DE69937048T2 - UNIPLANAR ANTENNA WITH TWO STRIPES - Google Patents

Description

BACKGROUND OF THE INVENTION

I. Field of the Invention

The The present invention relates generally to antennas and in particular to a uniplanar dual strip multi-frequency antenna. The invention further relates to internal antennas for wireless devices, especially with improved bandwidth and radiation characteristics.

II. Description of the Related Art

antennas are an important component of wireless communication devices and systems. Although antennas in many different Shapes and sizes are available each works according to the same basic electromagnetic Principles. An antenna is a structure that has an area of the transition between a guided wave and a wave in free space, or conversely, is associated. As a general principle, a guided wave, which moves along a transmission line, which opens or expands, as a wave in free space, as electromagnetic Wave known, radiate.

In Recent years have seen an increase in the use of personal wireless communication devices, such as portable and mobile Cellular and Personal Communication Services (Personal Communication Services, PCS) telephones, the need for suitable small antennas for such communication devices elevated. New developments in integrated circuits and in accumulator technology have made it possible the size and that Weight of such communication devices during the last years drastically to reduce. An area where a reduction in size always still desirable is, is that of communication antennae. This is on the fact that the size of the antenna play an important role in reducing the size of the Vorrich device can. additionally affect the size and shape the antenna's aesthetics and the manufacturing cost of the device.

One important factor in the design of antennas for wireless communication devices is to be noted, is the directional characteristic of the antenna. In a typical application must be able to the communication device be with another such device or base station, a hub or satellite that is in every possible Number of directions from the device may be to communicate. As a result, it is essential that the antennas for such wireless communication devices an approximately omnidirectional Directional characteristics have.

EP-A-0 757 405 commits a way to solve this problem by providing a bent inverted F-antenna, a capacitive line, and an inductive stub mounted on a corresponding curved ground plane.

One Another important factor in the design of antennas for wireless Communication devices to consider is the bandwidth the antenna. For example, wireless devices such as phones, those with PCS communication systems to be used over a frequency band of 1.85-1.99 GHz, so they require a usable Bandwidth of 7.29 percent. A phone for use with typical cellular communication systems operates over a frequency band of 824-894 MHz, which requires a bandwidth of 8.14 percent. Accordingly have to Antennas for Use on these types of wireless communication devices Designed to meet the appropriate bandwidth requirements to suffice, otherwise communication signals will be greatly attenuated.

One type of antenna commonly used in wireless communication devices is the whip antenna, which can be easily retracted into the device when not in use. However, there are some disadvantages associated with the whip antenna. Often, the whip antenna is damaged by being stuck to objects, people, or surfaces when it is extended for use, or even when retracted. Even if the whip antenna is designed to be retractable to avoid such damage, it may expand over an entire size of the device and hinder the placement of advanced features and circuits in some portions of the device. It may also require a minimum size of the device housing when retracted, which is greater than desired. While the antenna may be equipped with additional telescopic sections to reduce the size when retracted, it would generally perceived by customers as less aesthetic, weaker or more unstable or less operational.

Of Furthermore, a whip antenna has a directional characteristic which torus is, that is, like a donut shaped (Translator's note: or like a swimming ring is shaped), with a zero or cancellation in the middle. When a cellular telephone or other wireless device, which uses such an antenna, perpendicular to the ground, in one 90 degree angle to the ground or to the local horizontal plane If this zero or spot of extinction has a central center line, which is also inclined at a 90 degree angle. This prevents generally not receiving signals because incoming signals not limited to this are at a 90-degree angle relative to the antenna. Phone users tilt or tilt their cell phones during the call Use however often and cause each associated Whip antenna also tilted or tilted. It is has been observed that users of mobile phones use their phones usually by about a 30-degree angle relative to the local horizon (60 degrees to the vertical) and cause the whip antenna to slide in inclined at a 30 degree angle. This has the result that the central zero axis also aligned at a 30 degree angle becomes. At this angle, the zero reception prevents incoming Signals arriving at a 30 degree angle. Unfortunately incoming arrive Signals in cellular communication systems often at angles around or within Range of 30 degrees and there is an increasing probability that the misoriented zero will receive some Signals will prevent.

One another type of antenna used for appears suitable for use in wireless communication devices, is a compliant antenna. Compliant antennas generally follow the Shape of the surface, on which they are mounted, and generally have a very low Profile or a low height. There are several different types of compliant antennas, such as patch, Microstrip and stripline antennas. In particular, microstrip antennas have been in personal lately Communication devices have been used.

As the term suggests, a microstrip antenna includes a patch or microstrip element, commonly referred to as a radiator patch. The length of the microstrip element is related to the wavelength λ ₀ associated with a resonant frequency f ₀ chosen to correspond to the frequency of interest such as 800 MHz or 1900 MHz. Commonly used lengths of microstrip elements are half wavelength (λ _0/2) and quarter wavelength (λ _0/4). Although some types of microstrip antennas have recently been used in wireless communication devices, further improvement is desirable in some areas. One such area in which further improvement is desirable is a reduction in overall size. Another area where significant improvement is needed is in the bandwith. Current patch or microstrip antenna designs do not appear to achieve the characteristics of a bandwidth of 7.29 to 8.14 percent or more desired for use in advanced communications systems in a practical size or format.

consequently be a new antenna structure and a new manufacturing technique needed by antennas, for bandwidths that meet the demands of advanced communication systems better to reach. In addition, the antenna structure should internal assembly or assembly allow for more flexible positioning of components within wireless device, greatly improved aesthetics and reduced antenna damage to offer.

SUMMARY OF THE INVENTION

Of the According to the present invention is a uniplanar dual-strip antenna as recited in claim 1 discloses. Preferred embodiments become dependent claims presented.

The present invention relates to a uniplanar dual-strip antenna having a two-dimensional structure. The uniplanar dual-strip antenna includes a first and a second metallic strip, each printed on a thin planar substrate. The first and second strips are separated by a predetermined gap or region of non-conductive material. According to the present invention, the first and second strips are used as conductors of a two-wire transmission line. Air or other dielectric material deposited on the substrate between the strips acts as a dielectric medium between the first and second strips. In one embodiment of the present invention, the length of the first strip is less than the length of the second strip fens, and the width of the first strip is less than the width of the second strip.

