JP2531618Y2 - Broadband printed antenna - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an antenna device in a repeater case used for specific low power radio.

[0002]

2. Description of the Related Art Conventionally, a monopole antenna having a ground plate has been used. However, since a small radio device does not have a ground plate and has a resin body, the radio device is actually closed. At this time, the hand holding the wireless device, that is, the human body plays the role of grounding, and as shown in FIG. 5, the impedance greatly fluctuates depending on the way of holding and holding the wireless device.
(Body effect) In addition, the VSWR fluctuation is high, the balance of the antenna is poor, the current is loaded on the cable jacket, and the directivity and sensitivity fluctuate unstable. Damage was also caused by external forces coming from exposing the antenna to the antenna.

[0003]

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, the present invention is small and lightweight, and has no VSWR by installing a balanced antenna in the case of a radio. It is an object of the present invention to provide an antenna which has stable characteristics and sensitivity and can realize a wider band.

[0004]

According to the present invention, in order to solve the above-mentioned problems, the present invention has been made to reduce the size and to bend both ends of a dipole antenna into both sides of a printed circuit board in a repeater case.
The antenna element formed on the surface and the print balloon connected to the feed unit are formed and mounted on a printed circuit board, and the feed unit at the center of the antenna is equipped with an impedance correcting capacitor and the impedance correcting capacitor. The land pattern is provided for the purpose.

[0005]

FIG. 3 (b) shows how the bent portion of the element length is cut little by little in order to obtain resonance, as shown in the ANT impedance locus (Smith chart) of FIG. 3 (a). As described above, point A is the impedance of the printed antenna in free space (free space). When the antenna is placed in an empty repeater case, the impedance changes from point A to point B. Next, the TX combiner 10 and the TRX (transmit / receive) unit 13 shown in FIG.
, The impedance changes to the point C, and moves from the point C to the point D when the case is covered. Finally, a capacitor for impedance correction is mounted on the land pattern of the antenna, and the bent portion of the printed antenna is cut (for example, up to the portion shown in FIG. 3B) to shift the impedance to the best point E, and the printed antenna is mounted. Can be mounted in a repeater case.

[0006]

FIG. 1 shows a broadband print antenna according to the present invention.
FIG. 4 is a reference diagram showing a configuration of a printed circuit board on a printed circuit board , wherein a printed antenna element 1 is a PCB (Print Circuit);
TBoard) are those which are provided on both surfaces of the 4, those used in the examples of the present invention, the length of the element, lambda / 4
The wavelength is about 158 mm, and since the ε (permittivity) of the PCB 4 is large, the shortening rate (9
(8% to 96%), the shortening rate is 93%, and the size of the antenna can be reduced. Further, both ends of the antenna element 1 are bent for miniaturization, and the bent element A and the element B form a dipole antenna.

A chip capacitor 3 for reactance correction is soldered to the land pattern 2, and the PCB 4 is FR-
4 (glass epoxy) is used.

The print balloon section 5 is used for matching the electrically balanced print antenna section and the unbalanced coaxial section.

[0009] Figure 2 is a real施例of the present invention, both surfaces of the length of the element of the surface of the printed circuit board (Table antenna 6), the through hole 8 by changing the length of the back surface of the element (back antenna 7) And the like to form a double dipole, thereby achieving a wider band.

FIG. 4 is a view when the present invention is mounted in a plastic repeater case 14. The printed antenna of the present invention is used for TX (hereinafter referred to as transmission) and RX (hereinafter referred to as reception). The TX print antenna 9 is used on the inner wall of the repeater case, and the TX combiner 10
And the RX print antenna 11 is
It is provided to face the X distributor 12. Then, a TRX (transmission / reception) unit 13 is incorporated between the TX combiner 10 and the RX distributor 12.

[0011]

[Effects of the Invention] The present invention can prevent VSWR deterioration, sensitivity reduction, and noise generation due to water drops in rainy weather by storing the antenna in a repeater case in a small size.
Damage can be eliminated. Since both ends are bent to form a dipole antenna, both the horizontal and vertical polarization planes can be radiated simultaneously, so that the use in complex propagation is effective.

Also, by using a printed circuit board, it is possible to provide elements having different resonance frequencies on the front and back of the printed circuit board, respectively, and it is also possible to widen the band by coupling through through holes or the like. In addition, the use of a printed circuit board makes it possible to produce a large number of antennas having the same characteristics, and to provide an inexpensive product with little variation in quality.

[Brief description of the drawings]

FIG. 1 shows a print of a broadband printed antenna according to the present invention.
Reference diagram showing the configuration on the

Shows the real施例of FIG. 2 the present invention

FIG. 3 (a) ANT impedance locus (Smith chart) representing the impedance of the printed antenna of the present invention; FIG. 3 (b) is a diagram showing an example of cutting the elements of the printed antenna of the present invention;

FIG. 4 is a perspective view of an embodiment of the present invention mounted in a repeater case and a lid removed.

FIG. 5 is an external view of a conventional small wireless device in use.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print antenna element 2 Land pattern 3 Chip capacitor 4 PCB 5 Print balloon part 6 Front antenna 7 Back antenna 8 Through hole 9 TX print antenna 10 TX combiner 11 RX print antenna 12 RX distributor 13 TRX unit

Claims (1)

(57) [Scope of request for utility model registration] 1. An antenna mounted in a repeater case
Broadband characteristics on both sides of the printed circuit board
Die having two sets of resonance frequencies with different antenna lengths
A pole antenna is formed, and the desired antenna length is small
The shape bent at both ends of the printed board to obtain
And the feeder to be a dipole antenna
Land pattern on the part close to the antenna
And connect the impedance correction capacitor to its land.
Solder to the pattern to form a dipole antenna
A broadband printed antenna characterized by the following: