and at this time, the equivalent circuit is still a bandpass filter in the X-band, so that useful high-power signals can be normally transmitted with low insertion loss; the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit not only improves the high-power electromagnetic pulse protection capability and overcomes the limitations of traditional protection methods, but also increases the ability to allow the transmission of high-power signals, thereby improving the role of a protection device as a radio frequency front-end transceiver component.

[0026] (3) When faced with the threat of high-power electromagnetic pulses, the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit of the present invention not only distinguishes the power level of the incident signal normally, but also adds the function of transmitting high-power signals, thereby ensuring that the electronic equipment can normally receive and transmit working signals and maintain its functionality; at the same time, it prevents signals with power exceeding the threshold from passing through the surface to damage subsequent devices, and provides adaptive protection when the designed threshold is exceeded.

[0027] (4) The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit of the present invention is a strong electromagnetic space adaptive protection technology, which realizes adaptive protection by frequency shifting the resonance point of the equivalent circuit. The resonance point will change the capacitance of the PIN tube according to the change of the incident power, thereby automatically shifting the frequency; when a low-power signal is irradiated, the PIN tube in the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is capacitive, and the X-band equivalent circuit is a bandpass filter circuit, so that electromagnetic waves can pass normally; when a high-power signal is irradiated, the PIN tube of the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is a small resistor, and the X-band equivalent circuit is a band-stop filter circuit, which shields the incident signal, thereby effectively preventing high-power electromagnetic damage to the subsequent circuit and avoiding breakdown or damage to the subsequent system equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of an energy selective surface in one embodiment of the present invention.

[0029] Figure 2 Schematic diagram of the top structure of the energy selective surface in one embodiment of the present invention.

[0030] Figure 3 Schematic diagram of the intermediate layer structure of the energy selective surface in one embodiment of the present invention.

[0031] Figure 4 It is a schematic diagram of the underlying structure of the energy selective surface in one embodiment of the present invention.

[0032] Figure 5 Schematic diagram of the structure of a coupler in one embodiment of the present invention.

[0033] Figure 6 Schematic diagram of a power detection circuit in one embodiment of the present invention.

[0034] Figure 7 This is an equivalent circuit diagram of a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit when a low-power signal is incident thereon according to an embodiment of the present invention.

[0035] Figure 8 This is an equivalent circuit diagram of a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit when a high-power signal is incident on it according to an embodiment of the present invention.

[0036] Fig. 9 It is a schematic diagram of the transmission coefficient of the equivalent circuit and full-wave simulation of a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit when low-power signal and high-power signal are incident in one embodiment of the present invention.

[0037] Fig.10It is a schematic diagram of the transmission coefficients of a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit under TE polarization at different angles θ when a low-power signal and a high-power signal are incident according to an embodiment of the present invention.

[0038] Fig.11 It is a schematic diagram of the transmission coefficients of a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit under TM polarization at different angles θ when a low-power signal and a high-power signal are incident according to an embodiment of the present invention.

[0039] Fig.12 Schematic diagram of insertion loss and coupling degree of a coupler in one embodiment of the present invention.

[0040] Fig.13 It is a schematic diagram of input power and output DC voltage after passing through a coupler and a power detection circuit in one embodiment of the present invention.

[0041] Numbers in the figure:

[0042] 100, first dielectric substrate; 101, top metal unit; 102, first rectangular metal patch; 103, second rectangular metal patch; 104, top PIN diode; 105, top small square metal patch; 106, top trapezoidal metal patch; 107, seventh rectangular metal patch;

[0043] 200, second dielectric substrate; 201, middle layer metal patch; 202, rectangular horizontal metal patch; 203, rectangular vertical metal patch;

[0044] 300, third dielectric substrate; 301, bottom metal patch; 302, third rectangular metal patch; 303, fourth rectangular metal patch; 304, bottom trapezoidal metal patch; 305, bottom small square metal patch; 306, bottom PIN diode; 307, eighth rectangular metal patch;

[0045] 400, air barrier;

[0046] 500, fifth rectangular metal patch; 501, sixth rectangular metal patch; 502, arc-shaped metal patch. DETAILED DESCRIPTION

[0047] In order to more clearly explain the embodiments of the present invention or the technical solutions of the prior art, the following briefly introduces the drawings required for use in the embodiments. 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. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0048] When describing the embodiments of the present invention, the terms "top", "bottom", "up", "down", "left" and "right" express the orientation or position relationship based on the orientation or position relationship shown in the relevant drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0049] In addition, in the present invention, the descriptions such as "first", "second", etc. 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" or "second" may explicitly or implicitly include at least one of the features.

