TW201810802A - Antenna structure with tunable radiation pattern - Google Patents

Abstract

An antenna structure with tunable radiation pattern comprises a monopole antenna, a control unit and a first reflector unit. The monopole antenna is vertically disposed on a ground plane. The first reflector unit comprising a first metal arm, a first RF diode, a second metal arm and a first capacitor is located at a first side of the monopole antenna. The first metal arm is parallel to the monopole antenna. The first RF diode is connected between the first metal arm and the ground plane. The second metal arm is connected to the first metal arm. The second metal arm is connected to the control unit via a first wire. The second metal arm is connected to the ground via the capacitor. Traces of the first wire starts from a second terminal of the second metal arm, and then goes along neighbors of the first capacitor until the ground plane for connecting to the control unit. When the first RF diode is conducted, the first metal arm enhances the antenna gain of a first opposite side.

Description

Adjustable radiation field type antenna structure

The present invention relates to an antenna, and more particularly to an antenna structure that can adjust the radiation pattern.

Nowadays, terminal devices such as notebook computers and tablet computers must have wireless networking functions, so wireless modules and antennas are necessary components. In view of the fact that the wireless network environment used by the terminal device products may be different with time and place, the antenna design conventionally applied to the terminal device generally only considers its antenna efficiency, antenna gain, and specific absorption rate (SAR), or Consider the omnidirectional radiation pattern as a basic requirement for design considerations.

However, the radiation pattern of the antenna varies depending on the basic operating principle of the antenna. For example, a dipole antenna can generate an omnidirectional radiation pattern, and a patch antenna can generate a lateral side (broadside). The radiation field type. In the case where the antenna design on the product is fixed, in response to various communication environments encountered by the notebook computer and the tablet computer, communication failure or data transmission speed may be deteriorated at certain times or in some applications.

In order to solve the foregoing prior art problem, the embodiment of the present invention provides An antenna structure with adjustable radiation field type, which utilizes a single antenna design to achieve an adjustable effect of the radiation field type, thereby achieving a change (or promotion) of data transmission speed in response to the use environment.

Embodiments of the present invention provide an antenna structure capable of adjusting a radiation field type, including a monopole antenna, a control unit, and a first reflection unit. The monopole antenna is vertically disposed on the ground plane and receives the RF signal feed to produce a quarter-wave resonance mode having an omnidirectional radiation pattern in a horizontal plane. The control unit is controlled by the first control signal to determine whether to output the first DC control voltage by using the first wire and the second wire, the first DC control voltage is such that the DC potential of the first wire is greater than the DC potential of the second wire, The two wires are electrically connected between the ground plane and the control unit. The first reflective unit is disposed on the first side of the monopole antenna, and the first reflective unit includes a first metal arm, a first radio frequency diode, a second metal arm, and a first capacitor. The first metal arm has a first end and a second end, the first metal arm is parallel to the monopole antenna, and the first end of the first metal arm is at a greater distance from the ground plane than the second end of the first metal arm and the ground plane distance. The first RF electrode has an anode end and a cathode end. The anode end of the first RF diode is connected to the second end of the first metal arm, and the cathode end of the first RF diode is connected to the ground plane. The second metal arm has a first end and a second end, the first end of the second metal arm is connected to the second end of the first metal arm, and the second end of the second metal arm is electrically connected to the first wire. The first capacitor has a first end and a second end, the first end of the first capacitor is connected to the second end of the second metal arm, and the second end of the first capacitor is connected to the ground plane, wherein the trace of the first wire is connected by the second The second end of the metal arm begins and extends along the vicinity of the first capacitor to the ground plane for electrical connection to the control unit. When the control unit outputs the first DC control voltage by using the first wire and the second wire, the first RF diode is turned on, and the first metal arm is short-circuited with the ground plane by the first RF diode to improve Relative to the first The antenna gain of the first opposite side of one side, wherein the length of the first metal arm that is shorted to the ground plane is equivalent to one quarter of the wavelength corresponding to the operating frequency of the monopole antenna. When the control unit does not use the first wire and the second wire to output the first DC control voltage, the first RF diode is not turned on, and for the RF signal, the first metal arm and the second metal arm are first The capacitor is shorted to the ground plane to form a half-wave short-circuit path, thereby avoiding affecting the omnidirectional radiation pattern of the monopole antenna.

