CN103545602A - Ku-band Circularly Polarized Dielectric Resonator Antenna - Google Patents

Abstract

The invention relates to a Ku-band circularly polarized dielectric resonator antenna which comprises a metal grounding plate and a micro-strip feeder line. The metal grounding plate is arranged on the upper surface of a dielectric substrate, and the feeder line is arranged on the lower surface of the dielectric substrate. A three-tier dielectric resonator is arranged at the center of the upper surface of the metal grounding plate; a crisscrossed gap is formed in the center of the metal grounding plate; the inner end of the micro-strip feeder line is arranged right below the crisscrossed gap and forms a 45-degree angle with the same; two cascade-connection dumbbell-shaped groove gaps are formed in the grounding plate. Impedance bandwidth of the antenna is 27.67%, circularly polarized axial ratio bandwidth 6.56%. within working frequency, the maximum gain of the antenna is 8.2dB, the minimum gain is 6.0dB, and the antenna has wider coverage range. Axial ratio of the 12.2GHz position is approximately 0.09dB, and the antenna has good circularly polarized characteristics. The antenna covers commonly used working frequency bands of satellite television broadcasting in IT3, and is applicable to a satellite television broadcasting system within 11-14.5GHz frequency bands.

Description

Ku-band Circularly Polarized Dielectric Resonator Antenna

technical field

The invention relates to a Ku-band circularly polarized dielectric resonator antenna. The antenna works in the Ku band, the impedance bandwidth is 27.67%, the circular polarization axis ratio bandwidth is 6.56%, the gain is 6.0dB-8.2 dB, and the directivity is relatively good. The antenna covers the common working frequency band of satellite TV broadcasting in IT3 area, so it can be applied to the satellite TV broadcasting system in the frequency band of 11GHz-14.5GHz.

Background technique

With the development of modern wireless communication technology and the popularization of wireless application products, people put forward higher requirements for antennas that are indispensable for wireless communication systems, such as good circular polarization characteristics, high gain, small size and light weight. It has a high transmission rate, suppresses rain and fog interference and anti-multipath reflection, etc. Especially in satellite communication systems, the requirements for antenna performance are even higher. Typically, satellite communication systems use reflector antennas with high gain. The antenna has high application value, but the cost of the antenna is high and the volume is large, especially in mobile communication, it is very inconvenient to use. The dielectric resonator antenna has attracted widespread attention because of its outstanding advantages such as small dielectric loss, small antenna size, no surface wave loss, and can be designed into various three-dimensional geometric shapes, and the feeding method is simple and diverse. A research hotspot in the world.

According to the regulations of ITU, the world is divided into three regions. my country belongs to IT3 region, and other Asian countries and the South Pacific region are located in this region. The common operating frequency band of satellite broadcasting in this area is the Ku-band (10GHz-18GHz). This is because the Ku-band has the characteristics of high frequency, wide frequency range, and large signal capacity. Therefore, circularly polarized dielectric resonator antennas can be used in Ku-band to suppress rain and fog interference and improve system performance.

Contents of the invention

The purpose of the present invention is to provide a kind of Ku band circularly polarized dielectric resonator antenna aiming at the defects existing in the prior art. The operating frequency of this antenna is 11GHz-14.5GHz, which covers the common working frequency band of satellite broadcasting in IT3 area, and can be used for satellite TV broadcasting system.

The technical scheme that the present invention adopts is as follows:

A kind of Ku-band circularly polarized dielectric resonator antenna, comprising a layer of metal ground plate on the upper surface of the dielectric substrate and a microstrip feeder on the lower surface of the dielectric substrate, is characterized in that: there is a three-layer Stacked dielectric resonators; there is a cross gap at the center of the metal grounding plate; the inner end of the microstrip feeder is directly below the cross gap, and the microstrip feeder and the cross gap are at 45°; there are two on the metal grounding plate cascaded dumbbell-shaped slots to widen the antenna impedance bandwidth. The three-layer stacked dielectric resonator is formed by stacking a lower layer dielectric cylinder, a middle layer dielectric cylinder, and an upper layer dielectric cylinder. The three layers of dielectric cylinders have the same radius, but different materials and heights. The main influence is the resonant frequency of the antenna, and its size has a great influence on the axial ratio bandwidth of the antenna. The three-layer stacked circularly polarized dielectric resonator is coupled and fed by the microstrip feeder through the cross gap in the center of the metal ground plate; the two arms of the cross gap have unequal lengths and equal widths. Left-handed or right-handed circular polarization is realized by controlling the length of the two slits. The smaller the width of the dumbbell handle of the dumbbell-shaped slot, the higher the cut-off frequency of the antenna; the larger the distance between the two dumbbell-shaped slots, the stronger the gating performance of the filter.

Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant advantages:

1. This design uses a three-layer stacked dielectric resonator structure. Compared with the traditional dielectric resonator, the gain of the dielectric resonator antenna is effectively improved, up to 8.2dB.

2. A stacked dielectric resonator on a ground plane enables a small antenna size.

3. The cooperation between the microstrip feeder and the cross slot on the ground plate, the microstrip feeder and the cross slot are at 45°. The length and width of the microstrip feeder and the width of the cross slot achieve good matching of the antenna.

4. Adding two cascaded slot structures on the ground plane widens the impedance bandwidth of the antenna.

5. Circular polarization is achieved by means of cross-slit coupling feeding. The axial ratio of the antenna at 12.2GHz is about 0.09dB, and very good circular polarization characteristics are obtained.

6. Left-handed or right-handed circularly polarized waves can be easily realized by controlling the length of the two slits. The structure shown in Figure 1 is a left-handed circularly polarized antenna.

Description of drawings

Figure 1 Top view of circularly polarized dielectric resonator antenna.

Figure 2 Side view of circularly polarized dielectric resonator antenna.

Figure 3 Slot structure on the ground plate.

Figure 4 Antenna simulation S parameters.

Figure 5 Antenna axial ratio curve.

Figure 6 Antenna gain diagram.

Figure 7 Antenna radiation pattern (12.2GHz).

Detailed ways

Preferred embodiments of the present invention are described in detail as follows in conjunction with accompanying drawings:

Embodiment one:

Referring to Figures 1 to 3, the Ku-band circularly polarized dielectric resonator antenna includes a layer of gold on the upper surface of the dielectric substrate (1).

It belongs to the ground plate (6) and a microstrip feeder (5) on the lower surface of the dielectric substrate (1), and is characterized in that:

1) There is a three-layer stacked dielectric resonator (2) at the center above the metal ground plate (6);

2) There is a cross gap (3) at the center of the metal grounding plate (6);

3) The inner end of the microstrip feeder (5) is directly below the cross slit (3), and the microstrip feeder and the cross slit (3) are at an angle of 45°;

4) There are two cascaded dumbbell-shaped slots (4) on the metal ground plate (6) to widen the impedance bandwidth of the antenna.

Embodiment two:

This embodiment is basically the same as Embodiment 1, and the special feature is: the three-layer stacked dielectric resonator (2) is a lower dielectric cylinder (2-1), a middle dielectric cylinder (2-2) and an upper dielectric cylinder ( 2-3) Stacked, three layers of dielectric cylinders have the same radius, different materials and heights, the main effect of their height and the dielectric constant of the material on the antenna is the resonant frequency of the antenna, and its size affects the axial ratio bandwidth of the antenna Greater impact. The three-layer stacked circularly polarized dielectric resonator (2) is coupled and fed by the microstrip feeder (5) through the cross gap (3) in the center of the metal ground plate (6); the length of the two arms of the cross gap (3) Not equal, equal width. Left-handed or right-handed circular polarization is realized by controlling the length of the two slits. The smaller the width of the dumbbell handle of the dumbbell-shaped slot (4), the higher the cut-off frequency of the antenna; the larger the distance between the two dumbbell-shaped slots (4), the stronger the gating performance of the filter.

Embodiment three:

This embodiment is basically the same as Embodiment 1, and the special features are as follows:

1. The structure of the antenna is shown in Figure 1-2. The lower layer is the microstrip feeder (5), the middle layer is the dielectric substrate (1), and the microstrip feeder with a characteristic impedance of 50 ohms is etched on the dielectric substrate layer; the upper layer is the ground plate (6), the cross gap (3) and the dumbbell-shaped gap (4) are all slotted on this grounding plate (6); the lower layer medium cylinder (2-1); the middle layer medium cylinder (2-2); the upper layer Medium cylinders (2-3).

2. The three-layer stacked dielectric resonator (3) has the same medium radius, but different materials and heights. Their height and dielectric constant mainly affect the resonant frequency of the antenna, and their size has a great influence on the axial ratio bandwidth of the antenna.

3. The ground plate (6) and the microstrip feeder (5) are respectively located on the upper and lower sides of the dielectric substrate (1), and the cylindrical dielectric resonator (2) passes the microstrip line (5) through the cross gap in the center of the floor (6) ( 3) Coupling and feeding it. As shown in Figure 3, the two arms of the cross slot (3) are unequal in length and equal in width, and the two arms of the cross-shaped coupling slot and the microstrip feeder (5) are offset at an angle of 45 degrees to form circular polarization. The length of each slot realizes left-handed or right-handed circular polarization. Adjusting the width of the slot and the length of the microstrip feeder (5) can make the microstrip antenna well matched.

4. The structure of two cascaded dumbbell-shaped slots (4) on the grounding plate (6) is shown in Figure 3, which is located on the grounding plate (6), which is the other side of the 50-ohm microstrip line. The multi-slot cascaded structure has a significant effect on widening the impedance bandwidth of the antenna, and can improve the performance of the antenna well. The width of the dumbbell handle and the radius of the dumbbell have the greatest effect on the change of the cutoff frequency of the defect ground structure: the smaller the handle width, the higher the cutoff frequency of the antenna; when the cutoff frequency becomes higher, the area of the dumbbell is also smaller. The change of the cutoff frequency will also be caused by the change of the distance between the two defective grounds and the length of the handle. The larger the length of the handle, the smaller the cutoff frequency; the larger the distance between the two defective grounds, the stronger the gating of the filter .

5. Figure 4 is the antenna simulation S parameter. It can be seen from the figure that the impedance bandwidth of S ₁₁ ≤ -10dB reaches 27.67%. 6.56%, and the axial ratio of the antenna at 12.2GHz is about 0.09dB.

6. Figure 6 is the antenna gain diagram. In the operating frequency range of 11GHz-14.5GHz, the maximum gain of the antenna is 8.2dB, and the minimum gain is 6.0dB.

7. Figure 7 is the antenna pattern at 12.2GHz. It can be seen from the figure that the side lobe of the antenna is low and has better radiation characteristics. the

Claims (4)

1. a Ku wave band circularly polarized dielectric resonator antenna, comprises that medium substrate (1) upper surface has layer of metal ground plate (6) and a microstrip feed line (5) that is in medium substrate (1) lower surface, is characterized in that:

1) on metal ground plate (6), there is the dielectric resonator (2) of a three level stack center;

2) in metal ground plate (6) center, there is cross gap (3);

3) the inner of described microstrip feed line (5) be in described cross gap (3) under, microstrip feed line and cross gap (3) are 45 °;

4) on metal ground plate (6), there is the dumbbell shape line of rabbet joint (4) of two cascades, with broadening antenna impedance bandwidth.

2. Ku wave band circularly polarized dielectric resonator antenna according to claim 1, it is characterized in that: the dielectric resonator of described three level stack (2) is layer dielectric cylinder (2-1), middle level dielectric cylinder (2-2) and stacking the forming of top dielectric cylinder (2-3), the radius of three layers of dielectric cylinder is identical, material and highly different, the dielectric constant of their height and material is the resonance frequency of antenna to the major effect of antenna, and its size is larger on the axial ratio bandwidth impact of antenna.

3. Ku wave band circularly polarized dielectric resonator antenna according to claim 1, is characterized in that: the circularly polarized dielectric resonator of three level stack (2) by microstrip feed line (5) cross gap (3) by metal ground plate (6) center to its feed that is coupled; Two arm lengths of cross gap (3) are unequal, and width equates.By controlling the length in two gaps, realize left-handed or right-handed circular polarization.

4. Ku wave band circularly polarized dielectric resonator antenna according to claim 1, is characterized in that: the dumbbell lever width of the described dumbbell shape line of rabbet joint (4) is less, and the cut-off frequency of antenna is higher; Two dumbbell shape lines of rabbet joint (4) spacing is larger, and the gated nature of filter is stronger.

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