CN101527392A - Dual-band broadband E-shaped microstrip antenna - Google Patents

Abstract

The present invention provides a dual-frequency broadband E-shaped microstrip antenna, which includes an E-shaped patch 3, the main feeder 1 is directly connected to the coaxial feed point SMA connector 2 of the E-shaped patch 3, and the SMA connector passes through the The ground and the medium are in direct contact with the middle arm of the E-shaped patch 3. The other two arms of the E-shaped patch 3 are symmetrically distributed on both sides of the feeding point, and the distance from the edge of the middle arm is L ₃ . 3. The T-shaped patch (bent T-shaped patch) is connected by loading. 4. The main radiation unit of the antenna is formed. There is a width t between the E-shaped patch 3 and the T-shaped patch (bent T-shaped patch). , There are symmetrical grooves of width t2 and depth t1 on both sides of the connection between the T-shaped patch (bent T-shaped patch) and the E-shaped patch. The invention has high gain, wide operating frequency, uniform current distribution, can effectively improve communication quality, is light in weight, small in size, easy to integrate with circuits, and can be widely used in portable equipment and indoor coverage and wireless local area networks.

Description

Dual-band broadband E-shaped microstrip antenna

(1) Technical field

The invention relates to a dual-frequency E-shaped microstrip antenna. Specifically, it is a microstrip antenna used for low and medium gain indoor coverage and wireless local area network in mobile communication systems, and the working frequency band is 2400-2500 and 5100-5850MHz.

(2) Background technology

At present, antennas for the same purpose have the following disadvantages: (1) At present, the gain of the antenna is required to be relatively high, for example, a gain of 4-6 dBi is required. However, the existing indoor antennas and wireless LAN antennas are mostly in the form of traditional monopoles and symmetrical arrays, so the direction diagrams are equal up and down. In practical applications, almost all upward radio wave radiation is wasted, so the gain is relatively low and the frequency band is relatively narrow. Antennas with such gain waste signals in vain, thereby affecting communication quality. (2) Most of the currently used indoor coverage and wireless LAN antennas are ceiling-mounted antennas, whose frequency band control is relatively difficult, and users hope to use dual-band broadband antennas, which means making full use of resources and improving the flexibility of antennas. Current indoor coverage and WLAN antennas cannot meet this demand. (3) At present, the antennas used by users require miniaturization, but the microstrip antenna is easy to manufacture, easy to integrate, and can well realize miniaturization. Current indoor coverage and WLAN antennas cannot meet this demand. (4) The current communication has higher and higher bandwidth requirements. The current ceiling-mounted antennas and indoor antennas cannot meet the current communication needs, especially the dual-band broadband high-gain antennas cannot meet the requirements.

(3) Contents of the invention

The purpose of the present invention is to provide a dual-frequency wideband E-shaped microstrip antenna with high gain, wide operating frequency range, uniform current distribution, and effective communication quality improvement.

The purpose of the present invention is achieved like this:

It consists of an E-shaped patch 3, the main feeder 1 is connected to the coaxial feed point of the E-shaped patch 3 SMA joint 2, the SMA joint passes through the ground and the medium and the middle arm of the E-shaped patch 3 (width is W ₁ ) Direct contact, the length of the two arms is L ₁ , the other two arms of the middle E-shaped patch 3 are symmetrically distributed on both sides of the feed point, and the distance from the edge of the middle arm is L ₃ , passing through the E-shaped patch 3 The T-shaped patch 4 is loaded and connected to form the main radiation unit of the antenna. The gap width between the E-shaped patch 3 and the T-shaped patch is t, and there are symmetrical holes on both sides of the connection between the T-shaped patch and the E-shaped patch. For grooves with width t ₂ and depth t ₁ , the width of the coupling side between the E-shaped patch and the T-shaped patch is W ₅ .

The present invention may also include:

When the size of the T-shaped patch is long and the miniaturization design cannot be realized, the bent T-shaped patch structure is adopted, that is, the two non-connected ends of the T-shaped patch are bent to reduce the unit size of the antenna, thereby realizing Miniaturized design. At this time, the main radiation unit includes an E-shaped patch and a bent T-shaped patch.

