JPH06314924A - Partly shorted microstrip antenna - Google Patents

Abstract

PURPOSE: To provide a small-sized microstrip antenna which is useful in a portable electric device including a pager, a telephone and a portable computer. CONSTITUTION: A grounding surface layer 112, a dielectric block layer 114 and a radiation patch 116 which is short-circuited to the grounding surface layer 112 along a part of one edge are included in the microstrip antenna. The antenna is fit in a standardized PCMCIA slot and the portable computer and also useful for an independent computer. Furthermore, since the antenna is formed in small size, the direction to optimize radiation from the antenna is set inside a computer housing.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to small microstrip antennas for portable electronic devices. In particular, the present invention is for portable electronic devices that must operate in close proximity to human or computer equipment and that are small enough to be incorporated into a credit card sized pager, cell phone or portable computer. Of microstrip antenna.

[0002]

2. Description of the Related Art Portable electronic devices such as pagers and mobile phones use small antennas to receive radio frequency (rf) signals. The small antenna is located inside the structure. However, when used in portable computers, conventional techniques require an external antenna to send and receive signals. It would be advantageous to construct a small antenna that could be placed inside a portable computer.

One of the conventional small antennas suitable for pagers and mobile phones is the microstrip antenna. A typical two-conductor microstrip antenna includes a laminated planar structure having a conductive ground plane, a conductive radiating patch, and a dielectric layer disposed between the radiating patch and the ground plane. The ground plane of the antenna acts as a shield against adjacent materials such as circuit elements and other metallic materials.

Microstrip antennas have been developed with half-wave and quarter-wave structures. The length of a conventional half-wave microstrip antenna is about one-half the wavelength inside the dielectric. Quarter wave antennas halve the length by shorting one of the radiating edges to short the radiating patch to the ground plane. In a half-wave antenna, the ground plane and the radiating patch are open circuits that do not connect along both radiating edges. In a quarter-wave antenna, one radiating edge is shorted along its entire length.

The size of a quarter-wave antenna is considerably smaller than that of a half-wave antenna, but if the efficiency of the antenna can be kept within reasonable limits, further reduction in size is advisable. Would be advantageous. One of the advantages of miniaturizing the antenna is its ability to fit in a small area. If the antenna requirements specify a constant weight or a limited volume, the effect of reducing the surface area is to increase the thickness of the dielectric, which can significantly improve efficiency.

One of the problems with small antennas has been the considerable reduction in gain previously associated with size reduction. Therefore, attempts have been made to set up a small microstrip antenna with high gain. For example, a narrow slit formed in the radiating patch changes the reactance,
Therefore, it is known that the size of the antenna can be reduced, but the gain is sacrificed. For the same reason, a "C" shaped aperture could be used to reduce the size of the antenna, but the gain would be significantly reduced. It is also known that a quarter-wave antenna is more efficient if the dielectric extends from one radiating edge. However, the extension of the dielectric has the disadvantage of increasing the length, resulting in an increase in the size and weight of the overall device.

It would be advantageous to provide a microstrip antenna with a high level of efficiency per volume. Such a microstrip antenna could reduce the cost of portable electronics while maintaining high efficiency in a small volume.

Although any microstrip antenna radiates in a particular pattern that depends on its shape, its shape is often referred to as the "geometry" of the antenna. Many different geometries have been developed for microstrip antennas. In designing an antenna, for a particular application, a geometry is chosen that exactly meets the specific requirements of that application. If the geometry is properly selected, the rf signal can be transmitted and received efficiently. One of the common microstrip antenna geometries is a solid rectangle or square. Many geometries have been described and are listed in the catalog. For example, edited by James and Hall, "Hand
book of Microstrip Anten
as "(Peter Peregrin, London, UK)
us Ltd. , 1989, pp. 24-39), a number of geometries are shown.

