TWI458175B - Three bands antenna - Google Patents

Description

Tri-band antenna

The present invention relates to an antenna, and more particularly to a planar tri-band antenna.

With the rapid development of wireless communication technology and information processing technology, mobile wireless communication devices such as mobile phones and personal digital assistants (PDAs) are competing to enter and reach thousands of households, so that consumers can enjoy high anytime and anywhere. The convenience brought by technology makes these portable wireless communication devices become an indispensable part of modern people's daily life.

Among these wireless communication devices, an antenna device for transmitting and receiving radio waves to transmit and exchange radio data signals is undoubtedly one of the most important components in a wireless communication device. Single-frequency antenna devices are generally not easy to meet the needs of multi-band wireless communication devices. More and more consumers hope that their wireless communication devices can be used in GSM900/DCS1800 and WLAN2450 communication systems. However, because it operates in different frequency bands, theoretically there should be two antennas corresponding to each, but this will greatly increase the production cost of the antenna device, and also increase the size of the antenna device, thereby occupying a large area in the wireless communication device. Part of the space is not conducive to the trend of wireless communication devices in the direction of thinning.

In view of this, it is necessary to provide a tri-band antenna which is low in cost and occupies a small space.

A tri-band antenna, which is a planar type disposed on an insulating substrate An antenna, the tri-band antenna includes a signal feed line, a first radiator, a second radiator and a first grounding piece, wherein the first radiator is a rectangular annular sheet-like body, and one end of the antenna is fixed At the end of the signal feed line; the second radiator is three strip-shaped bodies arranged in parallel with each other, and the outer radiator is formed on the first radiator and is accommodated in the first radiator. In the rectangular space, the signal feeding line is shared with the first radiator; the first grounding piece is disposed on one side of the signal feeding line; when the three-frequency antenna is in operation, when the signal is along the first radiator When the path is transmitted, a first resonant frequency is obtained; when the signal is transmitted along the path of the second radiator, a second resonant frequency is obtained; when the signal is transmitted along the path of the first radiator and the second radiator , a third resonance frequency can be obtained.

Compared with the prior art, the tri-band antenna adopts a planar structure, and the overall volume is very small, so that the tri-band antenna does not occupy the mechanism configuration space in the wireless communication device, so as to facilitate the thinning of the wireless communication device. The tri-band antenna has lower cost, and can generate three resonance frequencies during operation, and increases the bandwidth of the tri-band antenna, so that the bandwidth of the tri-band antenna can cover three communications of GSM900, DCS1800 and WLAN2450. system.

Referring to FIG. 1 , the tri-band antenna 30 of the present invention is a planar antenna that feeds signals by using a coplanar waveguide, and is disposed on a portable wireless communication device such as a mobile phone and a personal digital assistant (PDA). An insulating substrate 10 is provided on one of the insulating substrates 10 for transmitting and receiving radio waves to transmit and exchange radio data signals. The substrate 10 is made of glass fiber and has a relative dielectric constant of about 4.4 and a positive tangent. The loss tangent is about 0.02 and a rectangular plate-like body having a thickness of about 1.6 mm. In the embodiment, the tri-band antenna 30 is formed on the substrate 10 by a copper material by an engraving and printing method.

Referring to FIG. 2 , the tri-band antenna 30 includes a signal feed line 31 , a first radiator 33 , a second radiator 35 , a first grounding strip 36 , and a second grounding strip 37 . The signal feed line 31 is a substantially rectangular sheet-like body having a length of about 14 mm and a width of about 2.4 mm. The first radiator 33 is a substantially rectangular annular sheet-like body having a width of about 2 mm and a total length of about a quarter of a first resonance frequency of 900 MHz, one end of which is opposite to the end of the signal feed line 31. Connected, the other end is a free end disposed parallel to the signal feed line 31.

The first radiator 33 includes a first radiation arm 331 , a second radiation arm 332 , a third radiation arm 333 , and a fourth radiation arm 334 . In the embodiment, the first radiating arm 331 is fixed to the end of the signal feeding line 31 in the direction perpendicular to the signal feeding line 31 and is located on one side of the signal feeding line 31. The length dimension of the first radiating arm 331 It is about 20mm. The length of the second radiating arm 332 is comparable to the length of the fourth radiating arm 334, both of which are about 18 mm. The third radiating arm 333 has a length dimension of about 26 mm. The fourth radiating arm 334 is a free end disposed parallel to the signal feeding line 31 and the second radiating arm 332. The end of the fourth radiating arm 334 is spaced apart from the starting end of the first radiating arm 331. And located on the opposite side of the signal feed line 31.