[0050] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments cannot be described one by one here, but the embodiments of the present invention are not therefore limited to the following embodiments.

[0051] Combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 As shown, according to one embodiment of the present invention, a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system is provided, including an X-band energy selective surface and a coupler, a power detection circuit, a fast response switch and a bias circuit designed to achieve non-reciprocal transmission.

[0052] The X-band energy selective surface includes a plurality of sub-units arranged in an array, is located at the front end of the entire link system, and has the function of low insertion loss transmission or shielding transmission of space electromagnetic waves.

[0053] The coupler circuit is located after the phased array antenna in the receiving link, and couples the detection signal from the input end to the power detection circuit. Changing different coupling degrees can control the protection threshold DC voltage output of the power detection circuit; other main signals are transmitted from the through end with low insertion loss to the subsequent limiting circuit.

[0054] The power detection circuit is located after the receiving link coupler circuit, and is mainly a diode rectifier circuit, which outputs the coupled power signal as a DC voltage signal for subsequent MOS tube switch conduction voltage.

[0055] The fast response switch is controlled by the DC voltage output by the power detection circuit. When the DC voltage output is greater than the conduction voltage, the MOS tube is turned on, short-circuiting the bias circuit, so that the energy selection surface works normally and the high-power signal is shielded from transmission.

[0056] The bias circuit is located on the upper and lower sides of the top and bottom layers of the energy selection surface, and is respectively connected to the positive and negative electrodes of each column of PIN tubes. An external reverse bias voltage is applied to reverse-bias all PIN tubes so that the energy selection surface is in a closed state, low-power signals are transmitted normally, and high-power signals in the transmission link are transmitted normally.

[0057] The X-band energy selective surface comprises three layers of dielectric substrates which are sequentially isolated by air, namely a first dielectric substrate 100, a second dielectric substrate 200, a third dielectric substrate 300, a top metal unit 101, a middle metal unit 201, a bottom metal unit 301, a top PIN diode 104 of the top metal unit, a bottom PIN diode 306 of the bottom metal unit, and air spaces 400 are filled between adjacent dielectric substrates; in a preferred embodiment of the present invention, the first dielectric substrate 100, the second dielectric substrate 200 and the third dielectric substrate 300 are made of the same material, have the same thickness, and have the same air spacing between two adjacent dielectric substrates.

[0058] Reference Figure 2 In one embodiment, a top metal unit 101 is disposed on the first dielectric plate 100 located on the top layer. The structure of the top metal unit 101 is symmetrical on all sides. The top metal unit 101 structure includes a small unit composed of a central square metal patch 105 and a trapezoidal metal patch 106, and a first rectangular metal patch 102 and a second rectangular metal patch 103 distributed on all sides. The top PIN diodes 104 are loaded horizontally and vertically between the first rectangular metal patches 102.

[0059] In one embodiment, the top metal unit includes nine square metal patches 105, thirty-six trapezoidal patches 106 and forty-eight rectangular metal patches. The square metal patches are located at the center of the front of the first dielectric substrate and are spread out equidistantly around. Each square metal patch is connected to a trapezoidal patch on all sides. A square metal patch and four trapezoidal metal patches on all sides form a small unit. The top dielectric substrate includes nine small units in total. Each small unit is surrounded by a rectangular metal patch, which is a first rectangular metal patch. Every two adjacent small unit metal patches are connected through two first rectangular metal patches and a PIN tube. The outer sides of the other eight small unit metal patches except the center are connected to the edge of the dielectric substrate through a first rectangular metal patch, a PIN tube and a second rectangular metal patch. The rectangular patches perpendicular to each other are the first rectangular patch 102 and the second rectangular patch 103.

[0060] Reference Figure 3In one embodiment, an intermediate layer metal unit 201 is provided on the second dielectric plate 200 located in the intermediate layer. The structure of the intermediate layer metal unit 201 is centrally symmetrical. The structure of the intermediate layer metal unit 201 includes a rectangular horizontal metal patch 202 and a rectangular vertical metal patch 203 vertically distributed in a cross shape.