One coplanar waveguide is to the uniplanar dual-strip antenna coupled. The coplanar waveguide is made by etching or Applying metal created on the substrate. The positive connection or positive pole of the waveguide is electrically connected to the first strip connected. The negative terminal or negative pole of the waveguide is electrically on both the first and second strips connected. Alternatively, a coaxial cable instead of a coplanar Waveguide can be used as a feed.

In an embodiment According to the invention, the coplanar waveguide has two negative poles and a positive pole. The positive pole is connected to the first strip. A negative pole is connected to the second strip, while the other negative terminal is connected to the first strip. The negative poles are electrically connected to each other at a suitable location.

In an embodiment The present invention is the uniplanar dual-strip antenna by Printing, etching or applying metallic strips on a thin flexible Substrate created. The coplanar waveguide is also etched or applied on flexible material. In another embodiment The present invention is the uniplanar dual-strip antenna by etching or applying metallic stripes on a printed circuit board or a printed circuit (PC) board created. This greatly simplifies the manufacture of the dual-strip antenna.

In an embodiment In the present invention, the first and second strips are approximately parallel to each other. In another embodiment of the present invention Invention run the first and the second strip to the open end apart, in the direction in which they are from where the first and second strips are electrically connected to the coplanar waveguide are, lead away, for improved impedance matching with the air or the free space to disposal to deliver. In yet another embodiment of the present invention Invention, the first and second strips are substantially bent. A variety of other forms for the first and second strips can also be used.

The uniplanar dual-strip antenna provides, according to the present invention, an increase in bandwidth over typical quarter-wavelength or Half wavelength patch antennas. Experimental results have shown that the uniplanar dual-strip antenna a bandwidth of about 8-20% has, which is very beneficial for PCS and cellular or mobile phones is.

BRIEF DESCRIPTION OF THE DRAWINGS

The The present invention will be described with reference to the accompanying drawings in which the same reference numbers are generally identical, denote functionally similar and / or structurally similar elements, wherein the drawing in which an element first appears, by the leftmost digit (s) are shown in the reference numerals is and in which:

1A and 1B illustrate a portable telephone having whip and external helical antennas;

2 illustrates a conventional microstrip patch antenna;

3 a side view of the microstrip patch antenna of 2 illustrated;

4 illustrates a dual-strip uniplanar antenna according to one embodiment of the invention;

5A - 5G Top views of the tops of some alternative embodiments of the present invention using square transitions to connect strips illustrate;

6A - 6C Top views of the tops of some other alternative embodiments of the present invention utilizing curved transitions to connect strips illustrate;

7A - 7E Top views of the tops again of some alternate embodiments of the present invention that use V-shaped transitions to connect strips illustrate;

8A - 8G Top views of the tops of further alternative embodiments of the Illustrate the present invention using curved, angular and composite strip shapes;

9A - 9B Perspective views of some other embodiments of the present invention useful in certain other applications illustrate;

10 illustrates a measured frequency response of an embodiment of the present invention suitable for use in cellular and mobile telephones, respectively;

11 illustrates a measured frequency response of another embodiment of the present invention suitable for use in wireless PCS telephones;

12 and 13 illustrate measured field characteristics of an embodiment of the present invention;

14 a top view of an embodiment of the present invention for use in the phone of 1 illustrated;

15 a top view of another embodiment of the present invention and a signal feed structure for use in the phone of 1 illustrated;

16A and 16B Top view of the bottom and view of a side cross-section of an embodiment of the present invention, which is within the phone of 1 is mounted, illustrate;

17 another wireless device in which the present invention may be used illustrated.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

1. Overview and discussion of invention

While one conventional Microstrip antenna possesses some properties that they use for in personal Making communication devices fit is further improvement in other areas of the microstrip antenna still desired to she for the use in wireless communication devices, such as cellular and PCS phones, more desirable close. One such area where further improvement is desired, is her bandwidth. Generally, PCS and cellular phones need about 8 percent bandwidth to work satisfactorily. There the bandwidth of currently available microstrip antennas about the order of magnitude is 1-2 percent, an increase in their bandwidth is desired for use to be suitable in PCS and cellular telephones.

One Another area where further improvement is desired is the size of one Microstrip antenna. A reduction in the size of a microstrip antenna would to For example, consider a wireless communication device in which it is used becomes, more compact and more aesthetic do. Indeed could This condition even if such an antenna in a wireless Communication device at all can be used, or whether it can not be used. In the past, a reduction in the size of a usual Microstrip antenna by reducing the strength of each dielectric used Substrates or by enlarging the dielectric constant allows. However, this had the unwanted Effect of reducing the antenna bandwidth, making it less suitable for wireless Made communication devices.

Of Further, the field characteristics of conventional microstrip antennas, like patch emitters or radiators, typically directional. Most patch radiators radiate, based on a local Horizon of the antenna, only starting in an upper hemisphere. Like previously described, this characteristic moves or rotates with a movement of Device and can be unwanted Zeros or cancellations in cause the cover. Consequently, microstrip antennas are due their directional characteristic for use in many wireless communication devices not very desired been.

The present invention provides a solution to the above and other problems. The present invention relates to a dual-strip uniplanar antenna which has a two-dimensional structure and operates as an open parallel-plate waveguide waveguide but with asymmetrical terminations of the conductors. He offers the uniplanar dual-strip antenna increased bandwidth and size reduction over other antenna designs, while maintaining other features desirable for use in wireless communication devices.

There the uniplanar dual-strip antenna has a two-dimensional structure it can be connected or worn in conformity from a variety of surfaces, like the plastic case a cellular telephone or other wireless devices. The uniplanar antenna may be near the top or bottom surface of a wireless communication device, such as a portable telephone, be installed, or it may be next to or behind other elements like speakers, headphones, Input / output circuits, keyboards and so on in the wireless Device to be mounted. The uniplanar antenna can also on or in a surface a vehicle in which a wireless communication device can be used to be installed.

Different as either a whip or external helix antenna is the uniplanar dual-strip antenna not susceptible to damage by snagging on objects or surfaces. Furthermore, the uniplanar dual-strip antenna as it is close a top surface a wireless communication device or along a wall can be installed, do not consume an interior, which is for advanced Features and circuits is required, nor will it be large housing dimensions for housing, when fed, require. The antenna of the present Invention can be made using automated methods become what work and costs associated with antennas, reduced and reliability elevated. Furthermore, the uniplanar dual-strip antenna emits an almost omnidirectional characteristic or an almost omnidirectional Pattern out what they do in many wireless communication devices makes it suitable.

