Coplanar-Waveguide-Based Hybrid Reconfigurable Antenna

Abstract

The present invention discloses a hybrid reconfigurable antenna based on a coplanar waveguide, which can realize the reconfiguration of the polarization characteristics and resonant frequency characteristics of the antenna. By using an external bias voltage and controlling the working mode of PIN diodes, the changes of left-handed circular polarization, right-handed circular polarization, linear polarization characteristics and the adjustment of the resonant frequency are realized. The present invention has the advantages of simple structure, low cost, multiple reconfigurable functions, easy adjustment and stable performance, and can be widely applied in wireless communication, etc.

Description

Technical Field

[0001] The present invention relates to the field of antenna design, and particularly to an antenna system with frequency tunable and polarization characteristic switching functions, especially an antenna for left / right circular polarization and linear polarization switching as well as frequency adjustment. Background Art

[0002] Today, wireless communication technology has developed rapidly. As long as there is wireless network coverage, people can freely transmit data with others. With the continuous development of wireless communication technology, new wireless technologies are constantly improving, so the wireless channels used are also constantly updated. Due to the different requirements of different wireless transmission systems, modern antennas with multiple electrical characteristics have a higher status. For example, systems such as the GSM900 system, DCS1800 system, 3G wireless communication system, and WLAN wireless local area network system all use different radio channels. Especially, the wireless communication system has now entered the 5G era. In the actual product R & D process, the space usually left for the antenna is relatively limited, and the device volume increases, which will lead to an increase in the complexity of antenna design, large interference between antennas, indirectly increasing the design cost of the product, and different requirements for each frequency band, resulting in low spectrum utilization. In addition, with the upgrade of the system, the device also needs to be updated, with high costs and low working efficiency.

[0003] During the propagation of radio waves, due to multipath conditions and poor antennas, etc., problems such as a decline in the transmission quality of signals are likely to occur. To solve the above technical problems, usually a single antenna is used to dynamically adjust its working frequency, radiation pattern, polarization and other characteristics, and thus the signal fading caused by the external environment can be effectively overcome. Among various different reconfigurable antenna designs, polarization reconfigurability can, under the same working frequency, utilize the different transmission characteristics of orthogonal polarizations to achieve polarized reception or transmission, and the change to the backend signal processing part is also the smallest, so it receives the highest attention. However, at present, most polarization reconfigurable schemes use MEMS RF switches, resulting in a very complex structure design, greatly increasing the production difficulty, leading to an increase in production costs. In addition, due to the complex structure, the damage rate is greatly increased, making the actual service life have certain limitations and large losses, which is not conducive to practical applications. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problems of complex reconfigurable antenna design, single performance, and relatively complex DC control, etc., and provide a frequency and polarization hybrid reconfigurable antenna based on a coplanar waveguide.

[0005] The technical solution adopted by the present invention to solve its technical problems is:

[0006] A hybrid reconfigurable antenna based on a coplanar waveguide, comprising a dielectric substrate, a circuit layer, PIN diodes and a bias voltage mounted on the dielectric substrate; the circuit layer includes a center conductor and ground planes disposed on both sides of the center conductor, the ground planes are divided into ground plane units by at least one straight slot, and adjacent ground plane units are electrically connected by PIN diodes bridging the straight slot, and the bias voltage is electrically connected to the PIN diodes.

[0007] Preferably, the center conductor includes a transmission line with impedance matching and an electromagnetic radiator.

[0008] Preferably, the shape of the electromagnetic radiator is symmetric about the central extension line of the transmission line.

[0009] Preferably, the ground plane is further provided with a U-shaped slot.

[0010] Preferably, one end of the U-shaped slot is bridged on the ground planes on both sides of the U-shaped slot by a PIN diode, the other end of the U-shaped slot is bridged on the ground planes on both sides of the U-shaped slot by a patch capacitor, and the bias voltage is electrically connected to the patch capacitor.

[0011] Preferably, the two ground planes are symmetrically arranged on both sides of the center conductor.

[0012] Preferably, the widths of the straight slot and the U-shaped slot are 0.1 mm - 5 mm.

[0013] Preferably, the transmission line is cascaded by one or several strip lines with different widths.

[0014] Preferably, a connector for accessing an electromagnetic signal is provided at the bottom end of the transmission line.

[0015] The beneficial effects of the present invention are as follows:

[0016] The present invention can realize the reconfiguration of the polarization characteristics and resonance frequency characteristics of the antenna. By controlling the working mode of the PIN diodes, the changes of left-handed circular polarization, right-handed circular polarization, linear polarization characteristics and the adjustment of the resonance frequency can be realized. It can dynamically provide frequency, pattern and polarization flexibility in a single antenna, and has the advantages of good signal reception performance, small size, low cost, multiple reconfigurable functions, easy adjustment and stable performance. It has a wide application range in the field of wireless communication, and is realized by placing switching elements on the antenna ground layer or radiator elements. The polarization diversity antenna can also alleviate the fading caused by multipath conditions and bad weather, so it is beneficial in satellite, mobile and wireless communication systems. Description of the Drawings

[0017] Figure 1 It is the overall structure diagram of the present invention.

[0018] Figure 2 This is the equivalent structure diagram of the present invention in the right - hand circular polarization mode.

[0019] Figure 3 This is the equivalent structure diagram of the present invention in the left - hand circular polarization mode.

[0020] Figure 4 This is the equivalent structure diagram of the present invention in the linear polarization mode.

[0021] Figure 5 This is the equivalent structure diagram of the frequency - reconfigurable of the present invention.

[0022] Figure 6 This is the scattering parameter diagram of the present invention in different states.

[0023] Figure 7 This is the axial ratio diagram of the present invention in different states. Detailed implementation manners

[0024] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] Embodiment 1

[0026] The present invention discloses a hybrid reconfigurable antenna based on a coplanar waveguide. As Figure 1 shown, it includes a dielectric substrate 1, a circuit layer 2, PIN diodes 7 and a bias voltage mounted on the dielectric substrate 1. The circuit layer 2 includes a center conductor and ground planes 5 arranged on both sides of the center conductor. The ground plane 5 is divided into ground plane units 51 by a straight - line slot 61. Adjacent ground plane units 51 are electrically connected by PIN diodes 7 bridging across the straight - line slot 61, and the bias voltage is electrically connected to the PIN diodes 7. The center conductor includes a transmission line 3 with impedance matching and an electromagnetic radiator 9. The shape of the electromagnetic radiator 9 is symmetric about the central extension line of the transmission line 3. The two ground planes 5 are symmetrically arranged on both sides of the center conductor. The transmission line 3 is cascaded by strip lines with one or several different widths.

[0027] In the above - mentioned technical solution, the PIN diodes 7 are bridged across both ends of the straight - line slot 61, and the working state of the PIN diodes 7 can be controlled by the bias voltage, thereby realizing the reconfigurable characteristics of the antenna parameters. By controlling the working mode of the PIN diodes 7, the changes in the left - hand circular polarization, right - hand circular polarization, linear polarization characteristics and the adjustment of the resonance frequency are realized.

[0028] It can be understood that the dielectric substrate 1 is used to support the circuit layer 2 and the PIN diodes 7.

[0029] It is understandable that the external bias voltage can be a DC source or the voltage output in a complex circuit, and the voltage can be controlled according to application requirements, making it very flexible to use.

[0030] In a further setting of the present invention, the floor 5 is further provided with a U-shaped slit 62. One end of the U-shaped slit 62 is bridged across the floor 5 on both sides of the U-shaped slit 62 through a PIN diode 7, and the other end of the U-shaped slit 62 is bridged across the floor 5 on both sides of the U-shaped slit 62 through a chip capacitor 8, and the bias voltage is electrically connected to the chip capacitor 8.

[0031] Furthermore, the widths of the straight slit 61 and the U-shaped slit 62 are 0.1 mm - 5 mm.

[0032] It can be conceived that, in combination with the slit length, PIN diodes can be loaded at the middle or both ends of the slit respectively, and the working states of these PIN diodes can be controlled simultaneously to enable the metal patch to achieve good disconnection and connection characteristics.

[0033] It is understandable that by isolating the DC connection of the metal patches at both ends of the patch, the short circuit of the external bias voltage is thereby avoided. The positive and negative poles of the bias voltage are respectively located at both ends of the chip capacitor 8, and the working state of the PIN diode 7 bridged across the U-shaped slit 62 is controlled by relying on its voltage magnitude.

[0034] A connector 4 for accessing an electromagnetic signal is provided at the bottom end of the transmission line 3.

[0035] It is understandable that the electromagnetic signal is fed into the antenna by the connector 4, impedance matching is performed through the transmission line 3, and the electromagnetic radiator 9 converts the electromagnetic wave from the conduction mode to the radiation mode according to a certain pattern.

[0036] It can be conceived that by relying on the DC voltage difference at both ends of the straight slit 61 and the U-shaped slit 62 to control the working mode of the PIN diode 7 bridged across the slit, the electromagnetic connection and disconnection of the chip capacitors 8 at both ends can be realized, thereby changing the current distribution on both sides of the floor and the magnitude of the resonant frequency, and forming the reconfigurable characteristic of the antenna parameters.

[0037] The hybrid reconfigurable antenna based on coplanar waveguide of the present invention can be applied to complex scenarios in a wireless communication system, can adopt polarization diversity reception and frequency adjustment operations, and can also be subjected to conformal design with other devices. The hybrid reconfigurable antenna based on coplanar waveguide of the present invention has the advantages of simple structure, polarization reconfigurability, frequency reconfigurability, stable performance, and being conducive to mass production.

[0038] It is understandable that, as Figure 2As shown, it is the equivalent structure diagram in the right-handed circular polarization mode. In this operating mode, the bias voltage turns on the PIN diodes on the straight slot 61 and the PIN diodes on the U-shaped slot 62 on the left floor 5, while the PIN diodes on the U-shaped slot 62 on the right floor 5 are turned off. At this time, the left floor of the antenna is equivalent to a larger metal plate, while the right floor is equivalent to a metal plate with an open slot loaded. The current distributions on the two floors are different, enabling the antenna to operate in the right-handed circular polarization mode.

[0039] Specifically, as Figure 6 shown, it is the scattering parameter diagram in different states. Due to the symmetry of the structure, the antenna operates in the right-handed circular polarization state. At the same time, by changing the on and off states of the PIN diodes on the straight slot, the resonant frequency can be adjusted. When the PIN diodes on the straight slot are off, the center frequency of the antenna is 1.25 GHz, while when the PIN diodes on the straight slot are on, the resonant frequency of the antenna is 1.13 GHz.

[0040] Furthermore, as Figure 7 shown, it is the axial ratio diagram in different states, and the antenna operates in the right-handed circular polarization state. Figure 7 The axial ratio curve of the circular polarization characteristic of the antenna is given while changing the on and off states of the PIN diodes on the straight slot simultaneously. It can be seen from Figure 7 that the axial ratio near the frequency point of 1.13 GHz is 2.88 dB, and the axial ratio near the frequency point of 1.25 GHz is 1.16 dB, having good circular polarization characteristics.

[0041] As Figure 3 shown, it is the equivalent structure diagram in the left-handed circular polarization mode. In this operating mode, the bias voltage turns on the PIN diodes on the straight slot 61 and the PIN diodes on the U-shaped slot 62 on the right floor 5, while the PIN diodes on the U-shaped slot 62 on the left floor 5 are turned off. At this time, the right floor of the antenna is equivalent to a larger metal plate, while the left floor is equivalent to a metal plate with an open slot loaded. The current distributions on the two floors are different, enabling the antenna to operate in the left-handed circular polarization mode.

[0042] As Figure 4 shown, it is the equivalent structure diagram in the linear polarization mode. In this operating mode, the bias voltage turns on all the PIN diodes 7. At this time, both the left and right floors of the antenna are equivalent to larger metal plates, and the current distributions on the two floors are the same, enabling the antenna to operate in the linear polarization mode.