[0061] Reference Figure 4 In one embodiment, a bottom metal unit 301 is disposed on the back side of the third dielectric plate 300 located at the bottom layer. The structure of the bottom metal unit 301 is symmetrical on all sides. The structure of the bottom metal unit 301 includes a small unit composed of a central square metal patch 305 and a trapezoidal metal patch 304, and a third rectangular metal patch 302 and a fourth rectangular metal patch 303 distributed on all sides. The bottom PIN diodes 306 are loaded horizontally and vertically in the intervals between the third rectangular metal patches 302.

[0062] The metal unit on the reverse side of the third dielectric substrate at the bottom layer in the energy selection surface is similar in structure design to the metal unit on the front side of the first dielectric substrate at the top layer. The bottom metal unit includes four square metal patches 305, sixteen trapezoidal metal patches 304 and twenty-four rectangular metal patches. The square metal patches 305 are located at the center of the front side of the first dielectric substrate and are spread out equidistantly around. Each square metal patch 305 is connected to a trapezoidal metal patch 304 on all sides. A square metal patch 305 and the four trapezoidal metal patches 304 on all sides form a small unit. The bottom dielectric substrate contains a total of 4 small units, and each small unit is surrounded by a first rectangular metal patch; every two adjacent small unit metal patches are connected through two third rectangular metal patches 302 and a bottom PIN diode 306. The left and right sides of each small unit metal patch are connected to the edge of the dielectric substrate through a third rectangular metal patch 302, a bottom PIN diode 306 and a fourth rectangular metal patch 303. The rectangular patches perpendicular to each other are the third rectangular metal patch 302 and the fourth rectangular metal patch 303.

[0063] Reference Figure 2 and Figure 4 ,The lateral and vertical directions of the PIN diodes of the top and bottom metal units are consistent.

[0064] According to one embodiment of the present invention, the non-reciprocal high-shielding ultra-wideband X-band energy selection surface unit of the present invention is a strong electromagnetic space adaptive protection technology, which realizes adaptive protection by frequency shifting the resonance point of the equivalent circuit, and its resonance point will change the capacitance of the PIN tube according to the change of the incident power, thereby automatically shifting the frequency. When a low-power signal is irradiated, the PIN tube in the non-reciprocal high-shielding ultra-wideband X-band energy selection surface unit is capacitive, and the X-band equivalent circuit is a bandpass filter circuit, and the electromagnetic wave can pass normally; when a high-power signal is irradiated, the PIN tube of the non-reciprocal high-shielding ultra-wideband X-band energy selection surface unit is a small resistor, and the X-band equivalent circuit is a band-stop filter circuit, which shields the incident signal, thereby effectively preventing high-power electromagnetic damage to the subsequent circuit and avoiding breakdown or damage to the subsequent system equipment.

[0065] Reference Figure 1 , Figure 2 , Figure 3 and Figure 4 The three-layer dielectric substrate has the same material, shape, and size, and the thickness is h. The interval between adjacent dielectric substrates is l. The first dielectric substrate 2, the second dielectric substrate 4, and the third dielectric substrate 5 are all made of F4BK225, with a dielectric constant of 2.25, a thickness h set to 0.25 mm, and a interval 1 between adjacent dielectric substrates set to 1.5 mm. It should be noted that in actual applications, the thickness and material of the dielectric plate can be adjusted.

[0066] The structure of the top metal unit 1 is a square with a side length of p. Nine small square metal patches 105 with a side length of e are arranged equidistantly from the center of the top metal unit. Each small square is attached with a trapezoidal metal patch 106 to form a small unit. The upper base of the trapezoid is c, the lower base is the same as the side length of the small square, and the height is d. Each small unit uses the upper base of the trapezoid as the edge and extends the first rectangular metal patch 102 in the four directions of up, down, left and right. The outer side of the metal patches of the other eight small units except the center is connected to the edge of the dielectric substrate through a first rectangular metal patch 102, a top PIN diode 104 and a second rectangular metal patch 103, wherein the second rectangular metal patch 103 is a long and c wide. Every two adjacent small units are connected through two first rectangular metal patches 102 and a top PIN diode 104 with a spacing of w. p is between 4-6mm, preferably 5.08mm; a is between 0.15-0.4mm, preferably 0.25mm; b is between 0.1-0.2mm, preferably 0.15mm; c is between 0.1-0.2mm, preferably 0.2mm; d is between 0.15-0.4mm, preferably 0.23mm; e is between 0.4-1mm, preferably 0.5mm; w is between 0.1-0.4mm, preferably 0.2mm.