2. Example environment

Before the invention is described in detail, it makes sense a to describe exemplary environment in which the invention implements can be. In a broad sense, the invention can be found in any wireless Device, such as a personal one Communication device, wireless telephones, wireless modems, Facsimile devices, portable computers, pagers, receivers for news broadcasting or message broadcasts and so on. A such environment is a portable or hand-portable wireless Phone, like that, that for cellular, PCS services or other commercial communications services used becomes. A variety of such wireless phones with correspondingly different housing forms and styles are known in the art.

The 1A and 1B illustrate a typical wireless phone 100 used in wireless communication systems, such as the cellular and PCS systems discussed above. The wireless phone that is in 1 ( 1A . 1B ) has, for the sake of compactness, a pop-up "clam-shell" body or the design of a flip-type phone or jerk-open phone Other wireless devices and phones use more conventional ones "bar-shaped" housings or designs.

The phone that is in 1 illustrated includes a whip antenna 104 and a whip-concentric helix antenna 106 coming from a housing 102 protrude. The front of the case is shown, it carries a speaker 110 , a display panel or a screen 112 , a keypad 114 , a microphone or microphone access holes 116 , a connection for an external power supply 118 and an accumulator 120 which are typical components of wireless telephones known in the art. In 1B becomes the antenna 104 shown in an extended position as typically encountered during use while the antenna is in use 104 in 1A is drawn in (not visible due to the viewing angle). This telephone is used for purposes of illustration only, as there are a variety of wireless devices and telephones and associated physical forms in which the present invention may be used.

As discussed above, the antenna has 104 some disadvantages. One is that it tends to be damaged by snagging on other objects or surfaces when deployed during use and sometimes when retracted. It also consumes the interior of the phone in such a manner that it limits the placement of components for advanced features and circuitry, including power sources such as batteries, and makes them less flexible. In addition, the antenna 104 when retracted, require minimum housing dimensions that are unacceptably large. The antenna 106 can also be used during use by being stuck to other things or surfaces to be damaged and can not in the phone case 102 be confiscated.

The The present invention will be described with reference to this example environment described. The description with this reference is for purpose only of clarity and simplicity provided. It is not intended limit the invention to the application in this example environment. To reading the following description will be apparent to a person skilled in the art, how the invention is implemented in alternative environments can. Rather, it will be clear that the present invention in any wireless communication device, such as, but not limited to this selection, a mobile fax machine or in a portable computer with capabilities can be used for wireless communication and so on as discussed below.

2 represents a conventional microstrip patch antenna 200 dar. The antenna 200 includes a microstrip element 204 , a dielectric substrate 208 , a mass area 212 and a feeding point 216 , The microstrip element 204 (also commonly referred to as a radiator patch) and the ground plane 212 are each formed of a layer of conductive material, such as a copper layer.

The most frequently used microstrip element and the associated ground surface exist from a rectangular element, although microstrip elements and related Ground planes, the other shapes, such as circular shapes, also have to be used. A microstrip element can be made using a variety of well known techniques, including the Production by means of photolithography on one side of a printed one Circuit board while a mass surface by photolithography on the other side or another layer the printed circuit board etched becomes. There are many ways such as a microstrip element and a ground plane can be created such as. by selectively applying conductive material a substrate, connecting sheets (Plates) with a Dielectric or coating of a plastic with a conductive Material.

Wobei

L

= Länge von Microstreifen-Element 204

ε_r

= relative dielektrische Konstante des dielektrischen Substrates 208

λ₀

= Wellenlänge im Vakuum bzw. im freien Raum,

λ_d

= Wellenlänge im dielektrischen Substrat 208

3 Fig. 3 is a side view of a conventional microstrip antenna 200 A coaxial cable that has a center conductor 220 and an outer conductor 224 has, gets to the antenna 200 connected. The center conductor (plus pole) 220 gets to the microstrip element 204 at the feeding point 216 connected. The outer conductor (negative pole) 224 gets to the ground plane 212 connected. The length L of the microstrip element 204 is generally equal to one-half or one-quarter wavelength at the frequency of interest in the dielectric substrate 208 (see Chapter 7, page 7-2, Antenna Engineering Handbook, Second Edition, Richard C. Johnson and Henry Jasik), and is expressed by the following equation:

In which

L

= Length of microstrip element 204

ε _r

= relative dielectric constant of the dielectric substrate 208

λ ₀

= Wavelength in vacuum or in free space,

λ _d

= Wavelength in the dielectric substrate 208

The variation of the dielectric constant and inductance of the feed make it difficult to predict the exact dimensions, so usually a test element is built to determine the exact length. The strength t is usually much smaller than a wavelength, usually of the order of 0.01 λ ₀ , to reduce or prevent cross-currents or modes. The chosen value of t is based on the bandwidth over which the antenna must operate and will be discussed in greater detail below.

The width "ω" of the microstrip element 204 must be less than one wavelength in the material of the dielectric substrate, that is, as λ _d , so that higher order modes are not excited. An exception to this is when multiple signal feeds are used to exclude higher order modes.

A second commonly used microstrip antenna is the quarter wavelength microstrip antenna. The ground plane of the quarter wavelength microstrip antenna generally has a much larger area than that of the microstrip element. The length of the microstrip element is approximately one quarter Wavelength at the frequency of interest in the substrate material. The length of the ground plane is approximately half a wavelength at the frequency of interest in the substrate material. One end of the microstrip element is electrically connected to the ground plane.

The bandwidth of a quarter wavelength microstrip antenna depends on the thickness of the dielectric substrate. As stated previously, the operation of PCS and cellular wireless telephones requires a bandwidth of about 8 percent. For a quarter wavelength microstrip antenna to meet the 8 percent bandwidth requirement, the thickness of the dielectric substrate must be 208 about 1.25 inches (3.18 cm) for the cellular frequency band (824-894 MHz) and 0.5 inches (1.27 cm) for the PCS frequency band. This great strength is apparently undesirable in a small wireless or personal communications device in which a thickness of about 0.25 inches (0.64 cm) or less is desired. An antenna of greater strength typically can not be accommodated within the existing volume of most wireless communication devices.

