KR100738265B1 - Substrate antenna - Google Patents

Abstract

A substrate antenna 400 comprising one or more conductive traces 402 supported over an insulating substrate 404 having a predetermined thickness. Based on the wavelength of interest, the connecting elements, and the space allocated, appropriate dimensions are selected for the length and width of the trace. The support substrate 404 is mounted perpendicular to and offset from the ground plane 502 generally associated with the device in which the antenna is used. The trace is electrically connected to conductive pad 408 at one end. The signal feed 410 for the antenna is connected to the conductive pad 408. The substrate antenna uses a very thin and compact structure that provides the appropriate band. Due to the compactness and more versatile and useful form of the antenna, the substrate antenna can be used very efficiently as an internal antenna for a wireless device.

Description

Board Antenna {SUBSTRATE ANTENNA}

Field of technology

BACKGROUND OF THE INVENTION Field of the Invention The present invention generally relates to antennas for wireless devices, and more particularly, to a board mounted antenna. The present invention also relates to an internal antenna for a wireless device having improved dimensions, coupling, band, and radiation characteristics.

Description of the related technology

Antennas are an important component of wireless communication devices and systems. Antennas are available in many shapes and sizes, but each operates according to the same basic electromagnetic principles. The antenna has a structure associated with a region of transition between a guided wave and a free space wave or vice versa. As a general principle, guided waves traveling along an open transmission line radiate as free space waves, also known as electromagnetic waves.

Recently, as the use of personal wireless communication devices such as hand-held and mobile cellular and personal communication service (PCS) telephones has increased, the need for suitable small antennas for such communication devices has increased. Recent advances in integrated circuit and battery technologies have allowed the size and weight of communication devices to be drastically reduced over the past few years. Still required to reduce size is the antenna area of the communication device. This is due to the fact that the size of the antenna can play an important role in reducing the device size. In addition, antenna size and shape affects device aesthetics and manufacturing costs.

An important factor in designing an antenna for a wireless communication device is the antenna radiation pattern. In a typical application, a communication device should be able to communicate with another device or base station, hub, or satellite, which may be located in various directions from the device. In turn, such antennas for wireless communication devices need to have a suitable omnidirectional radiation pattern, or pattern extending upward from the local horizon.

Another important factor in designing an antenna for a wireless communication device is the band of the antenna. For example, wireless devices such as telephones used in PCS communication systems operate at frequencies between 1.85 and 1.99 GHz and thus require 7.29 percent useful band. Telephones used in typical cellular communication systems operate at frequencies between 824 and 894 MHz, which requires 8.14 percent of the band. Thus, antennas for use in this type of wireless communication device must be designed to meet the appropriate bandwidth requirements, otherwise the communication signal will be significantly attenuated.

One type of antenna commonly used in wireless communication devices is a whip antenna, which easily enters the device when not in use. However, whip antennas have several disadvantages. Often, whip antennas are susceptible to damage by contact with objects, people, when entering a device or taken out for use. To minimize this damage, even if the whip antenna is designed to be retractable, it can protrude through the entire dimension of the device and interfere with the placement of enhanced features and circuitry within some areas of the device. have. It may also require a minimum device receiving area that is larger than necessary when entering the device.

A whip antenna is usually used with a short spiral antenna that is activated when the whip antenna enters the phone. The helical antenna provides the same radiator length in a more compact space to maintain proper radiation coupling characteristics. Although the helical antenna is shorter, it affects aesthetics and hits other objects and still protrudes a considerable length from the surface of the wireless device. Significant volume is required to place such an antenna within a wireless device, which is undesirable.

Another type of antenna that may be suitable for use in a wireless communication device is a conformal antenna. In general, compliant antennas follow the shape of the surface on which they are mounted and generally exhibit very low profiles. There are many different kinds of compliant antennas, such as patch, microstrip, and stripline antennas. In particular, microstrips have recently been used in personal communication devices.

For example, one type of antenna that may be suitable for use in a wireless communication device is an "inverted F" antenna. However, such antennas have several disadvantages. This tends to be larger than necessary, has the disadvantage of lower bands, and lacks a desirable omnidirectional radiation pattern.

As the term suggests, microstrip antennas include patches or microstrip elements, commonly referred to as radiator patches. The length of the microstrip element is set in proportion to the resonance frequency f ₀ and the associated wavelength λ ₀ , which is selected to match a frequency of interest, such as 800 MHz or 1900 MHz. The length of the microstrip element commonly used is a half-wavelength (λ _0/2) and quarter wavelength (λ _0/4). Several types of microstrip antennas have been used in wireless communication devices recently, but further improvements are needed in many areas. Another area that needs improvement is the overall size reduction. Another area where specific improvements are needed is the band. Current patch or microstrip designs do not appear to achieve a band size greater than 7.29 to 8.14 percent needed for use in most communication systems in substantial size.