[0067] The structure of the intermediate layer metal unit 201 is a square with a side length of p, and inside it are rectangular horizontal metal patches 202 and rectangular vertical metal patches 203 vertically distributed in a cross shape, with the same width, and the width of the rectangular horizontal metal patch 202 and the rectangular vertical metal patch 203 is k. k is between 0.05-0.25mm, preferably 0.1mm.

[0068] The bottom metal unit 301 is a square with a side length of p. Four small square metal patches 305 with a side length of m are arranged equidistantly around the center of the top metal unit. Each small square metal patch is attached with a trapezoidal metal patch 304 to form a small unit. The upper base of the trapezoid is n, the lower base is the same as the side length of the small square, and the height is j. Each small unit extends a third rectangular metal patch 302 in four directions, up, down, left and right, with the upper base of the trapezoid as the edge. The length is c and the width is b. The left and right sides of each small unit metal patch are connected to the edge of the dielectric substrate through a third rectangular metal patch 302, a bottom PIN diode 306 and a fourth rectangular metal patch 303, wherein the length of the fourth rectangular metal patch 303 is a and the width is c. Every two adjacent small units are connected through two third rectangular metal patches 302 and bottom PIN diodes 306 with a spacing of w. p is between 4-6mm, preferably 5.08mm; m is between 0.5-1.5mm, preferably 0.89mm; n is between 0.3-0.6mm, preferably 0.35mm; b is between 0.1-0.2mm, preferably 0.15mm; j is between 0.3-0.5mm, preferably 0.4mm.

[0069] Reference Figure 5 In one embodiment, the input end and the through end of the coupler are connected by a fifth rectangular metal patch 500, with a length l0 between 15mm-20mm, preferably 16.5mm, and a width l1 between 0.5mm-1mm, preferably 0.75mm, wherein two small rectangular cutouts are embedded in the fifth rectangular metal patch 500; the coupling end and the isolation end are connected by a sixth rectangular metal patch 501 and an arc-shaped metal patch 502, the length l2 of the fifth rectangular metal patch 500 is between 15mm-20mm, preferably 4.5mm, and the width is l1, the radius r0 of the arc-shaped metal patch 502 is between 3mm-4mm, preferably 3.5mm, and the width is l1.

[0070] Reference Figure 6 In one embodiment, the power detection circuit is mainly composed of a diode rectifier circuit, the input is a power signal transmitted from the coupling end, and the output is a DC voltage signal, which is the conduction voltage of the subsequent MOS high-speed switch.

[0071] Reference Figure 2 , Figure 4 In one embodiment, the bias circuit is located at the upper and lower edges of the front surface of the top first dielectric substrate 100 and the back surface of the bottom third dielectric substrate 300, which are the seventh rectangular metal patch 107 and the eighth rectangular metal patch 307, respectively, with a length p preferably of 5.08 mm and a width f preferably of 0.15 mm, which is consistent with the width b of the first rectangular metal patch.

[0072] When the top and bottom six small unit metal patches of the top metal unit are connected to the seventh rectangular metal patches on the upper and lower sides, the first rectangular metal patch in the middle that is connected is swapped with the PIN tube, and the connection sequence is small unit metal patch to PIN tube to the first rectangular metal patch to the second rectangular metal patch to the seventh rectangular metal patch. Similarly, when the upper and lower sides of each small unit metal patch of the bottom metal unit are connected to the seventh rectangular metal patch, the first rectangular metal patch in the middle that is connected is swapped with the PIN tube, and the connection sequence is small unit metal patch to PIN tube to the third rectangular metal patch to the fourth rectangular metal patch to the eighth rectangular metal patch.