3. The present invention

A dual-strip uniplanar antenna constructed in accordance with an embodiment of the invention and operating in accordance with one embodiment of the invention is disclosed in US Pat 4 shown. In 4 The uniplanar dual-strip antenna includes a first strip 404 and a second strip 408 , a dielectric substrate 412 and a coplanar waveguide 416 , The first strip 404 is electrically connected to second strips 408 connected at or near one end. This end is referred to as the "closed end" of the antenna.

The first and second stripes 404 and 408 are each on a dielectric substrate 412 printed, etched or applied and are each made of conductive material, such as copper, brass, aluminum, silver, gold or other known conductive materials whose impedance and current characteristic are known. The first and second stripes 404 and 408 are spaced from each other by a predetermined gap t which, if desired, could also be filled with a dielectric material (normally air) such as a foam rubber known for such use. In one embodiment of the present invention, the first and second strips are 404 and 408 positioned substantially parallel to each other over their respective lengths. In another embodiment (see for example 5A - 5C and 9B ), the first and second strips widen at an open end to provide better impedance matching with the air or free space.

A coplanar waveguide 416 , which is a positive pole 420 and two minus poles 424 and 428 has is on the first and second stripes 404 and 408 coupled. In one embodiment of the present invention, plus and minus poles are used 420 . 424 and 428 formed from three parallel metallic strips. The median strip is called plus pole 420 and is electrically connected to the first strip 404 connected. An outer stripe becomes a negative pole 424 and the other outer strip is called negative pole 428 designated. The negative pole 424 is electrically at first strip 404 connected and negative pole 428 is electrically connected to second strips 408 connected. In one embodiment of the present invention, the coplanar waveguide becomes 416 by printing, etching or depositing metal on the substrate 412 created. The coplanar waveguide 416 is made of a conductive material such as copper, silver, gold, aluminum or other known conductive materials. Alternatively, a coaxial cable may be used as the feed instead of a coplanar waveguide.

The uniplanar dual-strip antenna has a two-dimensional structure. So she can with many surfaces, like plastic housings of a cellular telephone. In one embodiment of the present invention, the antenna is placed on a flexible layer, which is capable of being used as a dielectric substrate or medium work, such as Mylar, Kapton or other known flexible dielectric Material, etched, printed or applied. The dual-strip antenna can advantageously on thin Subregions of wireless devices, such as the flip-type part, the clam shell part or the foldable part of a wireless mobile Telephone are mounted, as discussed below.

The lengths of the first and second stripes 404 and 408 mainly determine the resonant frequency of the uniplanar dual-strip antenna. The length of the first and second stripes 404 and 408 are sized appropriately so that the first and second stripes 404 and 408 act as a two-wire transmission line capable of receiving and transmitting signals having a preselected desired frequency. The procedure, appropriate lengths for the first and second strips 404 and 408 to choose to operate as with a two-wire transmission line at a desired frequency, is well known in the art. In short, so that the first and second stripes 404 and 408 When working as a two-wire transmission line, each must have a length of about λ / 4, where λ is the wavelength of an electromagnetic wave of frequency of interest. Subsequently, the bandwidth of the resulting antenna formed by the two-wire transmission line is increased. This is done by simultaneously reducing the length and width of the first strip while increasing the length and width of the second strip until a desired bandwidth is achieved.

The coplanar waveguide 416 connects a signaling unit (not shown) to the dual strip antenna. Please note that the signaling unit is used herein to refer to the functionality that a signal source and / or a signal receiver offers. Whether the signaling unit provides one or both of these functionalities depends on which operation the antenna is configured for. For example, the antenna could be configured to operate only as a transmitting element, in which case the signaling unit operates as a signal source. Alternatively, the signaling unit operates as a signal receiver when the antenna is configured to operate only as a receiving element. The signaling unit provides both functions in the form of a transceiver or a transceiver unit when the antenna is configured to work both as a transmitting and as a receiving element.

The Antenna or stripes can be formed in a variety of other forms, like (but not limited to): quarter-circular, semicircular, semi-elliptic, parabolic, angled, both round and angular C-shaped, L-shaped, U-shaped, and V-shaped. The V-shaped Structures can vary from less than 90 degrees to almost 180 degrees. The curved ones Structures can relatively small or large Use radii. The width of the conductors, i. of the first and second Strip, can change along the length so that they taper, bend or otherwise stepwise to a narrower width towards the outer end (the part without power) to change. As professionals will understand, several of these effects can or shapes are combined in a single antenna structure.

Several plan views of alternative embodiments or shapes for the strips of the present invention are shown in FIGS 5A - 5G . 6A - 6C . 7A - 7E and 8A - 8F the last digit of the reference numbers indicates whether an element is a first or second strip, ie 4 and 8, respectively. The first number and the last letter indicate the figure in which the element occurs, as in 504A For 5A . 708B For 7B and so on. For the sake of clarity of illustration, the widths of the strips used in these figures are not to scale, and are usually the same. However, as described above and elsewhere, and as will be appreciated, these two strips will generally have different widths to achieve a desired bandwidth.

The antenna embodiments included in the 5A - 5G illustrate alternative forms of the present invention wherein rectangular or square transitions are used to join the strips together. That is, for the closed end of the antenna in the embodiments shown in FIGS 5A - 5G 1 and 2, the first and second strips are joined or joined together using a substantially straight conductive interconnecting element or transition strip 506 ( 506A - 506G ). In addition, further directional changes of the strips are made with respect to each other at substantially right angles. Each change of direction involves the positioning of a new part of each strip substantially perpendicular or at a 90 degree angle to a previous part. Of course, these angles need not be exact for most applications, and other angles, along with curved or bevelled corners, may be used as desired.

5B shows that in order to accommodate a longer second strip, this strip may be folded to obtain a total desired length for the antenna structure. 5C shows that the convolution may either point towards or away from the area in which the first strip is located. 5D shows that the second strip may be folded back, around the first strip, either partially or completely. While 5E the extension also represents the first strip through a folded architecture. 5F represents direction changes for the first and second strips, which are executed in smaller "steps". Alternatively, an end portion of each strip may be diffracted or angled, as in FIG 5G shown to form a total of Y-shape. Typically, the separation angle is a 90 degree angle, although not required, eg, where a blunt V-shaped end structure is acceptable.