The second radiator 35 is three strip-shaped sheets arranged in parallel with each other, and spaced apart from each other in a direction parallel to the first radiation arm 331 The extension is formed on the second radiation arm 332 and accommodates a rectangular annular space surrounded by the first radiator 33. The first radiator 33 and the second radiator 35 share the signal feed line 31. Each of the strip-shaped bodies of the second radiator 35 has a length dimension of about 20 mm and a width dimension of about 2 mm, and the distance between them is about 2 mm.

The first grounding strips 36 and the second grounding strips 37 are substantially rectangular in shape, and are respectively disposed on opposite sides of the signal feeding line 31 with respect to each other. The distance between the first grounding strip 36 and the signal feed line 31 can be adjusted to adjust the third resonant frequency of the tri-band antenna 30 to a certain extent to obtain an optimal third resonant frequency. In this embodiment, the distance between the signal feed line 31 and the first grounding strip 36 and the second grounding strip 37 is about 0.3 mm. The distance between the left side of the first grounding piece 36 and the left side of the second radiating arm 332 of the first radiator 33 is about 4 mm.

When the tri-band antenna 30 is in operation, the RF signal is transmitted from the first radiator 33 and the second radiator 35 of the tri-band antenna 30, respectively, and the propagation paths of different lengths are respectively generated. Different signals. When the signal is transmitted along the path of the first radiator 33, the first resonance frequency of 900 MHz can be obtained. At this time, the tri-band antenna 30 can operate under the GSM900 system. When the signal is transmitted along the path of the second radiator 35 of the tri-band antenna 30, a second resonance frequency of 1800 MHz can be obtained. At this time, the tri-band antenna 30 can operate under the DCS1800 system. When the signal is transmitted along the path of the first radiator 33 and the second radiator 35, a third resonance frequency of 2450 MHz can be obtained. At this time, the tri-band antenna 30 can work under WLAN2450. Therefore, the tri-band antenna 30 can meet the requirements of working in three frequency bands of GSM900, DCS1800 and WLAN2450 respectively.

Referring to FIG. 3, a comparison diagram of the return loss (RL) measurement results obtained by the tri-band antenna 30 under simulated software detection and actual measurement is shown. As can be seen from FIG. 3, during the test, the tri-band antenna 30 obtains a resonant frequency at frequencies of 900 MHz, 1800 MHz, and 2450 MHz, respectively, and the return loss (RL) measurement results obtained under actual measurement are The predicted return loss (RL) measurements measured under simulated software detection are very close and meet the design requirements. Therefore, the bandwidth of the tri-band antenna 30 can cover the bandwidth of three communication systems of GSM900, DCS1800 and WLAN2450.

Please refer to FIG. 4 to FIG. 6 together, which shows the electromagnetic radiation pattern of the horizontal and vertical polarization of the three-frequency antenna 30 operating at 900 MHz in the X-Y, Y-Z, and Z-X planes respectively. It can be concluded that the tri-band antenna 30 has a maximum radiation intensity at 80 degrees and 270 degrees in the X-Y plane when operating at 900 MHz.

Please refer to FIG. 7 to FIG. 9 together for the electromagnetic radiation pattern of the horizontal and vertical polarizations of the three-frequency antenna 30 operating at the 1800 MHz frequency in the X-Y, Y-Z, and Z-X planes, respectively. It can be concluded that the tri-band antenna 30 operates at a frequency of 1800 MHz and has a maximum radiation intensity near 0 degrees and 180 degrees in the Y-Z plane.

Please refer to FIG. 10 to FIG. 12 together for the water of the X-Y, Y-Z, and Z-X planes when the tri-band antenna 30 operates at 2450 MHz. For the electromagnetic radiation pattern of the flat and vertical polarization, it can be concluded that the tri-band antenna 30 operates at a frequency of 2450 MHz and has a maximum radiation intensity near 45 degrees and 135 degrees of the Y-Z plane.

Please refer to FIG. 13 to FIG. 15 together, which shows the gain map measured by the tri-band antenna 30 operating at 900 MHz, 1800 MHz and 2450 MHz respectively, and the gain value in the operating range of the first resonant frequency of 900 MHz can be obtained. The gain value in the operating range of -3.77~-0.4; the second resonant frequency of 1800MHz is -1.44~0.11; the gain value in the operating range of the third resonant frequency of 2450MHz is 3.09~4.13. It can be seen from the test results that the gain of the tri-band antenna 30 can meet the requirements at the three operating frequencies, and there is no obvious radiation dead zone.

