Bandwidth reconfigurable dual-polarized dielectric patch antenna for full-duplex communication

Abstract

This invention discloses a bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication. The antenna consists of a rectangular dielectric patch with a pair of grooves etched along its edges and two substrate layers. In the X-polarization direction, a single port is used to excite the fundamental mode TM. 10 mode and higher mode TE 12 This mode is used for broadband transmitter operation. For the Y-polarization direction, a differential feed structure is used to excite a degenerate TM. 01 Mode and Inversion™ 02 This mode is used for broadband receiver operation. A metal ground plane is placed between two substrates, and two sets of slots are etched on it for aperture coupling between the dielectric patch resonator and the metal microstrip line located at the bottom of the lower substrate. A variable capacitor is placed in the coupling slot in the Y-polarization direction to tune the operating bandwidth of the dielectric patch antenna in the Y-polarization direction. This gives the antenna advantages such as bandwidth reconfigurability, high isolation, low profile, and simple structure, making it promising for applications in full-duplex systems.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication. Background Technology

[0002] Currently available spectrum resources are very limited, and with the rapid development of wireless communication, these resources are becoming increasingly congested. Improving spectrum utilization has become a key research topic. Most wireless communication systems currently function as terminals that both transmit and receive signals (e.g., base stations, relays, and mobile terminals). These systems are mostly time-division or frequency-division duplex systems, meaning that these terminals transmit and receive signals at different times or frequency bands. However, simultaneous full-duplex communication systems (SDMS) ensure that transmission and reception are completed simultaneously on the same frequency, thus doubling the data transmission speed, communication capacity, and spectrum utilization. As the front end of a full-duplex system, using high-isolation antennas is crucial for achieving high-quality communication in engineering applications. Antenna separation, near-field cancellation, parasitic structures, and placing absorbers between antennas can all achieve high isolation. These techniques typically employ multiple separate antennas or large and complex antenna structures, resulting in a large physical size.

[0003] Dual-polarized antennas have attracted widespread attention due to their miniaturization advantages through shared radiating apertures and the natural isolation between orthogonal polarizations. To meet the high isolation requirements of full-duplex applications, various low-profile differentially fed dual-polarized antennas have been extensively developed. However, these designs are all metal-based, mostly operate in single-mode, and have narrow bandwidths, making them unsuitable for high-speed, high-capacity applications. Recently, a novel feeding structure—magnetic loop—has been developed to enhance bandwidth; antennas composed of magnetic and electrical feeds have achieved wider bandwidths, but port isolation only exceeds 20 dB. Furthermore, superimposing metasurface structures on the feed patch has achieved a bandwidth of 28.4%; however, high profile remains a limiting factor, and complexity increases with the introduction of overhead structures.

[0004] Dielectric resonator antennas are also suitable for dual-polarization designs and have been extensively studied over the past few decades. Dielectric patch antennas represent the best trade-off between dielectric resonator antennas and microstrip patch antennas in terms of shape, efficiency, and gain, developed to overcome the limitations of traditional dielectric resonator antennas, such as their large size and poor gain. More importantly, the higher-order modes of dielectric patch resonators can achieve bandwidth extension, thanks to the multi-mode characteristics inherited from dielectric resonators. In the literature S.-C. Tang, X.-Y. Wang, W.-W. Yang and J.-X. Chen, “Wideband low-profile dielectricpatch antenna and array with anisotropic property,” IEEE Trans. Antennas Propag., vol. 68, no. 5, pp. 4091-4096, May. 2020, by introducing silver-plated grooves, the higher-order modes can be shifted down to near the fundamental mode, thereby achieving bandwidth extension for linearly polarized antennas. To our knowledge, the design of dual-polarized dielectric patch antennas is rare. The dual-polarized dielectric patch antenna described in the literature X.-Y. Wang, S.-C. Tang and J.-X. Chen, “Differential-fed dual-polarized dielectric patch antenna with gain enhancement based on higher order modes,” IEEE Antennas Wireless Propag. Lett., vol. 19, no. 3, pp. 502-506, March. 2020, achieves a high isolation of 34 dB using differential feeding technology. Although the introduced grounding rod can combine the higher order modes of the dielectric patch, the bandwidth can only be extended to 4.88%.

[0005] On the other hand, with the rapid development of wireless communication systems, bandwidth-reconfigurable communication systems have attracted increasing attention due to their efficient use of spectrum. However, there is currently no dual-polarized dielectric patch antenna design that can simultaneously achieve bandwidth reconfigurability and high port isolation. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and propose a bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication. This antenna fully utilizes the multimode characteristics of the dielectric patch resonator, and by adjusting the aspect ratio of the dielectric patch, the high-order TE can be reduced. 12 The pattern is made closer to the fundamental mode TM. 10This mode enables broadband performance in the X-polarization direction, while simultaneously enhancing the TM through a pair of grooves etched at the edge of the dielectric patch and improved coupling gaps on the ground plane. 01 Mode and Inverting TM 02 The antenna achieves broadband performance in the Y-polarization direction through mode-to-mode coupling. Four varactor diodes are placed on the U-shaped coupling slots in the Y-polarization direction to electrically tune the operating bandwidth in that direction, thus enabling bandwidth reconfigurability. High isolation of the antenna is achieved through a differential feeding scheme.

[0007] To achieve the objectives of this invention, a bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication is proposed. This antenna consists of a rectangular dielectric patch with a pair of grooves etched along its edges and two substrate layers. The dielectric patch is placed on the top substrate and excited by three ports. In the X-polarization direction, a single port is used to excite the fundamental mode TM. 10 mode and higher mode TE 12 This mode is used for broadband transmitter (Tx) operation. For the Y-polarization direction, a differential feed structure is used, and a degenerate TM is excited through a pair of differential input ports. 01 Mode and Inversion™ 02 This mode is used for broadband receiver (Rx) operation. A metallic ground plane is placed between two substrates, on which coupling slots are etched for aperture coupling between the dielectric patch resonator and the metal microstrip line located at the bottom of the lower substrate. Specifically, the coupling slot corresponding to the single-feed input feed is a linear coupling slot for aperture coupling in the X-polarization direction; the coupling slot corresponding to the differential input feed consists of two sets of composite coupling slots symmetrically arranged on the outer sides of the linear coupling slot. Each set of composite coupling slots includes a rectangular slot and two U-shaped coupling slots arranged symmetrically along the Y-polarization direction outside the rectangular slot. A variable capacitor is located in the center of each U-shaped coupling slot. The composite coupling slots are used for aperture coupling in the Y-polarization direction.

[0008] This invention achieves high antenna isolation through a differential feeding scheme. By adjusting the aspect ratio of the dielectric patch, higher-order TE can be reduced. 12 The pattern is made closer to the fundamental mode TM. 10 The mode achieves broadband performance in the X-polarization direction; TM is achieved through a pair of grooves etched at the edge of the dielectric patch and an improved coupling gap on the metallic reflective floor. 01 Module upshift and inversion TM 02 The mode is shifted downwards to achieve broadband performance in the Y-polarization direction; at the same time, the operating bandwidth in the Y-polarization direction is electrically tuned by a varactor diode.

[0009] This antenna has advantages such as reconfigurable bandwidth, high isolation, low profile, and simple structure, and has broad application prospects in full-duplex systems. Attached Figure Description

[0010] The invention will now be further described with reference to the accompanying drawings.

[0011] Figure 1 This is a three-dimensional view of the bandwidth-reconfigurable dual-polarized dielectric patch antenna of the present invention.

[0012] Figure 2 This is a schematic diagram of the bandwidth-reconfigurable dual-polarized dielectric patch antenna structure of the present invention.

[0013] Figure 3 This invention relates to the simulated return loss and port isolation of the bandwidth-reconfigurable dual-polarized dielectric patch antenna.

[0014] Figure 4 This is a simulation pattern of the single-feed input port of the bandwidth-reconfigurable dual-polarized dielectric patch antenna of the present invention at 4.98 GHz.

[0015] Figure 5 This is a simulation pattern of the single-feed input port of the bandwidth-reconfigurable dual-polarized dielectric patch antenna of the present invention at 5.98 GHz.

[0016] Figure 6 This is a simulated radiation pattern at 5.06 GHz of the differential input port of the bandwidth-reconfigurable dual-polarized dielectric patch antenna of the present invention with an adjustable capacitor of 0.6 pF.

[0017] Figure 7 This is the simulated radiation pattern at 5.58 GHz of the differential input port of the bandwidth-reconfigurable dual-polarized dielectric patch antenna of this invention, with an adjustable capacitance of 0.6 pF.

[0018] Figure 8 This is the simulated radiation pattern at 5.24 GHz of the differential input port of the bandwidth-reconfigurable dual-polarized dielectric patch antenna of this invention, with an adjustable capacitance of 0.1 pF.

[0019] Figure 9 This is the simulated radiation pattern of the differential input port of the bandwidth reconfigurable dual-polarized dielectric patch antenna of the present invention at 5.58 GHz with an adjustable capacitance of 0.1 pF.

