Antenna control method

An antenna unit, an antenna system and an antenna control method are disclosed. The antenna unit includes a first radiation metal element, a second radiation metal element, and a third radiation metal element. The first radiation metal element includes a signal feed point, a first ground point, and a second ground point. The signal feed point, the first ground point, and the second ground point are disposed approximately in a straight line. The second radiation metal element is disposed away from the first radiation metal element with a gap and includes a third ground point. The third radiation metal element surrounds the first radiation metal element and the second radiation metal element and includes a fourth ground point.

BACKGROUND

Technology Field

The present disclosure relates to an antenna. More particularly, the present disclosure relates to a high-directivity multi-frequency antenna control method.

Description of Related Art

Beam-switching antennas are usually designed in a form of a dipole antenna architecture. However, a dipole antenna is an omni-directional antenna, and multiple dipole antennas will interfere with one another. In addition, the beam switching antennas in the dipole antenna architecture have a poorer signal quality in one certain polarization direction and have a bulky size, which is disadvantageous to a trend of shrinking sizes of electronic devices recently. As a result, miniaturized antenna systems having a high-directivity radiation pattern are currently one of the important development directions in the field of the communication technology.

SUMMARY

An antenna unit is provided. The antenna unit comprises a first radiation metal element, a second radiation metal element, and a third radiation metal element. The first radiation metal element comprises a signal feed point, a first ground point, and a second ground point. Positions of the signal feed point, the first ground point, and the second ground point are arranged approximately in a straight line. The second radiation metal element is disposed away from the first radiation metal element with a gap and comprises a third ground point. The third radiation metal element surrounds the first radiation metal element and the second radiation metal element and comprises a fourth ground point.

The present disclosure provides an antenna system. The antenna system comprises a plurality of antenna units. Each of the antenna units has a directional radiation pattern, and the antenna units are disposed to surround a center point and each of the a directional radiation patterns extends from the center point towards an outside. Each of the antenna units comprises a first radiation metal element, a second radiation metal element, and a third radiation metal element. The first radiation metal element comprises a signal feed point, a first ground point, and a second ground point. Positions of the signal feed point, the first ground point, and the second ground point are arranged approximately in a straight line. The second radiation metal element is disposed away from the first radiation metal element with a gap and comprises a third ground point. The third radiation metal element surrounds the first radiation metal element and the second radiation metal element and comprises a fourth ground point.

The present disclosure further provides an antenna control method. The antenna control method is for the above antenna system. The antenna control method comprises the following steps: controlling an on/off state of each of the antenna units to switch among a plurality of antenna unit configurations; detecting a signal intensity of each of the antenna unit configurations; determining one of the antenna unit configurations having an optimized signal intensity based on a detection result; and using the one of the antenna unit configurations to receive or transmit signals.

According to the present disclosure, the antenna unit has the characteristics of small size, small back radiation, etc., and can also have the characteristics of transmitting and receiving frequency bands of the 2.4G Wi-Fi antenna and the 5G Wi-Fi antenna. In addition, the antenna unit can further allow the antenna pattern of the 2.4G Wi-Fi antenna that is originally an omni-directional radiation pattern to have the effect of forward radiation or even high directivity. The antenna system and antenna control method disclosed by the present application can allow the electronic device to maintain the optimized signal receiving and transmitting ability at all times.

DESCRIPTION OF THE EMBODIMENTS

Reference will now be made in detail to the present embodiments of the disclosure, examples of which are illustrated in the accompanying drawings. However, the embodiments provided herein are intended as illustrative only since numerous modifications and variations therein will be apparent to those skilled in the art. Description of the operation does not intend to limit the operation sequence. Any structures resulting from recombination of elements with equivalent effects are within the scope of the present disclosure. In addition, drawings are only for the purpose of illustration and not plotted according to the original size.