[0009]

When applied to a portable electronic device, the radiation pattern and resonant frequency can be significantly affected by adjacent physical objects such as electrical circuits, computer equipment and humans. The shift in resonant frequency can be significant. For example, frequencies can shift by tens of megahertz or more, with the effect that the microstrip antenna becomes less useful. Operating characteristics such as antenna gain are also affected by adjacent physical objects. It would be advantageous to provide a microstrip antenna having a geometry that has reduced effects on the human body. Such antennas would be useful in numerous applications for portable electronic devices, such as pagers, which have to operate in the presence of humans.

Many of the geometries of conventional microstrip antennas are disadvantageous around some physical object because the geometry of conventional microstrip antennas is primarily excited by electric current rather than magnetic current. It is generally known that if a microstrip antenna can be excited mainly by a magnetic current rather than an electric current, the influence of adjacent substances including the human body on the antenna performance can be considerably reduced. Further, in such a microstrip antenna, a ground plane, or some other adjacent metallic material, or a magnetic current image of the human body would enhance radiation at the front of the microstrip antenna.

Another disadvantage of the conventional microstrip antenna geometry is an anisotropic radiation pattern with peaks oriented perpendicular to the plane of the microstrip (ie, the pattern is not evenly distributed). ). If the antenna is located within the housing of the electronic device, peak location is believed to be critical for proper signal transmission and reception. An "isotropic" antenna is one in which the radiation pattern is approximately evenly distributed in every direction, ie, is almost omnidirectional. It would be advantageous to provide an isotropic microstrip antenna that radiates in almost all directions without the emission peaks pointing to the electronic device to which the antenna is connected or a person located in close proximity.

In addition, it would be advantageous to provide a microstrip antenna having a generally square shape that can be installed in a generally square space. Such a shape would allow the manufacturer to place the microstrip antenna in a small area and to optimize the radiation pattern for its adjoining circuits, elements and the human body.

[0013]

SUMMARY OF THE INVENTION The present invention provides a microstrip antenna having a small area without significantly reducing gain. In this microstrip antenna, the efficiency per antenna volume is improved, so that the size and cost can be reduced. The small size and relatively high gain of microstrip antennas are useful in portable electrical devices, including pagers and phones. In addition, the antenna is small enough to fit in a standard PCMCIA slot,
It can be newly used for a portable computer having an A card. Due to the small size of the antenna, the position and orientation of the antenna inside the computer can be easily optimized to obtain maximum radiation power from the antenna inside the computer.

[0014] A partially shorted microstrip antenna having a short circuit along one of its radiating edges and along only a portion of its length provides the above and other advantages. The partially shorted microstrip antenna includes a ground plane layer of conductive material, a radiating patch layer of conductive material, and a dielectric layer disposed between the radiating patch layer and the ground plane layer. The microstrip antenna includes a partially shorted edge and a radiating edge located opposite the partially shorted edge. A short circuit portion is formed along a partial radiating edge of the microstrip antenna, and the short circuit portion is made of a conductive material, and the short circuit portion has a length of 10% to 90% of the total length of the first radiating edge. To combine, but 2
It is preferably 0% to 50%. Not all of the features and advantages described in the specification are obvious, and numerous additional features and advantages will be apparent to those of ordinary skill in the art, especially with reference to the drawings, the description, and the claims. Furthermore, it is noted that the language used in the specification has been chosen primarily for readability and teaching and, therefore, the claims should be relied upon to establish the subject matter of the invention. Should be.

[0015]

1-8 of the drawings disclose various embodiments of the present invention for purposes of illustration only. It will be readily appreciated by those skilled in the art from the following description that alternative embodiments of the structures and methods presented herein may be employed without departing from the principles of the invention. In the following description, 93
A microstrip antenna designed with dimensions suitable for a pager (radio pager) operating at 1.5 MHz will be described. Therefore, the dimensions listed for the preferred embodiment correspond to that particular operating frequency. It will be apparent to those skilled in the art that the microstrip antenna can be designed for other frequencies of interest by changing the dimensions of the antenna.

Reference is now made to FIG. 1, which illustrates a partially shorted microstrip antenna 100. A ground plane made of a conductive material is formed on the ground plane layer 112. A dielectric layer 114 is adhered to the ground plane layer 112. Ground plane layer 1
A radiation patch 116 is formed on a surface of the dielectric layer 114 opposite to the surface 12. The dielectric layer 114 has a very low tangential loss and its controlled dielectric constant is 2.94 ± 0.0.
It is preferably 4. Radiant patch layer is 1.0 oz thick
/ M ² of copper foil is preferable.

Partially shorted microstrip antenna 10
0 is the radiating edge 120 and the partial short-circuit edge 1 facing it.
22 including four sides. The other two edges are the first side edge 124 and the opposite second side edge 12
6 and. Elsewhere, side edges 124 and 126 are often referred to as "non-radiating" edges, but they also typically emit a small amount. However, the amount is 1
Less than the radiation emitted by 20.

The radiating edge 120 is an open circuit along its entire length, and has a first side edge 124 and a second side edge 1.
26 is also the same. The partially shorted edge 122 is shorted along a portion of its length. If specified, the partial short-circuit edge 1
22 includes a short circuit portion 130 that couples the radiating patch layer 116 to the ground plane layer 112. The shorting portion 130 is formed of some electrically conductive material, preferably a copper foil, such as the foil forming the radiating patch layer 116. The short circuit part 130 is
It has a width l _s that is less than the overall width l _w of the partially shorted edge 122. A first open circuit portion 132 having a length l _rs1 is located between the short circuit portion 130 and the first side edge 124. A second open circuit portion 134 having a length l _rs2 is located between the short circuit portion 130 and the second side edge 126.

As shown, the short circuit portion 130 is formed as one continuous portion. However, in other embodiments, the short circuit portion 130 may be formed from two or more separate portions (not shown). It is believed that the combined length of all shorts, whether directly connected or not, should be sufficient to form a mirror image of the radiating patch on the ground plane. Therefore, the total length l
_s should not be shorter than the length that forms such a proper mirror image. In other words, the short length l _s must be sufficient to image the ground plane layer 112.

The width l _s of the short circuit portion 130 is selected to primarily meet the required input impedance of 50 ohms. It is acknowledged that varying the width l _s will affect the input impedance, and thus varying the width l _s as a percentage of the total length l _w can be useful in tuning the antenna. However, it has been accepted by experiments that if the width l _s is reduced to, for example, 10% or less, the antenna may not operate efficiently or may not operate at all. Needless to say, when the length l _{s of the} short circuit is reduced to zero, the characteristic of the antenna changes to the characteristic of a half wavelength. On the other hand, if the length l _s is imaged at 90% or more, the partially short-circuited microstrip antenna 100 begins to take on the characteristics of the conventional quarter-wave antenna. Therefore, the length l _s is 10% to 90% of the value of l _w.
Should be between%. At present, the length of the short circuit l
_s is 5% from 20% of the total length l _w of the partial short-circuit edge 122.
It is preferably in the range of 0%. The presently preferred length l _s is about 30%.

A typical quarter wave antenna (not shown)
, The length between all short-circuited and radiating edges is
It is approximately equal to a quarter of the wavelength of the resonant frequency of the material. Only
However, in the example described here, a partial short circuit
Antenna length from edge 122 to total radiating edge 120
Is the length l_a Is a quarter for a given resonance frequency
Shorter than wavelength. Partial short circuit established by the short circuit part 130
Reduces the resonant frequency, thereby causing the antenna 10
Length 0_a Is a quarter wavelength for a given resonance frequency
It gets shorter. In the preferred embodiment, 931.5 MHz
Antenna length l with respect to resonance frequency_a Is 30 mm
However, this is the same as any known conventional microphone with equivalent gain.
It is about 40% shorter than the Losstrip antenna. Short circuit part 1
Width of 30 _s Is about 9 mm, which is about 30% of the total width. First
The length l of the open circuit portion 132 of 1_rs1Is about 10.5 mm
The length l of the second open circuit portion 134_rs2 Is about 10.5
mm.