[0020] The labels in the diagram are as follows:

[0021] 1-Dielectric patch, 2-Groove, 3-Top substrate, 4-Metal reflective ground plane, 5-Linear coupling slot, 6-Composite coupling slot, 7-Variable capacitor, 8-Bottom substrate, 9-Single-feed microstrip feed line, 10-Differential microstrip feed line, S1-Single-feed input port, S2-Differential input port. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0023] See Figure 1 This is a schematic diagram of a bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to an embodiment of the present invention. The dual-polarized dielectric patch antenna of the present invention includes a bottom substrate 8, a metal reflective ground 4, a top substrate 3, and a dielectric patch 1 stacked sequentially from bottom to top. The dielectric patch 1 is a rectangular dielectric patch, glued to the center of the top substrate 3, with its short side located in the X-polarization direction. A pair of grooves 2 are etched along the edge of the short side of the dielectric patch 1, symmetrical about the vertical midline of the dielectric patch 1. The lower surface of the bottom substrate 8 is provided with a single-feed microstrip feed line 8 and a differential microstrip feed line 9. Both the single-feed microstrip feed line 8 and the differential microstrip feed line 9 consist of a 50Ω transmission line near the input port and a λ / 4 impedance transformation line for matching. The 50Ω transmission line is connected to the signal input port. The bottom substrate 7 is a double-sided printed circuit board. The top layer of the double-sided printed circuit board is a metal reflective ground plane 4, and the bottom layer consists of a single-feed microstrip feed line 9 and a differential microstrip feed line 10. The single-feed microstrip feed line 9 is arranged along the X-polarization direction, and the differential microstrip feed line 10 is arranged along the Y-polarization direction. Coupling slots orthogonal to the corresponding microstrip feed lines are etched on the metal reflective ground plane 4. The coupling slots include a straight coupling slot 5 located in the center of the metal reflective ground plane 4 and orthogonal to the single-feed microstrip feed line 9, and two sets of composite coupling slots 6 located at both ends of the straight coupling slot 5 and orthogonal to the differential microstrip feed line 10. Each set of composite coupling slots 6 includes a rectangular slot and two U-shaped coupling slots arranged symmetrically along the Y-polarization direction outside the rectangular slot. A variable capacitor 7 is arranged in the center of the U-shaped coupling slot. Four variable capacitors 7 are placed on two pairs of U-shaped slots respectively. The bandwidth of the differential input port of the dielectric patch antenna (the operating bandwidth of the dielectric patch antenna in the Y polarization direction) is tuned by adjusting the capacitance C of the variable capacitors.

[0024] The lower surface edge of the substrate 7 is also provided with a single-feed input port S1 connected to the single-feed microstrip feed line 9, and differential input ports S2+ and S2- connected to the differential microstrip feed line 10.

[0025] In the X-polarization direction, the fundamental mode TM is excited by a single-fed microstrip feeder 9. 10 mode and higher mode TE 12 The mode is used for broadband transmitter operation; in the Y-polarization direction, a degenerate TM is excited through a differential microstrip feed line 10. 01 Mode and Inversion™ 02 This mode is used for broadband receiver operation.

[0026] The dimensions of each part of the antenna are optimized in this embodiment of the invention. The specific antenna parameters are shown in the table below:

[0027] parameter <![CDATA[L g ]]> <![CDATA[W g ]]> h <![CDATA[l d ]]> <![CDATA[w d ]]> <![CDATA[h d ]]> <![CDATA[l c ]]> <![CDATA[w c ]]> <![CDATA[l s1 ]]> Value (mm) 55 60 0.813 36.8 26 1.5 8 6.2 8.3 parameter <![CDATA[w s1 ]]> <![CDATA[l s2 ]]> <![CDATA[l s3 ]]> <![CDATA[l s4 ]]> <![CDATA[w s2 ]]> <![CDATA[d s1 ]]> <![CDATA[d s2 ]]> <![CDATA[w f1 ]]> <![CDATA[w f2 ]]> Value (mm) 0.9 10.2 8 6 1.1 24 1 1.5 1.4

[0028] In the table, h represents the height of the top substrate 3 and the bottom substrate 8, and l represents the height of the bottom substrate 8. d w is the length of dielectric patch 1 d h is the width of media patch 1 d For the thickness of the dielectric patch, l c w is the length of groove 2 c l is the width of groove 2 s1 w is the length of the linear coupling gap 5. s1 For the straight coupling gap 5, the width of the coupling gap is l s2 The length of the rectangular gap in the composite coupling gap 6, l s3 and l s4 w represents the length of the middle and bent portions of the U-shaped coupling gap in the composite coupling gap. s2 d is the width of the composite coupling gap. s1 d is the distance between the rectangular gaps of the two composite coupling gaps. s2 This is the distance between the U-shaped coupling gap and the rectangular gap in the composite coupling gap.

