TWI553959B - Slot antenna with multiple boundary conditions - Google Patents

Description

Slot antenna with multiple boundary conditions 【0001】

 The present invention relates to an antenna, and more particularly to a slot antenna having multiple boundary conditions.

【0002】

 With the rapid development of wireless communication technology and information processing technology, mobile wireless communication devices such as mobile phones and personal digital assistants (PDAs) are competing to enter and reach thousands of households, so that consumers can enjoy high anytime and anywhere. The convenience brought by technology makes these portable wireless communication devices become an indispensable part of modern people's daily life.

[0003]

 A conventional slot antenna can be roughly divided into two types. FIG. 1 shows a metal surface 101 formed on a substrate 100. The metal surface 101 defines a slot 102. The two ends of the slot 102 form a closed end 102a. The signal is fed to the point 103 at the middle of the slot 102. When the signal is transmitted and received, the current is concentrated around the slot 102 to form a one-half wavelength resonant slot antenna. As shown in FIG. 2, a metal surface 201 is formed on a substrate 200. The metal surface 201 defines a slot 202. The slot 202 has an open end 202a at one end and a closed end 202b at the other end. A signal feeding point 203 is disposed at a middle position of the slot 202. A signal feeding wire 204 is electrically connected to the signal feeding point 203. When the signal is transmitted and received, the current is concentrated on the closed end 202b to form a quarter. A slot resonator with a wavelength resonance.

[0004]

 Due to the above two-half-wavelength resonance and quarter-wave resonance slot antennas, although the mobile communication device operates in a multi-band mode, the two slot antennas have a relatively simple working mechanism. It is not easy to implement multi-frequency architecture, and it is also limited in the application of mobile devices.

[0005]

 Therefore, the main object of the present invention is to solve the problem of the conventional slot antenna. The present invention electrically couples several passive components in the slot of the slot antenna. The passive components (inductors and capacitors) are at different frequencies. The impedance value will change with frequency, and the impedance matching of the antenna and the resonant mode have a higher degree of freedom, allowing the slot antenna to operate in a multi-band operating environment.

[0006]

 To achieve the above objective, the present invention provides a slot antenna having multiple boundary conditions, including: a substrate, a first passive component, a second passive component, a third passive component, a signal feed point, and a signal. Feed the wire. A side surface of the substrate has a metal surface, and a slot is formed in the metal surface, and the slot defines the metal surface as an upper metal surface and a lower metal surface. The first passive component is located at one end of the slot and electrically connected to the upper metal surface and the lower metal surface. The second passive component is located at the other end of the slot and is electrically connected to the upper metal surface and the lower metal surface. The slot antenna has three resonant modes, which are a low frequency mode, a first high frequency mode, and a second high frequency mode. The third passive component is located at a position of the slot between the first passive component and the second passive component, and is electrically connected to the upper metal surface and the lower metal surface. The signal feeding point is located at a position of the slot between the first passive component and the third passive component, and can be fed directly or coupled. The distance between the first passive component and the second passive component corresponds to a quarter wavelength of the low frequency mode. At this time, the first passive component can be equivalently short-circuited, and the third passive component can be equivalently open, the second passive The component is equivalent to an inductive boundary condition, which can achieve a better impedance matching of the low frequency resonant mode. The distance between the first passive component and the third passive component corresponds to a wavelength of the first high frequency mode. At this time, the first passive component can be equivalently short-circuited, the second passive component can be equivalently open, and the third passive component can be equivalent. Equivalent short circuit. Wherein, the position of the signal feeding point and the distance of the third passive component correspond to a half wavelength of the second high frequency mode. At this time, the first passive component can be equivalently opened, and the second passive component can be equivalently open, The three passive components can be equivalently shorted.

【0007】

 In an embodiment of the invention, the slot is elongated.

[0008]

 In an embodiment of the invention, the substrate is a microwave substrate.

【0009】

 In an embodiment of the invention, the first passive component is an inductor.

[0010]

 In an embodiment of the invention, the second passive component is an inductor, and the inductance of the inductor is greater than the inductance of the first passive component inductor.

[0011]

 In an embodiment of the invention, the third passive component is a capacitor.