In the preferred embodiment, the width l _w is approximately equal to the length l _a (30 mm) so that a substantially square structure is obtained. Increasing the width l _w will increase the gain somewhat. However, it has been found that reducing the width l _w to approximately the length l _a does not significantly reduce the gain. The square structure provides advantages including convenient installation and small size. In other embodiments, the width l _w could be made wider to increase the gain,
Thereby, of course, the microstrip antenna 100
Would increase the overall size of. Also, the width l _w could be further narrowed to reduce the overall size of the microstrip antenna 100.

In the preferred embodiment, ground plane layer 112 and
The first side edge 124 and the second side edge 126 are closely cut so that the respective edges of the dielectric layer 114 and the radiating patch layer 116 are substantially flat (ie, aligned flat). To be done. It is believed that cutting the edges 124 and 126 flat will provide a more isotropic radiation pattern.

The feeding point 140 is arranged close to the short-circuited portion 130 and substantially at the center of its width l _s . The position of the feed point 140 is selected so that the input impedance is 50 ohms. The feeding point 140 is connected to a conventional coaxial cable 142. Coaxial cable 1
42, at the feed point 140 its outer conductor is coupled to the ground plane layer 112 and its center conductor is the radiating patch layer 116
Is bound to bind to. However, other conventional techniques for connecting the transmission line to the microstrip antenna could be used.

Since the characteristic impedance of the coaxial cable 142 and the receiver is typically 50 ohms, the input impedance of the antenna 100 is selected to match 50 ohms in the preferred embodiment. Some antenna characteristics that are apparent to those skilled in the art, including feed point 140 and other characteristics discussed below, affect the input impedance and should all be taken into account when setting the input impedance. is there.

In order to reduce size with substantially little or no corresponding gain reduction, microstrip antenna 100 includes several optimized configurations. One of the advantages of reducing the size is that the width ω _d of the dielectric layer can be increased to further increase the gain at low cost. In the preferred embodiment, the width ω _d is from 0.015 inches to 0.090 inches, preferably about 0.060 inches. Of course, the area of the antenna does not change even if the width ω _d of the dielectric layer 114 is increased. Additionally, an exposed dielectric portion 150 is provided to increase the gain. Since the radiating patch 116 does not extend to cover this portion 150, the dielectric remains "exposed". The ground plane layer 112 continues to the edge 120.

Referring now to FIG. 2, FIG. 2 is a perspective view of a microstrip antenna 200 including a rectangular ring 250 described below. As shown in FIG. 2, a ground plane 212 made of a conductive material is formed on the ground plane layer 212. A dielectric layer 214 is adhered to the ground plane layer 212. A radiation patch 216 is formed on the surface of the dielectric layer 214 opposite to the ground plane layer 212. The dielectric layer 214 preferably has a very low tangential loss and its controlled dielectric constant is 2.94 ± 0.04. The radiation patch layer has a thickness of 1.0 oz. / M ² of copper foil is preferable. The microstrip antenna 200 has a radiating edge 2
20 includes four sides including a shorting edge 222 opposite it. The other two edges are the first side edges 224.
And a second side edge 226. First radiating edge 22
0 is an open circuit along its entire length, and the first side edge 224 and the second side edge 226 are also the same. As shown in FIG. 2, and as mentioned above, the shorting edge 222 is completely shorted along its entire length. However,
In other embodiments, the shorting edge 222 may be only partially shorted along its length, as will be described below with particular reference to FIG.

The feed point 240 is located near the short-circuit edge 222, above the rectangular ring 250, and in the approximate center thereof. The ring 250 has a width l _ww and a height l
It has a rectangular shape with _wh and. Needless to say, the width l _r of the microstrip antenna 200 is larger than the ring width l _ww . Width l _r is preferably about 30 mm and width l _ww is preferably about 18 mm. The ring 250 is spaced from the first side edge 224 by a length l _{ws 1} ,
Also, the second side edge 226 has a length l from the ring 250.
They are separated by _ws2 . Their length l _ws1 and l _ws2 is preferably equal. The length l _ws1 and l _ws2 is preferably a 6 mm, it is possible to change their length in order to change the input impedance.

