High-isolation miniaturized dual-panel circular antenna and application

Abstract

The utility model discloses a kind of high-isolation miniaturization double-sided panel circular antenna and application.It is through the mode of adjusting feedback short line length and position and adjusting the shape of antenna vibrator, in addition, the length of transmission feed line is also limited, finally realize improved antenna isolation, improve low-power Doppler effect radar sensor performance, applicable to low-cost double-sided panel radar module, can be used in low-cost radar, RFID transceiver and multiple scenes such as RFIDs transceiver.Effective as compared with prior art: while providing small size, improve the isolation of antenna, greatly reduce the noise of radar module, and sensing distance is greatly improved.The utility model solves the problem that 1mA low-power radar module is applied to globe lamp, and greatly reduces production cost, with very high commercial value.

Description

TECHNICAL FIELD

[0001] The utility model relates to electronic equipment, electronic device technical field, especially a kind of high-isolation miniaturized double-sided panel round antenna and application. BACKGROUND

[0002] 5.8GHz Doppler effect radar sensor chip cost has been close to even lower than discrete radar scheme, and radar scheme is more suitable for globe lamp than infrared pyroelectric scheme. However, radar module power supply restricts radar induction lamp cost. Under normal circumstances, it needs a DC-DC switching power supply chip with withstand voltage 300V or more, cooperates a freewheeling inductor, obtains 5V direct current for radar module. This power supply scheme needs about 1 yuan additional cost, limits 2 yuan or so radar module to be widely used in globe lamp. As shown in FIG. Figure 6 If radar module consumes 1mA, then, using about 300k ohm resistance RL from silicon bridge (four rectifier diodes) output high-voltage direct current (about 300V, namely 220V*1.414) electricity, using a diode (voltage stabilizing diode, clamping diode or protection triode) and a low-voltage filter capacitor (general withstand voltage value is less than or equal to 50V) can be used. In the case where current is less than 1mA, power consumption is less than 300mW. Under the condition that radar induction lamp is continuously powered for 24 hours, 300mW power consumption is less than 1 degree in 138 days. If 10W radar induction lamp saves 4 hours per day (actual power saving time in public corridor with less people can reach more than 6 hours per day), 25 days save 1 degree, it can not only make up for power loss, but also save nearly 1 degree per quarter.

[0003] However, the low-power radar chip of about 1 mA is generally the same chip as the 50 uA radar chip of the battery-powered product, except that the duty cycle of the radio frequency circuit is different (the 50 uA radar chip uses a duty cycle of 1 / 500-1 / 1000, and the 1 mA radar chip uses a duty cycle of 1 / 25-1 / 50). In order to support ultra-low power consumption, the intermediate frequency amplifier on the radar chip generally has a working current of less than 10 uA. With such low power consumption, it is difficult for the intermediate frequency amplifier to maintain a very high common-mode rejection ratio and open-loop gain. Therefore, whether it is a differential active mixer plus differential amplifier scheme or a passive double-balanced mixer plus differential transconductance amplifier scheme, it is difficult to maintain a high common-mode rejection capability to eliminate common-mode interference caused by power supply interference (the interference path is generally electromagnetic field interference through the inductive coupling inside the chip of the frequency source, i.e. the voltage-controlled oscillator (VCO)). Generally, in this low-cost bulb lamp power supply scheme, the rectifier silicon bridge, high-voltage filter capacitor (generally a 3.3 uF aluminum electrolytic capacitor with a withstand voltage of 400 V), LED driving chip, freewheeling inductor, and about 10 LED lamp beads are all soldered on the circuit board made of aluminum substrate. Even though the four-layer back-fed antenna itself has a relatively high transmit-receive isolation, because the chip on the four-layer board is on the back of the antenna, that is, very close to the LED lamp bead power supply board (the distance between the radar module and the power supply board is generally less than or equal to 5 mm), therefore, this low-cost power supply scheme has a lot of interference, and it is very difficult to achieve a detection requirement of a hanging height of 3 meters and an induction radius of 3 meters.

[0004] Antennas are commonly used in transmit and receive ports of integrated radio frequency SOC chips. In cases where cost requirements are relatively high, double-sided boards are a cost-effective choice because they are less expensive than four-layer boards. Moreover, because the radar chip of the double-sided board radar module is on the antenna surface, it is isolated from the LED driving power supply by a layer of ground (the chip is also isolated by the heat dissipation pad again). However, conventional double-sided board edge-fed antennas are large in size and have poor isolation, resulting in a cost comparable to that of four-layer boards, and the large size can easily block the light of the lamp beads inside the bulb lamp, causing shadows in the center. If the size of the double-layer circuit board is the same as that of the four-layer board, the double-sided board antenna generally cannot meet the requirement of a hanging height of 3 meters and an induction radius of 3 meters due to its low transmit-receive isolation.

[0005] The reasons why the radar module has a too close sensing distance when the antenna isolation is poor are as follows: the Doppler sensing radar belongs to a self-mixing system, and the transmission and reception are performed simultaneously, because the transmission-reception isolation of the system is limited, a part of the transmitted signal will directly return to the receiving end to form a direct current level of self-mixing. Although the direct current level can be eliminated through a direct current elimination capacitor, because the Doppler frequency is very low, the phase noise of the frequency source will form low-frequency noise through the self-mixing effect to become a main noise source of the radar system. This low-frequency noise, although partly derived from the 1 / f noise of the mixer and the intermediate frequency amplifier, is mainly derived from the near-end phase noise of the voltage-controlled oscillator. Even if the phase-locked loop technology is used to greatly improve the in-loop phase noise at a slightly far position, it is difficult to reduce the near-end phase noise. The Doppler sensing radar chip with the phase-locked loop has high power consumption and cost, and needs an external crystal oscillator, and is at a cost and power consumption disadvantage in low-end applications of intelligent lighting. For example, for a 5.8GHz Doppler radar module, when a person walks at a speed of 1m / s, the Doppler frequency is 38Hz. This low-frequency phase noise is difficult to improve through optimization of the voltage-controlled oscillator. The main method in the industry is to improve the transmission-reception isolation. For a low-power radar module with a current of about 1mA, there is an urgent need for a double-layer circuit board transmission-reception integrated antenna with an isolation of more than 40dB in the market. Practical new type content

[0006] The purpose of the utility model lies in: provide a kind of high isolation miniaturization double panel round antenna, it is applied to Doppler effect radar sensor. It realizes the isolation effect similar to 4-port electric bridge by feed line length and antenna shape, improves antenna isolation, improves the performance of low-power Doppler effect radar sensor, suitable for low-cost double panel radar module, can be used in low-cost radar, RFID transceiver and multiple scenes.

[0007] The utility model discloses a kind of high isolation miniaturization double panel round antenna, it is characterized by including PCB board 9, the PCB board 9 is divided into top layer and bottom layer;Top layer is formed antenna oscillator 1 by copper, feed line, chip pin and ground wire, the rest area is green oil and silk printing blank area, bottom layer is whole layer ground copper foil;

[0008] The antenna oscillator 1 is circular, two feed points are provided in the antenna oscillator 1, and the included angle between the two feed points and the center of the antenna oscillator 1 is 90 degrees;Slot 11 is opened in the antenna oscillator 1 from the feed point along the radial direction, antenna transmitting feed line 2 is provided in one slot 11, and extends out of the antenna oscillator 1, and antenna receiving feed line 3 is provided in another slot 11, and extends out of the antenna oscillator 1;Antenna ground via 12 is provided on both sides of any slot 11, and the two antenna ground vias 12 corresponding to any slot 11 are connected by copper sheet 8 at the bottom layer of the PCB board 9;

[0009] The antenna receiving feeder 3 is adjacent to and connected with the receiving pin 41 of the chip pin, and the transmitting pin 42 of the chip pin is also connected with a transmitting feeder, wherein the transmitting feeder is divided into a transmitting feeder A section 51, a transmitting feeder B section 52, a transmitting feeder C section 53 and a transmitting feeder D section 54; the transmitting feeder A section 51 is connected with the transmitting pin 42, and the transmitting feeder A section 51 overlaps the circular tangent line passing through the transmitting pin 42 in the antenna oscillator 1; the transmitting feeder C section 53 is a straight line and is parallel to the side edge of the PCB 9; the transmitting feeder B section 52 is an arc-shaped line section and two ends thereof are connected with the transmitting feeder A section 51 and the transmitting feeder C section 53, respectively; and the transmitting feeder D section 54 is an arc-shaped line section and two ends thereof are connected with the transmitting feeder C section 53 and the antenna transmitting feeder 2, respectively; and the ground wire of the transmitting feeder is provided with a plurality of coplanar line ground vias 6 on both sides thereof.

[0010] The feedback short line 7 is connected at the antenna ground via 12 on one side of the antenna receiving feeder 3; by adjusting the length of the feedback short line 7 and the distance between the feedback short line 7 and the transmitting feeder, the size of the feedback signal is adjusted, so that the size of the feedback signal is equal to the size of the leakage signal transmitted by the antenna and received.

[0011] Further, the antenna transmitting feeder 2 is laid in the slot 11, so that a gap is formed between the antenna transmitting feeder 2 and the antenna oscillator 1, and the width of the gap is 1 / 3 of the width of the antenna transmitting feeder 2; and the antenna receiving feeder 3 is laid in the slot 11, so that a gap is formed between the antenna receiving feeder 3 and the antenna oscillator 1, and the width of the gap is 1 / 3 of the width of the antenna receiving feeder 3.

[0012] Further, the transmitting feeder, the copper sheet 8, the antenna transmitting feeder 2 and the antenna receiving feeder 3 are all equal in width, so as to ensure that the characteristic impedances are the same.

[0013] Further, the total length of the transmitting feeder is equal to 1 / 2 wavelength.

[0014] Further, the chip pin is also provided with a chip ground via 43; or a center via ground is arranged at the center of the antenna oscillator 1.

[0015] Further, the PCB 9 is a double-sided board, and the thickness thereof is 1.6±0.1 mm.

[0016] Further, the length of the outer end of the antenna transmitting feeder 2 extending out of the edge of the antenna oscillator 1 is 3±1 mm.

[0017] The application of the high-isolation small-sized double-sided board circular antenna in a low-power consumption radar module.

[0018] Compared with the prior art, the high-isolation small-sized double-sided board circular antenna has the following beneficial effects:

[0019] 1, while providing small size, improve the isolation of the antenna, greatly reduce the noise of radar module, the induction distance greatly improves.

[0020] 2, solve the problem of 1mA low power consumption radar module applied to the bulb, and greatly reduce the production cost, has very high commercial value. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 For the high isolation of the antenna top layer feedback signal size before the adjustment of the circular antenna profile.

[0022] Figure 2 For the high isolation of the antenna top layer feedback signal size after the adjustment of the circular antenna profile.

[0023] Figure 3 For the high isolation of the antenna bottom layer circular antenna profile.

[0024] Figure 4 For the feedback signal size before the adjustment of the radar module bottom noise (left half white) and hand Doppler (right half white) waveform diagram.

[0025] Figure 5 For the feedback signal size after the adjustment of the radar module bottom noise (left half white) and hand Doppler (right half white) waveform diagram.

[0026] Figure 6 Resistor voltage division power supply radar induction lamp circuit principle diagram.