In summary, the embodiment of the present invention provides an antenna structure capable of adjusting a radiation field. When the first RF diode that controls the first reflection unit is turned on, the first metal arm of the first reflection unit forms a quarter. The resonant reflector of the wavelength enhances the antenna gain relative to the first opposite side of the first side, thereby achieving the purpose of adjusting the radiation field of the antenna structure as a whole. When the first RF diode is not conducting, the first reflecting unit forms a half-wavelength grounding structure, and has no reflection effect, and the radiation pattern of the antenna structure as a whole is maintained the same as the original radiation field of the monopole antenna.

For a better understanding of the features and technical aspects of the present invention, reference should be made to the accompanying drawings The scope is subject to any restrictions.

1‧‧‧Processing unit

2‧‧‧Wireless Module

3‧‧‧An antenna structure with adjustable field type

31, 71‧‧‧ monopole antenna

32‧‧‧Control unit

33‧‧‧First reflection unit

CT1‧‧‧ first control signal

34a‧‧‧First wire

34b‧‧‧second wire

V1‧‧‧ first DC control voltage

X, Y, Z‧‧‧ axes

D‧‧‧distance

331‧‧‧First metal arm

331a‧‧‧First end of the first metal arm

331b‧‧‧The second end of the first metal arm

332‧‧‧second metal arm

332a‧‧‧ the first end of the second metal arm

332b‧‧‧ second end of the second metal arm

333‧‧‧first capacitor

334‧‧‧First RF Diode

321‧‧‧ switch

322‧‧‧DC power supply

62‧‧‧Microwave substrate

CT2‧‧‧second control signal

34c‧‧‧ third conductor

34d‧‧‧fourth wire

35‧‧‧second reflection unit

351‧‧‧ Third metal arm

351a‧‧‧First end of the first metal arm

351b‧‧‧The second end of the first metal arm

352‧‧‧fourth metal arm

352a‧‧‧First end of the second metal arm

352b‧‧‧second end of the second metal arm

353‧‧‧second capacitor

354‧‧‧Second RF diode

V2‧‧‧second DC control voltage

73‧‧‧Reflective unit

FIG. 1 is a partial functional block diagram of a terminal device having an antenna structure with an adjustable radiation field according to an embodiment of the present invention.

2 is a schematic structural diagram of an antenna structure of an adjustable radiation field according to an embodiment of the present invention.

FIG. 3A is an antenna structure of an adjustable radiation field according to an embodiment of the present invention. A radiation pattern of a radio-frequency diode in a conducting state.

FIG. 3B is a radiation pattern diagram of the antenna structure of the adjustable radiation field type in the non-conducting state of the first radio frequency diode according to the embodiment of the present invention.

FIG. 4 is a structural diagram of an actual application of an antenna structure capable of adjusting a radiation field according to an embodiment of the present invention.

FIG. 5 is a structural diagram of an actual application of an adjustable radiation field type antenna structure having two reflection units according to another embodiment of the present invention.

FIG. 6A is a radiation pattern diagram of the antenna structure of the adjustable radiation field of the embodiment of FIG. 5 when the first RF diode and the second RF diode are not conducting.

6B is a radiation pattern diagram of the antenna structure of the adjustable radiation field of the embodiment of FIG. 5 when the first RF diode is turned on.

6C is a radiation pattern diagram of the antenna structure of the adjustable radiation field type of the embodiment of FIG. 5 when the two radio frequency diodes are turned on.

FIG. 7 is a structural diagram of an actual application of an adjustable radiation field type antenna structure having four reflection units according to another embodiment of the present invention.