It goes _without saying that the length l _nr of the microstrip antenna 200 is larger than the height l _{wh of the} ring 250. Preferably the length l _nr is 30 mm and the height l _wh is 9 mm. The ring 250 is spaced from the radiating edge 220 by a length l _g , and the ring 25
0 is located a distance l _ws from the fully shorted edge 222. Ring 2 to shorten the total length of the antenna
50 may be offset toward the short-circuit edge 222. In other words, the length l _g may be greater than the length l _ws . It is considered that the length l _rn of the microstrip antenna becomes shorter as the length l _g becomes larger. At present, length l _g
Is preferably about one half of the total length l _nr of the ring antenna 200, which in the preferred embodiment is about 15 mm. The length l _ws1, l _ws2 and l _ws 6
It is preferably mm, but it is possible to change any of their lengths to change the input impedance.

The rectangular shape of the ring 250 may be square, but in other embodiments the ring 250 could have any shape, and the ring could be any of the radiating patches 216. It may be located in the place. For example, ring 250 may be square,
Alternatively, it may be offset to the side of the radial edge 220, the side edge 224, or the second side edge 226. Needless to say, changing the shape and position of the ring also affects other antenna operating characteristics including the input impedance.

The exposed dielectric portion 270 is preferably provided to increase gain. Since the radiating patch 216 does not extend to cover the exposed dielectric portion 20,
The dielectric remains "exposed". The ground plane layer 212 continues to the edge 220. According to conventional techniques, the exposed dielectric portion has been found to increase gain, but the length l _d of the exposed dielectric portion 270 is substantially shorter than the prior teaching would suggest. There is. Antenna 2
It is conceivable that the length l _d can be shortened by the double ring structure of 00 and the gain does not decrease significantly. In the preferred embodiment, the length l _d is in the range 2.0 mm to 3.0 mm. As the prior art references suggest, this width can be quite large, for example, a total height of l _nr of 35
%, And in the preferred embodiment exposed dielectric portion 270 should be about 15 mm (5 times larger or more).

Referring now to FIG. 3, FIG.
FIG. 7 is a diagram of a double rectangular ring microstrip antenna 300. Antenna 300 combines the partial short-circuit characteristics of microstrip antenna 100 discussed with reference to FIG. 1 with rectangular ring 250 discussed in connection with microstrip antenna 200 of FIG. Each of those features has already been fully described in connection with the above figures, and thus the microstrip antenna 300 of FIG.
See those figures for further details on the.

The structure shown in FIG. 3 will be briefly described below.
A ground plane layer 312 of electrically conductive material is formed with a dielectric layer 314, and a radiating patch 316 is formed on the opposite side of the dielectric layer 314. The microstrip antenna 300 has a substantially square shape including four sides, each of which is about 30 mm. Antenna 300
Is the radiating edge 320 and the opposing short-circuit edge 32.
Including 2 and. The other two edges are first side edges 324,
A second side edge 326 opposite thereto.

The radiating edge 320 is an open circuit along its entire length, and has a first side edge 324 and a second side edge 3.
26 is also the same. The partially shorted edge 322 has a length l _r
Shorted along part of. Specifically, the partial shorting edge 322 includes a shorting portion 330 that couples the radiating patch layer 316 with the ground plane layer 312. The short-circuit portion 330 is made of some conductive material. The short-circuit portion 330 is made of some conductive material. Short circuit part 33
0 has a width l _s that is less than the full width l _r of the partially shorted edge 322. For example, its width can range from 20% to 50% of its width l _r , but its length l
_s is approximately equal to 30% (9 mm). In order to obtain the required input impedance at the selected resonance frequency,
The width l _s of the short-circuit portion 330 can be set based on experiments.

