CN101369685A - A photonic crystal patch antenna - Google Patents

Abstract

The invention discloses a photonic crystal patch antenna, the patch antenna fixed on the antenna base is connected with a microstrip feeder, the excitation source feeds the patch antenna through the feed port through the microstrip feeder, and is arranged vertically and horizontally on the front of the antenna base There are round holes with equal intervals, and a rectangular metal frame is fixed on the reverse side of the antenna base, and the rectangular metal frame is embedded in the periphery of the round holes. In the present invention, a photonic crystal structure is added to the substrate medium of the patch antenna to form a photonic band gap. Electromagnetic waves within the band gap frequency range will be bound and cannot propagate in any direction. The band gap effect of the photonic crystal can be used to suppress the The surface wave propagated by the base plate medium reduces the absorption of electromagnetic waves by the antenna base, greatly reflects the energy in the antenna base of the photonic crystal, increases the reflected energy of electromagnetic waves to free space, effectively reduces the return loss of the antenna, and increases the gain of the antenna , making it play its role in many fields such as mobile communication, satellite communication and aerospace.

Description

A photonic crystal patch antenna

technical field

The invention relates to the technical field of communication, in particular to a photonic crystal patch antenna.

Background technique

Photonic crystal refers to the structure whose refractive index is distributed periodically in space. The characteristics of electromagnetic wave transmission inside the crystal are similar to the movement characteristics of electrons in semiconductor crystals, so they are also called photonic crystals or electromagnetic crystals. When the electromagnetic wave is incident on the electromagnetic (photonic) crystal, the propagation of the electromagnetic wave can be prohibited in a certain frequency range, which is called the frequency forbidden band. In 1989, Yablonovitch and Gmitte took the lead in producing a photonic crystal with 8000 "atoms" composed of nine layers of styrene plates, and observed a forbidden band exceeding 2 GHz in the microwave frequency band of 6.5 GHz, which makes the electromagnetic (photon ) crystals have been applied to many aspects such as microwave circuits and antennas. Photonic crystal structures are used in many new antennas called photonic crystal antennas. The advantages of wide bandwidth, improving the directivity of the antenna, and greatly improving the radiation efficiency of the antenna make it widely used in many fields such as mobile communications, satellite communications, and aerospace. However, the defects in the application of the photonic crystal antenna are: the energy in the substrate of the reflective photonic crystal antenna is insufficient, and the return loss is relatively large.

Invention content:

The purpose of the present invention is to provide a photonic crystal patch antenna, which can largely reflect the energy in the antenna substrate of the photonic crystal, and effectively realize smaller return loss and higher gain characteristics.

The technical solution adopted by the present invention is: the patch antenna fixed on the antenna base is connected to the microstrip feeder, the excitation source feeds the patch antenna through the feeder port through the microstrip feeder, and the circles with equal spacing are arranged vertically and horizontally on the front of the antenna base. A rectangular metal frame is fixed on the reverse side of the antenna base, and the rectangular metal frame is embedded in the periphery of the circular hole.

Compared with the prior art, the present invention has the following advantages:

The present invention embeds a circular hole photonic crystal structure in the rectangular metal frame on the reverse side of the antenna base, that is, adds a photonic crystal structure to the base medium of the patch antenna to form an electromagnetic (photonic) forbidden band, and within the forbidden band frequency range Electromagnetic waves will be bound and cannot propagate in any direction. Using the bandgap effect of photonic crystals, the surface waves propagating along the substrate substrate medium can be suppressed. Therefore, the absorption of electromagnetic waves by the antenna substrate will be reduced, and the antenna of photonic crystals can be greatly reflected The energy in the substrate increases the reflected energy of electromagnetic waves to free space, effectively reduces the return loss of the antenna, increases the gain of the antenna, and makes it play its role in many fields such as mobile communications, satellite communications, and aerospace.

Description of drawings

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Fig. 1 is a schematic diagram of the front structure of the substrate photonic crystal patch antenna of the present invention;

Fig. 2 is a schematic diagram of the reverse structure of the substrate photonic crystal patch antenna of the present invention;

FIG. 3 is a schematic diagram of distribution of return loss S11 with frequency in Embodiment 1 of the present invention.

