INSET TYPE FEED ANTENNA STRUCTURE

Abstract

An inset type feed antenna structure is disclosed includes a substrate, a patterned conductive layer disposed on an upper surface of the substrate, and a grounding layer disposed on a lower surface of the substrate. The patterned conductive layer includes a conductive line and a plurality of radiation units, wherein each radiation units includes a conductive patch provided with a notch on one side thereof, and a feeding line electrically connecting the conductive line and the notch, wherein the feeding line is a quarter-wave feeding line. The present invention not only decreases the distance between the radiation units and the conductive line to control the vertical side lobes, but also increases the impedance of each radiation unit, so that more radiation units can be fed in.

Claims

1. An inset type feed antenna structure, comprising: a substrate provided with an upper surface and a lower surface; a patterned conductive layer disposed on the upper surface of the substrate, the patterned conductive layer further comprising: a conductive line; and plural radiation units disposed on two lateral sides of the conductive line, each radiation unit further comprising: a conductive patch provided with a notch disposed on one edge thereof; and a feeding line connecting the conductive line and the notch of the conductive patch, wherein the feeding line is a quarter-wave feeding line; and a grounding layer disposed on the lower surface of the substrate.

2. The antenna structure of claim 1, wherein the radiation units are disposed on two sides of the conductive line in a strip shape array arrangement.

3. The antenna structure of claim 1, wherein the notch of the conductive patch is provided with a first section having a first length, a second section having a second length, and a third section having a third length, wherein the first section and the third section are disposed in opposite to each other, and the feeding line is connected with the second section.

4. The antenna structure of claim 3, wherein the first length is identical to the third length.

5. The antenna structure of claim 4, wherein the first section is disposed in parallel to the third section.

6. The antenna structure of claim 4, wherein the first length is larger than the second length.

7. The antenna structure of claim 3, wherein a length of the conductive patch is 3.3 mm, and the first length is 1.2 mm.

8. The antenna structure of claim 3, wherein a width of the conductive patch is 3.1 mm, and the second length is 0.6 mm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a top view of the inset type feed antenna structure in accordance with an embodiment of the present invention.

[0014] FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1.

[0015] FIG. 3 is a partially enlarged view of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0016] The aforementioned and further advantages and features of the present invention will be understood by reference to the description of the preferred embodiment in conjunction with the accompanying drawings where the components are illustrated based on a proportion for explanation but not subject to the actual component proportion.

[0017] An embodiment of an inset type feed antenna structure 1 is provided. By use of a quarter-wave feeding structure which fees each microstrip antenna structure, distance between the radiation units 124 and the conductive line 122 is shortened, vertical side lobes are under controlled, and the impedance of each radiation unit 124 is enlarged, such that more radiation units 124 are allowed to be provided to be fed in.

[0018] FIG. 1 is a top view of the inset type feed antenna structure 1 in accordance with an embodiment of the present invention; FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1. As shown by the drawings, an embodiment of the inset type feed antenna structure 1 comprises a substrate 10 provided with an upper surface 102 and a lower surface 104, a patterned conductive layer 12 disposed on the upper surface 102 of the substrate 10, and a grounding layer 14 disposed on the lower surface 104 of the substrate 10. The patterned conductive layer 12 includes a conductive line 122 and plural radiation units 124, wherein the radiation units 124 are disposed on two lateral sides of the conductive line 122 and provided with a conductive patch 1242 and a feeding line 1244. The conductive patch 1242 includes a notch 12422 disposed on one edge of the conductive patch 1242. The feeding line 1244 connects the conductive line 122 and the notch 12422 of the conductive patch 1242, wherein the feeding line 1244 is a quarter-wave feeding line 1244. In an embodiment, the radiation units 124 are disposed on two lateral sides of the conductive line 122 in a strip shape array arrangement.

[0019] In the antenna array structure, each radiation unit 124 feeds each microstrip antenna through a section of a quarter-wave transmitting line in a manner of inset feeding. According to antenna related theory, the impedance of the edge portion of the microstrip antenna is at the maximum value, and the impedance gradually decreases toward the central point of the microstrip antenna. Therefore, when the antenna feeds from a portion in adjacent to the central point thereof, the impedance is controlled in a relatively small value. Then, through the quarter-wave transmitting line, the impedance increases to a higher value. Such configuration is able to effectively control the vertical side lobes.

[0020] Accordingly, referring to FIG. 1 and FIG. 3, FIG. 3 is a partially enlarged view of FIG. 1, illustrating an enlarged structure of one of the radiation units 124. In an embodiment, the notch 12422 of the conductive patch 1242 is provided with a first section having a first length L.sub.1, a second section having a second length L.sub.2, and a third section having a third length L.sub.3, wherein the first section and the third section are disposed in opposite to each other, and the feeding line 1244 is connected with the second section. Referring to FIG. 2, the first section and the third section are disposed in parallel, and the first length L.sub.1 is identical to the third length 3. In the embodiment, the first length L.sub.1 and the third length L.sub.3 are larger than the second length L.sub.2. The shape of the notch 12422 includes but is not limited to a rectangular. In an embodiment, a length of the sides of the conductive patch 1242 that are disposed in vertical to the conductive line 122 is defined as the length of the conductive patch 1242, and the length of the conductive patch 1242 is 3.3 mm; a length of the sides of the conductive patch 1242 that are disposed in parallel to the conductive line 122 is defined as the width of the conductive patch 1242, and the width of the conductive patch 1242 is 3.1 mm. Under such circumstances in this embodiment, the first length L.sub.1 is 1.2 mm; the second length L.sub.2 is 0.6 mm; the width of the feeding line 1244 is one-third of the second length L.sub.2.

[0021] With the foregoing configuration, the inset type feed antenna structure 1 of the present invention applies the quarter-wave feeding structure to feed the recess-like structure of the conductive patch 1242 in a manner of inset feeding, the distance between of the radiation units 124 disposed in an array arrangement and the conductive line 122 is shortened by about 10%, such that the vertical side lobes thereof are effectively under controlled. Also, the impedance of each radiation unit 124 is enlarged, such that more radiation units 124 are allowed to be provided to be fed in.

[0022] Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims.