A self-response clipping antenna that blocks front-door coupling

Abstract

The present invention discloses a self-responsive limiting antenna that blocks front-door coupling, belonging to the field of electromagnetic compatibility technology. The antenna comprises a dielectric substrate, an upper metal layer, a PIN diode, an inductor, and a capacitor arranged on the upper surface of the dielectric substrate, and a lower metal floor arranged on the lower surface of the dielectric substrate; the antenna feeds the F-shaped radiation patch through a grounded coplanar waveguide, and the PIN diode, inductor, and capacitor constitute a limiting circuit and are loaded on the radiating end of the inverted-F antenna. The present invention loads the limiting circuit on the radiating end of the inverted-F antenna, realizing the integrated design of the limiter and the antenna, and can achieve the effect of suppressing high-power microwaves without the need for external bias. The present invention has both the advantages of the ESS's high power tolerance and the small size advantage of the limiter itself.

Description

Technical Field

[0001] The invention belongs to the technical field of electromagnetic compatibility, and in particular relates to a self-response limiting antenna capable of blocking front door coupling. Background Art

[0002] High-power microwaves refer to strong electromagnetic pulses with frequencies up to 300 GHz and peak powers exceeding 1 mW. They can enter transceiver electronics through front-door coupling or back-door coupling. Currently, effective technologies for preventing front-door coupling include energy selective surfaces (ESSs) and limiters. ESSs provide field-based protection. When high-power microwaves strike the ESS, the surface impedance changes, scattering the high-power microwaves and achieving protection. Their advantage is a higher power tolerance, but their disadvantage is their bulkiness. Limiters provide path-based protection. When high-power microwaves are coupled into and transmitted along the signal link, the limiter generates a conductivity modulation effect, reducing its own impedance and creating a short-circuit in the transmission line, reflecting the high-power microwaves. Their advantage is effective protection, but their disadvantage is a lower power tolerance. Small communications equipment cannot be protected with a bulky ESS. Instead, they must be protected by a limiter after high-power microwaves enter the transmission line via front-door coupling. However, a single-stage limiter cannot achieve both high power handling and high response speed due to the thickness of zone I. A multi-stage limiter can increase the upper power handling limit, but at the cost of additional size and cost. Summary of the Invention

[0003] In order to overcome the above technical defects, the present invention provides a self-responsive limiting antenna that blocks front-door coupling, aiming to solve the problem that the limiter cannot prevent high-power microwaves from coupling into the transmission link and has poor tolerance to power.

[0004] The present invention is achieved by adopting the following technical solutions:

[0005] A self-response limiting antenna for blocking front door coupling comprises a dielectric substrate, an upper metal layer arranged on the upper surface of the dielectric substrate, a first PIN diode, a first inductor, a first capacitor, and a lower metal floor arranged on the lower surface of the dielectric substrate.

[0006] The upper metal layer includes a first metal patch, a second metal patch, a third metal patch, a fourth metal patch, and a fifth metal patch.

[0007] The first metal patch is "F"-shaped, including a horizontal branch and two longitudinal branches, one of which is connected to the fifth metal patch; the other longitudinal branch is connected to the second metal patch, and the other end of the second metal patch extends to the edge of the dielectric substrate.

[0008] The fourth metal patch and the fifth metal patch are respectively connected to the lower metal floor through a row of ground vias; the second metal patch, the fourth metal patch, the fifth metal patch, the lower metal floor, and the ground vias together constitute a grounded coplanar waveguide for feeding the first metal patch.

[0009] The first PIN diode is placed in parallel with the first inductor, one end of which is connected to the end of the horizontal branch of the first metal patch, and the other end of which is connected to the third metal patch; the first PIN diode, the first inductor and the first capacitor constitute a limiting circuit.

[0010] The amplitude limiting circuit formed by the first PIN diode, the first inductor, and the first capacitor does not require an external DC voltage bias.

[0011] Furthermore, the dielectric substrate is made of a material with a relative dielectric constant of 4.7.

[0012] Furthermore, the first inductor adopts SCW1005C14NJST, the first capacitor adopts HV0603X7R221K101NT, and the first PIN diode adopts SMP1331-079LF.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] In the field of electromagnetic protection, the traditional protection mode is to load the limiter at the antenna feed or in the transmission link, or to install an energy selective surface on the periphery of the antenna. The present invention loads the limiter circuit at the radiating end of the inverted F antenna, realizing the integrated design of the limiter and antenna. It can achieve the effect of suppressing high-power microwaves without the need for external bias. When there is high-power microwave radiation, because the limiter circuit is loaded at the radiating end of the antenna, the impedance of the limiter circuit becomes low, which produces a negative feedback effect on the antenna, causing the antenna's reception performance to deteriorate. This causes field scattering of the high-power microwaves, suppressing the high-power microwaves from coupling into the antenna and the back-end transmission line, achieving the "scattering" characteristic of field protection. By changing the loading position of the limiter in this way, the overall power tolerance of the limiter antenna can be greatly increased, preventing high-power microwaves from coupling into the transmission link. It combines the advantages of the high power tolerance of the ESS with the small size of the limiter itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a structural diagram of the upper metal layer in the present invention.

