A non-reciprocal high-shielded ultra-wideband x-band energy selective surface unit and system

Abstract

The application discloses a kind of non-interacting high shielding ultra-wide band X wave energy selection surface unit and system, the system includes the design of X wave energy selection surface and the coupler designed for realizing non-interacting transmission, power detection circuit, fast reaction switch and bias circuit.X wave energy selection surface includes three-layer unit structure arranged periodically in array, top layer and bottom layer have straight microstrip line as bias circuit in upper and lower ends, coupler includes left-right symmetrical straight microstrip and circular arc microstrip, and power detection circuit is diode detection circuit.The non-interacting high shielding ultra-wide band X wave energy selection surface unit system of the application has very low insertion loss for low-power signal of different incident angles in transceiver link, which is convenient for lossless transmission of useful signal.Due to the effect of bias circuit, high-power signal in transmitting link is normally transmitted, and high-power signal in receiving link is shielded and protected, so that an adaptive protection array for non-interacting transmission of receiving and transmitting signals in radio frequency front-end transceiver link is designed.

Description

Technical Field

[0001] The present 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 long faced the threat of strong electromagnetic interference, making protecting them from interference and damage a crucial task. Protecting electronic devices from potential damage from strong electromagnetic threats such as strong electromagnetic pulses (EMPs) and high-power microwaves (HPMs) requires protective measures. Traditional protective measures, such as limiters and frequency-selective surfaces (FSSs), can limit the transmission of pulses. However, because limiters not only restrict the transmission of incident high-power signals but also interfere with the passage of normal signals, they are becoming increasingly unsuitable for protecting against HPMs. While FSSs offer a reliable signal transmission method, they lack selectivity for the electromagnetic energy within their passband and are unable to block interfering signals within the passband, effectively preventing the transmission of high-power pulses. To overcome these challenges, a self-actuated protection structure, known as an energy-selective surface (ESS), has been proposed. ESSs ensure that low-power operating signals can be transmitted while preventing unwanted high-power signals from reaching downstream devices, thereby preventing damage and effectively preventing the transmission of high-power pulses.

[0003] In addition, based on the working principle of the transceiver components, not only low-power signals need to be transmitted normally and high-power signals need to be shielded, but 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. Nonreciprocal X-band energy-selective surface elements improve protection against high-power electromagnetic pulses (HEPs), overcome the limitations of traditional protection methods, and expand the practicality of nonreciprocal high-power signal transmission. They provide a new solution for the stable operation of electronic equipment and systems. However, current solutions do not operate across the entire X-band and have low shielding effectiveness. The energy-selective surface described in patent publication number "CN 114824812B" operates in the 6-10 GHz range with a shielding effectiveness greater than 20 dB. The energy-selective element and surface described in patent publication number "CN 113131221 B" operates in the 8-10 GHz range with a shielding effectiveness greater than 10 dB. The energy-selective surface described in patent publication number "CN 115566437 B" operates in the 8.55-12.95 GHz range with a shielding effectiveness greater than 15 dB. These patents do not fully operate across the entire X-band and exhibit low shielding effectiveness across the entire frequency band. Therefore, strengthening research on nonreciprocal, high-shielding, dual-polarization, and ultra-wideband energy-selective surfaces in the X-band is of great significance.

[0004] Therefore, this paper proposes a nonreciprocal energy selective surface unit system. A bias circuit applies a reverse bias voltage to the ends of the PIN diode in the energy selective surface, placing the PIN diode in a reverse-biased cutoff state. This allows normal transmission of low-power electromagnetic waves in the transceiver link and normal emission of high-power useful electromagnetic waves in the transmit link. When an external high-power signal is incident on the receive link, the signal is coupled to the power detection circuit through a coupler and exceeds the set protection threshold voltage. The output DC signal quickly activates a switch, short-circuiting the bias circuit. The PIN diode in the energy selective surface operates normally, shielding the high-power signal from entering, thus achieving nonreciprocal transmission of guided electromagnetic waves in the transceiver link system. The result is a nonreciprocal protection array that can be placed in the RF front end to protect downstream equipment. Summary of the Invention

[0005] In response to 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 entire 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 to and simultaneously process signals of different powers, and the transmission performance changes with the change of the incident field strength.

[0006] The technical solutions for achieving the purpose of the present invention are:

[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 each is provided with a metal unit, wherein every two dielectric substrates are separated by an equidistant air gap layer, wherein:

[0008] The metal unit on the front surface of the first dielectric substrate on the top layer and the metal unit on the back surface of the third dielectric substrate on the bottom layer are both symmetrical structures and include multiple metal small units. The multiple metal small units are connected to each other through first rectangular patches and PIN tubes. The metal small units near the edge of the dielectric substrate are connected to the edge of the dielectric substrate through the first rectangular patch, PIN tube, and second rectangular patch.

[0009] The metal unit located on the front surface of the second dielectric substrate in the middle layer includes two rectangular metal patches that are arranged vertically in a cross shape and have equal lengths and widths.

[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 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 nearest 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 nearest 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, with a dielectric constant of 2.25, a thickness h of 0.25 mm, and a spacing between adjacent dielectric substrates of 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, ranging from 0.1 to 0.2 mm, the height is ranging from 0.15 to 0.4 mm, and the side length of the square metal patch is ranging from 0.4 to 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. 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 the subsequent MOS tube switch conduction voltage;

[0021] The fast-response switch is a MOS transistor, which is controlled by the DC voltage output by the power detection circuit. When the output DC voltage is greater than the conduction voltage, the MOS transistor 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 base 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 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 is frequency shifted, and it is a band-stop filter in the X-band, so that high-power electromagnetic waves are highly shielded when they are incident; when a useful high-power electromagnetic wave is emitted, a reverse bias voltage is applied to the PIN tube through the 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 the protection device as a radio frequency front-end transceiver component.

[0026] (3) The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit of the present invention faces the threat of high-power electromagnetic pulses. While normally distinguishing the power level of the incident signal, it also adds the function of transmitting high-power signals, ensuring that 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 equipment, and provides adaptive protection when the design 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 band-pass filter circuit, so that the electromagnetic wave can pass normally; when a high-power signal is irradiated, the PIN tube in 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 the 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 Schematic diagram of the underlying structure of the energy selective surface in one embodiment of the present invention.

[0032] Figure 5 1 is a schematic structural diagram of a coupler in one embodiment of the present invention.

[0033] Figure 6 FIG. 4 is a circuit 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 on it 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 one embodiment of the present invention.

[0036] Figure 9 This 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 under low-power signal and high-power incident conditions according to an embodiment of the present invention.

[0037] Figure 10This 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 low-power signals and high-power signals are incident, according to an embodiment of the present invention.

[0038] Figure 11 This 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 low-power signals and high-power signals are incident, according to an embodiment of the present invention.

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

[0040] Figure 13 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 illustrate the embodiments of the present invention or the technical solutions of the prior art, the following is a brief introduction to the drawings required for the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended 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 efforts 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, the terms "first," "second," and so on, used in this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include at least one of these features.

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

[0051] Combine 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 the coupling degree 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 the 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 output DC voltage is greater than the conduction voltage, the MOS tube is turned on, short-circuiting the bias circuit, allowing the energy selection surface to work normally and shielding the high-power signal from transmission.

[0056] The bias circuit is located on the upper and lower sides of the top and bottom layers of the energy selective surface, and is respectively connected to the positive and negative electrodes of each column of PIN tubes. When a reverse bias voltage is applied, all PIN tubes are reverse-biased and cut off, and 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.

[0057] The X-band energy selective surface comprises three layers of dielectric substrates sequentially separated 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, and a bottom PIN diode 306 of the bottom metal unit. 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 and have the same thickness, and the air spacing between adjacent dielectric substrates is the same.

[0058] Reference Figure 2 In one embodiment, a top metal unit 101 is provided 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 consisting 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 around the top metal patch. Horizontal and vertical top PIN diodes 104 are loaded between the first rectangular metal patch 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 surface of the first dielectric substrate and are evenly spaced outward. Each square metal patch is connected to a trapezoidal patch on each side. A square metal patch and the four surrounding trapezoidal metal patches form a small unit. The top dielectric substrate contains a total of nine small units, each surrounded by a rectangular metal patch (the first rectangular metal patch). Every two adjacent small unit metal patches are connected via two first rectangular metal patches and a PIN tube. The outer sides of the other eight small unit metal patches, except for the centermost one, are connected to the edge of the dielectric substrate via a first rectangular metal patch, a PIN tube, and a second rectangular metal patch. The perpendicular rectangular patches 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 rectangular horizontal metal patches 202 and rectangular vertical metal patches 203 vertically distributed in a cross shape.

[0061] Reference Figure 4 In one embodiment, a bottom metal unit 301 is provided 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. The structure of the bottom metal unit 301 includes a small unit consisting 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 around the periphery. The bottom PIN diodes 306 are loaded horizontally and vertically between the third rectangular metal patches 302.