A description is provided with reference toFIG. 1AandFIG. 1B.FIG. 1AandFIG. 1Brespectively depict a top view and a side view of an antenna unit100according to one embodiment of the present disclosure. The antenna unit100is, for example, a panel antenna unit. In greater detail, a volume size is, for example, 35 mm×35 mm×8 mm. As seen from the top view ofFIG. 1A, a body of the antenna unit100has a first radiation metal element110, a second radiation metal element120, and a third radiation metal element130. As seen from the side view ofFIG. 1B, the antenna unit100is constituted by a top body, a first substrate150, a second substrate160, a third substrate170, and a bottom ground plane180.

The first substrate150is configured to carry the first radiation metal element110, the second radiation metal element120, and the third radiation metal element130of the body of the antenna unit100. The first substrate150, the second substrate160, and the third substrate170are collectively a dielectric support of the antenna unit100. In addition, a bottom side of the third substrate170is connected to the ground plane180. A total thickness t of the first substrate150, the second substrate160, and the third substrate170is, for example, 8 mm. The ground plane180is configured to form coupling resonance with the first radiation metal element110, the second radiation metal element120, and the third radiation metal element130of the antenna unit100. The first substrate150, the second substrate160, and the third substrate170are all dielectric materials. Although the first substrate150, the second substrate160, and the third substrate170are formed by a combination of three individual substrates inFIG. 1B, the present disclosure is not limited in this regard. In applications, the first substrate150, the second substrate160, and the third substrate170may also be integrally formed as a single dielectric support.

As mentioned above, the first radiation metal element110, the second radiation metal element120, and the third radiation metal element130are disposed on the first substrate150. The first radiation metal element110has a signal feed point F, a first ground point G1, and a second ground point G2. The signal feed point F is electrically coupled to a positive terminal of a coaxial transmission line190of a signal transceiver (not shown) and is configured to transmit an antenna transmitting and receiving signal. The first ground point G1and the second ground point G2are electrically coupled to a negative terminal of the coaxial transmission line190of the signal transceiver, respectively, and are connected to the ground plane180. Positions of the signal feed point F, the first ground point G1, and the second ground point G2can be arranged approximately in a straight line. The approximate straight line indicates a line that may have curves or angles generally accepted in practical applications.

Since the thickness t of the first substrate150, the second substrate160, and the third substrate170will cause the antenna unit100to have a higher inductance, a slot140is disposed around and at a distance h from the signal feed point F. A capacitive character of the slot140is used to adjust impedance matching of the antenna unit100. In the present embodiment, a radius of the signal feed point F is, for example, 1 mm, and the distance h is, for example, 0.5 mm.

A detailed structure of the first radiation metal element110is shown inFIG. 2.FIG. 2depicts a top view of the first radiation metal element110of the antenna unit100according to one embodiment of the present disclosure. The first radiation metal element110is divided into a first metal part112, a second metal part114, and a third metal part116. According to the present embodiment, the first metal part112is formed by a combination of a semicircle of radius r1and a semicircle of radius r2. The radius r1may be the same as or different from the radius r2and they are designed depending on practical applications. It is noted that a shape of the first radiation metal element110is not limited to a combination of circle-like shapes or semicircles, which may be any geometrically symmetrical shape.

The second metal part114is connected to one side of the first metal part112on the semicircle with radius r1, the third metal part116is connected to one side of the first metal part112on the semicircle with radius r2, and a position of the third metal part116is opposite to that of the second metal part114, as shown inFIG. 2. The signal feed point F is disposed on the second metal part114. The first ground point G1may be disposed on the second metal part114or on the first metal part112adjacent to the second metal part114, and the second ground point G2may be disposed on the third metal part116or on the first metal part112adjacent to the third metal part116. The positions of the signal feed point F, the first ground point G1, and the second ground point G2form a straight line L. The first metal part112, the second metal part114, and the third metal part116are mirror-symmetric with respect to the straight line L.

In the present embodiment, a distance between the signal feed point F and a center point c of the first metal part112is, for example, approximately 11.5 mm. A distance between the first ground point G1and the center point c is, for example, approximately 5.25 mm, and a distance between the second ground point G2and the center point c is, for example, approximately 11.5 mm. Through the connection of the first ground point G1with the ground plane180, the antenna unit100can resonate, for example, a resonant frequency (2400 MHz to 2500 MHz) of a 2.4G Wi-Fi antenna. Through the connection of the second ground point G2with the ground plane180, the antenna unit100can resonate, for example, a resonant frequency (5100 MHz to 5875 MHz) of a 5G Wi-Fi antenna. Hence, the antenna unit100has the capability of transmitting and receiving a 2.4G Wi-Fi signal and a 5G Wi-Fi signal at the same time.

A resonant frequency of 2.4G Wi-Fi is approximately determined by an area of the first metal part112, and a resonant frequency of 5G Wi-Fi is approximately determined by a length of the first radiation metal element110along the straight line L (e.g., a total length of the first metal part112, the second metal part114, and the third metal part116along the straight line L). The resonant frequency position and impedance bandwidth of 2.4G Wi-Fi can be adjusted by changing the position of the first ground point G1on the semicircle of radius r1or the second metal part114along the straight line L. The resonant frequency position and impedance bandwidth of 5G Wi-Fi can be adjusted by changing the position of the second ground point G2on the semicircle of radius r2or the third metal part116along the straight line L.

With additional reference toFIG. 1A, the second radiation metal element120is a quarter-wave U-shaped metal sheet, and adjacent to the first radiation metal element110with gaps b1and b2so as to be capacitively coupled to an end of the first radiation metal element110(the third metal part116). In the present embodiment, the gap b1is, for example, 0.7 mm, the gap b2is, for example, 0.5 mm. However, the present disclosure is not limited in this regard. The gaps b1, b2may be adjusted depending on practical applications to achieve suitable coupling effects.

The second radiation metal element120has a ground point G3. Similar to the ground points G1and G2, the ground point G3is also connected to the ground plane180on the bottom. Generally speaking, 2.4G Wi-Fi has an omni-directional radiation pattern. However, by capacitively coupling the second radiation metal element120with the first radiation metal element110, the radiation pattern of 2.4G Wi-Fi of the antenna unit100can have the characteristic of forward radiation, and the forward radiation pattern of 5G Wi-Fi is also maintained at the same time. That is, not only can the antenna unit100disclosed by the present application have the capability of transmitting and receiving the 2.4G Wi-Fi signal and the 5G Wi-Fi signal at the same time, but the antenna unit100also has the radiation patterns of 2.4G Wi-Fi and 5G Wi-Fi that are both forward radiation patterns.

Although the radiation pattern of 2.4G Wi-Fi of the antenna unit100has the characteristic of forward radiation because of cooperation of the first radiation metal element110and the second radiation metal element120, it is difficult for the radiation pattern of 2.4G Wi-Fi to have high directivity owing to the limitation of an area of the ground plane180(35 mm×35 mm). In order to improve the antenna performance of 2.4G Wi-Fi, it is typically necessary to increase the area of the ground plane180to approximately 45 mm×45 mm (approximately half the wavelength of 2.4G Wi-Fi). According to one embodiment of the present disclosure, the third radiation metal element130of the antenna unit100may serve as an extension ground plane. In other words, without increasing the area of the ground plane180on the bottom of the antenna unit100, a high-directivity radiation pattern of the 2.4G Wi-Fi can be realized.

The third radiation metal element130is a closed loop that surrounds the first radiation metal element110and the second radiation metal element120and has a fourth ground point G4. The ground point G4is electrically connected to the ground plane180on the bottom. InFIG. 1A, the third radiation metal element130is a rectangular loop with width w, where width w is, for example, 1.3 mm. The ground point G4is disposed on one side of the antenna unit100adjacent to the signal feed point F. A distance d between the ground point G4and a lower left corner of the antenna unit100is, for example, 14 mm.

It should be understood that a shape of the third radiation metal element130is not limited according to the present disclosure. In practical applications, the third radiation metal element130may be any radiation metal element in a symmetrical shape or in an irregular shape that has the effect of extending the ground plane. In addition, although the third radiation metal element130is disposed on a top of the antenna unit100(on the first substrate150) according to the present embodiment, the third radiation metal element130may be disposed on sides of the antenna unit100, that is, disposed on sides of the first substrate150, the second substrate160, or/and the third substrate170.

Through the electrical connection of the ground point G4and the ground plane180, the third radiation metal element130serves as the extension ground plane of the antenna unit100and resonates with the first radiation metal element110. The radiation pattern of 2.4G Wi-Fi thus has the characteristic of high directivity.FIG. 3depicts a relational diagram between a voltage standing wave ratio (VSWR) and a frequency of the antenna unit100according to one embodiment of the present disclosure. A line segment310indicates a relation between a VSWR and a frequency when the antenna unit100has no third radiation metal element130as the extension ground plane, and a line segment320indicates a relation between a VSWR and a frequency when the antenna unit100has the third radiation metal element130as the extension ground plane. As can be seen fromFIG. 3, the second radiation metal element120will resonate at a frequency of approximately 2100 MHz, and the third radiation metal element130will resonate at a frequency of approximately 2550 MHz. These frequencies can assist the resonant frequency band of 2.4G Wi-Fi and improve the bandwidth of 2.4G Wi-Fi to allow 2.4G Wi-Fi to have a directional effect.

A description is provided with reference to Table 1 below:

TABLE 1Without TheThird RadiationWith The Third RadiationMetal Element 130Metal Element 130FrequencyAntennaMaximumAntennaMaximum(MHz)Efficiency (dB)Gain (dBi)Efficiency (dB)Gain (dBi)2400−1.62.3−2.02.92412−1.52.3−1.93.42422−1.52.4−1.83.42437−1.72.7−1.92.92442−1.62.6−1.82.82450−1.62.5−1.72.82452−1.52.5−1.62.82462−1.62.2−1.62.82484−1.82.0−1.82.72500−1.72.0−1.62.95100−1.35.2−1.85.55150−1.55.2−1.75.95250−1.26.0−1.26.55350−1.55.9−1.76.35470−1.26.0−1.86.05600−1.95.5−2.94.75725−2.54.6−2.74.55850−2.53.6−2.74.15875−2.93.3−3.13.6
Antenna efficiencies and maximum gain values of the antenna unit100are listed in Table 1. As can be obviously seen from Table 1, antenna efficiencies of 2.4G Wi-Fi (2400 MHz to 2500 MNz) of the antenna unit100are all higher than −2 dB, and antenna efficiencies of 5G Wi-Fi (5100 MHz to 5875 MNz) are approximately higher than −3 dB, showing a good performance of the antenna efficiency performance. Additionally, the antenna unit100is significantly improved in the 2.4G Wi-Fi antenna gain after the third radiation metal element130surrounding the first radiation metal element110and the second radiation metal element120.

FIG. 4AandFIG. 4Bdepict radiation patterns of 2.4G Wi-Fi of the antenna unit100according to one embodiment of the present disclosure. The top view of the antenna unit100depicted inFIG. 1Ais on the X-Y plane, and a direction perpendicular toFIG. 1Ais the Z direction. A line segment410and a line segment420inFIG. 4Aare radiation patterns of 2.4G Wi-Fi generated on the X-Z plane respectively before and after the third radiation metal element130is disposed in the antenna unit100. A line segment412and a line segment422inFIG. 4Bare radiation patterns of 2.4G Wi-Fi generated on the Y-Z plane respectively before and after the third radiation metal element130is disposed in the antenna unit100. As can be seen fromFIG. 4AandFIG. 4B, the radiation patterns of 2.4G Wi-Fi have the characteristics of large forward radiation and small back radiation. In addition, the directivity of radiation patterns of 2.4G Wi-Fi is improved after the third radiation metal element130is disposed.