Conventional patch and strip antennas have additional problems when placed near the broad ground plane found in most wireless devices. Ground planes can change the resonant frequency, resulting in a non-repeatable manufacturing design. In addition, hand loading, i.e., the position of the user's hand near the antenna, sharply switches the antenna's performance and resonance frequency.

Radiation patterns are very important not only in establishing a communication link as described above, but also in relation to governmental radiation standards for wireless device users. The radiation pattern must be controlled or adjusted so that the minimum amount of radiation can be absorbed by the device user. Various government standards have been established for allowable radiation in the vicinity of wireless device users. One effect of these regulations is that internal antennas cannot be located in many locations within a wireless device because of theoretical radiation exposure to the user. However, as noted above, when current antennas are used in other locations, ground planes and other structures can often prevent their effective use.

Accordingly, new antenna structures and techniques are needed to fabricate antennas in order to obtain internal radio device antenna structures with advanced radiation requirements and more corresponding radiation patterns for end users. At the same time, the antennas need to meet advanced communication system requirements for band and coupling efficiency, and are internally mounted to provide more flexible component placement, significantly improved aesthetics, and reduced antenna damage within wireless devices. Is more useful.

Summary of the Invention

In view of the above and other problems found in the related art of manufacturing internal antennas for wireless devices, one object of the present invention is to provide the antennas with reduced size and increased flexibility when mounted inside a wireless device.

A second object of the present invention is to reduce the interaction between the wireless device user and the antenna, which can degrade performance.

One advantage of the present invention is that it provides a physically deformable support substrate capable of conformal mounting in a wireless device.

Other advantages include reduced manual labor and time for connecting and installing antennas in wireless devices, and a reduction in the number of cables and connectors required for this purpose.

These and other objects, and advantages, are realized in a substrate antenna for use in a wireless device that includes one or more conductive traces supported over an insulating substrate having a predetermined thickness. Based on the wavelength of interest and the allocated space for the wireless device, appropriate dimensions for the trace length and width are selected. The support substrate is offset from the ground plane associated with the circuits and components in the device, and is generally mounted perpendicular to the ground plane, with the antenna being used together. That is, the substrate is mounted adjacent to the edge of the ground plane and has a surface offset from the plane of the ground plane at an angle of less than 90 degrees. The substrate is not located directly below or above the ground plane.

The trace is electrically connected to a conductive pad on one end that interfaces with a signal feed for the antenna. Since conductive pads are used, the signal feed includes a conductive spring loaded, spring, or clipped device in electrical contact with the conductive pads through pressure. This enables automatic connection to the antenna when the board is installed in a wireless device, without the need to manually install cables or connectors or the like.

The substrate antenna uses a very thin and compact structure that provides the appropriate band. Due to the compactness and more versatile and useful form of the antenna, the substrate antenna can be used very efficiently as an internal antenna for a wireless device. The substrate antenna may be placed in the device housing to utilize the available space despite the many possible interference features or structures within the housing.

Brief description of the drawings
BRIEF DESCRIPTION OF THE DRAWINGS The present invention is described in conjunction with the accompanying drawings, wherein like reference numerals generally designate elements that have the same function and / or are structurally similar, and the drawing in which the element first appears is the leftmost digit (s) of the part number. Is displayed.

1A and 1B are perspective and side views of a portable cordless phone with a whip and an external spiral antenna.

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2A and 2B are perspective and side views of yet another portable cordless phone having a hip and an external spiral antenna;

3A and 3B illustrate a cross-sectional and side view of the FIG. 1B telephone, with internal circuitry;

3C is a side cross-sectional view of the phone of FIG. 2B with an internal circuit;

4A-4C illustrate a substrate antenna in accordance with one embodiment of the present invention.

5A and 5B are side cross-sectional and back views of the FIG. 1B telephone utilizing the present invention.

5C is a side plan view of the FIG. 1B telephone employing the present invention.

FIG. 6 is a side cross-sectional view of the telephone of FIG. 5A in conjunction with another embodiment of the present invention.

7A-7H illustrate various other embodiments of the present invention.

Detailed description of the preferred embodiment

Conventional microstrip antennas, such as inverted F-type antennas, have some properties that are potentially available in personal communication devices, and are useful in other areas to make these types of antennas useful in wireless communication devices such as cellular and PCS telephones. Improvement is also needed. Another area that needs improvement is bandwidth. In general, PCS and cellular telephones require wider bandwidths than are currently available with microsized antennas of substantial size in order to operate reliably.

Another area that needs improvement is the size of the microstrip antenna. For example, the reduced size of the microstrip antenna can make the wireless communication device more compact and aesthetic. Indeed, this may determine whether such an antenna can be used in a wireless communication device. The size reduction of conventional microstrip antennas is possible by reducing the thickness of the insulating substrate used or by increasing the insulation constant value, whereby the required length is shortened. However, this has the undesirable effect of reducing the antenna band, thus making it unsuitable for wireless communication devices.