[0029] The substrate used in the design is Rogers RO4003, with a dielectric constant of ε. r =3.38, the loss tangent is tanδ = 2.7 × 10 -3 The volume of the top substrate 3 and the bottom substrate 8 is L. g ×W g ×h, the bottom substrate 8 is a double-sided printed circuit board, the upper surface of the double-sided printed circuit board 8 is a metal reflective ground 4, and the lower surface is a microstrip feed line.

[0030] Figure 3 This example demonstrates the simulated reflection coefficient and port isolation of a bandwidth-reconfigurable dual-polarized dielectric patch antenna under different capacitance values. The single-feed input port bandwidth is 26.8%, and the bandwidth of the differential input port with a reflection coefficient less than -10dB can be flexibly adjusted from 12.1% to 16.9%. The port isolation is greater than 57dB. As shown in the figure, the low-frequency resonant point of the differential input port shifts downwards as capacitance (C) increases.

[0031] Simulated E-plane and H-plane radiation patterns at different adjustable capacitor values ​​are as follows: Figure 4-9 As shown in the figure, it can be seen that the cross polarization of the antenna is at least 20dB lower than the main polarization. It can also be inferred that the antenna can exhibit a stable wide-side radiation pattern throughout the entire bandwidth tuning range.

[0032] In addition to the embodiments described above, the present invention may have other implementations. All technical solutions formed by equivalent substitution or equivalent transformation fall within the protection scope claimed by the present invention.

Claims

1. A bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication, comprising a bottom substrate (8), a metal reflective ground plane (4), a top substrate (3), and a dielectric patch (1) stacked sequentially from bottom to top, characterized in that: The lower surface of the substrate (8) is provided with a single-fed microstrip feed line (9) along the X-polarization direction and a pair of differential microstrip feed lines (10) along the Y-polarization direction. The metal reflective ground plane (4) has coupling slots (5, 6) orthogonal to the corresponding microstrip feed lines. In the X-polarization direction, the fundamental mode TM is excited through the single-fed microstrip feed line (9). 10 mode and higher mode TE 12 The mode is used for broadband transmitter operation; in the Y-polarization direction, a degenerate TM is excited through a differential microstrip feed line (10). 01 Mode and Inversion™ 02 The mode is used for broadband receiver operation; the dielectric patch (1) is a rectangular dielectric patch with a pair of grooves (2) symmetrically arranged in the vertical center. The coupling gaps (5, 6) include a straight coupling gap (5) located in the center of the metal reflector (4) and orthogonal to the single-feed microstrip feed line (9) and two sets of composite coupling gaps (6) located at both ends of the straight coupling gap (5) and orthogonal to the differential microstrip feed line (10). Each set of composite coupling gaps (6) includes a rectangular gap and two U-shaped coupling gaps arranged outside the rectangular gap and symmetrical along the Y polarization direction. A variable capacitor (7) is arranged in the center of the U-shaped coupling gap.

2. The bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to claim 1, characterized in that: The variable capacitor (7) is used to tune the working bandwidth of the dielectric patch antenna in the Y-polarization direction.

3. The bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to claim 1, characterized in that: The lower surface edge of the substrate (8) is also provided with a single-feed input port (S1) connected to the single-feed microstrip feed line (9), and a differential input port (S2+, S2-) connected to the differential microstrip feed line (10).

4. The bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to claim 1, characterized in that: The short side of the dielectric patch (1) is located in the X polarization direction, and the groove (2) is formed on one side of the short side of the dielectric patch (1).

5. The bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to claim 3, characterized in that: The single-feed microstrip feed (9) and the differential microstrip feed (10) consist of a 50Ω transmission line and a λ / 4 impedance transformation line for matching, wherein the 50Ω transmission line is connected to the signal input port.

6. The bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to claim 1, characterized in that: The bottom substrate (8) is a double-sided printed circuit board. The top layer of the double-sided printed circuit board is a metal reflective ground plane (4), and the bottom layer is a single-feed microstrip feed line (9) and a differential microstrip feed line (10).

7. The bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to claim 1, characterized in that: The dielectric patch (1) is glued to the center of the upper surface of the top substrate (3).

8. The bandwidth-reconfigurable dual-polarized dielectric patch antenna for full-duplex communication according to claim 1, characterized in that: The variable capacitor (7) is a varactor diode.

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