KR100667149B1 - Broadband Printed Inverted F Antenna - Google Patents

Abstract

1. TECHNICAL FIELD OF THE INVENTION

The present invention relates to a wideband reverse antenna (PIFA).

2. The technical problem to be solved by the invention

An object of the present invention is to provide a wideband PIFA for lowering the height of an antenna and at the same time having a wideband characteristic by disposing a PIFA element on a PCB by protruding a predetermined length.

3. Summary of Solution to Invention

The present invention provides a broadband PIFA having a planar inverted-f antenna (PIFA) element portion disposed on one surface of a printed circuit board (PCB), wherein a predetermined length of the PIFA element portion protrudes out of an edge of a PCB. A predetermined portion of the portion is arranged to be connected to the feeding portion of the PCB, wherein the PIFA element portion is characterized in that the height is substantially low.

4. Important uses of the invention

The present invention is used in a UWB communication system.

PIFA, broadband, PCB, ground planes, UWB

Description

Broadband Inverted F Antenna             

Figure 1a is a perspective view of a conventional chip-shaped PIFA,

FIG. 1B is a structural diagram of the device portion of FIG. 1A;

1C is a structural diagram of the dielectric part of FIG. 1A;

FIG. 2 is a structural diagram illustrating a state in which the PIFA of FIG. 1A is mounted on a PCB; FIG.

3 is a graph for explaining a change in the standing wave ratio bandwidth characteristics according to the change in the antenna thickness (H) of the PIFA of FIG.

4 is a structural diagram of a first embodiment of a broadband PIFA according to the present invention;

FIG. 5 is a graph illustrating an embodiment of S11 parameter characteristics of FIG. 4; FIG.

6 is a graph illustrating an embodiment of the antenna radiation efficiency of FIG. 4;

7 is a graph illustrating an embodiment of the antenna gain of FIG. 4;

8A is a structural diagram of a second embodiment of a broadband PIFA according to the present invention;

8B is a detailed structural diagram of an embodiment of the PIFA element of FIG. 8A;

FIG. 8C is a detailed structural diagram of an embodiment of a conductor portion of the PIFA element portion of FIG. 8A;

9 is a structural diagram of a third embodiment of a broadband PIFA according to the present invention;

10 is an exploded perspective view of an embodiment of FIG. 9;

FIG. 11 is a graph illustrating an embodiment of S11 parameter characteristics of FIG. 9; FIG.

12 is a graph illustrating an embodiment of the antenna radiation efficiency of FIG. 9;

FIG. 13 is a graph illustrating an embodiment of the antenna gain of FIG. 9; FIG.

14 is a structural diagram of a fourth embodiment of a broadband PIFA according to the present invention;

15 is a structural diagram of a fifth embodiment of a broadband PIFA according to the present invention;

FIG. 16 is an example for explaining a case in which the PIFA of FIG. 15 is installed in a notebook computer by attaching to a wireless LAN card;

17 is an example for explaining the case where the PIFA of FIG. 9 or FIG. 14 is installed in a notebook computer by attaching to a wireless LAN card;

18A is an example for explaining the case where PIFA of FIG. 14 is installed in a mobile phone;

18B is an example for explaining the case where PIFA of FIG. 15 is installed in a mobile phone;

19A is an example for explaining the direction of polarization when using the mobile phone of FIG. 18A;

Fig. 19B is an example for explaining the direction of polarization when using the mobile phone of Fig. 18B.

* Explanation of symbols for the main parts of the drawings

210: PIFA feed part 220: PCB metal foil

230: PCB dielectric portion 240: PCB ground portion

410, 810: PIFA element portion 420: edge intersection

910, 1410: antenna element portion 920: power supply portion

940: RF transmitter

The present invention relates to a broadband inverted F antenna (hereinafter referred to simply as "PIFA"), as well as a broadband communication system such as an ultra wide band (hereinafter referred to as "UWB"), Personal Communication Service (PCS), Cellular, International Mobile Telecommunication (IMT) -2000, Global System for Mobile Communications (GSM), Wireless LAN (LAN), etc. It relates to a wideband PIFA used in communication systems of various frequency bands.

In general, PIFA is designed to operate on a printed circuit board (hereinafter, simply referred to as 'PCB').

FIG. 1A is a perspective view of a conventional chip type PIFA, FIG. 1B is a structural diagram of the element portion of FIG. 1A, and FIG. 1C is a structural diagram of the dielectric portion of FIG. In addition, FIG. 2 is a structural diagram illustrating a state in which the PIFA of FIG. 1A is mounted on a PCB.

As shown in FIG. 1, the conventional PIFA is composed of an inverted-F-shaped antenna conductor portion 110 and a dielectric portion 120 supporting it.