[0034]

 Convention:

[0035]

 Substrate 100

[0036]

 Metal surface 101

[0037]

 Slot 102

[0038]

 Closed end 102a

[0039]

 Signal feed point 103

[0040]

 Substrate 200

[0041]

 Metal surface 201

[0042]

 Slot 202

[0043]

 Open end 202a

[0044]

 Closed end 202b

[0045]

 Signal feed point 203

[0046]

 Signal feed wire 204

[0047]

 this invention:

[0048]

 Slot antenna 10

[0049]

 Substrate 1

[0050]

 Metal surface 11

[0051]

 Upper metal surface 111

[0052]

 Lower metal surface 112

[0053]

 Slot 12

[0054]

 First passive component 2

[0055]

 Second passive component 3

[0056]

 Third passive component 4

[0057]

 Signal feed point 5

[0058]

 Electrical connection parts 51, 52

[0059]

 L1 quarter-wave resonance

[0060]

 L2 one wavelength resonance

[0061]

 L3 half-wave resonance

[0012]

 FIG. 1 is a schematic structural view of a conventional slot antenna.

[0013]

 FIG. 2 is a schematic structural view of another slot antenna.

[0014]

 FIG. 3 is an exploded perspective view showing the structure of a slot antenna having multiple boundaries according to the present invention.

[0015]

 FIG. 4 is a schematic diagram showing the structure combination of a slot antenna having multiple boundaries according to the present invention.

[0016]

 FIG. 5 is a schematic diagram of the low frequency resonant mode of the slot antenna structure with multiple boundaries of the present invention.

[0017]

 Figure 6, is a schematic diagram of the reflection coefficient curve of Figure 5.

[0018]

 Figure 7 is a schematic diagram of the first high frequency resonant mode of the slot antenna structure with multiple boundaries of the present invention.

[0019]

 Figure 8, is a schematic diagram of the reflection coefficient curve of Figure 7.

[0020]

 Figure 9 is a schematic diagram of the second high frequency resonant mode of the slot antenna structure with multiple boundaries of the present invention.

[0021]

 Figure 10 is a schematic diagram of the reflection coefficient curve of Figure 9.

[0022]

 The technical content and detailed description of the present invention are now described as follows:

[0023]

 Please refer to FIG. 3 and FIG. 4 , which are schematic diagrams showing the decomposition and combination of the slot antenna structure with multiple boundaries according to the present invention. As shown in the figure, the slot antenna 10 with multiple boundaries of the present invention includes: a substrate 1, a first passive component 2, a second passive component 3, a third passive component 4, and a signal feed point 5. .

[0024]

 The substrate 1 has a metal surface 11 on the upper side thereof, and an elongated slot 12 having a width of about 4 mm is formed on the metal surface 11. The slot 12 divides the metal surface 11 into an upper metal surface 111. And the lower metal surface 112. In the present drawing, the substrate 1 is a microwave substrate.

[0025]

 The first passive component 2 is located at one end of the slot 12 and electrically connected to the upper metal surface 111 and the lower metal surface 112. In the figure, the first passive component 2 is an inductor having an inductance value of 15 nH (Henry).

[0026]

 The second passive component 3 is located at the other end of the slot 12 and electrically connected to the upper metal surface 111 and the lower metal surface 112. The second passive component 3 has an impedance matching portion that enhances low frequency. . In the figure, the second passive component 3 is an inductor having an inductance value of 30 nH (Henry).

[0027]

 The third passive component 4 is located at a position of the slot 12 between the first passive component 2 and the second passive component 3, and is electrically connected to the upper metal surface 111 and the lower metal surface 112. In the figure, the third passive component 4 is a capacitor having a capacitance value of 1 PF (Pefala).

[0028]

 The signal feeding point 5 has two electrical connecting portions 51 and 52. The two electrical connecting portions 51 and 52 are located on the upper metal surface 111 and the lower metal surface 112 on the two sides of the slot 12, and The signal feed point 5 is coupled to the positive and negative ends of the feed element.

[0029]

 The inductor and the capacitor are designed at different frequencies by the first passive component 2 and the second passive component 3 of the slot antenna 10 being the inductor and the third passive component 4 being capacitors. The impedance value will change with frequency. Different boundary conditions will induce different resonance mechanisms, so that the slot antenna can work in multi-band signal transmission and reception modes.

[0030]

Please refer to FIG. 5 and FIG. 6 , which are schematic diagrams showing the reflection coefficient curve of the slot antenna structure with multiple boundaries in the low frequency resonant mode and FIG. 5 . As shown in the figure: when the slot antenna 10 is at a low frequency, the first passive component (the inductance of the inductor is 15nH) 2 is short-circuited, and the third passive component (the capacitance of the capacitor is 1PF) 4 When the open circuit state is present, the second passive component (inductor 30nH) 3 and the corresponding one to an inductive boundary condition can achieve a better matching of the low frequency mode, and the current flows from the upper metal surface 111 through the first Passive element 2 to the lower metal surface 112 such that L1 between the first passive component 2 and the second passive component 3 of the slot antenna 10 is a quarter-wavelength resonant mode (which is a low frequency mode), a point in FIG. 6 is a frequency at 600MH _Z, is -30dB.

[0031]

Please refer to FIG. 7 and FIG. 8 , which are schematic diagrams showing the reflection coefficient curve of the slot antenna structure with multiple boundaries in the first high frequency resonant mode and FIG. 7 . As shown in the figure: when the slot antenna 10 is near the first high frequency resonant mode frequency, the first passive component (inductance of the inductor is 15nH) 2 and the third passive component (capacitor value of the capacitor) When the 1PF) 4 is in a short-circuit state, when the second passive component (inductor 30nH) 3 assumes an open state, L2 between the first passive component 2 and the third passive component 4 of the slot antenna 10 is one wavelength. resonance mode, point B in FIG. 8 is a frequency at 1.775GH _Z, is -18.5dB.

[0032]

 Please refer to FIG. 9 and FIG. 10 , which are schematic diagrams of the second high frequency resonant mode and the reflection coefficient curve of FIG. 9 of the slot antenna structure with multiple boundaries according to the present invention. As shown in the figure: when the slot antenna 10 is near the second high frequency resonant mode frequency, the first passive component (inductance of the inductor is 15nH) 2 and the second passive component (inductor 30nH) 3 All open circuit, the third passive component (capacitor capacitance value 1PF) 4 presents a short circuit, so that the signal feeding point 5 of the slot antenna 10 to the L3 between the third passive component 4 is one-half The mode of the wavelength resonance is -32.8 dB when the frequency at point C of Fig. 10 is 2.225 GHz.

[0033]

 The above are only the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. That is, the equivalent changes and modifications made by the scope of the patent application of the present invention are covered by the scope of the invention.

Slot antenna 10

Substrate 1

Metal surface 11

Upper metal surface 111

Lower metal surface 112

Slot 12

First passive component 2

Second passive component 3

Third passive component 4

Signal feed point 5

Electrical connection parts 51, 52

Claims (6)

A slot antenna having multiple boundary conditions includes: a substrate having a metal surface on an upper side thereof, and a slot on the metal surface, the slot distinguishing the metal surface into an upper metal surface and a lower metal surface a signal feeding point having two electrical connecting portions, the two electrical connecting portions are located on the upper metal surface and the lower metal surface on two sides of the slot; a first passive component is located in the slot The first passive component is electrically connected to the upper metal surface and the lower metal surface. When the slot antenna resonates in the low frequency mode and the first high frequency mode, the first passive component is equivalent to a short circuit. When the antenna resonates in the second high frequency mode, the first passive component is equivalent to an open circuit; and a second passive component is located at the other end of the slot and electrically connected to the upper metal surface and the lower metal surface When the slot antenna resonates in a low frequency mode, the second passive component is equivalent to an inductive boundary condition, and when the slot antenna resonates in the first high frequency and the second high frequency mode, the second passive component is equivalent to Open circuit; a third passive component, And electrically connecting to the upper metal surface and the lower metal surface at a position of the slot between the first passive component and the second passive component, wherein the slot antenna resonates in a low frequency mode, the third The passive component is equivalent to an open circuit. When the slot antenna is resonant with the first high frequency and the second high frequency mode, the third passive component is equivalent to a short circuit; wherein the distance between the first passive component and the second passive component is corresponding to a quarter wavelength to a low frequency resonant mode; wherein a distance between the first passive component and the third passive component corresponds to a first high frequency a wavelength of the resonant mode; wherein a pitch of the signal feed point and the third passive component corresponds to a half wavelength of the second high frequency resonant mode. A slot antenna having multiple boundary conditions as described in claim 1 wherein the slot is elongated. A slot antenna having multiple boundary conditions as described in claim 1, wherein the substrate is a microwave substrate. A slot antenna having multiple boundary conditions as described in claim 1 wherein the first passive component is an inductor. The slot antenna with multiple boundary conditions as described in claim 1, wherein the second passive component is an inductor, and the inductance of the inductor is greater than the inductance of the first passive component inductor. A slot antenna having multiple boundary conditions as described in claim 1, wherein the third passive component is a capacitor.