The antenna structure with adjustable radiation field type of the embodiment of the invention can be applied to various wireless terminal devices, such as a notebook computer, a tablet computer, an integrated computer or a smart TV, which can enable the wireless terminal device to adjust the strength of the transmission and reception signals for various application scenarios. direction. Hereinafter, a partial functional block diagram of the terminal device of the antenna structure of the adjustable radiation field type of FIG. 1 will be described. The terminal device has a processing unit 1, a wireless module 2 and an antenna structure 3 having an adjustable radiation field type. The antenna structure 3 having an adjustable radiation pattern includes a monopole antenna 31, a control unit 32 and a first reflection unit 33. At The processing unit 1 is connected to the wireless module 2 and the control unit 32. The processing unit 1 controls the wireless module 2 to transmit and receive signals (and processes the transmitted and received signals), and the processing unit 1 controls the operating state of the first reflecting unit 33 via the control unit 32. The wireless module 2 is connected to the monopole antenna 31 to provide RF signal feed. Other related functional blocks of the terminal device (for example, a power supply circuit, a display unit, an input unit) are omitted herein, and those skilled in the art should be able to easily understand a terminal such as a notebook computer, a tablet computer, an integrated computer or a smart TV. The main functions of the devices and their associated circuit blocks are not described herein.

The embodiment of the present invention utilizes the state of switching the first reflecting unit 33 to achieve the purpose of adjusting the radiation field type. Please refer to FIG. 2. FIG. 2 is a schematic structural diagram of an antenna structure of an adjustable radiation field according to an embodiment of the present invention. The antenna structure of FIG. 2 is not drawn to scale, and is merely illustrative to help illustrate that the shapes of the various components of the antenna of FIG. 2 are not intended to limit the invention. In FIG. 2, the monopole antenna 31 is vertically disposed on the ground plane 39 and receives the RF signal feed to generate a quarter-wave resonance mode having an omnidirectional radiation pattern in a horizontal plane (XY plane). The ground plane 39 is the system ground of a terminal device (such as a notebook computer), such as the system ground plane of the upper edge of the screen of a notebook computer or an integrated computer (or smart TV).

Referring again to FIG. 2, the monopole antenna 31 mainly produces a linearly polarized radiation pattern, and the monopole antenna 31 receives the RF feed signal to generate a radiation pattern of the first polarization direction. The monopole antenna 31 in FIG. 2 is A vertically polarized radiation pattern is produced (in Figure 2, the vertical polarization direction is a parallel Z axis). The control unit 32 is controlled by the first control signal CT1 to determine whether to output the first DC control voltage V1 by using the first wire 34a and the second wire 34b. The first DC control voltage V1 makes the DC potential of the first wire 34a larger than the first The DC potential of the two wires 34b is electrically connected between the ground plane 39 and the control unit 32. The first reflecting unit 33 is disposed on the first side of the monopole antenna 31 (in FIG. 2 The right side is located on the side of the +Y axis. The distance d between the first reflection unit 33 and the monopole antenna 31 is preferably 0.15 to 0.5 times the wavelength corresponding to the operating frequency of the monopole antenna 31 (ie, 0.15). λ to 0.5 λ), but the invention is not limited thereby. The first reflective unit 33 includes a first metal arm 331, a first RF diode 334, a second metal arm 332, and a first capacitor 333. The first metal arm 331 has a first end 331a and a second end 331b. The first metal arm 331 is parallel to the monopole antenna 31, and the first end 331a of the first metal arm 331 is at a greater distance from the ground plane 39 than the first metal arm. The distance between the second end 331b of the 331 and the ground plane 39. The first RF terminal 334 has an anode end and a cathode end. The anode end of the first RF diode 334 is connected to the second end 331b of the first metal arm 331. The cathode end of the first RF diode 334 is connected to the ground plane 39. . The second metal arm 332 has a first end 332a and a second end 332b. The first end 332a of the second metal arm 332 is connected to the second end 331b of the first metal arm 331, and the second end 331b of the second metal arm 331 is electrically connected. The first wire 34a is connected. The first capacitor 333 has a first end and a second end, the first end of the first capacitor 333 is connected to the second end 332b of the second metal arm 332, and the second end of the first capacitor 333 is connected to the ground plane 39, wherein the first lead The trace of 34a is initiated by the second end 332b of the second metal arm 332 and extends along the vicinity of the first capacitor 333 toward the ground plane to be electrically connected to the control unit 32. The trace of the first wire 34a in Figure 2 is for illustration only, and the embodiment of the trace of the first wire 34a will be further illustrated in Figure 4 below.