[0073] The positive electrodes of the PIN diodes in the horizontal direction are all connected to the first adjacent rectangular metal patch on the left, and the negative electrodes are all connected to the first adjacent rectangular metal patch on the right. The positive electrodes of the PIN diodes in the vertical direction are all connected to the first adjacent rectangular metal patch below, and the negative electrodes are all connected to the first adjacent rectangular metal patch above. A gap w less than or equal to the package size of the PIN diode is left between the two first rectangular metal patches; the center of the small unit composed of the square patch and the surrounding trapezoidal patches is on the same straight line as the center of the first rectangular metal patch and the second rectangular metal patch.

[0074] The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit of the present invention realizes adaptive protection through the frequency shift of the resonance point of the equivalent circuit. The resonance point will automatically shift the frequency according to the change of the incident power so as to change the capacitance of the PIN tube, thereby changing the transmission characteristics of the electromagnetic wave. Figure 7 As shown in the figure, when a low-power electromagnetic wave is incident, the diode is in the cut-off state, which is equivalent to the capacitor Coff. At this time, the device layer in the equivalent circuit of the top metal unit is a low-pass filter circuit, and the middle layer is a high-pass filter circuit. The three layers are cascaded to form a bandpass filter circuit with low insertion loss in the X-band. Therefore, under low power, the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is in transmission mode, and the transmitted wave passes with low insertion loss. When we need to transmit a useful high-power electromagnetic wave signal, a reverse bias voltage is applied to the PIN tube through the bias circuit to force the PIN tube to reverse bias and reach the cut-off state, so that the equivalent circuit is still Figure 7 Therefore, the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is in the transmission mode under high-power transmission, so that the useful high-power electromagnetic signal can be transmitted normally.

[0075] like Figure 8 As shown in the figure, when a high-power electromagnetic wave is incident, the signal is coupled to the power detection circuit through the coupler and exceeds the set protection threshold voltage, the output DC signal will turn on the quick response switch, short-circuit the bias circuit, and the PIN diode in the energy selective surface works normally. The diode is in the on state, equivalent to the resistor Ron. At this time, the parallel capacitance of the device layer in the equivalent circuit of the top metal unit is reduced, and the overall capacitance is increased, so that the resonance point of the overall circuit is shifted to the left, and the original passband position is changed to a stopband, forming a band-stop filter circuit in the X-band. Therefore, the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is in protection mode under high power, the transmitted wave is shielded, and non-reciprocal transmission is achieved.

[0076] The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit described in the present invention can achieve highly selective transmission, works in the X-band, and has a shielding effectiveness greater than 30 dB across the entire frequency band.

[0077] The high-shielding ultra-wideband X-band energy selective surface unit described in the present invention is a strong electromagnetic space adaptive protection technology, which realizes adaptive protection by frequency shifting the resonance point of the equivalent circuit, and its resonance point will change the capacitance of the PIN tube according to the change of the incident power, thereby automatically shifting the frequency. When a low-power signal is irradiated, the PIN tube in the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is capacitive, and the X-band equivalent circuit is a bandpass filter circuit, and the electromagnetic wave can pass normally; when a high-power signal is irradiated, the PIN tube of the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is a small resistor, and the X-band equivalent circuit is a band-stop filter circuit, which shields the incident signal, thereby effectively preventing high-power electromagnetic damage to the subsequent circuit and avoiding breakdown or damage to the subsequent system equipment. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit described in the present invention can transmit a working signal of 6.7-14.1 GHz, with an insertion loss of less than 1 dB and a relative bandwidth of 71.2%, and can shield high-power microwaves in this frequency band and the entire X-band, with a shielding effectiveness greater than 30 dB. Within the angle range of 0° to 60°, the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit has good angular stability.

[0078] The high-shielding ultra-wideband X-band energy selective surface unit described in the present invention can selectively transmit or reflect energy according to the frequency of the electromagnetic wave, and the transmission performance changes with the change of the incident field strength; the power processing capability of the high-shielding ultra-wideband X-band energy selective surface unit is significantly enhanced, and it is directly triggered by the incident electromagnetic signal, and does not require additional response time to detect high power, thereby achieving rapid response.

