CN105811094A - Slot antenna with coplanar waveguide feed capacitance loading stepped impedance - Google Patents

Abstract

A slot antenna with step impedance loaded by a coplanar waveguide feeding capacitance relates to a slot antenna, which includes a dielectric substrate (1), a metal ground (2) on the dielectric substrate (1), a radiation slot (3), a common Surface waveguide feeder (4); radiation slot (3) on metal ground (2); short circuit at both ends (6) of radiation slot (3); several capacitors (7) in the middle of radiation slot (3) connected in parallel across its edge to form a low-resistance slot (8); the rest of the radiation slot (3) is a high-resistance slot (9); the coplanar waveguide feeder (4) outer conductor (5) and the metal ground (2 ) is connected, and its terminal inner conductor (12) straddles the high-resistance slot (9) at its edge (11), and is connected with the metal ground (2). The antenna is multi-band operation which reduces antenna size, cross polarization, shadowing and improves isolation.

Description

Slot antenna with step impedance fed by coplanar waveguide

technical field

The invention relates to a slot antenna, in particular to a slot antenna with step impedance loaded by a coplanar waveguide feeding capacitance.

Background technique

The slot antenna is the dual antenna of the dipole antenna and has a wide range of applications. However, the ordinary slot antenna not only needs half the wavelength of the radiation slot itself, but also needs a large metal ground area around the radiation slot, usually the length of the metal ground is 1/2 larger than the length of the slot One wavelength, the width of the metal ground is one-half wavelength larger than the width of the slot. A larger metal ground will make the slot antenna unsuitable for multiple-input multiple-output (MIMO) applications, resulting in poor cross-polarization of the antenna, which will lead to a decrease in spectral efficiency and channel capacity. At the same time, the impedance of the slot is very large, which also makes it difficult to match the impedance of the slot antenna feeding transmission line. At the same time, the development of modern communication also requires that the antenna can work in multiple frequency bands, and the two frequency bands can be adjusted separately.

Contents of the invention

Technical problem: the purpose of this invention is to propose a kind of slot antenna of coplanar waveguide feeding capacitance loading step impedance, this antenna can not only have a plurality of operating frequency bands, and a plurality of frequency bands can be adjusted separately; This antenna can reduce radiation The length of the slot and the area of the metal ground.

Technical solution: The coplanar waveguide feeding capacitively loaded slot antenna with step impedance of the present invention includes a dielectric substrate, a metal ground and a radiation slot arranged on the dielectric substrate, and a coplanar waveguide feeder line; one side of the dielectric substrate is a metal ground and a Coplanar waveguide feeder, the ground plane of the coplanar waveguide feeder is the metal ground; there are radiation slots on the metal ground, the shape of the radiation slot is rectangular, and the radiation slot is located in the center of the metal ground; the two ends of the radiation slot are short-circuited; In the middle part of the slot, several capacitors are connected in parallel across the two edges of the radiation slot, so that the characteristic impedance of the middle part of the radiation slot becomes lower, forming a low-resistance slot; the rest of the radiation slot is a high-resistance slot, The high-resistance slot and the low-resistance slot together form a step impedance radiation slot, which produces a low-frequency operating band with a low frequency and a high-frequency operating band with a high frequency; one end of the coplanar waveguide feeder is the port of the antenna. The conductor at the other end of the surface waveguide feeder crosses the high-resistance slot, and is connected to the metal ground at the edge of the high-resistance slot.

Changing the thickness, permeability and permittivity of the dielectric substrate can change the characteristic impedance of the high-resistance slot and the low-resistance slot, change the high-to-low impedance ratio of the step impedance radiation slot, and then change the antenna's low-frequency working frequency band. frequency and the operating frequency of the high-frequency operating band.

By changing the length of the low-resistance slot and the position of the low-resistance slot in the radiation slot, the electrical length of the radiation slot can be adjusted to achieve different degrees of miniaturization of the antenna, and the working frequency and The operating frequency of the high-frequency operating frequency band.

Changing the number, capacitance and spacing of the loading capacitors can adjust the characteristic impedance of the low-resistance slot, change the high-to-low impedance ratio of the step impedance radiation slot, and then change the working frequency of the antenna's low-frequency working frequency band and high-frequency working frequency band. frequency.

Changing the width of the radiation slot can adjust the characteristic impedance of the low-resistance slot and the high-resistance slot, change the high-to-low impedance ratio of the step impedance radiation slot, and then change the working frequency of the low-frequency working frequency band and the high-frequency working frequency band of the antenna. working frequency.

Capacitors are loaded in parallel to the two edges of the radiation slot, which not only reduces the characteristic impedance of the slot transmission line to easily match the feed transmission line, but also reduces the phase velocity of the slot transmission line, reducing the length of the half-wavelength radiation slot. Small, realize the miniaturization of the radiation slot and the antenna. The working frequency of the low-frequency working frequency band and the high-frequency working frequency band of the slot antenna with coplanar waveguide feeding capacitance loaded with step impedance are mainly determined by the resonant frequency of the radiation slot, but the size of the metal ground, the coplanar waveguide feeder conductor The position connected with the radiation slot can also adjust the working frequency and matching degree of the antenna. Since the radiation slots have both low-resistance slots and high-resistance slots, the radiation slots with step impedance are formed, which not only makes the antenna miniaturized, reduces the cross polarization, but also reduces the size of the metal ground, and It is also possible to make the antenna have multiple working frequency bands, and by changing the relative length and impedance of the low-resistance slot and the high-resistance slot, the positions of the two working frequency bands can be adjusted respectively.

Beneficial effect: the beneficial effect of the coplanar waveguide fed capacitor-loaded slot antenna with step impedance of the present invention is that the antenna can reduce the electrical size of the entire antenna and realize miniaturization. At the same time, the antenna can not only have multiple frequency bands, Moreover, multiple frequency bands can be adjusted separately, and it also has the effect of suppressing cross-polarization of the antenna.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of a slot antenna with a step impedance loaded by a coplanar waveguide feeding capacitor.

In the figure there are: dielectric substrate 1, metal ground 2, radiation slot 3, coplanar waveguide feeder 4, ground plane 5, both ends 6, capacitor 7, low resistance slot 8, high resistance slot 9, port 10, edge 11 and conductor 12.

detailed description

The present invention will be further described below in conjunction with drawings and embodiments.

The embodiment adopted in the present invention is: the slot antenna with coplanar waveguide feeding capacitor loading step impedance includes a dielectric substrate 1, a metal ground 2 and a radiation slot 3 arranged on the dielectric substrate 1, and a coplanar waveguide feeder 4; One side of the dielectric substrate 1 is the metal ground 2 and the coplanar waveguide feeder 4, the ground plane 5 of the coplanar waveguide feeder 4 is the metal ground 2; there is a radiation slot 3 on the metal ground 2, and the shape of the radiation slot 3 is a rectangle, radiating The slot 3 is located in the center of the metal ground 2; the two ends 6 of the radiation slot 3 are short-circuited; in the middle part of the radiation slot 3, several capacitors 7 are connected in parallel across the two edges of the radiation slot 3, so that the radiation slot 3 The characteristic impedance of the middle part becomes lower, forming a low-resistance slot 8; the rest of the radiation slot 7 is a high-resistance slot 9, and the high-resistance slot 9 and the low-resistance slot 8 together form a step impedance radiation slot 3, A low-frequency operating frequency band with a lower frequency and a high-frequency operating frequency band with a higher frequency are generated; one end of the coplanar waveguide feeder 4 is the port 10 of the antenna, and the conductor 12 at the other end of the coplanar waveguide feeder 4 crosses the high-resistance slot 9 , at the edge 11 of the high-resistance slot 9 , connected to the metal ground 2 .

Changing the thickness, magnetic permeability and dielectric constant of the dielectric substrate 1 can change the characteristic impedance of the high-resistance slot 9 and the low-resistance slot 8, change the high-to-low impedance ratio of the step impedance radiation slot 3, and then change the low frequency of the antenna The working frequency of the working frequency band and the working frequency of the high frequency working frequency band.

By changing the length of the low-resistance slot 8 and the position of the low-resistance slot 8 in the radiation slot 3, the electrical length of the radiation slot 3 can be adjusted to achieve different degrees of antenna miniaturization, and the low-frequency working frequency band of the antenna can also be changed The operating frequency and the operating frequency of the high-frequency operating frequency band.

By changing the quantity, capacitance and spacing of the loading capacitors (7), the characteristic impedance of the low-resistance slot 8 can be adjusted, the high-to-low impedance ratio of the step impedance radiation slot 3 can be changed, and the working frequency and high The working frequency of the frequency working frequency band.

Changing the width of the radiation slot 3 can adjust the characteristic impedance of the low-resistance slot 8 and the high-resistance slot 9, change the high-to-low impedance ratio of the step impedance radiation slot 3, and then change the working frequency and high frequency of the low-frequency working frequency band of the antenna. The working frequency of the frequency working frequency band.