[0027] Label explanation: 1-antenna oscillator, 11-slotted, 12-antenna ground via, 2-antenna transmitting feed line, 3-antenna receiving feed line, 41-receiving pin, 42-transmitting pin, 43-chip ground via, 51-transmitting feed line A section, 52-transmitting feed line B section, 53-transmitting feed line C section, 54-transmitting feed line D section, 6-coplanar line ground via, 7-feedback short line, 8-copper, 9-PCB board DETAILED DESCRIPTION

[0028] The utility model will be described in detail in combination with the drawings:

[0029] As Figures 1-3 Indicated: a high isolation small-sized double-sided panel circular antenna, including PCB board 9, the PCB board 9 is divided into top layer and bottom layer;The top layer is formed by copper paving antenna oscillator 1, feed line, chip pin and ground wire, the rest area is green oil and silk screen blank area, the bottom layer is whole layer ground copper foil;

[0030] The antenna oscillator 1 is circular, two feeding points are arranged on the antenna oscillator 1, and the included angle between the two feeding points and the center of the antenna oscillator 1 is 90 degrees; a slot 11 is arranged in the antenna oscillator 1 along the radial direction of the circle from the feeding point, one of the slots 11 is provided with an antenna transmitting feeder 2 connected with the feeding point and extending out of the antenna oscillator 1, and the other slot 11 is provided with an antenna receiving feeder 3 connected with the feeding point and extending out of the antenna oscillator 1; the two sides of any slot 11 are provided with antenna ground vias 12, and the two antenna ground vias 12 corresponding to any slot 11 are connected by the copper sheet 8 at the bottom layer of the PCB 9.

[0031] The antenna receiving feeder 3 is adjacent to and connected with the receiving pin 41 of the chip pin, and the transmitting pin 42 of the chip pin is also connected with a transmitting feeder, wherein the transmitting feeder is divided into a transmitting feeder A section 51, a transmitting feeder B section 52, a transmitting feeder C section 53 and a transmitting feeder D section 54; the transmitting feeder A section 51 is connected with the transmitting pin 42, and the transmitting feeder A section 51 overlaps the tangent line of the circle passing through the transmitting pin 42 in the antenna oscillator 1; the transmitting feeder C section 53 is a straight line and is parallel to the side of the PCB 9; the transmitting feeder B section 52 is an arc-shaped section and has two ends connected with the transmitting feeder A section 51 and the transmitting feeder C section 53 respectively; the transmitting feeder D section 54 is an arc-shaped section and has two ends connected with the transmitting feeder C section 53 and the antenna transmitting feeder 2 respectively; and the two sides of the transmitting feeder are ground lines with a plurality of coplanar line ground vias 6.

[0032] The antenna ground via 12 on one side of the antenna receiving feeder 3 is connected with a feedback short line 7, and the size of the feedback signal is adjusted by adjusting the length of the feedback short line 7 and the distance between the feedback short line 7 and the transmitting feeder, so that the size of the feedback signal is equal to the size of the leakage signal of the antenna from transmitting to receiving.

[0033] The antenna oscillator of the utility model is circular, and the circle radius of the antenna oscillator is determined according to the electromagnetic wave wavelength simulation of the antenna operating frequency. The feeding point position is similar to the position of the ordinary four-layer back-fed antenna, the included angle between the feeding point and the center of the antenna oscillator is 90 degrees, and the distance between the feeding point and the center of the antenna oscillator is determined according to the electromagnetic wave wavelength simulation of the antenna operating frequency.

[0034] The antenna transmitting feeder 2 is laid in the slot 11 to form a gap between the antenna transmitting feeder 2 and the antenna oscillator 1, and the width of the gap is 1 / 3 of the width of the antenna transmitting feeder 2; the antenna receiving feeder 3 is laid in the slot 11 to form a gap between the antenna receiving feeder 3 and the antenna oscillator 1, and the width of the gap is 1 / 3 of the width of the antenna receiving feeder 3.

[0035] Further, the transmitting feeder, the copper sheet 8, the antenna transmitting feeder 2 and the antenna receiving feeder 3 are all equal in width to ensure that the characteristic impedances are the same.