By effectively adjusting the slot on the E-shaped patch and the length and width of the two arms of the T-shaped patch (bent T-shaped patch), the operating frequency and bandwidth of the antenna's high-frequency and low-frequency bands are changed to achieve dual-band Steerable operation of broadband microstrip antennas.

The entire radiating unit is printed on a dielectric substrate with a dielectric constant of 4.4. L ₃ and t can change the operating frequency band of the E-shaped microstrip antenna, and the E-shaped antenna can work at 5.1GHz to 5.8GHz through simple adjustments. By adjusting W ₄ , the designed T-shaped loaded microstrip antenna can work at 2.4GHz to 2.5GHz, but adjusting t ₁ and t ₂ will affect the current distribution of the E-shaped patch and affect the radiation of the E-shaped patch. Generally, when in use, only adjusting W ₄ and t can satisfy the radiation performance of the low frequency band.

Beneficial effects: (1) The present invention utilizes the principle of electric wave conduction to gradually guide electric waves to the T-shaped patch, and the slot area includes a coupling area t, an excitation area _t2 , and a radiation area _L3 , because electric waves radiate along the guiding direction, and its direction The picture focuses on the E-shaped patch and the T-shaped patch, so the bandwidth of the antenna and the radiation efficiency of the antenna are effectively increased, which is about 10% higher than the efficiency of the usual microstrip antenna, and the bandwidth of the antenna is higher than that of the existing application The antenna bandwidth is more than 2 times wider. (2) The present invention utilizes the principle of electric wave conduction to increase the impedance bandwidth of the microstrip antenna by using characteristics such as microstrip antenna slotting, and at the same time utilizes the coupling parasitic characteristic to enhance the current intensity of the T-shaped patch, thereby increasing its radiation bandwidth. (3) The present invention is basically an omnidirectional antenna, which can be installed in plastic barrels and radomes of any shape. Because of its high gain, the tangential pattern is ideal, the pattern can cover the entire space, and the current distribution is even, realizing wireless antenna. Blind zone coverage greatly improves the communication quality and communication environment. (4) The present invention uses the form of microstrip antenna, which is light in weight, small in size, easy to integrate with circuits, and can be widely used in portable devices and indoor coverage and wireless local area networks, showing a small and exquisite shape.

(4) Description of drawings

Fig. 1 is the front schematic diagram of the example of the present invention;

Fig. 2 is the side schematic diagram of the example of the present invention;

Fig. 3 is the schematic diagram of the bottom surface of the example of the present invention;

Fig. 4 is the return loss test curve of the example of the present invention;

Fig. 5 is the direction diagram of the example of the present invention tested on the 5.1GHzE plane;

Fig. 6 is the directivity diagram of the example of the present invention tested on the 5.1GHz H plane;

Fig. 7 is the direction diagram of the example of the present invention tested on the 5.5GHzE plane;

Fig. 8 is the direction diagram of the example of the present invention tested on the 5.5GHz H plane;

Fig. 9 is the direction diagram of the example of the present invention tested on the 5.85GHz E plane;

Fig. 10 is the direction diagram of the example of the present invention tested on the 5.85GHz H plane;

Fig. 11 is the direction diagram of the example of the present invention tested on the 2.4GHzE plane;

Fig. 12 is the direction diagram of the 2.4GHz H plane test of the example of the present invention;

Fig. 13 is the direction diagram of the example of the present invention tested on the 2.5GHz E plane;

Fig. 14 is the direction diagram of the 2.5GHz H plane test of the example of the present invention;

Fig. 15 is a schematic front view of the structure of another example of the present invention.

(5) Specific implementation methods

The present invention is described in more detail below in conjunction with accompanying drawing example:

Based on the design principle of the E-shaped broadband antenna, the structure of the modified antenna is simplified, and the form of loading is adopted, and the width of the coupling slot, the thickness of the dielectric plate and the dielectric constant are selected appropriately, and good matching performance is achieved, and then the E-shaped antenna is improved. The structure of the patch is properly slotted at the connection between the T-shaped patch and the E-shaped patch, and the shape and size of the E-shaped patch and the T-shaped patch are optimized to make it a miniaturized dual-band broadband E-shaped patch. The antenna, which consists of an excitation area, a transmission area and two radiation pieces, realizes omnidirectional radiation characteristics. Due to the original omnidirectional characteristics of the E-shaped patch and the shared feed of the T-shaped and E-shaped patches, the T-shaped loaded patch can be regarded as a pair of symmetrical array (dipole) antennas, so that the high-frequency and low-frequency All frequency bands have good omnidirectional radiation characteristics. Finally, in order to make the radiation characteristics of the designed antenna more ideal, that is, to achieve uniform coverage on the horizontal plane, grooves are designed at the E-shaped and T-shaped patches of the antenna, so that it can well realize the common feeding structure.