[0016] Figure 2 This is a structural diagram of the lower metal layer in the present invention.

[0017] Figure 3 This is the S11 simulation curve of the normal state of the limiting antenna.

[0018] Figure 4 It is a simulation curve diagram of the limiting state S11 of the limiting antenna.

[0019] Figure 5 This is the radiation simulation diagram of the inverted F antenna with a short-circuit block loaded at the antenna feed.

[0020] Figure 6 This is a simulation diagram of the radiation of an inverted F antenna with a short-circuit block loaded at the antenna radiating end.

[0021] Figure 7 This is a port diagram for simulating the loading of a resistor on an inverted-F antenna.

[0022] Figure 8 The simulation results of the relationship between the resistance value of the two loading positions and the antenna S11 are shown in FIG. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] Reference Figure 1 、 2 In this embodiment, a self-response limiting antenna for blocking front door coupling includes a dielectric substrate, an upper metal layer arranged on the upper surface of the dielectric substrate, a first PIN diode, a first inductor, a first capacitor, and a lower metal floor arranged on the lower surface of the dielectric substrate.

[0025] The dielectric substrate 202 is made of FR4 material with a dielectric constant of 4.7, with a length X of 50 mm and a width Y of 40 mm. The lower metal floor 201 has a long side X of 50 mm and a short side Y1 of 20 mm.

[0026] The upper metal layer includes a first metal patch 101, a second metal patch 102, a third metal patch 103, a fourth metal patch 104, and a fifth metal patch 105;

[0027] The first metal patch is F-shaped, consisting of one transverse branch and two longitudinal branches. One longitudinal branch connects to the fifth metal patch; the other longitudinal branch connects to the second metal patch. The other end of the second metal patch extends to the edge of the dielectric substrate. The width (W) of the transverse branch, longitudinal branch, and second metal patch is 1.5 mm. The long side (L) of the transverse branch is 15.78 mm, and the long sides (H) of the two longitudinal branches are 3.8 mm.

[0028] The fourth metal patch 104 and the fifth metal patch 105 have a horizontal side X1 of 35.75 mm and X2 of 10.07 mm, and a longitudinal side Y1 of 20 mm, and are respectively connected to the lower metal floor 201 through a row of ground vias 203 with a diameter of 0.35 mm; the second metal patch 102, the fourth metal patch 104, the fifth metal patch 105, the lower metal floor 201, and the ground vias 203 together constitute a grounded coplanar waveguide for feeding the first metal patch.

[0029] The first PIN diode 106 and the first inductor 107 are placed in parallel, with one end connected to the end of the horizontal branch of the first metal patch 101 and the other end connected to the third metal patch 103. The first PIN diode 106, the first inductor 107, and the first capacitor 108 form a limiter circuit. The first inductor 107 can be SCW1005C14NJST, the first capacitor 108 can be HV0603X7R221K101NT, and the first PIN diode 106 can be SMP1331-079LF.

[0030] Reference Figure 3 , is a simulation curve diagram of the normal state S11 of the limiting antenna of this embodiment. At this time, the PIN limiting circuit is not turned on, the antenna center frequency is 2.45 GHz, and the -10 dB bandwidth is 2.33 GHz to 2.53 GHz.

[0031] refer to Figure 4 , is a simulation curve diagram of the limiting state S11 of the limiting antenna of this embodiment. At this time, the PIN limiting circuit is turned on, and the S11 at 2.45GHz is -0.428dB, which is close to total reflection and has good limiting performance.

[0032] refer to Figure 5 , which is a simulation diagram of the radiation of an inverted F antenna with a short-circuit block loaded at the antenna feed. Loading a PIN limiting circuit at the antenna feed is an existing common loading method. Since the PIN diode in the limiting circuit will enter the working conduction state when subjected to high-power microwave impact, the purely ideal model of the conduction state at this time can be regarded as a short-circuit point. Therefore, by modeling in CST, a loaded conductor short-circuit block 501 is used to replace the PIN diode in the limiting working state, and the short-circuit block 501 is placed at the feed of the inverted F antenna to simulate the inverted F antenna with a limiting circuit loaded at the feed in the ideal limiting state, and the antenna is irradiated with a plane wave. The simulation results are as follows: the maximum amplitude of the waveform received by the port is 0.003W 1 / 2 The field strength at the maximum voltage point coupled to the antenna is 621V / m, and the maximum current distribution at the short-circuit block is 0.47A / m.