When the antenna of FIG. 1 is installed on a PCB as shown in FIG. 2, as shown in FIG. 2, the PIFA feed part 210, the PCB metal foil 220, the PCB dielectric part 230, and the PCB ground part 240 are shown. ), And the polarization direction of electromagnetic waves is perpendicular to the PCB and radiates.

The antenna is radiated more than a certain size compared to the length L of the conductor portion 110. This will be described with reference to FIG. 3.

3 is a graph for explaining the variation of the standing wave ratio bandwidth characteristics according to the change in the antenna thickness H of the PIFA of FIG. 2, wherein the width and length of the antenna are constant (W = 0.4 cm, L = 3.6 cm). In the case where the dielectric constant of the dielectric part 120 is 2.8, the S11 parameter characteristics according to the antenna height H are shown.

As shown in the figure, the PIFA mounted on the conventional PCB can be seen that the resonance occurs only when the ratio (H / L) of the antenna length to the antenna height is maintained high. In other words, the resonance of less than -10dB occurs at 2GHz above H / L = 0.40, which also has a very narrow band characteristics.

Because of this, the existing PIFA is difficult to use in a broadband wireless communication system, and also has a problem that it is difficult to use as an antenna for wireless communication that requires a very thin structure, such as a mobile phone, a wireless LAN card.

Currently, the trend of wireless communication is that the impulse signal must be copied and received in space like UWB system, which is very demanding broadband communication, and IMD-2000 like broadband mobile CDMA, cellular and PCS common cell, cellular and GPS simultaneously Wireless communication systems with very wide transmit / receive bands are being developed, such as mobile phones capable of receiving mobile phones, PCS and wireless LAN mobile phones.

In order to be applicable to such a wireless communication system, it is necessary to develop an antenna having a wide broadband characteristic, but there is a problem that the existing PIFA cannot be used due to the narrow bandwidth characteristic.

The present invention has been proposed to solve the problems described above, by providing a PIFA element protruding a predetermined length on the PCB, to provide a wideband PIFA for reducing the height of the antenna and at the same time having a broadband characteristic There is this.

In addition, the present invention is another object to provide a broadband PIFA for easy mounting on the PCB by manufacturing the PCB integrally using the etching surface and the ground surface of the PCB.

The present invention for achieving the above object is a broadband PIFA having a planar inverted-f antenna (PIFA) element portion disposed on one surface of a printed circuit board (PCB), the predetermined length of the PIFA element portion outside the edge of the PCB Protruding, wherein a predetermined portion of the PIFA element portion is arranged to be connected to the feed portion of the PCB, the PIFA element portion provides a broadband PIFA having a substantially low height.

In addition, the present invention for achieving the above object, Broadband PIFA integrally formed on a PCB consisting of a metal foil, a dielectric portion and a ground portion, the antenna element portion of the inverted 'F' shape disposed on one side of the corner of the metal foil; And a feeding part disposed to be electrically connected to the antenna element part, wherein one end of the antenna element part provides a broadband PIFA connected to a ground part of the PCB.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same components have the same number as much as possible even if displayed on different drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 4 is a structural diagram of a first embodiment of a broadband PIFA according to the present invention, for explaining the structure of the PIFA disposed on the edge of the conductor portion of the PCB.

As shown in the figure, the broadband PIFA according to the first embodiment of the present invention includes a PIFA element portion 410 and the edge crossing portion 420, the edge crossing portion 420 of FIG. Reference numeral “111” and the PCB feeder 210 are arranged to be connected.

The broadband PIFA of the present invention has a structure that protrudes a predetermined length D portion of the PIFA element 410 out of the PCB. This is different from the existing PIFA, its operation principle and operation characteristics itself. That is, the operation principle of the general monopole antenna may be added to the existing PIFA operation principle.

Therefore, the existing PIFA is not simply projecting the broadband characteristics, but the height of the antenna must be very low in order to achieve the resonance mode change due to the charge induced in the edge intersection portion 420, which is the PCB edge, the constant protrusion length When is reached, the desired wideband characteristic can be generated.

That is, in the broadband PIFA of the present invention, the broadband intersection portion 420, the low height of the PIFA element 410, and the structure of the protrusion of the PIFA element 410 may be included in order to realize broadband characteristics.

FIG. 5 is an exemplary graph for describing the S11 parameter characteristic of FIG. 4. In the case where the dielectric constant of the dielectric part 120 is 2.8, a ratio of antenna width to antenna length of a predetermined antenna (H / L) is shown in FIG. = 0.06) shows the S11 parameter characteristics.

As shown in the figure, in the broadband PIFA of the present invention, a bandwidth of -10 dB or less is maintained at 3 to 7 GHz, and it can be seen that impedance matching of a very wide band is achieved.