The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and implementation examples.

In Figures 1 to 3, 1 is the feed cable, 2 is the feed connector (SMA connector), 3 is the E-shaped patch, and 4 is the T-shaped loading patch (bent T-shaped patch).

Implementation example 1:

As shown in Figures 1, 2 and 3, the 50Ω main feeder 1 is directly connected to the feed SMA connector 2 of the microstrip antenna, passes through the ground plane and the dielectric plate through the SMA connector, and directly contacts the E-shaped patch. Adjusting L ₃ , t ₁ and t ₂ can determine the operating frequency and operating bandwidth of the high frequency band. The designed antenna works at 5.1GHz to 5.8GHz to meet the communication needs of wireless local area networks.

Adjusting the size of W ₄ can change the working frequency of the designed antenna in the low frequency band. When W ₄ is narrow, the antenna resonates below 2.4GHz at the low end. When the width of W ₄ is increased, the resonance point at the low end of the antenna will be High frequency mobile. L ₄ is the length of the T-shaped patch, W ₂ is the width of the feeding arm of the T-shaped patch, the gap t is the distance between the E-shaped patch and the T-shaped patch, changing the size of t mainly changes the E-shaped patch The coupling degree between the chip and the T-shaped patch mainly determines the resonance bandwidth of the low frequency band. When t increases, the resonance bandwidth will be narrowed. When t is small, the antenna will have a better resonance bandwidth. t ₂ is the feed of the T-shaped patch connected to the slotted gap, and t ₂ has an important influence on the high frequency band. S is the distance from the feed connector to the edge of the middle arm of the E-shaped patch.

In order to reduce the reflection of the incident wave by the E-shaped and T-shaped radiators, its shape mainly adopts an appropriate slotted shape. A combination of slotted coupling and direct coupling.

In this example, the dimensions of Figure 1 are: L ₁ =25.5mm; L ₂ =6.8mm; L ₃ =8mm; L ₄ =32mm; W ₄ =6.5mm; W ₂ =1.9mm; W ₃ =4mm; W ₁ = 8mm; t = 2.5mm; t ₁ = 1.8mm; t ₂ = 3.6mm.

Implementation example 2:

As shown in FIG. 15 , according to the relationship between antenna size and frequency (wavelength), the size of the E-shaped antenna and the size of the T-shaped antenna are appropriately changed. This antenna can be used in mobile communications of GSM, WCDMA, CDMA2000 and TD-SCDMA. The specific design dimensions are shown in Figure 15. In Fig. 15, L=120mm; W ₃ =36mm, L ₁ =58mm; W ₁ =18mm; L ₃ =5mm; t≈4mm. Among them, the parameters of the curved T-shaped patch can be determined as a symmetrical dipole antenna. The two non-connecting ends of the T-shaped patch are bent to realize miniaturization.

Implementation example 3:

As shown in Figure 1 and Figure 15, the proposed dual-band broadband E-shaped antenna and T-shaped antenna can also be used as a broadband omnidirectional antenna.

Claims (2)

1, a kind of double-frequency broadband E-shaped microstrip antenna, it comprises E shape paster (3), it is characterized in that: main feeder (1) is connected to the coaxial feed point sub-miniature A connector (2) of E shape paster (3), sub-miniature A connector passes ground and directly contacts with the intermediate arm of medium with E shape paster (3), and other two arms of E shape paster (3) are distributed in the both sides of distributing point symmetrically, be L apart from the distance at intermediate arm edge ₃, go up the primary radiation unit that connects T shape paster (4) formation antenna by loading at E shape paster (3), between E shape paster (3) and the T shape paster width clearance t is arranged, the both sides, junction of T shape paster and E shape paster have the width t of symmetry ₂With degree of depth t ₁Groove.

2, double-frequency broadband E-shaped microstrip antenna according to claim 1 is characterized in that: two front of motor bendings of described T shape paster.

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