FIG. 5depicts a schematic diagram of a structure of an antenna system500according to one embodiment of the present disclosure. The antenna system500has an antenna array, that are, for example, constituted by antenna units A1-A6as the antenna units100, where the detailed structure of each antenna unit may be referred to the description in above paragraphs relevant to the antenna unit100. It should be understood that in the present embodiment only the six antenna units A1-A6are taken as an example for illustration, however, the present disclosure is not limited in this regard. In practical application, more or less antenna units may be disposed in the antenna array of the antenna system500depending on needs.

The antenna system500has a base510. The base510is used for disposing the antenna units A1-A6. Metal radiation elements of the antenna units A1-A6all face an outside of the antenna system500to transmit and receive signals, and each of the metal radiation elements of the antenna units A1-A6covers a radiation angle of approximately 60 degrees. Directions in which the metal radiation elements of each of the antenna units A1-A6are disposed are orthogonal to (90 degrees to) directions in which the metal radiation elements of an antenna unit adjacent to the each of the antenna units A1-A6are disposed so as to be responsible for the vertical and horizontal polarization respectively. For example, a polarization direction of the antenna unit A1is perpendicular to the polarization directions of the antenna units A2and A6, and the polarization direction of the antenna unit A2is perpendicular to the polarization directions of the antenna units A1and A3, and so on.

It can be inferred from the above that the antenna units A1, A3, A5have the same polarization direction, and the antenna units A2, A4, A6have the same polarization direction that is perpendicular to the polarization direction of the antenna units A1, A3, A5. Each of the antenna units A1, A3, A5is respectively responsible for a radiation angle of approximately 120 degrees and are, for example, a wireless signal in a horizontal/vertical polarization direction, and each of the antenna units A2, A4, A6is responsible for the radiation angle of approximately 120 degrees and are, for example, a wireless signal in a vertical/horizontal polarization direction.

From the above embodiments, the antenna system500further has a processing module520, as shown inFIG. 6.FIG. 6depicts a schematic diagram of a processing architecture of an antenna system500according to one embodiment of the present disclosure. The processing module520may be integrated into the base510or disposed outside the antenna system500so as to control on and off or operation of each of the antenna units A1-A6by, for example, electrically connection. In greater detail, the processing module520is, for example, a processor, which can control a switch unit530through a switch control table, so as to control an on/off state or an operation state of each of the antenna units A1-A6. The switch unit530may be a mechanical switch or may be implemented by using a transistor.

An example of the switch control table is as Table 2 below:

When the antenna system500is in a signal receiving state, the processing module520can switch between the configurations M1, M2, and detect which configuration has a better signal intensity. After a determination is made, the processing module520uses the configuration having the better signal intensity to receive signals. Similarly, when the antenna system500is in a signal transmitting state, the processing module520can switch the configurations M3to M10by turns and detect which configuration has a better signal intensity. After a determination is made, the processing module520uses the configuration having the better signal intensity to transmit signals.

By using the switch control table to perform switching of the antenna units, the antenna system500does not need to activate all the antenna units at all times, but only uses the antenna combination with the best efficiency to transmit and receive signals, not only reduce the system power consumption, but also to achieve the performance of dual frequency smart beam switching antenna. In addition, since the antenna array constituted by, for example, a plurality of antenna units100is used, interferences caused by back radiation of the antenna system500is less. In addition to that, not only 2.4G Wi-Fi but also 5G Wi-Fi can be equipped with the characteristic of high directivity because the third radiation metal element130is used. Since each antenna units100in the antenna system500will have an antenna pattern with high-directivity toward its forward radiation, the each antenna unit100will induce less interference to adjacent antenna units.

FIG. 7depicts a flowchart of a control method700of the antenna system500according to one embodiment of the present disclosure. The control method700has steps S1to S3. In step S1, the processing module520of the antenna system500controls an on/off state of each of the antenna units A1-A6to switch among a plurality of antenna unit configurations (such as the configurations M1to M10), so as to detect a signal intensity of each of the antenna unit configurations. In step S2, the processing module520determines an antenna unit configuration having an optimized signal intensity or a maximum transmission rate based on a detection result. In step S3, the processing module520switches an antenna array to the antenna unit configuration that is determined to have the optimized signal intensity in step S2to start to receive or transmit signals.