[0033] refer to Figure 6, which is a simulation diagram of the radiation of an inverted F antenna with a short-circuit block loaded at the radiating end of the antenna. Loading a limiting circuit at the radiating end is the limiting antenna loading method of this embodiment. By modeling in CST, placing the short-circuit block 601 at the radiating end of the inverted F antenna, simulating the inverted F antenna with a limiting circuit loaded at the radiating end in an ideal limiting state, and irradiating the antenna with a plane wave, the simulation results are as follows: The maximum amplitude of the waveform received by the port is 0.0023W 1 / 2 , the field strength at the maximum voltage point coupled to the antenna is 154V / m, and the maximum current distribution at the short-circuit block is 0.18A / m. Under the plane wave irradiation of the same intensity and direction, Figure 5 Compared with the simulation results in , the inverted-F antenna with a short-circuit block loaded at the antenna radiating end has smaller maximum amplitude of the waveform coupled to the port, the maximum voltage point field strength coupled to the antenna, and the maximum current distribution at the short-circuit block.

[0034] This is because when an inverted-F antenna with a short-circuit block at the feed point is in operation, incoming plane waves are first coupled through the antenna into the transmission line, then reflected off the short-circuit block, forming a standing wave on the antenna. The field strength at the point of maximum voltage coupled to the antenna is high, and when this standing wave is generated, the current density at the short-circuit block is also high. When an inverted-F antenna with a short-circuit block at the radiating end primarily acts as a "field scatterer" for incoming plane waves. Most of the high-power microwaves are scattered and do not pass through the antenna into the transmission line. As a result, the field strength at the point of maximum voltage coupled to the antenna is minimal, and the current density at the short-circuit block is also minimal.

[0035] It is proved that when the equivalent resistance of the PIN diode is the same, the inverted-F antenna loaded with PIN at the radiation end has better protection effect, smaller current and greater power tolerance.

[0036] refer to Figure 7 Figure 2 shows the port diagram for the simulation of a resistor loaded on an inverted-F antenna. By adding resistors at different locations on the antenna—R1 at port 1 and R2 at port 2—the sensitivity of the inverted-F antenna to the resistor values at different locations is compared.

[0037] refer to Figure 8 , which shows the simulation results of the relationship between the resistor values and the antenna S11 at two different loading positions. This graph shows that, for the same protection effect (i.e., the same S11), R1 is larger when loaded at the radiating end of the inverted-F antenna. This simulation demonstrates that when the PIN diode is loaded at the radiating end of the inverted-F antenna, the equivalent resistance has a greater impact on S11, meaning it can withstand greater power.

[0038] The above description is only one embodiment of the present invention and does not constitute any limitation to the present invention. Obviously, for professionals in this field, after understanding the content and principles of the present invention, it is possible to make various modifications and changes in form and details without departing from the principles and structure of the present invention. However, these modifications and changes based on the ideas of the present invention are still within the scope of protection of the claims of the present invention.

Claims

1. A self-response clipping antenna for blocking front-door coupling, comprising a dielectric substrate, an upper metal layer disposed on the upper surface of the dielectric substrate, a first PIN diode, a first inductor, a first capacitor, and a lower metal floor disposed on the lower surface of the dielectric substrate; The upper metal layer includes a first metal patch, a second metal patch, a third metal patch, a fourth metal patch, and a fifth metal patch; The first metal patch is F-shaped and includes a transverse branch and two longitudinal branches, wherein one longitudinal branch is connected to the fifth metal patch; the other longitudinal branch is connected to the second metal patch, and the other end of the second metal patch extends to the edge of the dielectric substrate; The fourth metal patch and the fifth metal patch are respectively connected to the lower metal floor through a row of ground vias; The second metal patch, the fourth metal patch, the fifth metal patch, the lower metal floor, and the ground via together constitute a grounded coplanar waveguide for feeding the first metal patch; The first PIN diode is placed in parallel with the first inductor, with one end connected to the end portion of the horizontal branch of the first metal patch and the other end connected to the third metal patch; one end of the first capacitor is connected to the third metal patch and the other end is connected to the fourth metal patch; the first PIN diode, the first inductor and the first capacitor form a limiter circuit; The amplitude limiting circuit formed by the first PIN diode, the first inductor, and the first capacitor does not require an external DC voltage bias.

2. The self-response limiting antenna for blocking front door coupling according to claim 1, characterized in that: The dielectric substrate is made of a material with a relative dielectric constant of 4.

7.

3. The self-response limiting antenna for blocking front door coupling according to claim 2, characterized in that: The first inductor is SCW1005C14NJST, the first capacitor is HV0603X7R221K101NT, and the first PIN diode is SMP1331-079LF.

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