[0062] The metal units on the back surface of the third dielectric substrate at the bottom layer of the energy selective surface are similar in structure to the metal units on the front surface of the first dielectric substrate at the top layer. The bottom layer metal units include 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 surface of the first dielectric substrate and are evenly spaced and spread outward. Each square metal patch 305 is connected to a trapezoidal metal patch 304 on each side. A square metal patch 305 and the four surrounding trapezoidal metal patches 304 form a small unit. The bottom dielectric substrate contains a total of four small units, each surrounded by a first rectangular metal patch. Every two adjacent small unit metal patches are connected via 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 selective surface unit of the present invention is a strong electromagnetic spatial adaptive protection technology, which achieves adaptive protection through the frequency shift of the resonant point of the equivalent circuit. The resonant point causes the capacitance of the PIN tube to change 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, allowing electromagnetic waves to pass normally. When a high-power signal is irradiated, the PIN tube in the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is a low resistor, and the X-band equivalent circuit is a bandstop filter circuit, shielding the incident signal, thereby effectively preventing high-power electromagnetic damage to the subsequent circuit, avoiding breakdown or damage to the subsequent system equipment.

[0065] Reference Figure 1 、 Figure 2 、 Figure 3 and Figure 4 The three dielectric substrates are made of the same material, shape, and size, with a thickness of 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. The thickness h is set to 0.25 mm, and the interval l between adjacent dielectric substrates is 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 top metal unit 1 has an overall square structure with side length p. Nine small square metal patches 105 with side length e are evenly spaced outward from the center of the top metal unit. Each small square is surrounded by a trapezoidal metal patch 106, forming a small unit. The trapezoid's upper base is c, its lower base is the same length as the small square's side, and its height is d. Each small unit extends a first rectangular metal patch 102 with a length c and a width b in the four directions, extending from the trapezoid's upper base. Except for the centermost one, the outer edges of the metal patches in the other eight small units are connected to the edge of the dielectric substrate via a first rectangular metal patch 102, a top PIN diode 104, and a second rectangular metal patch 103. The second rectangular metal patch 103 has a length a and a width c. Each adjacent small unit is connected via two first rectangular metal patches 102 and a top PIN diode 104 spaced a distance w apart. 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 intermediate metal unit 201 is generally square with a side length of p. Inside, rectangular horizontal metal patches 202 and rectangular vertical metal patches 203 are arranged vertically in a cross shape. These patches have the same width, and the width of these patches is k. The range of k is 0.05-0.25 mm, preferably 0.1 mm.

[0068] The bottom metal unit 301 is a square with a side length of p. Four small square metal patches 305 with side lengths of m are evenly spaced outward from the center of the top metal unit. Each small square metal patch is surrounded by a trapezoidal metal patch 304, forming a small unit. The trapezoid's upper base is n, its lower base is the same length as the small square's side, and its height is j. Each small unit extends a third rectangular metal patch 302 with a length of c and a width of b in all four directions, extending from the trapezoid's upper base. Each small unit's metal patch is connected to the edge of the dielectric substrate on both sides via a third rectangular metal patch 302, a bottom PIN diode 306, and a fourth rectangular metal patch 303. The fourth rectangular metal patch 303 has a length of a and a width of c. Each adjacent small unit is connected via two third rectangular metal patches 302 and bottom PIN diodes 306 spaced at intervals 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 15 mm and 20 mm, preferably 16.5 mm, and a width l1 between 0.5 mm and 1 mm, preferably 0.75 mm, 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, with a length l2 of the fifth rectangular metal patch 500 between 15 mm and 20 mm, preferably 4.5 mm, and a width l1, and the radius r0 of the arc-shaped metal patch 502 is between 3 mm and 4 mm, preferably 3.5 mm, and the width l1.

[0070] Reference Figure 6 In one embodiment, the power detection circuit is mainly composed of a diode rectifier circuit, the input of which is the 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, and is respectively the seventh rectangular metal patch 107 and the eighth rectangular metal patch 307. The length p is preferably 5.08 mm, and the width f is preferably 0.15 mm, which is the same as 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, which serves as the connection, is swapped with the PIN transistor. The connection order is: small-unit metal patch to PIN transistor to the first rectangular metal patch to the second rectangular metal patch to the seventh rectangular metal patch. Similarly, when the top and bottom 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, which serves as the connection, is swapped with the PIN transistor. The connection order is: small-unit metal patch to PIN transistor to the third rectangular metal patch to the fourth rectangular metal patch to the eighth rectangular metal patch.