The working frequency of the low-frequency working frequency band and the high-frequency working frequency band of the slot antenna with coplanar waveguide feeding capacitor loading step impedance are mainly determined by the resonant frequency of the radiation slot 3, but the size of the metal ground 2, the coplanar waveguide The position where the conductor 12 of the feeder 4 is connected to the radiation slot 3 can also adjust the working frequency and matching degree of the antenna. Since the radiation slot 3 has both a low-resistance slot 8 and a high-resistance slot 9, a radiation slot 3 with a step impedance is formed, which not only makes the antenna miniaturized, reduces cross-polarization, but also reduces the metal ground 2, but also can make the antenna have multiple working frequency bands, and change the relative length, position and impedance of the low-resistance slot 8 and the high-resistance slot 9, and the positions of the two working frequency bands can be adjusted respectively.

In terms of technology, the slot antenna with coplanar waveguide feeding capacitor loaded with step impedance can adopt either ordinary printed circuit board (PCB) technology, low temperature co-fired ceramic (LTCC) technology or CMOS, Si substrate and other integrated Circuit technology is realized. Capacitor 7 can select the chip capacitor 7 of the corresponding package according to the working frequency, and select the width of the low-resistance slot 8 according to the distance between the electrodes of the two pins of the capacitor 7 .

According to the above, the present invention can be realized.

Claims (5)

1. the slot antenna of a coplanar wave guide feedback capacitive load Stepped Impedance, it is characterised in that this antenna includes medium substrate (1), metal ground (2) that is arranged on medium substrate (1) and radiate the line of rabbet joint (3), coplanar waveguide feeder line (4)；The one side of medium substrate (1) is metal ground (2) and coplanar waveguide feeder line (4), and the ground plane (5) of coplanar waveguide feeder line (4) is exactly metal ground (2)；Having the radiation line of rabbet joint (3) on metal ground (2), the shape of the radiation line of rabbet joint (3) is rectangle, the center of the radiation line of rabbet joint (3) with being positioned at metal (2)；Two ends (6) short circuit of the radiation line of rabbet joint (3)；At the radiation line of rabbet joint (3) mid portion, several electric capacity (7) is had to be connected in parallel across two edges of the radiation line of rabbet joint (3), make the characteristic impedance step-down of the radiation line of rabbet joint (3) mid portion, form the low-resistance line of rabbet joint (8)；The remainder of the radiation line of rabbet joint (3) is the high resistant line of rabbet joint (9), the high resistant line of rabbet joint (9) and the low-resistance line of rabbet joint (8) constitute the Stepped Impedance radiation line of rabbet joint (3) together, produce a relatively low low frequency operation frequency band of frequency and the higher high-frequency work frequency band of a frequency；One end of coplanar waveguide feeder line (4) is the port (10) of antenna, the conductor (12) of coplanar waveguide feeder line (4) other end strides across the high resistant line of rabbet joint (9), at the edge (11) of the high resistant line of rabbet joint (9), with metal (2) be connected.

2. the slot antenna of a kind of coplanar wave guide feedback capacitive load Stepped Impedance according to claim 1, it is characterized in that changing the thickness of medium substrate (1), pcrmeability and dielectric constant, the high resistant line of rabbet joint (9) and the characteristic impedance of the low-resistance line of rabbet joint (8) can be changed, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint (3), and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.

3. the slot antenna of a kind of coplanar wave guide feedback capacitive load Stepped Impedance according to claim 1, it is characterized in that changing the length of the low-resistance line of rabbet joint (8), the low-resistance line of rabbet joint (8) position in the radiation line of rabbet joint (3), the electrical length of the radiation line of rabbet joint (3) can be regulated, to realize antenna miniaturization in various degree, it is also possible to change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.

4. the slot antenna of a kind of coplanar wave guide feedback capacitive load Stepped Impedance according to claim 1, it is characterized in that changing the quantity of loading capacitance (7), capacitance and spacing, the characteristic impedance of the low-resistance line of rabbet joint (8) can be regulated, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint (3), and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.

5. the slot antenna of a kind of coplanar wave guide feedback capacitive load Stepped Impedance according to claim 1, it is characterized in that changing the width of the radiation line of rabbet joint (3), the low-resistance line of rabbet joint (8) and the characteristic impedance of the high resistant line of rabbet joint (9) can be regulated, change the height impedance ratio of the Stepped Impedance radiation line of rabbet joint (3), and then change the operating frequency of the low frequency operation frequency band of antenna and the operating frequency of high-frequency work frequency band.