The antenna embodiments included in the 6A - 6C Illustrate alternative forms of the present invention which use curved or curvilinear transitions to control the scattering To connect with each other. That is, in the embodiments shown in the 6A - 6C 5, the first and second strips are formed at the closed end using a bent conductive fastener or transition strip 1606 , connected or merged. The stripe 1606 may have a variety of shapes, including but not limited to, quarter-circle, semi-circular, semi-elliptical or parabolic, or combinations of these shapes. The bent structures may use relatively small or large radii, as desired for a particular application. Additionally, each of the strips may be folded to a desired overall length of the antenna structure, as in FIG 5A - 5G shown to receive. 6A represents a mainly semicircular curved transition, 6B represents a mainly quarter-circle or elliptical, curved transition and 6C represents a mainly parabolic curved transition. These types of transitions can also be used in combinations.

The antenna embodiments included in the 7A - 7E Illustrate alternative forms of the present invention which use V-shaped transitions to interconnect the strips. That is, in the embodiments shown in the 7A - 7E 4, the first and second strips are joined or joined together at the closed end without the use of a separate conductive connector or transition strip or using a very small size. Instead, the first and second strips extend from a common connection point to an outwardly separating or diverging configuration. Additionally, as before, each of the strips may be folded to a desired overall length of the antenna structure, as in FIGS 5A - 5H shown to receive.

The 7A and 7B represent a mainly straight V-shaped or sharp-angled transition where they merge 7B the two strips are diffracted again to form mainly parallel strips or to form a reduced increase of the angle with respect to each other. In the 7C - 7E At least one of the two strips is bent to the initial V-shaped connection point. In 7C Both strips are bent following an exponential or parabolic curve function. In 7D only one strip is bent and in 7E both strips are bent, but after folding in straight sections. As before, these types of transitions may also be used in combination as desired for a particular application.

The 8A - 8G illustrate some alternative embodiments or shapes of the strips of the present invention using bent, angled and composite strips. Here, the strips are arranged substantially parallel to one another over their respective lengths, but they follow circular, serpentine or V-shaped paths as they extend outwardly from where they terminate at the closed end using a conductive fastener or transition strip 806 ( 806A - 806F ), or in the circular or elliptical case of 8G without the use of a connection strip, connected or merged together. The use of composite shapes allows the formation of antenna structures on carrier substrates that also carry switching or discrete components and assemblies or allow gaps in the gap around other assemblies within a given wireless device.

While this antenna structure is a two-dimensional structure lying in a single plane, it is a conformal or conformable structure, so the plane need not be flat. That is, by bending or molding the carrier substrate, the shape of the uniplanar antenna can effectively also vary in a third dimension. A pair of strips appearing in the second dimension as flat planar surfaces may be bent in a third dimension (here z) along an arc or angled at an angle. Some embodiments of the present invention in which a pair of strips are bent or angled in the z-direction are incorporated in FIGS 9A - 9C shown. These embodiments are very useful when it is desired to place the antenna within certain spaces in a wireless device that may require it to "match" the antenna with certain components or structures within the device.

9A shows the first and second stripes as in 4 also bent along their respective lengths in a third dimension, using a simple curve. 9B shows the first and second stripes as in 7A seen connected in a V-shaped or acute-angled transition, but viewed three-dimensionally with a V-shaped bend. A more complex set of curves or convolutions is used to define the plane in which the stripes are in 9C lie, shape.

The dual-strip antenna can also be up by etching or applying a metallic strip two opposite sides of a dielectric substrate and electrically interconnecting the metallic strips at one end using one or more plated-through vias, bridges, interconnects, or wires. In this form, the antenna uses some of the substrate material as a dielectric, which is positioned between the two strips. This is taken into account in the design of the antenna as far as bandwidth and other characteristics, as is well known. The dual strip antenna may also be formed by molding or molding a plastic or other known insulating or dielectric material into a support structure having a desired shape (U, V or C shaped or bent, rectangular and so on). and subsequent metallization or coating of the plastic at the respective conductive material portions using well-known methods, including conductive material in liquid form.

The Dielectric substrate may be within the subregions of the housing wireless device using stands, ridges, guides or the like, what in the material from which the housing is made is, is trained to be secured. That is, such carriers will be molded during manufacture in the wall of the housing of the device cast or otherwise shaped, such as e.g. by injection molding or Injection-compression molding. These support elements can then hold the substrate in place when it is in the process of making the phone, put on them or used in them. Other techniques include the use of a layer of adhesive material to the assembly within the housing to fix the device or a form of fastener or a holder with holes in the substrate or at the edges of the substrate interacts.

As previously stated, the first and second stripes function 404 and 408 ( 504 . 508 ; 1604 . 1608 ; 704 . 708 ; 804 . 808 etc.) according to the present invention as a two-wire transmission line. An advantage of a two-wire transmission line is that it does not require a ground plane. This allows the antenna to be a two-dimensional structure of negligible strength. The majority of the strength of the antenna is due to the thickness of the dielectric substrate 412 certainly. For example, a thin sheet of Mylar or Kapton having a thickness in the range of 0.0005 inches (0.013 mm) to 0.002 inches (0.051 mm) can be used as the dielectric substrate. In contrast, a conventional microstrip antenna designed for operation in the cellular frequency band requires a dielectric substrate having a thickness of 1.25 inches (3.175 cm) while a microstrip antenna intended for the PCS frequency band requires a dielectric substrate which has a thickness of 0.5 inches (1.27 cm). Thus, the present invention allows significant reduction in the overall strength of the antenna, making it more desirable for personal communication devices, such as a PCS or cellular telephone. However, those skilled in the art will readily recognize that other strengths, including thicker material, may be used to obtain a desired structural integrity of the antenna, either during use or during assembly in the manufacture or maintenance of the wireless device.

The uniplanar dual-strip antenna according to the present invention provides an increase in bandwidth over typical quarter-wavelength or half-wavelength patch antennas. Experimental results have shown that the antenna has a bandwidth from about 8-20 percent has what for PCS and cellular phones is extremely desirable. As before noticed, have conventional Microstrip antennas very narrow bandwidths, they less desirable for the Use in personal Make communication devices.