[0079] The non-reciprocal energy selection surface described in the present invention is embodied in that a reverse bias voltage is applied to both ends of the PIN diode in the energy selection surface through a bias circuit, so that the PIN tube is in a reverse bias cut-off state, at which time the normal transmission of low-power electromagnetic waves in the transceiver link and the normal transmission of high-power useful electromagnetic waves in the transmission link are allowed. When an external high-power signal is incident in the receiving link, the signal is coupled to the power detection circuit through a coupler and exceeds the set protection threshold voltage, the output DC signal will quickly respond to the switch to short-circuit the bias circuit, the PIN diode in the energy selection surface works normally, shielding the high-power signal from entering, and realizing the non-reciprocal transmission of the guided electromagnetic wave in the transceiver link system. It can respond quickly and process different power signals at the same time, and the transmission performance changes with the change of the incident field strength.

[0080] In order to further illustrate the working performance of the present invention, the present invention is further illustrated by examples.

[0081] Example

[0082] In a specific embodiment, a non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system is provided, using Figures 1 to 6 The unit structure is shown in the figure. The dielectric plate is F4BK225 with a dielectric constant of 2.25. Other parameters are given in Table 1 (unit: mm).

[0083] Table 1 Energy selective surface unit parameters

[0084] p 5.08 m 0.89 a 0.25 n 0.35 b 0.15 h 0.25 c 0.2 l 1.5 d 0.23 <![CDATA[l0]]> 16.5 e 0.5 <![CDATA[l1]]> 0.75 w 0.2 <![CDATA[l2]]> 4.5 j 0.4 <![CDATA[r0]]> 3.5

[0085] Based on the above parameters, the non-reciprocal high shielding ultra-wideband X-band energy selective surface unit system of the present invention is simulated. The transmission coefficient results of the equivalent circuit model simulation and full-wave simulation of the high shielding ultra-wideband X-band energy selective surface unit when low-power signals and high-power signals are incident and useful high-power signals are transmitted are as follows: Fig. 9 As shown, when a low-power signal is incident, it is in a wave-transmitting state, and the high-shielding ultra-wideband X-band energy selective surface unit is in a transmission mode. The insertion loss is less than 1dB in the range of 6.7-14.1GHz, and the relative bandwidth reaches 71.5%; when a high-power signal is incident, it is in a shielding state, and the high-shielding ultra-wideband X-band energy selective surface unit is in a protection mode, and the shielding effectiveness is greater than 30dB, which can effectively protect electronic equipment from damage by strong electromagnetic pulses and improve the safety performance of the equipment; when a useful high-power signal is transmitted, a reverse voltage is applied to the PIN tube through a bias circuit to force the PIN to be reverse biased to a cut-off state. At this time, it is also in a wave-transmitting state, and the high-shielding ultra-wideband X-band energy selective surface unit is in a transmission mode, which meets the application requirements of communication equipment such as transceiver broadband antenna covers and multi-frequency antennas.

[0086] The transmission coefficient of the TE polarization of the high shielding ultra-wideband X-band energy selective surface unit in the above example at different θ angles for low power signals and high power signals is as follows: Fig.10 As shown in the figure, when low-power electromagnetic waves are incident, the diode is in the cut-off state. When θ is 0°, the center frequency of the passband is 10GHz, and the insertion loss at this frequency is 0.01dB. In the frequency band of 6.7-14.1GHz, the transmission coefficient is less than 1dB, and the bandwidth is 7.4GHz. As the angle of θ increases, the transmission curve shifts to high frequency, and the passband bandwidth increases. When θ is 60°, the passband center frequency is concave downward, and the insertion loss at the lowest point of the concave reaches -1dB. When θ is less than 45°, the passband is within 1dB, and the transmission coefficient remains stable. The situation when high-power electromagnetic wave signals are emitted is the same as when low-power signals are incident. When high-power electromagnetic wave signals are incident, the diode is in the on state, and the full-band shielding effectiveness is greater than 30dB. As the angle of θ increases, the shielding effectiveness gradually increases. When θ is 60°, the full-band shielding effectiveness is greater than 38dB.

[0087] The transmission coefficient of TM polarization of the X-band energy selective surface unit of the above example high shielding ultra-wideband is as follows at different θ angles for low power signals and high power signals: Fig.11 As shown, when low-power electromagnetic waves are incident, the diode is in the cut-off state. When θ is 0°, the center frequency of the passband is 10GHz, and the insertion loss at this frequency is 0.01dB. In the frequency band of 6.7-14.1GHz, the transmission coefficient is less than 1dB, and the bandwidth is 7.4GHz. As the angle θ increases, the transmission curve shifts to high frequency, and the passband bandwidth increases. When θ is 60°, the 1dB insertion loss band is. The situation when high-power electromagnetic wave signals are emitted is the same as when low-power signals are incident. When high-power electromagnetic wave signals are incident, the diode is in the on state, and the full-band shielding effectiveness is greater than 30dB. As the angle θ increases, the shielding effectiveness gradually decreases. When θ is 60°, the full-band shielding effectiveness is still greater than 20dB.