[0036] FromFigure 1 As can be seen, the slot is opened along the radial direction of the circle from the feeding point. In addition, the feeder uses coplanar line and microstrip line for impedance transformation. Because the slot destroys the problem of electromagnetic wave advancing along the metal edge, the antenna ground via 12 needs to be provided at the position on both sides of the slot, the antenna ground via 12 is connected by copper skin on the opposite side (bottom layer) of the antenna vibrator, the width of the connected copper skin is the same as the width of the feeder (including the transmitting feeder, the antenna transmitting feeder 2 and the antenna receiving feeder 3), that is, the characteristic impedance is the same, and they are all designed according to 50 ohms.

[0037] In the design process, the antenna receiving feeder 3 is very close to the receiving pin 41 of the chip pin of the radar chip, which is beneficial to reduce the receiving insertion loss and improve the receiving signal amplitude.

[0038] The total length of the transmitting feeder is equal to 1 / 2 wavelength.

[0039] It should be noted that the shape and length of the transmitting feeder of the utility model are very critical. The transmitting feeder starts from the transmitting pin 42 and is divided into four sections, that is, the transmitting feeder A section 51, the transmitting feeder B section 52, the transmitting feeder C section 53 and the transmitting feeder D section 54. Among them, the transmitting feeder A section extends outward in the form of a straight line close to a circular tangent to improve the antenna isolation; further improve the isolation; the transmitting feeder is designed according to the 50 ohm impedance matching of the coplanar line (the internal impedance of the transmitting port of the chip is 50 ohms). The transmitting feeder B section is connected to the C section in the form of a circular arc, the C section is a straight line parallel to the edge of the radar module PCB board to reduce the size. The transmitting feeder D section is connected to the antenna transmitting feeder in the form of a circular arc.

[0040] In addition, the length of the outer end of the antenna transmitting feeder 2 extending out of the edge of the antenna vibrator 1 is 5±1mm. Specifically, the antenna transmitting feeder 2 extends outward along the diameter direction of the circle by about 5mm, further improving the isolation.

[0041] The ground of the transmitting feeder on both sides is provided with a plurality of coplanar line ground vias 6; here, the ground line can also be laid.

[0042] Another key link of the utility model is the feedback stub. In the case that the total length of the transmitting feeder is equal to 1 / 2 wavelength, the transmitting feeder has a phase shift of about 180 degrees. In addition, there is a phase shift of about 90 degrees in the leakage from the transmitting to the receiving of the antenna, so that the feedback signal coupled by the parasitic capacitance between the feedback stub and the transmitting feeder has a phase shift of about 90 degrees; that is, at the receiving point, the feedback signal has a phase difference of 180 degrees with the leakage signal of the transmitting signal through the antenna.

[0043] The size of the feedback signal can be adjusted by adjusting the length of the feedback stub and the distance between the feedback stub and the transmitting feeder. In the actual design, two schemes can be used for adjustment design.

[0044] Scheme 1 under the condition of antenna simulation, the feedback stub is appropriately a little longer, after the PCB antenna is processed back, the length of the feedback stub is cut manually to adjust to the appropriate feedback size, finally the PCB antenna is processed according to the length of the feedback stub cut manually.

[0045] Scheme 2 is to process 5 or so different length feedback line PCB boards at one time, and select the most appropriate length of the feedback stub after testing.

[0046] Further, the chip pin is also provided with a chip ground via 43 (a ground balun is internally provided in the chip) or a center via ground is provided at the center of the antenna oscillator 1. Through the design, the static charge accumulation is eliminated.

[0047] Further, the PCB board 9 is a double-sided board, and the thickness is 1.6+ / -0.1mm. The utility model is made of a double-sided board, and the production cost can be effectively reduced. Figures 1-2 The middle dark color is the top layer pattern of the antenna, which is composed of copper foil; the light color area is a reserved area on the top layer, and no copper is laid, and no other things such as green oil and silk printing are laid; Figure 3 The bottom layer is a whole layer of copper foil. Because the thickness of the board has a great influence on the Q value of the antenna, and the thicker the circuit board is, the lower the Q value of the antenna is, and the flatter the isolation curve is, so the antenna is preferably 1.6mm thick standard board.