[0043] As Figure 5As shown, it is a frequency-reconfigurable equivalent structure diagram. In this operating mode, by simultaneously controlling the on or off state of the PIN diodes on the straight slot, the sizes of the two sides of the ground plane can be effectively changed, thereby changing the operating frequency of the antenna. The antenna can adjust the operating frequency of the antenna in three modes: right-hand circular polarization, left-hand circular polarization, and linear polarization. Thus, a hybrid reconfigurable antenna is formed.

[0044] Embodiment 2

[0045] The difference between this embodiment and Embodiment 1 is that the ground plane 5 is divided into ground plane units 51 by two straight slots 61, and adjacent ground plane units 51 are electrically connected by PIN diodes 7 bridging the straight slots 61.

[0046] It can be understood that by controlling the on and off of different PIN diodes, the current distributions on the two sides of the ground plane are different, so that the antenna can adjust different operating modes. The principle is the same as that of Embodiment 1. Therefore, no specific description is given in this embodiment.

[0047] Embodiment 3

[0048] The difference between this embodiment and Embodiment 1 is that the ground plane 5 is divided into ground plane units 51 by no less than two straight slots 61, and adjacent ground plane units 51 are electrically connected by PIN diodes 7 bridging the straight slots 61.

[0049] It can be understood that by controlling the on and off of different PIN diodes, the current distributions on the two sides of the ground plane are different, so that the antenna can adjust different operating modes. The principle is the same as that of Embodiment 1. Therefore, no specific description is given in this embodiment.

[0050] It should be noted that with different numbers of straight slots, by turning on the PIN diodes, current distributions with different areas on the two sides of the ground plane can be realized, so that the antenna can adjust different operating modes.

[0051] The above-mentioned hybrid reconfigurable antenna based on coplanar waveguide is only given as a preferred example and is not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A hybrid reconfigurable antenna based on a coplanar waveguide, characterized in that It includes a dielectric substrate (1), a circuit layer (2) mounted on the dielectric substrate (1), a PIN diode (7), and a bias voltage; the circuit layer (2) includes a center conductor and ground planes (5) arranged on both sides of the center conductor, the ground planes (5) are divided into ground plane units (51) through at least one straight slot (61), adjacent ground plane units (51) are electrically connected through a PIN diode (7) bridging across the straight slot (61), the bias voltage is electrically connected to the PIN diode (7), and a U-shaped slot (62) is further provided on the ground plane (5), one end of the U-shaped slot (62) is bridged across the ground planes (5) on both sides of the U-shaped slot (62) through a PIN diode (7), the other end of the U-shaped slot (62) is bridged across the ground planes (5) on both sides of the U-shaped slot (62) through a chip capacitor (8), and the bias voltage is electrically connected to the chip capacitor (8).

2. The hybrid reconfigurable antenna based on a coplanar waveguide according to claim 1, characterized in that The center conductor includes a transmission line (3) with impedance matching and an electromagnetic radiator (9).

3. The hybrid reconfigurable antenna based on a coplanar waveguide according to claim 2, wherein The shape of the electromagnetic radiator (9) is symmetric about the central extension line of the transmission line (3).

4. The hybrid reconfigurable antenna based on coplanar waveguide according to claim 3, wherein, Two ground planes (5) are symmetrically arranged on both sides of the center conductor.

5. The hybrid reconfigurable antenna based on a coplanar waveguide according to claim 3, wherein The widths of the straight slot (61) and the U-shaped slot (62) are 0.1 mm - 5 mm.

6. The hybrid reconfigurable antenna based on a coplanar waveguide according to claim 3, wherein The transmission line (3) is cascaded by one or several strip lines with different widths.

7. The hybrid reconfigurable antenna based on a coplanar waveguide according to claim 2, characterized in that A connector (4) for accessing an electromagnetic signal is provided at the bottom end of the transmission line (3).

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