[0088] The insertion loss of the through end of the above example coupler and the coupling degree of the coupling section are as follows: Fig.12 As shown, in the receiving link, the power signal is coupled out as a detection signal through the coupling end of the coupler at 25dB, and other signals are transmitted to the subsequent limiter circuit through the through end with low insertion loss.

[0089] The input of the power detection circuit in the above example is the detection signal coupled by the coupler. The input power of the receiving link and the output DC voltage of the power detection circuit are as follows: Fig.13As shown, when the signal power in the receiving link exceeds 45dBm, the signal power passing through the coupler to the power detection circuit is 20dBm. At this time, the output DC voltage is 1V, reaching the turn-on voltage of the subsequent MOS high-speed switch, turning on the switch, short-circuiting the external bias circuit, and allowing the energy selection surface to work normally. It is shielded when a high-power signal is incident.

[0090] Further, in order to more intuitively illustrate the advantages of the present invention, an ultra-wideband energy selective surface based on a multilayer structure of the patent with a publication number of "CN 114824812B" is used as comparative example 1, an X-band energy selective surface of the patent with a publication number of "CN 113131221B" is used as comparative example 2, and an X-band broadband energy selective surface of the patent with a publication number of "CN 115566437 B" is used as comparative example 3. The performance parameters of the comparison are shown in Table 2:

[0091] Table 2 Performance parameter comparison

[0092] Transmittance band 1dB bandwidth Relative bandwidth Shielding effectiveness Comparative Example 1 6-10GHz 4GHz 50％ >20dB Comparative Example 2 8-10GHz 2GHz 22％ >10dB Comparative Example 3 8.55-12.95GHz 4.4GHz 41％ >15dB

[0093] Compared with Comparative Example 1, Comparative Example 2 and Comparative Example 3, the operating frequency band of the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system in the present invention is 6.7-14.1GHz, the transmission bandwidth is 7.4GHz, the relative bandwidth is 71.5%, and the full-band shielding effectiveness is greater than 30dB. And it meets the angle stability of 0° to 60° under TE and TM dual polarization. At the same time, the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system of the present invention also has non-reciprocal transmission characteristics, which can not only meet the normal transmission of low-power signals and high-performance shielding of useless high-power signals, but also provide a reverse bias voltage to cut off the PIN diode when a useful high-power signal needs to be transmitted, thereby achieving a low insertion loss transmission state to enable the normal transmission of useful high-power signals.

[0094] The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system can achieve spatial adaptive protection according to the strength of the incident electromagnetic wave. Without affecting the normal working signal transmission, it can perform high-performance shielding on the incident high-power useless signals and perform low insertion loss normal transmission on the useful high-power working signal transmission, thereby achieving the ability to combine non-reciprocity with high shielding performance. It not only improves the ability of the communication system to send and receive useful signals, but also enhances the anti-interference capability against high-power electromagnetic pulse weapons.

[0095] The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit of the present invention has low insertion loss and high shielding effectiveness for input signals of different powers, and can normally transmit useful high-power signals, while having good angular stability and dual-polarization characteristics. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system of the present invention has very low insertion loss for low-power signals of different incident angles in the transceiver link, which facilitates lossless transmission of useful signals. Due to the effect of the bias circuit, high-power signals in the transmission link are normally transmitted, and high-power signals in the receiving link are shielded and protected, thereby designing an adaptive protection array for non-reciprocal transmission of receiving and transmitting signals in the RF front-end transceiver link.

[0096] The protection scope of the present invention is not limited to the above preferred embodiments, but covers all technical solutions that conform to the concept of the present invention. For ordinary technicians in this technical field, improvements and modifications made under the premise of following the principles of the present invention should be regarded as the protection scope of the present invention.