In the present invention, the increase of the bandwidth is made possible mainly by the operation of the antenna as a two-wire transmission line instead of a conventional microstrip patch antenna. Unlike a conventional microstrip patch antenna having a radiator patch and a ground plane, in the antenna according to the present invention, both the first and second stripes function 404 and 408 as active radiators. In other words, the length and width of the first and second strips are carefully sized so that both the first and second strips 404 and 408 work as active radiators on the wavelength or frequency of interest. During operation of the antenna, surface currents are induced in the first strip as well as in the second strip. The present inventor initially selected appropriate dimensions, ie, length and width, of the first and second strips using analytical techniques and EM simulation software known in the art. Thereafter, the inventor writing here checked the simulation results by experimental methods known in the art.

In order to increase the radiator or antenna bandwidth, in a preferred embodiment, the dimensions of each strip are chosen to be at different center frequencies that are contiguous in one another chosen way to establish. For example, let's say that f _{0 is} the desired center frequency of the antenna. The length of the shorter stripe may be chosen such that its center frequency is at or around f ₀ + Δf, and the length of the longer stripe may be chosen so that its center frequency is at or around f ₀ -Δf. This equips the antenna with a wide bandwidth on the order of 3Δf / f ₀ to 4Δf / f ₀ . That is, the use of the f ₀ -related +/- frequency offset results in a model that increases the bandwidth of the antenna radiator. In this configuration will be. Δf is chosen in a much smaller size than f ₀ (Δf << f ₀ ), so that the distance of the resonance frequencies of the two strips is small. It is assumed that the antenna will not work satisfactorily if Δf is chosen to be as large as f ₀ . In other words, this is not intended as a dual-band antenna in which each stripe acts as an independent antenna radiator.

In The present invention will increase the bandwidth without corresponding increase in the size of the antenna achieved. This is in contrast to the teachings of conventional ones Patch antennas, according to which the bandwidth in general by increasing the Thickness of patch antennas increased will, resulting in a larger overall size of the patch antennas results.

In one example of an embodiment of the present invention, the cellular frequency band antenna, ie 824-894 MHz, is sized appropriately. The dimensions of the antenna for the cellular frequency band are given below in Table 1. Table 1 Length (L1) of the first strip 404 2.4 inches (6,096 cm) Length (L2) of the second strip 408 4.53 inches (11.506 cm) Width (B1) of the first stripe 404 0.062 inches (0.157 cm) Width (B2) of the second strip 408 0.125 inches (0.318 cm) Gap (t) between the first and second stripes 404 and 408 0.125 inches (0.318 cm)

In the above example of an embodiment, 1 ounce of copper was used to form the first and second strips 404 and 408 and 0.031 inch (0.079 cm) thick FR4 (a known commercially available printed circuit board (PCB)) material was used as the dielectric substrate 412 used. Furthermore, the positive pole of the coplanar waveguide became 416 at the first strip 404 at a distance of 0.330 inches (0.838 cm) from the closed end of the antenna 404 connected.

10 Figure 4 illustrates the measured frequency response of an embodiment of the antenna sized to operate over the cellular frequency band. 10 shows that the antenna has a frequency response of -15.01 dB at 825 MHz and a frequency response of -17.38 dB at 895.0 MHz. So the antenna has a bandwidth of 8.14 percent.

In another example of an embodiment of the present invention, the antenna is sized to operate over the PCS frequency band, ie, 1.85-1.99 GHz. The dimensions of the antenna for the PCS frequency band are given in Table 2 below. Table 2 Length (L1) of the first strip 404 0.89 inches (2.261 cm) Length (L2) of the second strip 408 2.1 inches (5.334 cm) Width (B1) of the first stripe 404 0.062 inches (0.157 cm) Width (B2) of the second strip 408 0.125 inches (0.318 cm) Gap (t) between the first and second stripes 404 and 408 0.125 inches (0.318 cm)

In the above example of one embodiment, 1 ounce of copper was again used to form the first and second strips 404 and 408 and 0.031 inch (0.079 cm) thick FR4 (PCB material) was used as the dielectric substrate 412 used. Furthermore, the positive pole of the coplanar Wel lenleiters 416 at the first strip 404 at a distance of 0.2 inches (0.508 cm) from the closed end of the antenna.

11 Figure 4 illustrates the measured frequency response of an embodiment of the antenna sized to operate over the PCS frequency band. 11 shows that the antenna has a frequency response of -9.92 dB at 1.79 GHz and a response of -10.18 dB at 2.16 GHz. So the antenna has a bandwidth of 18.8 percent.

The 12 and 13 show the measured field characteristic of an embodiment of the antenna operating in the PCS frequency band. More specific 12 a plot of the magnitude of the field characteristic or intensity in the azimuth plane, while 13 represents a plot of the magnitude of the field characteristic or strength in the elevation plane. Either 12 as well as 13 show that the dual-strip antenna has an approximately omnidirectional directivity, making it suitable for use in personal communication devices.

One embodiment has been developed with a "D" -shaped radiator strip assembly, the second strip being much longer than the first and generally folded to expand "in" and away from the first, if desired, can even be back in itself be folded into it. This antenna structure is in 14 illustrates where an antenna 1400 using stripes 1404 and 1408 on a substrate 1412 be positioned or applied is formed. The upper part of the antenna is from the first conductive strip 1404 formed as slightly bent in the "C" shape (or the front side of D). This bend is used to place the antenna 1400 in a housing of a device having curved side walls and near the side of this housing. The second strip is wider than the first strip to improve bandwidth as discussed above.

One Model of such an antenna with the overall dimensions in the size of 37.59 mm (Y) to 51.89 mm (X) has been created and tested, which is roughly the Inside dimension of the Flip-top portion of a clam-shell type wireless phone, in which the antenna has been positioned corresponds to.

The antenna 1400 is by means of a feed section 1416 connected to an appropriate transceiver circuit within a wireless device. An element 1420 illustrates how various known circuit components or assemblies also on the substrate 1412 can be mounted, or alternatively can passages or holes 1422 be formed, through which various components or cables, as desired, extend.

A preferred embodiment has also been developed with a D-shaped radiator strip assembly, the second strip being much longer and wider than the first and generally expanding to "wrap around" the first one 15 illustrates where an antenna 1500 using stripes 1504 and 1508 on a substrate 1512 be positioned or applied is formed. The upper part of the antenna 1500 , as formed by the second strip, is again shown as being slightly bowed for improved placement of the antenna 1500 in a wireless device.

This type of antenna can be formed as a modularized structure with the conductors used to feed the signals. The coaxial feed structure may consist of the same flexible substrate ( 1512 ) how the conductors forming the antenna are formed. For example, on a thin sheet of Mylar, Kapton or Teflon based material; These are all materials known in the art. An example of how this can be done is in 15 illustrates where a long flexible signal conditioning structure or section 1520 in the form of a "coplanar waveguide". The waveguide 1520 stops or closes at one end to the negative supply strips 1524 and 1528 which form part of the mass part of a coplanar waveguide. The feeding strip 1524 connects or is coupled to the connector 1506 during the feeding strip 1528 with the second strip 1508 connected is. A positive supply strip 1522 or the middle of the feed structure 1520 is right with the first strip 1504 connected. The distance between the connection point for this supply strip and the strip 1528 is chosen to give a particular impedance according to the frequency that is used and the length and other dimensions of the conductive material 1506 to offer, as we know.

The positive feed 1522 is shown as a short distance along the material 1512 completes, and is generally associated with or coupled with, or expands to, a third center ter 1526 , similar to the ladders 1524 and 1528 , to become. ladder 1526 extends along the length of the material 1512 to the connection end 1530 where it forms the middle or positive part of a coplanar waveguide.

However, other configurations, including the placement of one or more feeder strips on opposite sides of the substrate, could be used. For example, the positive feed conductor may be on one side of the material 1512 and the negative feeds are formed on the other. Conductive passages are then used to pass signals through the material where appropriate. Other combinations of conductors and vias may be used to realize signal transmissions as known.

Therefore, the antenna can 1500 along with these ladders ( 1522 . 1524 . 1528 ) are formed as a single monolithic structure, offering increased cost efficiency, reliability and manufacturing efficiency. The ladder ( 1524 . 1526 . 1528 ) on the feed section 1520 usually ends in conductive pads, or a small connector 1532 which are used to connect to various spring or spring connections on a board to which the antenna is coupled.

The configuration or overall shape of the waveguide or feed section 1520 and substrates 1512 , in the 15 is used only for purposes of illustration and for most effective fit within the wireless device 100 , as shown, used. However, those skilled in the art will readily understand that other configurations may be useful and are included in the teachings of the invention. For example, instead of using angled bends along the length of the waveguide 1520 which are angles of about 45 degrees, a series of 90-degree bends, folds or turns are used for the wires. Of course, when thin cables are used, a variety of bends and turns can be used. Such convolutions and phrases are used to minimize the path length of the conductors while accommodating physical limitations applied to the substrate or antenna. In addition, the ladder 1524 . 1526 and 1528 typically in width at one or more points along the waveguide 1520 narrowed and these positions can also change according to specific applications. The small air bridges in 15 for electrical connection of the line 1524 and 1528 are useful but not required for the invention.

When they are inside a wireless device, like the wireless phone 100 is placed allows the feed structure or waveguide 1520 efficient transmission of signals between the antenna 1500 and various receive and transmit elements and components used within the wireless device. By forming the antenna and the coplanar waveguide on a common but thin and flexible dielectric substrate, the antenna can be mounted within many parts of a device because it requires very little space and around many other discrete components such as speakers can be formed. The feeders can make connections around flexible, hinged or collapsible joints as found in many wireless devices (telephones, computers).

Alternatively, a mini-coaxial line could be used instead of the waveguide (the feed) 1520 used to achieve similar results. For example, one known type of coaxial line or cable, which has a diameter of 0.8 mm or 1.2 mm, has been shown to be suitable for signal transmission between the antenna 1500 and the appropriate or suitable circuit, if desired. Other types and types of conductors may be used for certain applications depending on signal transmission characteristics, as known.

The 16A and 16B illustrate a side and rear sectional view, respectively, of an embodiment of the present invention used in the telephone 100 from 1 is mounted. Such phones have various internal components that are generally carried on one or more boards for performing the various required or desired functions. A circuit board 1602 containing various components, such as integrated circuits or chips 1604 , discrete components 1606 such as resistors and capacitors and various connections 1608 wears inside the case 102 in the 16A and 16B shown. The display panel and keyboard are typically at the back of the board 1602 attached so that they are the front of the phone case 102 With cables, conductors and terminals (not shown), the various other components, such as the accumulator or an external power source, a loudspeaker, a microphone or other similar known elements to the circuit on the board 1602 Docking.

In this embodiment, a connection 1610 plug-in or plug-in type on the underside of the board, mounted near the front of the phone, and is thus constructed, the terminal end of the feeding section 1520 for antenna 1500 take. Alternatively, one or more known spring contacts or clips may be used to terminate conductive pads 1530 to contact and the antenna 1500 electrically to the board 1602 to pair or connect. Such spring contacts or clips are mounted using known techniques such as soldering or (the use of) conductive adhesives, and are electrically connected to appropriate terminals to transmit signals to and from desired transmit and receive circuitry. Other types of termination techniques, including the use of solder or the use of miniature coaxial connectors (if thin cable is used) are also known to be useful. Specialized impedance matching elements or circuits within the wireless device may also be used to connect to the feed structure, as desired and as well known.

In the side view of 16B will the board 1602 as it comprises multiple layers of conductive and dielectric material joined together to what is referred to in the art as a multilayer printed circuit board (PCB). Such circuit boards are well known and understood in the art. This is illustrated as a layer of dielectric material 1612 , in addition to the metallic conductor layer 1614 is applied, in turn, next to the layer of dielectric material 1616 is applied to the metallic conductor layer 1618 wears or is upset next to her. Conductive vias (not shown) are used to join together different conductors on different layers or planes with components on the outer surfaces. Etched structures on any given layer determine the interconnect structures for that layer. In this configuration could be for the board 1602 either the shift 1614 or the layer 1618 as known in the art, form a ground layer or ground plane, as generally designated.

Typically, a series of load-bearing stands, pedestals or ridges 1620 used for mounting circuit boards or other components inside the enclosure. These may be formed as part of the housing, if it is z. B. is made of injection molded plastic, or otherwise secured in position, such as by the use of adhesives or other known mechanisms. In addition, there are typically one or more fasteners 1622 , which are used to hold fasteners to sections of housing 102 as removable or hinged covers to fasten together.

As previously discussed, the antenna can 1500 within subareas of the housing 102 using some known techniques, such as, but not limited to, the use of adhesives, adhesives, adhesive tapes, castings or bonded joints and the like, the benefits of which are known in the art. For example, the antenna 1500 be supported on a side wall or other portion or other element of the wireless device, using an adhesive layer or adhesive strip 1630 , connected to the substrate 1512 , The antenna is generally attached to the side of the housing, preferably over an insulating material or to a mounting bracket which can be mounted in place with clips, screws or similar fasteners.

alternative Mechanisms for mounting or fixing the antenna in place are known in the art. For example, burrs, guides or similar, what formed from the material from which the housing was made is used to physically place the substrate in the right place Place to fix. A number of protrusions and elevations can also used to carry the antenna and can have different shapes, as for the desired Application suitable.

As in 16B Seen, the substrate could be 1512 bent or otherwise angled or curved to conform well to the shape of the housing or to accommodate other elements, features or components within the wireless device. In the figure is a speaker 1632 which is positioned so that the antenna radiators or strips are "wrapped" around a portion of it.

The substrate may be manufactured in a bent or folded form or deformed during installation. The use of a thin substrate allows the substrate, when installed, to be curved, sometimes providing tension or pressure against curved or curved adjacent surfaces, to place the substrate in place without the need for fasteners to fix. A form of fortification is then simply through. Install adjacent assemblies, components or circuit boards and covers or sub-sections of the enclosure that will be secured in place. However, in order to function properly, the present invention does not require that the substrate be deformed or bent either during manufacture or installation.

17 illustrates additional wireless devices in which the present invention may be used, such as, but not limited to, a portable computer, modem, data terminal, facsimile, or similar mobile electronic device. In 17 becomes a wireless device or apparatus that is a wireless device 1700 used, which represented a main body or a main body 1702 with an upper corner section 1704 Has. In the cut-away perspective of 17 becomes an antenna 500 at one point in the upper corner 1704 attached, and a set of cables or ladders 1708 is used to feed the antenna 516 to connect to suitable circuits within the wireless device. Those skilled in the art will readily understand that other configurations and orientations for the antenna are possible within the teachings of this invention.

While different embodiments of the present invention have been described above be understood that they are presented only as examples and not as a limitation were. So should the breadth and scope of the present invention not by any of the exemplary embodiments described above limited but should only according to the following claims and their equivalents To be defined.

Claims (16)

A uniplanar dual strip antenna that has a first electrically conductive strip ( 404 ) and an electrically conductive second strip ( 408 ) mounted on a dielectric substrate ( 412 ), wherein the first and second strips ( 404 . 408 ) are spaced from each other by a selected gap, characterized in that the length and the width of the first and second strips ( 404 . 408 ) are selected to form a two-wire transmission line for receiving and transmitting electromagnetic energy having a preselected desired frequency and bandwidth, wherein the length or width of the first strip is less than the length of the second strip, so that the bandwidth of the antenna is at least 7.29 percent. A uniplanar dual-strip antenna according to claim 1, wherein the first and second strips ( 404 . 408 ) metallic strips printed on the same surface of the dielectric substrate ( 412 ) exhibit. The uniplanar dual-strip antenna of claim 1, wherein the first and second strips ( 404 . 408 ) have metallic stripes on the same surface of the dielectric substrate ( 412 ) are applied. The uniplanar dual-stripe antenna of claim 1, wherein the first and second stripes ( 404 . 408 ) on opposite surfaces of the dielectric substrate ( 412 ) are formed. The uniplanar dual strip antenna of claim 1, wherein the first strip ( 404 ) substantially parallel to the second strip ( 408 ). The uniplanar dual-strip antenna of claim 1, wherein the first and second strips ( 404 . 408 ) run away from each other near an open end. The uniplanar dual strip antenna of claim 1, further comprising a co-planar waveguide ( 416 ), with a positive ( 420 ) and a negative ( 424 . 428 ) Connection, wherein the co-planar waveguide ( 416 ) is formed by applying metal on the same surface of the substrate ( 412 ), whereby the positive connection ( 420 ) is electrically coupled to the strip ( 404 ) and the negative connection ( 424 . 428 ) is electrically coupled to the first and second strips ( 404 . 408 ), with surface currents on the first and second strips ( 404 . 408 ) are formed when the uniplanar dual-strip antenna with electrical signals via the coplanar waveguide ( 416 ) is energized. The uniplanar dual strip antenna of claim 1, further comprising a co-planar waveguide ( 416 ) with positive ( 420 ) and negative ( 424 . 428 ), Wherein the co-planar waveguide ( 416 ) is formed by applying metal on the same surface of the substrate ( 412 ), where the positive An Enough ( 420 ) is electrically coupled to the first and second strips ( 404 . 408 ) and the negative connection ( 424 . 428 ) is electrically coupled to the second strip ( 408 ), with surface currents on the first and second strips ( 404 . 408 ) can be formed when the uniplanar dual-strip antenna by electrical signals via the coplanar waveguide ( 416 ) is energized. Uniplanar dual-strip antenna according to claim 1, wherein the bandwidth of the antenna is about 8 to 20 percent. A uniplanar dual-strip antenna according to claim 1, wherein the dielectric substrate ( 412 ) is a flexible sheet that is capable of functioning as a dielectric medium. A uniplanar dual-strip antenna according to claim 1, wherein the dielectric substrate ( 412 ) Mylar, with a preselected thickness. A uniplanar dual-strip antenna according to claim 1, wherein the dielectric substrate ( 412 ) Kapton, with a preselected thickness. The uniplanar dual-strip antenna of claim 1, wherein the length and width of the first and second strips ( 404 . 408 ) are dimensioned so that the unplanar dual-strip antenna is capable of receiving and transmitting signals having a frequency range of 1.85 to 1.99 GHz. The uniplanar dual-strip antenna of claim 1, wherein the length and width of the first and second strips ( 404 . 408 ) are dimensioned so that the uniplanar dual-strip antenna is capable of receiving and transmitting signals having a frequency range of 824 to 894 MHz. A uniplanar dual-strip antenna according to claim 1, wherein the length of the second strip ( 408 ) is about 4.53 inches and the width of the second strip ( 408 ) is about 0.125 inches, and where the length of the first strip ( 404 ) about 2.4 inches and the width of the first strip ( 404 ) is about 0.062 inches. A uniplanar dual-strip antenna according to claim 1, wherein the length of the second strip ( 408 ) is about 2.1 inches and the width of the second strip ( 408 ) is about 0.125 inches, and where the length of the first strip ( 404 ) about 0.89 inches and the width of the first strip ( 404 ) is about 0.062 inches.