First open circuit portion 33 having a length l _rs1
2 is disposed between the short-circuit portion 330 and the first side edge portion 324. Second open circuit portion 3 having length l _rs2
34 is disposed between the short circuit portion 330 and the second side edge portion 326. The lengths l _rs1 and l _rs2 are equal, about 1
It is preferably 0.5 mm.

The feeding point 340 is arranged close to the short-circuited portion 330 and substantially at the center of its width l _s . The position of the feeding point 340 is selected so that the input impedance is 50 ohms. The feed point 340 is connected to a conventional coaxial cable 342, which at feed point 340 has the outer conductor of the cable coupled to the ground plane layer 312 and the inner conductor being the radiating patch layer 3.
16 are coupled to each other.

An exposed dielectric portion 348 is provided to increase the gain of the antenna 300. The dielectric remains “exposed” because the radiating patch 316 does not extend to cover this portion 348. Ground plane layer 3
12 continues to edge 320.

The microstrip antenna 300 further includes a rectangular ring 350. The feeding point 340 is located above the rectangular ring 350 and approximately in the center thereof. The rectangular ring 350 has a rectangular shape with a length l _ww and a height l _wh . Preferably l _ww is 18 mm and l _wh is 9 mm. The ring 350 has a length l from the first side edge 324.
The second side edge portion 3 is located apart from _ws1.
It is located at a distance l _ws2 from 26. Length l
_ws1 and l _ws2 are equal, is preferably 6 mm. Rectangular ring 350 is preferably 15 mm from radial edge 320
Together are positioned apart by a length l _g is preferably located spaced apart by a distance l _ws is 6mm from short edge 322. The ring 350 is preferably offset toward the shorting edge 322. In other words, length l _g
Is greater than the length l _ws . The length l _g has been chosen to reduce size and is preferably equal to approximately one half of the total length l _nr of the microstrip antenna 300. The length l _ws from the rectangular ring 350 to the short edge 322 is preferably approximately equal to the length l _ws1 and l _ws2.

For pager applications, the preferred embodiment dimensions assume a resonant frequency of 931.5 MHz. It should be apparent to those skilled in the art that the dimensions may be changed to change the antenna characteristics, including resonance frequency and impedance. Other optimization configurations are included in the preferred embodiment. For example, side edges 324 and 326.
Are cut so that they line up with each other. It is considered that this makes it possible to obtain a radiation pattern that is more isotropic.

It has been observed experimentally that its radiation pattern exhibits less than a 5 dB change both inside and outside the computer environment as the antenna is rotated in a 360 degree arc. Furthermore, the filtering characteristics of the antenna 300 in the preferred embodiment have been found in the laboratory to exhibit a rejection of more than 20 dB for in-band gain at frequencies above 10 MHz from the center of the band.

Reference is now made to FIGS. 4A, 4B and 4C showing three different possible positions of the microstrip antenna 400 within the pager 402. FIG. 4A shows the first side edge portion 40 of the microstrip antenna 400a.
6 shows pager 402a as if facing outwards.
FIG. 4B shows the pager 402b with the second side edge 410 of the antenna 400b facing outward. Figure 4C
Shows a third microstrip antenna 400c positioned with the radiating edge 420 facing outward. The presently preferred embodiment is shown in FIGS. 4A and 4B, where the side edges 406 or 410 face outward from the edge of the pager. In another embodiment, the partially shorted edge of the microstrip antenna (not shown) could face away from the pager. Any of these configurations are operational and each configuration is
02 has the advantage that the configuration is largely determined by the specific circuit configuration of 02 and other factors. 4A, 4B and 4C also show the flexibility with which a small microstrip antenna 400 can be configured for installation in an electronic device such as pager 402.

Referring now to FIG. 5, FIG.
1 shows a small portable computer 500 provided with an IA slot 510. The PCMCIA slot 510 has a structure according to the well-known PCMCIA standard currently used in the computer industry, and was conventionally used to insert other elements such as additional memory and programs into a small portable computer. As shown, the microstrip antenna 520 is a PCMCIA
Located in card 530. A plurality of connectors 540 are provided for connection to corresponding connectors (not shown) inside the PCMCIA slot 510.