The tri-band antenna 30 adopts a planar structure, and the overall volume is very small, so that the tri-band antenna 30 does not occupy the mechanism configuration space in the wireless communication device, so as to facilitate the thinning of the wireless communication device. The tri-band antenna has lower cost, and can generate three resonance frequencies during operation, and increases the bandwidth of the tri-band antenna, so that the bandwidth of the tri-band antenna can cover three communications of GSM900, DCS1800 and WLAN2450. system.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited to the above-described embodiments, and equivalent modifications or variations made by those skilled in the art in light of the spirit of the present invention are It should be covered by the following patent application.

Insulating substrate ‧‧10

Tri-band antenna ‧ ‧ 30

Signal feeder ‧‧31

First shot ‧‧33

First shot arm ‧ ‧ 331

Second shot arm ‧ ‧ 332

Third shot arm ‧ ‧ 333

Fourth shot arm ‧ ‧ 334

Second radiator ‧‧35

First grounding piece ‧‧36

Second grounding piece ‧‧37

1 is a schematic diagram of a preferred embodiment of a tri-band antenna of the present invention disposed on a substrate 2 is a main dimension drawing of a preferred embodiment of the tri-band antenna of the present invention; FIG. 3 is a schematic diagram showing a comparison of the return loss results of the simulation and measurement of the preferred embodiment of the tri-band antenna of the present invention; FIG. 4 to FIG. The electromagnetic radiation pattern of the horizontal and vertical polarization of the X-Y, Y-Z, and Z-X planes when the tri-band antenna is operated at 900 MHz is used; FIG. 7 to FIG. 9 are the tri-band antennas of the present invention operating at 1800 MHz. The electromagnetic radiation pattern of the horizontal and vertical polarization of the X-Y, Y-Z, and Z-X planes at the frequency; FIG. 10 to FIG. 12 are the X-Y antennas of the present invention operating at the frequency of 2450 MHz respectively. The horizontal and vertical polarization electromagnetic radiation pattern of the Y-Z and Z-X planes; FIG. 13 to FIG. 15 are gain diagrams measured when the three-frequency antennas are respectively operated at 900 MHz, 1800 MHz and 2450 MHz frequencies.

Insulating substrate ‧‧10

Tri-band antenna ‧ ‧ 30

Signal feeder ‧‧31

First shot ‧‧33

First shot arm ‧ ‧ 331

Second shot arm ‧ ‧ 332

Third shot arm ‧ ‧ 333

Fourth shot arm ‧ ‧ 334

Second radiator ‧‧35

First grounding piece ‧‧36

Second grounding piece ‧‧37

Claims (7)

A tri-band antenna is a planar antenna disposed on an insulating substrate, wherein the tri-band antenna comprises a signal feed line, a first radiator, a second radiator and a first ground strip. The first radiator is a rectangular annular sheet-like body, one end of which is fixed to the end of the signal feeding line; the second radiator is three strip-shaped bodies arranged in parallel with each other, and the outward An extension is formed on the first radiator and is received in a rectangular space surrounded by the first radiator, and the signal feeder is shared with the first radiator; the first grounding piece is disposed on the signal One side of the feeder line; when the tri-band antenna is in operation, when the signal is transmitted along the path of the first radiator, a first resonance frequency is obtained; when the signal is transmitted along the path of the second radiator, a second is obtained. Resonance frequency; when the signal is transmitted along the path of the first radiator and the second radiator, a third resonance frequency is obtained. The tri-band antenna of claim 1, wherein the signal feed line is a rectangular sheet-shaped body, and the first radiator comprises a first radiation arm and a second radiation arm sequentially connected in sequence. a third radiating arm and a fourth radiating arm, the first radiating arm being fixed to an end of the signal feeding line and perpendicular to the signal feeding line and located on one side of the signal feeding line, the fourth radiating arm And a free end disposed parallel to the signal feeding line and the second radiating arm, the end of the fourth radiating arm is opposite to the starting end of the first radiating arm, and is located on the opposite side of the signal feeding line. The tri-band antenna according to claim 2, wherein the second One end of the radiator is formed to extend outwardly from each other in a direction parallel to the direction of the first radiating arm to form on the second radiating arm. The tri-band antenna according to claim 3, wherein the tri-band antenna further includes a second grounding strip, which is in the form of a rectangular sheet, and is disposed on the other of the signal feeding lines with respect to the first grounding strip. side. The tri-band antenna according to claim 4, wherein the tri-band antenna is formed on the substrate by a copper material by engraving and printing. The tri-band antenna according to claim 5, wherein the substrate is a rectangular plate-shaped body made of glass fiber. The tri-band antenna according to claim 6, wherein the substrate has a thickness of 1.6 mm, a relative dielectric constant of 4.4, and a tangent loss constant of 0.02.