[0073] The positive electrodes of the horizontal PIN diodes are all connected to the first rectangular metal patch adjacent to the left, and the negative electrodes are all connected to the first rectangular metal patch adjacent to the right. The positive electrodes of the vertical PIN diodes are all connected to the first rectangular metal patch adjacent to the bottom, and the negative electrodes are all connected to the first rectangular metal patch adjacent to the top. A gap w is left between the two first rectangular metal patches that is less than or equal to the package size of the PIN diode. The center of the small unit composed of the square patch and the surrounding trapezoidal patches is aligned with the centers of the first and second rectangular metal patches.

[0074] The non-reciprocal high shielding ultra-wideband X-band energy selective surface unit of the present invention realizes adaptive protection by frequency shifting the resonance point of the equivalent circuit. The resonance point will automatically shift the frequency according to the change of the incident power, causing the capacitance of the PIN tube to change, thereby changing the transmission characteristics of the electromagnetic wave. Figure 7 As shown in the figure, when low-power electromagnetic waves are 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, the middle layer is a high-pass filter circuit, and 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 selection surface unit is in transmission mode, and the transmitted wave passes with low insertion loss. When we need to transmit useful high-power electromagnetic wave signals, 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, when a high-power electromagnetic wave is incident, the signal is coupled to the power detection circuit through a coupler and exceeds the set protection threshold voltage. The output DC signal turns on the fast-reaction switch, short-circuiting the bias circuit. The PIN diode in the energy selective surface operates normally, the diode is in the on state, and is equivalent to the resistor Ron. At this time, the parallel capacitance of the device layer in the equivalent circuit of the top metal unit decreases, and the overall capacitance increases, causing the resonance point of the entire circuit to shift to the left, and the original passband position becomes a stopband, forming a band-stop filter circuit in the X-band. Therefore, at high power, the non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit is in protection mode, 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 30dB across the entire frequency band.

[0077] The highly shielded, ultra-wideband, X-band energy selective surface (ESS) unit described in this invention utilizes a highly adaptive electromagnetic spatial protection technology. This adaptive protection is achieved through frequency shifting of the resonant point of the equivalent circuit. This resonant point automatically shifts the frequency by causing the capacitance of the PIN transistor to change based on changes in incident power. When exposed to low-power signals, the PIN transistor in the NHSS unit becomes capacitive, and the X-band equivalent circuit becomes a bandpass filter, allowing electromagnetic waves to pass normally. When exposed to high-power signals, the PIN transistor in the NHSS unit becomes a low resistor, and the X-band equivalent circuit becomes a bandstop filter, shielding the incident signal. This effectively prevents high-power electromagnetic radiation from damaging downstream circuits and preventing breakdown or damage to downstream 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 6.7-14.1GHz, with an insertion loss of less than 1dB and a relative bandwidth of 71.2%. It can also shield high-power microwaves in this frequency band and the entire X-band, with a shielding effectiveness greater than 30dB. 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 nonreciprocal energy-selective surface described in the present invention applies a reverse bias voltage to the PIN diodes within the energy-selective surface via a bias circuit, placing the PIN diodes in a reverse-biased cutoff state. This allows normal transmission of low-power electromagnetic waves in the transceiver link and normal transmission of high-power useful electromagnetic waves in the transmit link. When a high-power external signal is incident on the receive link, the signal is coupled to the power detection circuit via a coupler and exceeds a set protection threshold voltage. The output DC signal activates a fast-response switch, short-circuiting the bias circuit and allowing the PIN diodes within the energy-selective surface to operate normally, shielding them from the high-power signal. This achieves nonreciprocal transmission of guided electromagnetic waves within the transceiver link system. This allows for rapid response and simultaneous processing of signals of varying power, with transmission performance varying with the intensity of the incident field.

[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 Figure 1. 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 and high-power signals are incident and useful high-power signals are transmitted are as follows: Figure 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 in the range of 6.7-14.1GHz is less than 1dB, 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. 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 the 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: Figure 10 As shown, when low-power electromagnetic waves are incident, the diode is in the cutoff state. When θ is 0°, the center frequency of the passband is 10 GHz, with an insertion loss of 0.01 dB at this frequency. In the 6.7-14.1 GHz band, the transmission coefficient is less than 1 dB, and the bandwidth is 7.4 GHz. As the angle θ increases, the transmission curve shifts to higher frequencies and the passband bandwidth increases. When θ is 60°, the passband center frequency dips downward, with the insertion loss reaching -1 dB at its lowest point. When θ is less than 45°, the passband is within 1 dB, and the transmission coefficient remains stable. The same situation occurs when high-power electromagnetic waves are transmitted. When high-power electromagnetic waves are incident, the diode is in the on state, and the full-band shielding effectiveness exceeds 30 dB. This shielding effectiveness gradually increases with increasing θ, reaching a full-band shielding effectiveness of over 38 dB at θ of 60°.