Detailed ways:

As shown in Figures 1 and 2, the photonic crystal patch antenna is composed of a photonic crystal area and a patch antenna area. The patch antenna area includes a patch antenna 3 fixed on the antenna base 1, and the length of the antenna base 1 is 50-360mm , The width is 50-360mm, and the thickness is 4-10mm. One end of the patch antenna 3 is connected to a microstrip feeder 4 , and the other end is a feeder port 5 . The patch antenna 3 and the microstrip feeder 4 , the excitation source feeds the patch antenna 3 through the feed port 5 and the microstrip feeder 4 . The photonic crystal area is circular holes 2 arranged vertically and horizontally at equal intervals on the front of the antenna base 1 to form a photonic crystal structure. The diameter of the circular holes 2 is 16-32 mm, and the distance between the centers of the two circular holes is 20-3 mm. The inside of the circular hole 2 is an air medium, and the relative dielectric constant of the medium of the antenna base 1 is 2.2-10.2. A rectangular metal frame 6 is fixed on the reverse side of the antenna base 1. The length and width of the rectangular metal frame 6 are 20-80 mm. The rectangular metal frame 6 is embedded in the periphery of the circular hole 2 to form an embedded circular hole photonic crystal structure.

The present invention is illustrated below in conjunction with 3 embodiments.

Example 1

As shown in Figures 1 and 2, the length of the antenna base 1 is set to 200 mm, the width is 100 mm, and the thickness is 8 mm. On the front of the antenna base 1, round holes 2 arranged vertically and horizontally with a diameter of 20 mm are drilled to form a photonic crystal structure. The round holes 2 The distance between the centers of the circles is 30mm. On the edge of the back side of the antenna base 1, add a length of 70mm and a rectangular metal frame 6 of 20mm in width, and embed the photonic crystal structure in the rectangular metal frame 6. The relative dielectric constant of the antenna base 1 medium is 6 (polytetrafluoroethylene material) ), add a patch antenna 3 of 26×16mm above the dielectric layer, the excitation source adopts a microstrip feeder 4 with a width of 4.7mm to feed the patch antenna 3 at the feed port 5, as shown in Figure 3, and the feedback Wave loss S11 characteristics, the minimum return loss S11 is about -41dB at the frequency of 3.16GHZ.

Example 2

As shown in Figures 1 and 2, the length of the antenna base 1 is set to 300 mm, the width is 50 mm, and the thickness is 10 mm. On the front of the antenna base 1, round holes 2 arranged vertically and horizontally and with a diameter of 32 mm are drilled to form a photonic crystal structure. The round holes 2 The distance between the centers of the circles is 40mm. On the edge of the back side of the antenna base 1, add a length of 80mm and a rectangular metal frame 6 of 50mm in width, and embed the photonic crystal structure in the rectangular metal frame 6. The relative dielectric constant of the antenna base 1 medium is 10.2 (polytetrafluoroethylene material ), add a patch antenna 3 of 26×16mm above the dielectric layer, the excitation source adopts a microstrip feeder 4 with a width of 4.7mm to feed the patch antenna 3 at the feed port 5, as shown in Figure 3, and the feedback Wave loss S11 characteristics, the minimum return loss S11 is about -41dB at the frequency of 3.16GHZ.

Example 3

As shown in Figures 1 and 2, the length of the antenna base 1 is set to 52 mm, the width is 50 mm, and the thickness is 4 mm. On the front of the antenna base 1, circular holes 2 arranged vertically and horizontally and with a diameter of 16 mm are drilled to form a photonic crystal structure. The circular holes 2 The distance between the centers of the circles is 20mm. On the edge of the back side of the antenna substrate 1, the length is 30mm, and the rectangular metal frame 6 with a width of 26mm is embedded in the rectangular metal frame 6. The photonic crystal structure is embedded, and the relative dielectric constant of the antenna substrate 1 medium is 2.2 (polytetrafluoroethylene material ), add a patch antenna 3 of 26×16mm above the dielectric layer, the excitation source adopts a microstrip feeder 4 with a width of 4.7mm to feed the patch antenna 3 at the feed port 5, as shown in Figure 3, and the feedback Wave loss S11 characteristics, the minimum return loss S11 is about -41dB at the frequency of 3.16GHZ.

Claims (4)

1. A photonic crystal patch antenna, the patch antenna (3) that is fixed on the antenna substrate (1) connects the microstrip feeder (4), and the excitation source is given by the feed port (5) through the microstrip feeder (4) Patch antenna (3) feeding is characterized in that round holes (2) with equal spacing are arranged vertically and horizontally on the front of antenna base (1), and a rectangular metal frame (6) is fixed on the reverse side of antenna base (1). The metal frame (6) is embedded in the periphery of the circular hole (2). 2. A kind of photonic crystal patch antenna according to claim 1, is characterized in that: the circular hole (2) is an air medium, and the relative permittivity of the antenna base (1) medium is 2.2～10.2; the antenna base ( 1) The length is 50-360 mm, the width is 50-360 mm, and the thickness is 4-10 mm. 3. A photonic crystal patch antenna according to claim 1, characterized in that: the diameter of the round hole (2) is 16-32 mm, and the distance between the centers of the two round holes is 20-40 mm. 4. A photonic crystal patch antenna according to claim 1, characterized in that: the length and width of the rectangular metal frame (6) are 10-60 mm.

Images