The PCMCIA card 530 has a length l _p represented by 532 of 85.60 mm and a length l _wp represented by 534.
Has a standard dimension of 54.0 mm. The thickness of the PCMCIA card depends on its type. That is, the I type card has a thickness of 3.3 mm and the II type card has a thickness of 5.0 mm.
It has a thickness of mm. The PCMCIA standard is also incorporated herein by reference. Needless to say, PC
The exact dimensions of the MCIA card are not critical to the practice of the invention and other housings with other dimensions could be used. However, the size of the PCMCIA card 530 is particularly useful as it has already established itself as a well-known standard within the computer industry.

FIG. 8 which is a block diagram of the antenna 520 and related circuits in the PCMCIA card 530 will be briefly described. Antenna 520 may be a conventional radio frequency (rf) front end 542 by any suitable means.
The front end is connected to the antenna 520.
From the digital processing and interface circuit 546. in order to receive the rf signal and interface through the output connector 540 with any suitable electronic device, such as a computer circuit,
The digital processing / interface circuit 546 includes conventional circuits.

The description will be made again with reference to FIG. Usually a PC
The MCIA slot 510 is separated from the rest of the portable computer by a metal case. Tests have shown that an antenna 520 constructed in accordance with the present invention, even when housed in metal, radiates well in all directions from a slot such as PCMCIA slot 510. It has been recognized that the preferred location within the slot is as shown in FIG. 5, that is, one of the side edges, eg, side edge 550, is facing outwardly from slot 510.

Referring now to FIG. 6, FIG. 6 is a perspective view of a cell phone 600 having an antenna installed therein, showing a cutaway view of a partially shorted dual rectangular ring microstrip antenna 610. This microstrip antenna 610 can be easily installed in the handset of a mobile phone, where it will operate effectively.

Microstrip antenna 400 of FIGS. 4A, 4B and 4C, antenna 520 of FIG. 5 and FIG.
Of course, an antenna such as antenna 610 can be sized according to user requirements. In particular, the overall dimensions of the microstrip antenna, the dimensions of the shorting strip, and the dimensions of the rectangular ring can be adjusted to suit the desired resonant frequency and user requirements. For example, antenna 520 and antenna 610, respectively used in portable computers and cell phones, have dimensions different from those described in connection with the preferred embodiment useful in pagers, but as a whole. It is preferred that the ratio remains approximately the same.

Referring now to FIG. 7, a housing 700 for computing device 704 is shown. The computer device 704 may be any of a wide variety of computer devices including large portable units, desktop computers and workstations. On the side 720 of the computer housing 700,
Slot 710 is shown. Antenna case 7 containing a microstrip antenna 740 for insertion into slot 710 of computer housing 700
30 are provided. In another embodiment, slot 71
It should be apparent to those skilled in the art that antenna 740 could be permanently installed in computer housing 700 without the need for zero. However, in order to achieve efficient reception and transmission, it is useful to place the antenna 740 in the opening 750 of the housing 700.

It will be apparent from the above description that the invention disclosed herein provides a novel and advantageous microstrip antenna. The above discussion discloses and describes illustrative methods and embodiments of the present invention. Without departing from the spirit or essential characteristics of the present invention, the present invention can be embodied in other specific forms, and therefore, the embodiments described above do not limit the scope of the present invention. Those of ordinary skill in the art will understand. For example, in Figure 2.
Shows a single rectangular ring 250, but the shorting part 2
A rectangular ring 250 on the ground plane layer 212 due to the presence of
It should be apparent to those skilled in the art that a ring is formed that is a mirror image of the. Therefore, a half-wave antenna could be constructed according to the invention, in which case two rings are formed symmetrically about the centerline between the two radiating edges of the half-wave antenna. Become. The claims set forth the scope of the invention. All modifications that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

[Brief description of drawings]

FIG. 1 is a perspective view of a partially shorted microstrip antenna.