Claims

1. A non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit, comprising a first dielectric substrate, a second dielectric substrate and a third dielectric substrate, characterized in that: The three dielectric substrates are all square and are provided with metal units, wherein every two dielectric substrates are separated by an equidistant air gap layer, wherein: The metal unit on the front side of the first dielectric substrate at the top layer and the metal unit on the back side of the third dielectric substrate at the bottom layer are both symmetrical structures, including a plurality of metal small units, the plurality of metal small units are connected to each other through a first rectangular patch and a PIN tube, and the metal small unit close to the edge of the dielectric substrate is connected to the edge of the dielectric substrate through the first rectangular patch, the PIN tube and the second rectangular patch; The metal unit located on the front side of the second dielectric substrate of the middle layer includes two rectangular metal patches which are arranged vertically and cross-shaped and have equal length and width.

2. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 1, characterized in that: Each small metal unit includes a square metal patch and four trapezoidal metal patches. The four trapezoidal metal patches are distributed around the square metal patch. The long bottom side of the trapezoidal metal patch is equal to the side length of the square metal patch and is connected to the square metal patch.

3. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 2, characterized in that: The metal unit on the front side of the first dielectric substrate includes nine uniformly distributed metal small units, and the metal unit on the back side of the third dielectric substrate includes four uniformly distributed metal small units.

4. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 2, characterized in that: The left and right edges of the first dielectric substrate and the third dielectric substrate are connected to the closest metal small unit through the second rectangular patch, the PIN tube and the first rectangular patch connected in sequence, and the upper and lower edges of the first dielectric substrate and the third dielectric substrate are connected to the closest metal small unit through the second rectangular patch, the first rectangular patch and the PIN tube connected in sequence.

5. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 1, characterized in that: The side length p of the first dielectric substrate, the second dielectric substrate and the third dielectric substrate is between 4-6 mm, all of which are made of F4BK225, with a dielectric constant of 2.25, a thickness h set to 0.25 mm, and a spacing between adjacent dielectric substrates set to 1.5 mm.

6. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 2, characterized in that: The length of the first rectangular metal patch and the width c of the second rectangular metal patch are between 0.1-0.2 mm, the width b of the first rectangular metal patch is between 0.1-0.2 mm, the length of the second rectangular metal patch 103 is a, between 0.15-0.4 mm, and the length of the PIN tube is between 0.1-0.4 mm.

7. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 6, characterized in that: The short bottom side of the trapezoidal metal patch on the first dielectric substrate is equal to the length of the first rectangular metal patch, which is between 0.1-0.2 mm, and the height is between 0.15-0.4 mm. The side length of the square metal patch is between 0.4-1 mm.

8. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 7, characterized in that: The short bottom side of the trapezoidal metal patch on the second dielectric substrate is between 0.3-0.6 mm, the height is between 0.3-0.5 mm, and the side length of the square metal patch is between 0.5-1.5 mm.

9. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 8, characterized in that: The two rectangular metal patches on the second dielectric substrate have the same width, which is between 0.05-0.25 mm.

10. A non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system, characterized in that: The device comprises a plurality of X-band energy selective surface units according to any one of claims 1 to 8 arranged in a periodic manner, a coupler, a power detection circuit, a fast response switch and a bias circuit, The coupler circuit is located after the phased array antenna in the receiving link, and couples the detection signal from the input end to the power detection circuit, wherein the input end and the through end are connected by a fifth rectangular metal patch, and the coupling end and the isolation end are connected by a sixth rectangular metal patch and an arc-shaped metal patch; The power detection circuit is located after the coupler circuit and outputs the coupled power signal as a DC voltage signal for subsequent MOS tube switch conduction voltage; The fast response switch is a MOS tube, which is controlled by the DC voltage output by the power detection circuit. When the DC voltage output is greater than the conduction voltage, the MOS tube is turned on, short-circuiting the bias circuit, so that the energy selection surface works normally and the high-power signal is shielded from transmission; The bias circuit is located at the upper and lower edges of the dielectric substrate of the top and bottom layers of the X-band energy selective surface unit, and is respectively connected to the positive and negative electrodes of the PIN tubes in each column. When a reverse bias voltage is applied, all PIN tubes are reverse biased and cut off, the energy selective surface is in a closed state, low-power signals are transmitted normally, and high-power signals in the transmission link are transmitted normally.

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