In addition, in order not to affect the distance setting of the first reflecting unit 33 and the monopole antenna 31, the second metal arm 332 may be disposed to extend from the second end 331b of the first metal arm 331 toward the direction away from the monopole antenna 31. In detail, the second end 332b of the second metal arm 332 is farther from the monopole antenna 31 than the first end 332a of the second metal arm 332. In other words, by arranging the first metal arm 331 between the monopole antenna 31 and the second metal arm 332, the shape and configuration of the second metal arm 332 are not limited. The spacing between the first reflecting unit 33 and the monopole antenna 31.

The control unit 32 can include a switch 321 controlled by the first control signal CT1 and a DC voltage source 322 for switching whether to transmit the first DC control voltage V1 of the DC voltage source 322 to the first RF diode 334. The value of the first DC control voltage V1 needs to be greater than the turn-on voltage (threshold voltage) of the first RF diode 334. Depending on whether the first RF diode 334 is turned on or not, the two states of the first reflecting unit 33 will be described below.

The first state of the first reflecting unit 33 is as follows: When the control unit 32 outputs the first DC control voltage V1 by using the first wire 34a and the second wire 34b, the first RF diode is turned on 334. The first metal arm 331 is short-circuited with the ground plane 39 by the first RF diode 334 for lifting the first opposite side (-Y axis) with respect to the first side (+Y axis) The antenna gain, wherein the length of the first metal arm 331 that is shorted to the ground plane 39 is equivalent to one quarter of the wavelength corresponding to the operating frequency of the monopole antenna 31. And the first capacitor 333 is always regarded as being turned on for the operating frequency of the monopole antenna 31, so that the second end of the second metal arm 332 is short-circuited to the ground by the first capacitor 333 for the operating frequency of the monopole antenna 31. . For the case where the frequency of the RF signal is 5 GHz, the capacitance value of the first capacitor 333 is preferably greater than 80 pF, for example, 200 pF, but the present invention does not limit the frequency of the RF signal (or the antenna operating frequency) and the first The capacitance value of the capacitor 333. That is, not only the first end 332a of the second metal arm 332 is grounded due to the conduction of the first RF diode 334, but also the second end 332b is also used by the first capacitor 333 for the RF signal used. The grounding is such that the second metal arm 332 is entirely grounded when the second RF diode 334 is turned on. In this first operational state, the radiation pattern shown in Fig. 3A is oriented toward the first opposite side (-Y) compared to the omnidirectional radiation pattern in the X-Y plane when the monopole antenna 31 is conventionally alone. Axial) offset. The first metal arm 331 becomes a quarter-wavelength resonant reflector, thus affecting the overall radiation pattern, so that the first reflecting unit produces a reflection effect. In practical applications, for example, when the monopole antenna 31 is operated at 5 GHz, the length of the first metal arm 331 is about 15 millimeters (mm) (a quarter of the wavelength of a 5 GHz electromagnetic wave in a vacuum), if When the first reflecting unit 33 is disposed on the microwave substrate (for example, the FR4 substrate), the actual length of the first metal arm 331 can be further shortened according to the dielectric coefficient of the microwave substrate material.

The second state of the first reflecting unit 33 is as follows: When the control unit 32 does not output the first DC control voltage V1 by using the first wire 34a and the second wire 34b, the first RF diode 334 is not turned on. For the operating frequency of the monopole antenna 31, the first metal arm 331 and the second metal arm 332 are short-circuited to the ground plane 39 by the first capacitor 333 to form a half-wave short-circuit path, thereby avoiding affecting the entire monopole antenna 31. Radiation radiation field type. That is to say, in addition to the approximately one-quarter wavelength path of the first metal arm 331, the second metal arm 332 further provides a short-wavelength path of a quarter wavelength, and the first metal arm 331 and the second metal arm 332 together form a half. Wavelength short circuit path. When the monopole antenna 31 is operated at 5 GHz, the first metal arm 331, the second metal arm 332, and the first capacitor 333 constitute a half-wavelength short-circuit path which is not a resonant reflector of 5 GHz frequency. Therefore, even if the monopole antenna 31 excites the current on the half-wavelength short-circuit path, the current on the half-wavelength short-circuit path does not affect the overall radiation pattern. Referring to Figure 3B, it can be seen that the radiation pattern still maintains an approximately omnidirectional radiation pattern.