Comparing the case of H / L = 0.06 in the non-protruding PIFA of Figure 3 and the S11 parameter characteristics, the conventional PIFA has no appearance of the resonance itself, the broadband PIFA according to the present invention is appeared in the resonance As a result, it can be seen that it is very broadband.

That is, when installed in a conventional manner, unlike the case where the height W of the antenna is operated high, it can be seen that the broadband PIFA according to the present invention is operated even if the height of the antenna is low.

FIG. 6 is a graph for explaining the antenna radiation efficiency of FIG.

As shown in the figure, the broadband PIFA of the present invention has a characteristic of more than 90% up to 3 ~ 7GHz, it can be seen that the antenna radiation efficiency is very excellent over a very wide bandwidth.

Radio Frequency (hereinafter, simply referred to as 'RF') signals used in UWB communication must copy and receive a very wideband pulse signal. Therefore, when copying the UWB signal over the 3 ~ 7GHz using the broadband PIFA of the present invention, it can be seen that most of the signal can be copied to the space.

FIG. 7 is a graph illustrating an antenna gain of FIG. 4.

As shown in the figure, in the broadband PIFA of the present invention, the antenna gain of about + /-1dB characteristics up to 3 ~ 7GHz, it can be seen that the antenna gain is kept constant over a very wide bandwidth.

In UWB communication, the technique of keeping the antenna gain constant is very important. This is because when the gain of the antenna is kept constant, the distortion of the signal waveform for the transmitted signal is low even if the receiving antenna is placed in any direction.

In the present invention, a frequency band having a S11 parameter of -10 dB or less, an antenna efficiency of 90% or more, and a +/- 1 dB antenna gain deviation is distributed from 3 to 7 GHz, and the frequency bandwidth is 80% based on the center frequency. It can be seen that excellent characteristics are shown.

FIG. 8A is a structural diagram of a second embodiment of a broadband PIFA according to the present invention, FIG. 8B is a detailed structural diagram of an embodiment of the PIFA element of FIG. 8A, and FIG. 8C is a detailed embodiment of the conductor portion of the PIFA element of FIG. 8A. It is a structural diagram.

As shown in the figure, the broadband PIFA according to the second embodiment of the present invention is a structure to reduce the protruding length (D) of Figure 4, in the protruding portion of the PIFA element unit 810, The conductor portion of the PIFA element portion 810 is zigzag-shaped.

In this case, about 20% of the antenna length can be reduced.

Unlike general meander chip antennas, the broadband PIFA of the present invention can maintain broadband characteristics only when the zigzag shape is started at the edge exchange part 420 protruding from the PCB.

FIG. 9 is a structural diagram of a third embodiment of a broadband PIFA according to the present invention, and is for explaining a PCB integrated type manufactured by the PCB itself without separately manufacturing a PIFA element. 10 is an exploded perspective view of an embodiment of FIG. 9.

As shown in the figure, the PCB is composed of a metal foil 220, a dielectric portion 231 and a ground portion 240, the inverted 'F' shape of the antenna element portion 910 of the PCB metal foil 220 Is disposed at the corner, the input and output signal feeding unit 920 of the antenna element unit 910 is arranged to be connected to the antenna element unit 910, the end portion 930 of the antenna element unit 910 is the PCB It is connected to the ground plane 240, the edge of the PCB metal foil 220 is removed leaving the antenna element portion 910.

The power supply unit 920 may be connected to the RF transmitter 940 including the duplexer using a microstrip line or the like. In addition, the corner portion where the antenna element portion 910 is located in the ground portion 240 may be removed as shown in FIG. 10.

FIG. 11 is a graph illustrating an S11 parameter characteristic of FIG. 9, wherein the PCB dielectric part (dielectric constant 2.8) 230 has a thickness of 0.05 cm, an antenna length H of 3.6 cm, and a width with respect to the antenna length. It is for explaining the S11 parameter characteristics when the ratio W / L is 0.06.

As shown in the figure, the broadband PIFA of the present invention can be seen that the S11 parameter is maintained at -10dB or less in the band of about 3 ~ 7GHz.

FIG. 12 is a graph illustrating an embodiment of the antenna radiation efficiency of FIG.

As shown in the figure, it can be seen that the broadband PIFA of the present invention maintains more than 85% of the antenna radiation efficiency in the 3 ~ 7GHz band.

FIG. 13 is a graph illustrating an embodiment of the antenna gain of FIG.

As shown in the figure, it can be seen that the broadband PIFA of the present invention maintains a +/- 1.5 dB deviation in the 3 to 7 GHz band.

As described above, it can be seen that the broadband PIFA of FIG. 9 is excellent in antenna efficiency and gain deviation performance, and these can also be sufficiently used for UWB communication. In addition, since the broadband PIFA of FIG. 9 can be immediately implemented in a PCB, it is expected to be easy to mount and to reduce manufacturing cost.