[0048] The effect of the utility model is shown in Figure 4 and Figure 5 . Figure 4 It is the radar intermediate frequency signal before the feedback signal size is adjusted, and the left half white curve is the noise when there is no Doppler signal; Figure 5 It is the radar intermediate frequency signal when the feedback signal size (that is, the length of the feedback line) is adjusted to the best feedback state (the feedback signal size is equal to the size of the antenna transmission to the receiving leakage signal), and the left half white curve is the noise when there is no Doppler signal, Figure 5 The middle and lower horizontal "Z" gray word waveforms are the triggering light-on signals. By comparison Figure 4 and Figure 5 It can be seen that the noise is reduced by about half, which means that the signal-to-noise ratio is increased by about 6dB. When the light is tested, the power frequency interference amplitude is smaller than that of the four-layer board module with a back feed antenna of the same size, and the ranging is farther than that of the four-layer board module.

[0049] According to the 1.6mm thick ordinary FR4 epoxy resin glass fiber 2-layer board designed in the manner, a 50 ohm coaxial line with an SMA head is welded at the chip pin position, and connected to a network analyzer to test the standing wave and isolation (S21), the isolation of the antenna at the center of the working frequency point is higher than 40dB; taking the 5.8GHz antenna as an example, the isolation in the range of +, -75MHz on both sides of the working frequency point is higher than 30dB, so the antenna has good application effect.

[0050] The following example illustrates the application of the high-isolation miniaturized double-panel circular antenna in low-power radar modules.

[0051] Let's take a 5.8GHz motion-triggered radar module as an example. Motion-sensing radar trigger chips, designed and manufactured using CMOS technology, are small, low-cost, and consume little power. Combined with a PCB board antenna, they form a radar module that can be installed inside LED lights, enabling smart lighting that turns on when someone approaches and turns off after a delay when they leave, saving overall electricity consumption. Currently, infrared sensor lights installed in building corridors rely on Fresnel lenses to partition the space and use differential input thermopile to detect human infrared thermal radiation. While inexpensive, the heat generated by LEDs interferes with the infrared detector, requiring the infrared sensor to be installed independently. Infrared sensor lights are only suitable for installation during the renovation of new houses and buildings, making them inconvenient for widespread use. Furthermore, Fresnel lenses made of acrylic glass are prone to aging over time, reducing the sensitivity of the infrared sensor. Additionally, in summer, the indoor temperature in southern buildings is close to body temperature, making it difficult to detect human movement and thus preventing lights from turning on when someone approaches.

[0052] Using motion-sensing chips based on the Doppler velocity principle to manufacture radar sensing modules offers the advantage of all-weather operation and allows for direct placement within lighting fixtures, particularly bulbs and T8 tubes. The original problem was that the radar module consumed over 10mA of power, requiring a separate switching power supply chip with a withstand voltage of over 300V. This switching power supply chip necessitated a filtering freewheeling inductor, increasing both cost and interference. To save costs, the industry began using a resistor divider scheme, directly drawing power from the 300V+ high voltage output of the rectified silicon bridge. This solution requires the radar module to consume less than 1.5mA; otherwise, heat dissipation becomes unavoidable. The performance of this double-layer circuit board radar module is not lower than that of a four-layer board radar module. Moreover, due to the isolation provided by the double-layer board, the radar chip is further away from the LED driver's freewheeling inductor and filtering capacitor (separated by a ground layer), resulting in less power frequency interference when used in bulbs compared to a four-layer board module. The double-layer plate antenna of this utility model allows radar modules with an amplitude of about 1mA to meet the application requirements of a sensing radius of more than 3 meters when mounted at a height of 3 meters, reducing material costs and patch costs, and enabling radar modules to be used more widely.

[0053] Finally, it should be noted that the above only for the preferred embodiments of the present application, and is not intended to limit the present application, although the foregoing embodiments of the present application has been described in detail, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included within the scope of the present application.

Claims

1. A high isolation compact dual panel circular antenna characterized by: The PCB board (9) is divided into a top layer and a bottom layer; the top layer is formed with an antenna oscillator (1), a feed line, a chip pin and a ground wire by copper plating, and the remaining area is a green oil and silk printing blank area; and the bottom layer is an entire layer of copper foil. The antenna oscillator (1) is circular, two feed points are arranged on the antenna oscillator (1), and the included angle between the two feed points and the line connecting the center of the antenna oscillator (1) is 90 degrees; a slot (11) is arranged in the antenna oscillator (1) from the feed point along the radial direction, one of the slots (11) is arranged with an antenna transmitting feed line (2) connected with the feed point and extending out of the antenna oscillator (1), and the other slot (11) is arranged with an antenna receiving feed line (3) connected with the feed point and extending out of the antenna oscillator (1); the two sides of any slot (11) are arranged with an antenna ground via (12), and the two antenna ground vias (12) corresponding to any slot (11) are connected by copper skin (8) at the bottom layer of the PCB board (9). The antenna receiving feed line (3) is adjacent to and connected with a receiving pin (41) of the chip pin, and a transmitting pin (42) of the chip pin is further connected with a transmitting feed line, wherein the transmitting feed line is further divided into a transmitting feed line A section (51), a transmitting feed line B section (52), a transmitting feed line C section (53) and a transmitting feed line D section (54); the transmitting feed line A section (51) is connected with the transmitting pin (42), and the transmitting feed line A section (51) overlaps with a tangent line of the antenna oscillator (1) passing through the transmitting pin (42); the transmitting feed line C section (53) is a straight line parallel to the side of the PCB board (9); the transmitting feed line B section (52) is an arc-shaped line section, and the two ends of the transmitting feed line B section (52) are connected with the transmitting feed line A section (51) and the transmitting feed line C section (53) respectively; the transmitting feed line D section (54) is an arc-shaped line section, and the two ends of the transmitting feed line D section (54) are connected with the transmitting feed line C section (53) and the antenna transmitting feed line (2) respectively; the two sides of the transmitting feed line are ground wires with a plurality of ground vias (6); The antenna ground via (12) on one side of the antenna receiving feed line (3) is connected with a feedback short line (7), and the size of the feedback signal is adjusted by adjusting the length of the feedback short line (7) and the distance between the feedback short line (7) and the transmitting feed line, so that the size of the feedback signal is equal to the size of the leakage signal of the antenna from transmitting to receiving.

2. The compact dual polarized circular antenna with high isolation according to claim 1, characterized in that: The antenna transmitting feed line (2) is arranged in the slot (11) to form a gap between the antenna transmitting feed line (2) and the antenna oscillator (1), and the width of the gap is 1 / 3 of the width of the antenna transmitting feed line (2); the antenna receiving feed line (3) is arranged in the slot (11) to form a gap between the antenna receiving feed line (3) and the antenna oscillator (1), and the width of the gap is 1 / 3 of the width of the antenna receiving feed line (3).

3. The compact dual polarized circular antenna with high isolation according to claim 1, characterized in that: The transmitting feed line, the copper skin (8), the antenna transmitting feed line (2) and the antenna receiving feed line (3) are all equal in width to ensure that the characteristic impedances are the same.

4. The compact dual polarized circular antenna with high isolation of claim 1, wherein: The total length of the transmitting feed line is equal to 1 / 2 wavelength.

5. The compact dual polarized circular antenna with high isolation of claim 1, wherein: The chip pin is further provided with a chip ground via (43); or the center of the antenna oscillator (1) is provided with a center via ground.

6. The compact dual polarized circular antenna with high isolation of claim 1, wherein: The PCB board (9) is a double-sided board with a thickness of 1.6±0.1mm.

7. The compact dual polarized circular antenna with high isolation of claim 1, wherein: The length of the antenna feed line (2) extending out of the edge of the antenna oscillator (1) is 3±1mm.

8. The application of the high-isolation miniaturized double-sided board circular antenna according to any one of claims 1-7 in a low-power radar module.

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