In addition, field patterns of conventional microstrip antennas, such as patch emitters, are typically directional. Most patch emitters emit only from the upper hemisphere with respect to the local horizontal to the antenna. This pattern moves or rotates as the device moves and can cause undesirable nulls in coverage. Thus, microstrip antennas were not very suitable for use in many wireless communication devices.

The present invention provides a solution to the above problem. The present invention relates to a substrate antenna that provides a band and reduced size suitable for antenna design while maintaining other desirable characteristics for use in a wireless communication device. The substrate antenna of the present invention may be formed near the top surface of a wireless or personal communication device such as a portable telephone, or may be mounted adjacent to or behind other elements of the wireless device such as support posts, I / O circuits, keypads, and the like. The substrate antenna may also be formed directly, such as embedded in the plastic forming the housing or on the surface of the wireless device.

Unlike wireless or external spiral antennas, the substrate antennas of the present invention are not sensitive to damage by contact with objects or surfaces. This antenna also does not consume the internal space needed for advanced features and circuits and does not require a large receiving volume when entering the device. The substrate antenna of the present invention can be manufactured using automation and minimal manual labor, which reduces costs and improves reliability. In addition, the substrate antenna emits an almost omni-directional pattern, which makes the substrate antenna suitable for many wireless communication devices.

In a broad sense, the present invention can be realized in any wireless device such as a personal communication device, a wireless telephone, a wireless modem, a fax device, a portable telephone, a pager, a message broadcast receiver and the like. Such environments include portable or handheld cordless telephones, such as those used in cellular, PCS or other commercial communications services. Various cordless telephones with corresponding different receiving forms and styles are known in the art.

1 and 2 show a typical wireless telephone such as the cellular and PCS system described above. The telephone shown in Fig. 1 (Figs. 1A and 1B) is a "clam shell" type or a clamshell type telephone, and the telephone shown in Fig. 2 (Figs. 2A and 2B) is a typical rectangular or "bar" type telephone. These telephones are typical wireless telephones used in wireless communication systems such as the cellular and PCS systems described above. As will be apparent from the description below, there are various wireless devices and telephones and related physical configurations, including other forms or styles, in which the present invention may be used, and therefore these telephones are used only as examples.

1A and 1B, phone 100 is shown having a main housing or body 102 that supports whip antenna 104 and spiral antenna 106. The antenna 104 is generally mounted to share a common central axis with the antenna 106 and thus extends or protrudes through the center of the helical antenna 106 when extended, but this is not necessary for proper operation. Such antennas are manufactured to a length appropriate for the frequency of interest or for use in the particular wireless device in which they are used. Their specific designs are well known in the art and can be appreciated.

The front side of the housing 102 is also shown to support a speaker 110, a display panel or screen 112, a keypad 114, a microphone or microphone opening 116, and a connector 118. In FIG. 1B, the antenna 104 is in an extended position that is commonly encountered while the wireless device is in use, but in FIG. 1A, the antenna 104 is shown being enclosed into the housing 102.

2A and 2B, phone 200 has a main housing or body 202 that supports whip antenna 204 and spiral antenna 206 in the same manner as shown for phone 100. The front of the housing 200 also supports the speaker 210, the display panel or screen 212, the keypad 214, and the microphone or microphone opening 216. In FIG. 2A, the antenna 204 is shown in an extended position, while in FIG. 2B, the antenna 204 is shown being entered into the housing 202.

As noted above, whip antennas 104 and 204 have several disadvantages. One is that they are susceptible to damage by contacting surfaces or other items when extended in use. Antennas 104 and 204 also include a power source, such as a battery, to consume the internal space of the phone in such a way that the placement of components for advanced features and circuits is more limited and less flexible. In addition, antennas 104 and 204 may require an unacceptably large minimum housing area when folded. Alternatively, the antennas 104 and 204 can be configured with additional telephoto to reduce their size when folded, but will generally be perceived as inferior in appearance, vulnerable and unstable and inoperable by the consumer. Antennas 106 and 206 also have the disadvantage of being in contact with other items or surfaces in use and cannot be folded into phone housings 102 and 202 respectively.

For clarity and convenience, the use of the present invention is described for these exemplary wireless telephones. Nevertheless, the invention is not limited to applications in this exemplary environment. After reading the following description, those skilled in the art will know how to implement the invention in other environments. Indeed, it is clear that the present invention can be used in wireless communication devices such as, but not limited to, pagers with a wireless communication function, portable fax machines, portable computers.

Each of these phones typically has various internal components supported on one or more circuit boards to perform the various functions required. 3A, 3B, and 3C are used to show the general internal structure of a typical wireless telephone. FIG. 3A shows a cross section when the telephone shown in FIG. 1B is viewed from one side to see how a circuit or component is supported within the housing 102. 3B shows a cross section when the same telephone is viewed from behind from the keyboard to see the relationship of the circuits or components typically installed within the housing 102. FIG. 3C shows a cross section when the telephone shown in FIG. 2B is viewed from one side. FIG.