In actual application, the switching of the control unit 32 may determine, according to a Received Signal Strength Indicator (RSSI), for example, which switching radiation field state is selected for wireless network communication, for example, selecting to receive. The signal strength indicates a large radiation field state for communication and The switching state of the radiation pattern is changed in response to a change in the received signal strength indication. However, the invention does not therefore limit the factors that determine how to switch the radiation pattern.

Please refer to FIG. 4. FIG. 4 is a structural diagram of an antenna structure of an adjustable radiation field according to an embodiment of the present invention. In practical applications, the monopole antenna 31 can be disposed on the microwave substrate 62, for example, formed on the microwave substrate 62 by an etching process, and fed through the coaxial cable. The first reflective unit 33 can also be disposed on the microwave substrate 63, and can also be formed on the microwave substrate 63 by an etching process. The first capacitor 333 and the first RF diode 334 are preferably surface-mounting components. Next, the manner in which the trace of the first wire 34a is initiated by the second end 332b of the second metal arm 332 and extends along the vicinity of the first capacitor 333 to the ground plane to be electrically connected to the control unit 32 is illustrated. The first wire 34a has a first end and a second end. The first wire 34a can be disposed on the other side (back surface) of the microwave substrate 62, and the first end of the first wire 34a is electrically connected to the second metal arm 332 by using the through hole. And the trace of the first wire 34a starts from the first end of the first wire 34a and extends along the vicinity of the first capacitor 333 to the ground plane 39 to the second end of the first wire 34a, and then the first wire 34a The two ends are electrically connected to the control unit 32. The reason why the trace of the first wire 34a is disposed along the first capacitor 333 is that the capacitor 333 is always regarded as the conductive state in terms of the operating frequency of the monopole antenna 31, so that the trace of the first wire 34a is close to the first A capacitor 333 can make the current path of the first wire 34a and the current path of the first capacitor 333 close to each other, and can regard the current path of the first wire 34a and the current path of the first capacitor 333 as being substantially at the same position. The current path, and thus the current of the first wire 34a, substantially (or substantially) does not change the effect of the current path of the structure formed by the first reflecting unit 33 on the radiation pattern of the monopole antenna 31. On the other hand, the second wire 34b can be directly connected between the grounding surface 39 and the control unit 32 for electrically connecting the cathode of the first RF diode 334 to form the first RF diode 334 and the control unit 32. Between Ground path.

An embodiment of field type control using two reflecting units will be further explained below. Please refer to FIG. 5. FIG. 5 is a structural diagram of an antenna structure of an adjustable radiation field type having two reflection units according to another embodiment of the present invention. Compared to the application example of FIG. 4, the antenna structure in the embodiment of FIG. 5 further includes a second reflection unit 35. The second reflecting unit 35 is substantially the same as the first reflecting unit 33 except that the position where the second reflecting unit 35 is disposed is different from the position where the first reflecting unit 33 is disposed, and the second reflecting unit 35 and the first reflection are Units 33 are controlled independently of each other by control unit 32. In detail, the control unit 32 is controlled by the second control signal CT2 to determine whether to output the second DC control voltage V2 by using the third wire 34c and the fourth wire 34d, and the second DC control voltage V2 is such that the DC potential of the third wire 34c is The fourth wire 34d is electrically connected between the grounding surface 39 and the control unit 32. The second reflection unit 35 is disposed on the second side (−Y axis) of the monopole antenna 31, and the second reflection unit 35 includes the third metal arm 351, the second RF diode 354, the fourth metal arm 352, and the Two capacitors 353. The second reflective unit 35 can be disposed on the microwave substrate 62. The third metal arm 351 and the fourth metal arm 352 are formed on the microwave substrate 62 by an etching process, and the second capacitor 353 and the second RF diode 354 are surface adhesion components. . The third metal arm 351 has a first end 351a and a second end 352b, the third metal arm 351 is parallel to the monopole antenna 31, and the first end 351a of the third metal arm 351 is at a greater distance from the ground plane 39 than the third metal arm The distance between the second end 351b of the 351 and the ground plane 39. The second RF diode 354 has an anode end and a cathode end, the anode end of the second RF diode 354 is connected to the second end 351b of the third metal arm 351, and the cathode end of the second RF diode 354 is connected to the ground plane 39. . The fourth metal arm 352 has a first end 352a and a second end 352b, and the first end 352a of the fourth metal arm 352 is connected to the second end 351b of the third metal arm 351, the fourth gold The second end 352b of the arm 352 is electrically connected to the third wire 34c. The second capacitor 353 has a first end and a second end, the first end of the second capacitor 353 is connected to the second end 352b of the fourth metal arm 352, and the second end of the second capacitor 353 is connected to the ground plane 39, wherein the third wire The trace of 34c is initiated by the second end 352b of the fourth metal arm 352 and extends along the vicinity of the second capacitor 353 to the ground plane 39 for electrical connection to the control unit 32. When the control unit 32 outputs the second DC control voltage V2 by using the third wire 34c and the fourth wire 34d, the second RF diode 354 is turned on, and the third metal arm 351 is connected to the ground plane by the second RF diode 354. 39 short-circuited to increase the antenna gain of the second opposite side (+Y-axis) with respect to the second side (-Y-axis), wherein the short-circuit is conducted to the third metal arm 351 of the ground plane 39 The length is equivalent to one quarter of the wavelength corresponding to the operating frequency of the monopole antenna 31. When the control unit 31 does not use the third wire 34c and the fourth wire 34d to output the second DC control voltage V2, the second RF diode 354 is non-conductive, and for the RF signal, the third metal arm 351 and the fourth metal The arm 352 is shorted to the ground plane 39 by the second capacitor 353 to form a half wavelength short circuit path, thereby avoiding affecting the omnidirectional radiation pattern of the monopole antenna 31. In FIG. 5, since the first reflecting unit 33 and the second reflecting unit 35 are opposed to each other, the second opposite side in the embodiment of FIG. 5 is exactly the first side of the first reflecting unit 33, but the present invention Not limited by this.

Moreover, similarly to the preferred arrangement of the first wire 34a, the preferred arrangement of the third wire 34c is described as follows. The third wire 34c can be disposed on the other side (back side) of the microwave substrate 62, and the third wire 34c The first end electrically connects the fourth metal arm 352 with the through hole, and the trace of the third wire 34c starts from the first end of the third wire 34c and extends along the vicinity of the second capacitor 353 to the ground plane 39 to the third The second end of the wire 34c, and then the second end of the third wire 34c is electrically connected to the control unit 32.

In addition, in order not to affect the second reflecting unit 53 and the monopole antenna 31 With the distance setting, the fourth metal arm 352 can be disposed to extend from the second end 351b of the third metal arm 351 toward the direction away from the monopole antenna 31. Furthermore, it is preferable that the distance between the third metal arm 351 and the monopole antenna 31 is 0.15 to 0.5 times the wavelength corresponding to the operating frequency of the monopole antenna 31. When the operating frequency of the monopole antenna is 5 GHz, the capacitance of the second capacitor 353 is preferably greater than 80 pF. The principle of the second reflecting unit 35 is substantially the same as that of the first reflecting unit 33, and will not be described again.

In the following, according to the conduction state of the first RF diode 334 and the second RF diode 354 of the first reflection unit 33 and the second reflection unit 35, the radiation pattern can be divided into three applications, corresponding to FIG. 6A respectively. The radiation pattern shown in Figures 6B and 6C. Referring to FIG. 6A, FIG. 6A is a radiation pattern diagram of the adjustable radiation field type antenna structure of the embodiment of FIG. 5 when the first RF diode 334 and the second RF diode 354 are not conducting. The field type generally maintains an omnidirectional radiation pattern. 6B is a radiation pattern diagram of the adjustable radiation field type antenna structure of the embodiment of FIG. 5 when the first RF diode 334 is turned on and the second RF diode 354 is not turned on, and the radiation pattern is oriented toward the second reflection. Unit 35 is offset (-Y axis). 6C, FIG. 6C is a radiation pattern of the adjustable radiation field type antenna structure of the embodiment of FIG. 5 when the second RF diode 354 is turned on and the first RF diode 334 is not conducting. The pattern is offset toward the first reflecting unit 33 (+Y axis).