FIG. 2 is a perspective view of a double rectangular ring microstrip antenna.

FIG. 3 is a perspective view of a partially shorted rectangular ring microstrip antenna.

FIG. 4 is a perspective view of a microstrip antenna in various orientations within a pager.

FIG. 5 is a perspective view of a microstrip antenna in a PCMCIA card to be inserted into a portable computer or pager.

FIG. 6 is a perspective view of a mobile phone including a cutout portion showing a microstrip antenna disposed inside.

FIG. 7 is a perspective view of a computer housing having a slot for receiving a microstrip antenna.

FIG. 8 is a block diagram of a microstrip antenna and associated circuits in a PCMCIA card.

[Explanation of symbols]

 100 partially short-circuited microstrip antenna 112 ground plane layer 114 dielectric layer 116 radiating patch layer 120 radiating edge 122 partial short-circuiting edge 124 first side edge 126 second side edge 130 short-circuiting section 132 first opening Circuit part 134 Second open circuit part 140 Feed point 142 Coaxial cable 150 Exposed dielectric part 200 Microstrip antenna 212 Ground plane layer 214 Dielectric layer 216 Radiating patch layer 220 Radiating edge 222 Shorting edge 224 First side edge Part 226 2nd side edge 240 Feed point 242 Coaxial cable 250 Rectangular ring 270 Exposed dielectric part 300 Microstrip antenna 312 Ground plane layer 314 Dielectric layer 316 Radiating patch layer 320 Radiating edge 322 Partial short-circuit edge 324 1st Side edge of 326 second Side edge part 330 Short circuit part 332 First open circuit part 334 Second open circuit part 340 Feed point 342 Coaxial cable 348 Exposed dielectric part 350 Rectangular ring 400a-400c Microstrip antenna 402a-402c Pager 500 Small portable computer 510 PCMCIA Slot 520 Microstrip antenna 530 PCMCIA card 610 Microstrip antenna 700 Computer housing 704 Computer equipment 710 Slot 730 Antenna case 740 Microstrip antenna 750 Opening

Claims (4)

[Claims] 1. A ground plane layer made of a conductive material; a radiation patch layer made of a conductive material; a dielectric layer arranged between the discharge patch layer and the ground plane layer; and a partial short circuit of a microstrip antenna. At the edge, made of conductive material,
A short-circuited microstrip antenna comprising: a short-circuited portion that joins 10% to 90% of the length of the partially-shorted edge. 2. A microstrip antenna for a portable electronic device including a housing for the portable electronic device, comprising: a ground plane layer made of a conductive material; a radiating patch layer made of a conductive material; A dielectric layer disposed between the ground layer and; at a partially shorted edge of the microstrip antenna, made of a conductive material, and coupling a length of 10% to 90% of the total length of the partially shorted edge. A microstrip antenna, the microstrip antenna being disposed in the housing for a portable electronic device. 3. A microstrip antenna assembly for insertion into a slot in a housing of an electronic device, comprising: a ground plane layer made of a conductive material; a radiation patch layer made of a conductive material; a radiation patch layer and a ground plane layer. A dielectric layer disposed between the short-circuited portion of the microstrip antenna, the short-circuited portion being formed of a conductive material and connecting a length of 10% to 90% of the total length of the short-circuited edge. A microstrip antenna including and;
An antenna housing for said antenna having a shape for insertion into a slot of a computer housing. 4. A microstrip antenna for use with a computer housed in a computer housing, a ground plane layer comprising a conductive material, a radiating patch layer comprising a conductive material, a radiating patch layer and a ground plane. A dielectric layer disposed between the layer and a partially shorted edge of the microstrip antenna,
A microstrip such that the microstrip antenna is located within the computer housing, the shorts comprising a conductive material and coupling a length of 10% to 90% of the total length of the partially shorted edge. antenna.