14 is a structural diagram of a fourth embodiment of a broadband PIFA according to the present invention.

As shown in the figure, the broadband PIFA of the present invention, in order to reduce the length of the antenna element portion 910, to produce a protruding element in a zigzag shape 1410 to reduce the overall length of the PIFA element portion.

Note that in the above structure, the PIFA element portion is manufactured in a zigzag shape only in the protruding portion.

FIG. 15 is a structural diagram of a fifth embodiment of a broadband PIFA according to the present invention, illustrating the case where the PIFA of FIG. 9 is installed on the upper side of the PCB.

As shown in the figure, in the broadband PIFA of the present invention, it can be seen that the polarization direction is horizontally polarized, unlike in FIG. In the case of such an antenna, it is applicable to a mobile terminal reception as well as a satellite broadcasting receiving terminal such as DMB.

FIG. 16 is an example for explaining a case in which the PIFA of FIG. 15 is mounted on a wireless LAN card and installed in a notebook computer.

As shown in the figure, when the broadband PIFA of the present invention is installed in a notebook computer, the protruding length DL can be reduced. The polarization direction of the electromagnetic wave at this time is as shown. That is, it can be seen that the physical characteristics are different from the existing wideband L-type antenna.

FIG. 17 is an example for explaining a case in which the PIFA of FIG. 9 or FIG. 14 is mounted on a wireless LAN card and installed in a notebook computer.

As shown in the figure, if the wideband PIFA of the present invention is arranged, the polarization direction can be adjusted in the vertical polarization direction. That is, when the broadband PIFA of the present invention is installed as shown in FIG. 17, omnidirectional radiation pattern characteristics can be maintained.

18A and 18B illustrate an example in which the PIFAs of FIGS. 14 and 15 are installed in a mobile phone, respectively.

As shown in the figure, when the broadband PIFA of the present invention is installed in a cellular phone, the down-length DP of the hinge can be reduced in the cellular phone installation.

19A and 19B are examples for explaining the direction of polarization when using the mobile phones of FIGS. 18A and 18B, respectively.

As shown in the figure, it can be seen that the broadband PIFA of the present invention has usable polarization.

When the hinged installation is performed on the folding mobile phone, the effect of reducing the electromagnetic wave effect of the human body can be reduced by eliminating the direct exposure between the PIFA element part and the head of the human body and securing a longer distance between the PIFA element part and the head of the human body. If the hinge length is kept small, the electromagnetic wave effect of the head tends to be somewhat large, but since the cover of the mobile phone is relatively turned on, it is possible to mount a larger display, and both of them have advantages and disadvantages. This is possible.

In addition, when used as shown in FIG. 19B, FIG. 18B is applicable to vertically polarized wave communication on the ground such as cellular, PCS, IMT-2000, and the like.

On the other hand, when the DMB satellite digital broadcasting service is realized, the terminal needs to hold by the hand rather than receive it in the ear as shown in Fig. 19, so the polarization direction needs to maintain the horizontal polarization. Therefore, it can be seen that the structure of FIG. 18B can be used as a combined antenna for DMB digital satellite reception.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention has an effect of lowering the height of the antenna and having broadband characteristics by disposing a PIFA element on a PCB by protruding a predetermined length.

In addition, the present invention has the effect of making it easy to mount on the PCB by making the integrated PCB using the etching surface and the ground surface of the PCB.

The broadband PIFA of the present invention was able to obtain a broadband characteristic of 80% or more based on the center frequency, and also provided a very low PIFA, so that the PIFA having a sufficiently wide bandwidth even at the height between the etching surface and the ground surface on the PCB could be obtained. It can be seen that it is implemented.

Therefore, the present invention further enables broadband wireless communication services such as UWB, as well as the ability to service various frequency bands with one antenna.

Claims (5)

In a broadband PIFA having a planar inverted-f antenna (PIFA) element portion disposed on one surface of a printed circuit board (PCB), The predetermined length of the PIFA element portion protrudes outside the edge of the PCB, A predetermined portion of the PIFA element portion is disposed so as to be connected to the feed portion of the PCB, The PIFA element portion is substantially low in height Broadband PIFA. The method of claim 1, The portion protruding outside the edge of the PCB of the PIFA element portion, Meander shape Broadband PIFA. In a broadband PIFA formed integrally on a PCB consisting of a metal foil, a dielectric part and a ground part, An inverted 'F' shape antenna element disposed on one edge of the metal foil; And A feeder disposed to be electrically connected to the antenna element Including but not limited to: One end of the antenna element portion is connected to the ground portion of the PCB Broadband PIFA. The method of claim 3, The metal foil Removed to match the shape of the antenna element Broadband PIFA. The method according to claim 3 or 4, The other end of the antenna element portion is a meander shape Broadband PIFA.

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