Further, the antenna structure of the adjustable radiation field type provided by the embodiment of the present invention may have more than two reflecting units, and the number of reflecting units and the position of each reflecting unit may be selected according to the needs of use, and the above has a reflection. Embodiments of the unit and the two reflecting units are only used to help illustrate the principle, and so can be pushed to the case of having three or more reflecting units. For example, referring to the example of Fig. 7, reflection units 73 symmetrically disposed on the four sides of the monopole antenna 71 are used, each of which The function of the reflecting unit 73 is the same as that of the first reflecting unit 33 of FIG. 2 and will not be described again. The components of the antennas in FIG. 7 are scaled to facilitate drawing. In actual implementation, the distance between each of the reflecting units 73 and the monopole antenna 31 is preferably 0.15 to 0.5 times the wavelength corresponding to the operating frequency of the monopole antenna 71. (ie 0.15 λ to 0.5 λ). The wires of the control unit and the control diode conduction state are also omitted in FIG. According to the operation mechanism proposed in the previous embodiment, the radiation pattern of the X-Y plane can be controlled by the state switching of the four reflection units 73. The structure and relative positions of the four reflecting units 73 in FIG. 7 are only for illustration, and the present invention is not limited thereto.

In summary, the antenna structure of the adjustable radiation field according to the embodiment of the present invention uses the first radio frequency diode that turns on the first reflection unit to form the first reflection unit to form a quarter-wavelength resonant reflector. The antenna gain of the first opposite side of the first side is increased, thereby achieving the purpose of adjusting the radiation field of the antenna structure as a whole. When the first RF diode is not conducting, the first reflecting unit forms a half-wave short-circuit grounding, and has no reflection effect, and the radiation pattern of the antenna structure as a whole is maintained substantially the same as the original radiation field of the monopole antenna. Similarly, when the second reflective unit is provided, the antenna gain of the second opposite side with respect to the second side can be increased by using the second radio frequency diode that turns on the second reflective unit. By analogy, the antenna structure of the adjustable radiation field type of the embodiment of the present invention can be applied to a case with multiple reflection units, thereby achieving the effect of multi-directional adjustment of the radiation field type and the gain.

The above description is only an embodiment of the present invention, and is not intended to limit the scope of the invention.

Claims (10)

An antenna structure capable of adjusting a radiation field type, comprising: a monopole antenna vertically disposed on a ground plane and receiving an RF signal feed to generate a quarter wavelength of an omnidirectional radiation pattern having a horizontal plane a resonant mode; a control unit controlled by a first control signal to determine whether to output a first DC control voltage by using a first wire and a second wire, the first DC control voltage making the first wire The DC potential is greater than the DC potential of the second wire, the second wire is electrically connected between the ground plane and the control unit; and a first reflection unit is disposed on a first side of the monopole antenna. The first reflecting unit includes: a first metal arm having a first end and a second end, the first metal arm is parallel to the monopole antenna, and the first end of the first metal arm is connected to the first end The distance from the ground is greater than the distance between the second end of the first metal arm and the ground plane; a first radio frequency diode having an anode end and a cathode end, the anode end of the first radio frequency diode being connected to the anode end The second of the first metal arm The cathode end of the first RF diode is connected to the ground plane; a second metal arm has a first end and a second end, and the first end of the second metal arm is connected to the first metal arm The second end of the second metal arm is electrically connected to the first wire; and a first capacitor has a first end and a second end, the first end of the first capacitor Connecting the second end of the second metal arm, the second end of the first capacitor is connected to the ground plane, wherein the first wire is routed by the second metal arm The two ends start and extend along the first capacitor to the ground plane to be electrically connected to the control unit; wherein, when the control unit uses the first wire and the second wire to output the first DC control When the voltage is applied, the first RF diode is turned on, and the first metal arm is short-circuited with the ground plane by the first RF diode to raise a first opposite direction with respect to the first side. a side antenna gain, wherein a length of the first metal arm that is short-circuited to the ground plane is equivalent to a quarter of a wavelength corresponding to an operating frequency of the monopole antenna; wherein, when the control unit does not utilize the When the first wire and the second wire output the first DC control voltage, the first RF diode is non-conductive, and for the RF signal, the first metal arm and the second metal arm are The first capacitor is shorted to the ground plane to form a half wavelength short circuit path, thereby avoiding affecting the omnidirectional radiation pattern of the monopole antenna. The antenna structure of the adjustable radiation pattern according to Item 1, wherein the distance between the first metal arm and the monopole antenna is 0.15 to 0.5 times the wavelength corresponding to the operating frequency of the monopole antenna. The antenna structure of the adjustable radiation pattern according to claim 1, wherein the monopole antenna has an operating frequency of 5 GHz, and the first capacitor has a capacitance value greater than 80 pF. The antenna structure of the adjustable radiation pattern according to claim 1, wherein the second metal arm extends from the second end of the first metal arm toward a direction away from the monopole antenna. The antenna structure of the adjustable radiation field according to Item 1, wherein the monopole antenna, the first metal arm and the second metal arm are formed on a microwave substrate by an etching process, and the first capacitor is The first radio frequency diode is a surface adhesive component. The antenna structure of the adjustable radiation pattern according to claim 1, wherein the control unit is controlled by a second control signal to determine whether to output a second DC control voltage by using a third wire and a fourth wire. The second DC control voltage is such that a DC potential of the third wire is greater than a DC potential of the fourth wire, and the fourth wire is electrically connected between the ground plane and the control unit, the adjustable radiation field type antenna The structure further includes: a second reflecting unit disposed on a second side of the monopole antenna, the second reflecting unit comprising: a third metal arm having a first end and a second end, the third The metal arm is parallel to the monopole antenna, and the distance between the first end of the third metal arm and the ground plane is greater than the distance between the second end of the third metal arm and the ground plane; a second RF pole The anode end of the second RF electrode is connected to the second end of the third metal arm, and the cathode end of the second RF diode is connected to the ground plane; a fourth metal arm having a first end And a second end, the first end of the fourth metal arm is connected to the second end of the third metal arm, the second end of the fourth metal arm is electrically connected to the third wire; and a second The capacitor has a first end and a second end, the first end of the second capacitor is connected to the second end of the fourth metal arm, and the second end of the second capacitor is connected to the ground plane, wherein the capacitor a trace of the third wire is initiated by the second end of the fourth metal arm and extends along the second capacitor to the ground plane to be electrically connected to the control unit; wherein, when the control unit utilizes the When the third wire and the fourth wire output the second DC control voltage, the second RF diode is turned on, and the third metal arm Short-circuiting with the ground plane by the second RF diode for boosting an antenna gain with respect to a second opposite side of the second side, wherein the short circuit is conducted to the third of the ground plane The length of the metal arm is equivalent to one quarter of a wavelength corresponding to the operating frequency of the monopole antenna; wherein, when the control unit does not use the third wire and the fourth wire to output the second DC control voltage, The second RF diode is non-conducting, and for the RF signal, the third metal arm and the fourth metal arm are short-circuited to the ground plane by the second capacitor to form a half-wave short circuit path, thereby avoiding An omnidirectional radiation pattern that affects the monopole antenna. The antenna structure of the adjustable radiation pattern according to Item 6, wherein the distance between the third metal arm and the monopole antenna is 0.15 to 0.5 times the wavelength corresponding to the operating frequency of the monopole antenna. The antenna structure of the adjustable radiation pattern according to claim 6, wherein the monopole antenna has an operating frequency of 5 GHz and the second capacitor has a capacitance greater than 80 pF. The antenna structure of the adjustable radiation pattern according to claim 6, wherein the fourth metal arm extends from the second end of the third metal arm toward a direction away from the monopole antenna. The antenna structure of the adjustable radiation field according to Item 6, wherein the monopole antenna, the first metal arm, the second metal arm, the third metal arm and the fourth metal arm are etched The process is formed on a microwave substrate, and the first capacitor, the first RF diode, the second capacitor and the second RF diode are surface adhesion components.