In FIGS. 3A and 3B, the circuit board 302 is a housing 102 that supports various components, such as an integrated circuit or chip 304, individual components 306 such as resistors and capacitors, and various connectors 308. Is shown inside. Typically, panel displays and keyboards are mounted to the back of the board 302, and their wires and connectors (not shown) interface speakers, microphones, or other similar elements with circuitry on the board 302. Antennas 104 and 106 are located on one side and are connected to circuit board 302 using special wire connectors and clips.

In particular, a number of support posts or stands 310 are used in the housing 102 to mount circuit boards or other components in the housing. One or more support ridges or ledges 311 may be used to support the circuit board. These posts may be formed as part of the housing, such as when formed by injection molding plastic or when fixed in place using an adhesive or other known mechanism. There is also one or more additional fastener posts 312 that receive screws, bolts, or similar fasteners 313, in particular for securing a portion of the housing 102. That is, the housing 102 is manufactured using a cover for a multi-part or main body part and an electronic component. Fastener posts 312 are then used to receive elements 313 for securing the housing portions together. The present invention provides a very efficient internal antenna design, while easily adapting to various posts 310 or 312.

As shown in the enlarged view of FIG. 3B, the circuit board 302 is generally fabricated as a multilayer circuit board having several alternating layers of conductors and insulating substrates joined together to form a fairly complex circuit interconnect structure. do. Such boards are known and understood in the art. As part of the overall structure, the board 302 is embedded in the board in an intermediate position or has one or more ground planes or ground planes on the bottom surface.

Applicants have recognized that forming a radiation pattern for a wireless device is the interaction of the ground plane with the antennas 104, 106, 204, 206. The antenna effectively excites the ground plane. That is, a current exists between the conductive material in the whip or spiral antenna and the ground plane to generate electromagnetic waves radiated into the air to form a communication signal. It is also a combination of the above to receive an input signal received by the wireless device. For this and other reasons, the Applicant has recognized that large and less useful antennas can be replaced by smaller and more compact antenna elements if properly positioned relative to the ground plane of the wireless device.

Note also that with respect to the ground plane there are other attempts to create internal antenna positions, particularly where a certain amount of radiation shielding is required. Unfortunately, this makes it impossible to create a low loss match in an antenna with sufficient operating band for use with normal cellular and PCS. As a result, these antennas are less efficient and have a lower gain, which is typically reduced by about 6 dB.

A substrate antenna 400 constructed and operative in accordance with one embodiment of the present invention is shown in FIGS. 4A-4C. In FIGS. 4A and 4B, the substrate antenna 400 includes a conductive trace 402, also referred to as a strip or elongated conductor, an insulating support substrate 404, and a signal feed region 406. Conductive traces 402 can be manufactured or viewed as one or more traces are electrically connected in series with each other to form the desired antenna radiator structure. Trace 402 is electrically connected to conductive pad 408 of signal feed region 406 at or near one end of substrate 404.

Substrate 404 is made from an insulating substrate or an insulating material, such as a circuit board or flexible material, which is known for this purpose. For example, a small fiber optic printed circuit board (PCB) can be used. Various materials can be used to manufacture the substrate. Typical commercial optical fiber, phenolic, plastic, or other printed circuit board or substrate materials available may be used. It is not necessary to use thin plates, but it has the advantage of being deformable and easily placed in place. Ultra-thin fiber reinforced Teflon sheets can be used for thin plates that need to bend or bypass a significant amount. However, such thin materials may not provide rigid support to prevent antenna characteristics from changing as the phone moves. Those skilled in the art of electronics and antenna design are very familiar with the many products available to fabricate suitable antenna substrates based on the desired insulating or antenna band characteristics.

The substrate serves as a support and spacing means for antenna radiator elements, ie traces, from other conductive surfaces or to provide a minimum spacing from hands or other radiation absorbing or interacting materials (such as tissue).

Traces are made from conductive materials such as, for example, copper, copper, aluminum, silver, or gold or other conductive materials or compounds known to be useful for making antenna elements. It may comprise a conductive material embedded in plastic or conductive epoxy and may also serve as a substrate.

Traces or traces are deposited on a supporting substrate using a number of known techniques, such as standard photoetching of conductive materials, plating or otherwise depositing conductive materials on a substrate, or adhesives such as thin metal plates on a supporting substrate. Using techniques that make it possible to deposit on dielectric or insulating substrates. In addition, known coating or deposition techniques can be used to deposit metal or conductive materials onto a moldable plastic support element or substrate.

The length of the trace 402 first determines the resonant frequency of the substrate antenna 400. The size of the trace 402, or a set or series of connected traces, is appropriate for the particular operating frequency. The trace used to construct the antenna is deposited to provide a conductive element that is about one quarter of the effective wavelength [lambda] for the frequency of interest. Those skilled in the art will appreciate the benefit of making the length slightly shorter or shorter than [lambda] / 4 to match the impedance to the corresponding transmit / receive circuit. In addition, coupling elements such as the exposed cables, wires, or clips described below contribute to the overall length of the antenna and are taken into account when selecting the dimensions of the trace.

When the substrate antenna 400 is used with a wireless device capable of communicating at one or more frequencies, the trace 402 length is based on the frequency relationship. That is, if multiple frequencies are related as a fraction of the wavelength, multiple frequencies can be accommodated. For example, λ / 4 length for one frequency corresponds to 3λ / 4 or λ / 2 for the second frequency. This relationship for using a single emission for multiple frequencies is well understood in the art.

The thickness of the trace, or traces 402, is in small fractional order of wavelength to prevent or minimize lateral current or mode and to maintain the minimum antenna size (thickness). The value chosen is based on the band within which the antenna should operate, as is known in the antenna design art. The width of the trace or traces 402 is also less than one wavelength in the insulative substrate material, and thus higher order modes will not be excited.

It should be noted that while the overall length of the trace 402 is about [lambda] / 4, the trace can be folded or bent or otherwise reset in the direction it has traveled so that the entire antenna structure can be less than [lambda] / 4 length. Due to the thin conductor dimensions combined with the relatively thin support substrate and the overall length of less than λ / 4, the overall size of the antenna is clearly reduced compared to conventional strip or patch antennas, thus making it more suitable for use in personal communication devices. It becomes appropriate. For example, this dimension is compared with the ground plane of a conventional microstrip antenna whose dimensions for proper operation are typically λ / 4 or more.

As shown in FIGS. 4A and 4C, the conductive pad 408 is disposed within the signal feed region 406 and is electrically coupled or connected to the trace 402. In general, the pad 408 and the trace 402 are formed of the same material and are formed as possible monoliths or structures, although not necessary, using the same manufacturing techniques. The pad 408 only needs to make good electrical contact with the trace 402 for the purpose of signal transmission without adversely affecting antenna performance or impedance.

In some configurations, the traces are directed towards circuit boards and signal sources or receivers, and in other configurations, away from the boards. In the latter case, the substrate is placed between the trace and the board. In such a situation, the conductive pad 408 may be placed in the wrong position of the substrate to easily receive a signal directly from the circuit board, without the need for wires or other conductors extending around the substrate. For many applications, this is undesirable because it requires more complex joining and installation procedures. Thus, as shown in FIG. 4C, on the opposite side of the substrate (as also shown in FIG. 5A) and the conductive vias used to transmit signals through the substrate, a second contact pad 410 may be used. .

The signal transmission feed is connected to the substrate antenna 400 using pads 408 and 410. By using conductive pads 408 and 410, the antenna can be installed and operated in a manner that provides convenient electrical connection and signal transmission through spring-type, or spring-attached contacts or clips known in the art. This simplifies the construction and manufacture of a wireless device by eliminating the need for manual installation of a particular connector or by manually inserting the antenna into the contact structure. This type of electrical connection also means that the antenna can be conveniently replaced when needed, without having to work with desoldering or specific connectors or the like to change or upgrade or repair the radio to another frequency. As noted above, spring contacts contribute to the overall length of the antenna or antenna emitter (trace) and are taken into account when dimensioning the trace.

The signal feed couples signals from a signal processing unit on circuit board 302 or circuitry (not specifically shown) to substrate antenna 400. Note that the term circuit herein relates to the functionality provided by known signal processing circuitry including general receivers, transmitters, amplifiers, filters, transceivers, and the like, which are known in the art.

5A and 5B, antennas 104 and 106 have been replaced with substrate antenna 400. The circuit board 302 is shown in FIG. 5A as having a conductive multilayer and an insulating material, such as copper and optical fiber, to form what is referred to in the art as a multilayer board or a printed circuit board (PCB). This is shown as the insulator layer 502 on top or next to the metal conductive layer 504 next to the insulator layer 506 that supports or is next to the metal conductive layer 508. Conductive vias (not shown) are used to interconnect various conductors with components on the outer surface over different layers or levels. The etched pattern on any given layer determines the interconnection pattern for that layer. In this configuration, layer 504 or 508 may form a ground layer or ground plane, as commonly referred to, for board 302, as known in the art.

Antenna 400 is mounted adjacent to circuit board 302 but is disposed with substrate 404 offset from the ground plane and substantially perpendicular to ground plane. This arrangement provides a very thin profile for the antenna 400 so that the antenna can be placed in a very narrow space and near the surface of the housing 102. For example, the antenna 400 may be disposed between the fastener or mounting post and the side (top) of the housing 102, but some cannot be implemented using conventional microstrip antenna designs.

Optionally, such a post can be used to automatically position and support the antenna 400 without the need for additional support mechanisms or attachments. Some support means are needed to position the substrate in place, which allows for a very simple mounting mechanism, reducing labor costs for antenna installation and potentially automated assembly. The property that the substrate can be mounted in place allows the substrate to simply be positioned relative to the housing. The circuit board may also be positioned relative to the housing using pressure pits of the display panel or connector 118 that fit through the openings or passages of the housing.

Alternatively, the substrate 404 may comprise small brackets, posts, bumps, ridges, slots, channels, support extrusions, protrusions, etc., formed of the material used to fabricate the walls of the housing 102 that may be used to position the board. Can be secured in place within the wireless device. That is, such a support is cast or formed on the wall of the device housing when manufactured by injection molding. This support element may then hold the substrate 404 in place when the substrate is inserted between or within the elements using fasteners attached to the element. Ridges or tabs formed in the wall of the housing (or support post) may snap to support supporting the board around the edge of the board.

Another means for mounting is to use an adhesive or tape to hold the substrate relative to the sidewall or other portion or element of the wireless device.

As shown in FIG. 5B, the substrate 404 can be bent or bent to conform substantially to the shape of the housing or to accommodate other elements, features, or components within the wireless device. The substrate may be manufactured or modified in this form during installation. By using thin plates, the substrate can be bent or flexed when installed, which can create a kind of tension or pressure by the substrate against the adjacent surfaces. These pressures can generally serve to hold the substrate in place without the need for other types of fasteners or screws.

However, those skilled in the art will appreciate that in order for the present invention to operate properly, there is no need to deform or warp the substrate during manufacture or installation. A straight planar substrate also functions very well as a base configuration. Other forms have the advantage of being able to accommodate a variety of mounting conditions, but do not alter the operation of the present invention.

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If everything is in place, the mounting back cover or plate is screwed, bolted, or otherwise fastened in place. This achieves a form of "capturing" holding the antenna or substrate in the housing by simply installing a portion of the adjacent circuit board and cover or housing to which it is fixed. No additional fasteners or fixed elements are necessary for the antenna of this approach. A set of tabs, or similar protrusions, can be used to interface with the cover in some portions to reduce the number of screws needed to hold it in place.

The conductive pads 408 are electrically coupled or connected to the board 302 using springs, spring contacts, or clips 510 and disposed adjacent thereto. Spring contacts or clips 510 are mounted over circuit board 302 using known techniques such as soldering or conductive adhesives. The clip 510 is electrically connected at one end to a suitable conductor or conductive via to transmit and receive signals with one or more desired transmit and receive circuits used within the wireless device, and the transmit and receive circuits are coupled to the antenna 400. The other end of the clip 510 is generally free floating and extends from the circuit board 302 toward which the antenna 400 is disposed. In more detail, the clip 510 is disposed adjacent the end of the trace 402 where the contact pad 408 is located. As shown in the figures, the clip 510 is curved in a circle to form an arc until it is away from the antenna and then directed back towards the antenna. Such circular arcs provide a more flexible and simpler structure to work with. However, other types of clips as shown in FIG. 6 are also known to be useful, and the present invention is not so limited. As is known in the art, the spring contact or clip 510 is made of a metallic material, in particular copper or copper, but any changeable conductive material known for this kind of application may be attenuated or other desired contact. May be used for properties.

Since the antenna 400 is not located directly adjacent to or parallel to the ground plane, such as layer 504, the antenna has or maintains a sufficiently large radiation resistance. This means providing proper matching to the antenna 400 without apparent loss, ie, the antenna has a good matching impedance. This efficiency is maintained even if the antenna 400 moves to various positions offset to one side of the circuit board 302, ie laterally but not close to the board 302. This antenna design acts as a very efficient means of exciting the ground plane without compromising performance.

The substrate need not be perpendicular to the ground plane, but the main feature of the present invention is the ability to utilize small size and minimum space. If the substrate is located in the same plane and parallel to the ground plane, it will occupy more space between the housing and the ground plane. This is less desirable. However, this orientation of the substrate does not prevent the antenna from operating. It is clear that conventional patch antennas are used in this situation and this is one reason it takes up a lot of space. The present invention is different in that a small amount of side space can be used in a wireless device.

By positioning the antenna off or adjacent to and above the edge of the ground plane with respect to the housing, the antenna provides an extremely omnidirectional pattern than conventional whip antennas. This antenna position also means that the resulting radiation pattern is substantially vertically polarized, as required for most wireless communication devices.

The substrate is not located below or above the ground plane with respect to the electronic components of the wireless device, as this position adversely affects impedance with performance as described above. It is important not to place the antenna on the ground plane. This can be expressed in several ways. For example, there is a volume or space located above the surface of the ground plane that occupies the entire ground plane towards the edge (bounded by the edge). This volume is the exclusion zone or area for the substrate. Placing the trace in this volume means placing it on the ground plane. In another aspect, the elevation or offset angle between the plane of the ground plane and the substrate antenna position cannot be 90 degrees. In fact, it must be substantially less than 90 degrees to be sufficiently or properly separated from the ground plane.

Another way of looking at the antenna, and thus the substrate placement, is to see the benefits that are caused by this design. Such an antenna may be mounted between the ground plane near the upper portion of the wireless device and the sidewall (or top or bottom, depending on the point of view). In the case of a folder telephone, the antenna can be mounted near the hinge or near a rotation or pivot joint between two m parts. This provides an antenna position that moves further away from the user, such as the user's head where the joint is located, due to the nature of the folder phone opening during use. This has obvious advantages in terms of head absorption and the like. In a bar phone or a wireless device, the substrate antenna can be mounted near the required side or top surface.

The present invention is the first invention having a configuration that can use such a space or region. The present invention is a novel method in that it utilizes the space, volume, or area of the wireless device adjacent to the circuit board, next to the housing, and offset from the ground plane. The new type of internal antenna can be mounted in an area directly adjacent to the ground plane.

An advantage of the present invention is that it is not necessary to remove the portion of the substrate that is in place or mounted. Large patch antennas or devices require a large amount of space or area so that part of the circuit board needs to be removed or circuitry removed to have room for mounting. Another aspect of such antennas is that they are generally mounted aligned in plane of a rounded surface. That is, the antenna radiator is formed in a planar configuration (even if it is curved) and its planar axis is aligned with the axis of the ground plane, which leads to excessive space use by the antenna, negating part of the purpose of using the internal antenna, and losing space. do.

It can be seen that the portion of the trace 402 shown in FIGS. 4 and 5 is considered more sensitive to efficient resonant length changes. This part will most likely represent antenna resonance changes from the presence of the wireless device user hand or head. There are three major energy losses that affect antenna 400 operation in a wireless device. Impedance mismatch loss caused by dielectric loading of user hand, user head absorption, and user hand absorption. This energy absorption or mismatch loss can degrade performance. For example, hand or head absorption can obviously attenuate the signal used by the wireless device, thus degrading performance.

The portion of antenna 400 that is most sensitive to this effect is the adjacent section, with the tip of trace 402 open, not fed, and bent. This portion of the antenna can be located in the phone housing so that the user's hand has minimal contact or maintains a clear distance from the hand. Due to this antenna design, placement flexibility within the wireless device can minimize hand absorption and, more importantly, reduce the mismatch loss that can be generated by the presence of a hand or other item adjacent to the antenna (except when shifting is required). Can be.

Another aspect of small antenna size and placement flexibility is the impact on energy levels present near the device user. The smaller size and flexible configuration of the antenna affects the placement of the antenna in the housing, which in turn can greatly affect the level of radiation seen at a particular location outside the device.

The antenna may be formed by placing or depositing a conductive material over the housing or surface in the wireless device to further allow for flexible placement within the housing 102 or to reduce antenna size. That is, if there is a clear path along the housing sidewall, the trace can be deposited or formed directly on the wall. This is shown in the side cross section of FIG. 6. In FIG. 6, the trace or traces 402 are disposed directly on the housing serving as the support substrate. This allows to use the least amount of space.

When a portion of the housing wall used is metalcoated or made of metal or other conductive material, an intermediate layer of insulating material can be used between the housing and the trace 402. In such a configuration, the metal layer with the desired trace configuration can be formed over a thin layer of material with an adhesive backing that can be easily placed within the wireless device by simply applying pressure against the side of the housing. This step can be automated using "pick and place" machines known in the art. Traces of this or any embodiment may use additional coatings, as known in the art, for surface protection.

However, it will be apparent to those skilled in the art that the relative arrangement of the antenna or the conductive material with respect to the ground plane should be the same as described above in the sense that it does not exist above the ground plane.

7A-7H illustrate various alternative embodiments for traces used to form the antenna of the present invention. In FIG. 7A, the trace 402 is shown as one thin conductive strip extending along the length of the substrate (not shown) and is connected to or rounded at the end with a round contact pad 408 at one end. It is formed to have). In FIG. 7B, the trace 402 is one thin conductive strip connected to the contact pad 408 and has a rounded or enlarged portion formed at the non-contact end. These traces have a dog bone shape. In FIG. 7C, the trace 402 is a longer, thinner conductive strip formed or connected with the rectangular contact pad 408. Here, the strip extends along the length of the substrate 404 and then folds or flexes near the non-contact end and is directed back to the contact pad. This allows the antenna to have an overall length shorter than the length of the trace used to form the lambda / 4 length element. As noted below, it can be appreciated that various patterns or shapes may be used to fold or reorient the traces along different directions. For example, square corners, circular bands, or other forms may be used for this function without departing from the teachings of the present invention. The trace is also wider in the folded part than in the other part. As shown in FIG. 4B, the increased width provides top loading or improved bandwidth for the antenna, which would be useful for some applications. However, such excessive width is not necessary in the present invention.