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

[0088] The insertion loss of the through end of the above example coupler and the coupling degree of the coupling section are as follows: Figure 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: Figure 13As shown in the figure, 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, which reaches the turn-on voltage of the subsequent MOS high-speed switch, turning on the switch and short-circuiting the external bias circuit. The energy selection surface works normally and is shielded when a high-power signal is incident.

[0090] Furthermore, to more intuitively illustrate the advantages of the present invention, an ultra-wideband energy selective surface based on a multilayer structure according to patent publication number "CN 114824812B" is used as comparative example 1, an X-band energy selective surface according to patent publication number "CN 113131221B" is used as comparative example 2, and an X-band broadband energy selective surface according to patent publication number "CN 115566437 B" is used as comparative example 3. The performance parameters of the comparisons 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 Examples 1, 2 and 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 6.7-14.1 GHz, the transmission bandwidth is 7.4 GHz, the relative bandwidth is 71.5%, and the full-band shielding effectiveness is greater than 30 dB. It also 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, 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 also 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 at different incident angles in the transceiver link, facilitating lossless transmission of useful signals. Due to the action of the bias circuit, high-power signals in the transmit link are normally transmitted, and high-power signals in the receive link are shielded and protected, thereby designing an adaptive protection array for non-reciprocal transmission of receive and transmit 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 those skilled in the art, improvements and modifications made under the premise of following the principles of the present invention should be considered 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. Every two dielectric substrates are separated by an equidistant air gap layer, wherein: The metal unit on the front surface of the first dielectric substrate on the top layer and the metal unit on the back surface of the third dielectric substrate on the bottom layer are both symmetrical structures and include multiple metal small units. The multiple metal small units are connected to each other through first rectangular metal patches and PIN tubes. The metal small units near the edge of the dielectric substrate are connected to the edge of the dielectric substrate through the first rectangular metal patch, PIN tube and second rectangular metal patch. The metal unit located on the front surface of the second dielectric substrate in the middle layer includes two rectangular metal patches of equal length and width that are arranged vertically in a cross shape; 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 is connected to the square metal patch.

2. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 1, characterized in that: The metal unit on the front surface of the first dielectric substrate includes nine evenly distributed metal small units, and the metal unit on the back surface of the third dielectric substrate includes four evenly distributed metal small units.

3. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 1, characterized in that: The left and right edges of the first dielectric substrate and the third dielectric substrate are connected to the nearest metal small unit through the second rectangular metal patch, the PIN tube, and the first rectangular metal patch connected in sequence. The upper and lower edges of the first dielectric substrate and the third dielectric substrate are connected to the nearest metal small unit through the second rectangular metal patch, the first rectangular metal patch, and the PIN tube connected in sequence.

4. 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 of 0.25 mm, and a spacing of 1.5 mm between adjacent dielectric substrates.

5. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 1, characterized in that: The length of the first rectangular metal patch and the width c of the second rectangular metal patch are between 0.1-0.2mm, the width b of the first rectangular metal patch is between 0.1-0.2mm, the length of the second rectangular metal patch is a, between 0.15-0.4mm, and the length of the PIN tube is between 0.1-0.4mm.

6. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 5, 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, ranging from 0.1 to 0.2 mm, and the height is ranging from 0.15 to 0.4 mm. The side length of the square metal patch is ranging from 0.4 to 1 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 third 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.

8. The non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit according to claim 7, characterized in that: The two rectangular metal patches on the second dielectric substrate have the same width, which is between 0.05 mm and 0.25 mm.

9. A non-reciprocal high-shielding ultra-wideband X-band energy selective surface unit system, characterized in that: The device comprises a plurality of periodically arranged X-band energy selective surface units according to any one of claims 1 to 7, a coupler, a power detection circuit, a fast response switch and a bias circuit, The coupler is located after the phased array antenna in the receiving chain and couples the detection signal from the input end to the power detection circuit. 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 and outputs the coupled power signal as a DC voltage signal for the subsequent MOS tube switch conduction voltage; The fast-response switch is a MOS transistor, which is controlled by the DC voltage output by the power detection circuit. When the output DC voltage is greater than the conduction voltage, the MOS transistor 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 substrates on 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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