Also in FIG. 7D, the trace 402 is shown as a conductive strip connected to the contact pad 408 extending along the length of the substrate 404. In this embodiment, the trace assumes a more complex shape along the edge of the substrate made to have tabs or protrusions according to depressions or corresponding insets at one edge and the opposite edge. The trace has two bends before reaching the end of the substrate, which is directed back towards the end of the contact. The last part of the trace after being folded is also slightly longer than the initial length of the trace.

Depression along the length of the substrate and other angles and tabs interact with the features or aspects of the wireless device housing and various support elements. That is, the edge of the substrate 404 may be formed or used in various forms to fit within the housing. The edges of the corresponding deformable housing may be used to avoid known bumps or irregularities from the various bumps, exits, or surfaces of the housing walls, or to leave gaps for wires, conductors, and cables that need to be disposed within the wireless device. It may be located or formed around the wall. The sides or edges of the substrate may use a variety of round, square or other shapes for this purpose. This edge allows the antenna to be mounted in a space that is inappropriate for the mistrip antenna.

In addition, the shape of the trace 402 or substrate antenna 400 can be modified in three dimensions. That is, while the traces are generally formed in a plane, the substrate, or the substrate plane that supports the traces, can be bent or bent to accommodate various mounting configurations. In other words, the substrate is generally thin but strong because of its strong properties and can be manufactured as a structure that is simply deformed or bent or curved during installation. This is shown at 7e which shows the substrate 404 with the highest edge of the substrate crossing the length. It will be apparent to those skilled in the art that various curves or warps may be used in this dimension. For example, the substrate surface may form a kind of curved pattern.

Preferred embodiments of the present invention constructed and tested are shown in the front plan view of FIGS. 7F-7H. Here, the substrate 402 was made to be about 52 mm in total length with a trace width of about 1 mm. The trace widened near the end of the folded portion 702, while its width was approximated to 1.5 mm. Contact pads 408 and 410 are about 6.75 mm squares with a suitable series of conductive vias extending through the substrate to connect the two. The optical fiber substrate is about 1 mm thick and the trace and pad thickness is about 0.01 mm. Note the space 704 between the end of the folded trace and the substrate edge. This optional space or gap with an edge serves to reset the trace and also reduces the influence of the hand approaching or touching the edge of the antenna.

Although not limited to various forms, ie, as follows, it is understood that round, oval, parabolic, angled, and square C, L, or V-type folds, joints, and edges can be used for traces and substrates. It will be apparent to those skilled in the art. The width of the conductor can be changed along the length as the outer end (non feed portion) is changed to a wider or narrower width, or bent or tapered. As will be apparent to those skilled in the art, various such effects or forms may be combined in one antenna structure. For example, an angled stepped strip is bent along another dimension.

The result of removing both the whip antenna 104 and the spiral antenna 106 can be clearly seen in the side plan view of FIG. 5C showing the telephone of FIG. 1B using the present invention.

Description of the preferred embodiments is provided so that any person skilled in the art can use or practice the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, as the type of wireless device used and the general principles defined herein may be applied to other embodiments without utilizing creativity. Thus, the present invention is not limited to the above embodiments but is to be accorded the widest scope consistent with the principles and novel features described herein.

Claims (26)

delete delete delete delete delete delete delete delete delete delete delete A substrate antenna for use in a wireless communication device having a planar ground plane for embedded circuitry, A non-conductive support substrate having a structure separated from the ground plane and having a predetermined thickness and length; And An antenna emitter element in the form of a conductive trace formed on the support substrate, having a feed end and an open end, and having a length selected to serve as an active emitter of electromagnetic energy at one or more predetermined frequencies, The length of the conductive trace is about one quarter wavelength of the electromagnetic energy, And the support substrate is disposed within the wireless device adjacently apart from an edge of the planar ground plane. The method of claim 12, And the trace is formed by depositing a metal material over the insulating material. The method of claim 12, And a conductive pad coupled to the supply end of the trace and configured to transfer a signal between the radiator and other circuitry. The method of claim 14, And the conductive pad interfaces with a spring type signal feed. The method of claim 12, Wherein the length and width of the trace are determined to enable the substrate antenna to transmit and receive signals having a frequency range of 824 to 894 MHz. The method of claim 12, Wherein the length and width of the trace are determined such that the substrate antenna can transmit and receive signals having a frequency range of 1.85 to 1.99 GHz. The method of claim 12, And the substrate is located adjacent an edge of the ground plane and has a central plane axis that is offset by less than 90 degrees from the plane. The method of claim 12, And the substrate has a central planar axis positioned parallel to an edge of the ground plane. The method of claim 19, And the substrate is in a plane positioned perpendicular to the plane of the ground plane. delete The method of claim 12, And the substrate is disposed between an edge of the ground plane and a housing wall of the wireless device. The method of claim 12, And the radiator extends along a linear path between the first and second ends of the substrate. The method of claim 23, And the radiator extends one end adjacent the substrate further back toward the opposite end. The method of claim 12, And the support substrate comprises an integral part of the housing for the wireless device. The method of claim 12, And the support substrate has a support element secured to a housing for the wireless device.

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