CN1168175C - Substrate Antenna - Google Patents

Abstract

A substrate antenna (400) that includes one or more conductive traces (402) supported on a dielectric substrate (404) having a predetermined thickness. Appropriate dimensions are selected for the lengths and widths of traces, based on the wavelength of interest, connecting elements, and space allocated. The supporting substrate (404) is mounted offset from and generally perpendicular to the ground plane (502) associated with the device with which the antenna is being used. The trace is electrically connected to a conductive pad (408) on one end. A signal feed (410) for the antenna is coupled to the conductive pad (408). The substrate antenna employs a very thin and compact structure which provides appropriate bandwidth. Antenna compactness and a greater variety of useful shapes allow the substrate antenna to be used very efficentiyl as an internal antenna for wireless devices.

Description

Substrate Antenna

Background technique

The present invention relates to an antenna for a wireless device, and more particularly, the present invention relates to a substrate-mounted antenna. The invention also relates to an internal antenna for a wireless device, in particular with improved size, coupling, bandwidth and radiation characteristics.

Antennas are important elements of wireless communication devices and systems. Although antennas are available in many different shapes and sizes, they operate according to the same basic electromagnetic principles. Antennas are structures concerned with the transition field between guided waves and free-space waves (and vice versa). As a general principle, a guided wave propagating along an unrolled transmission line will radiate as a free-space wave, also known as an electromagnetic wave.

In recent years, with the increased use of personal wireless communication devices, such as handheld and mobile cellular and Personal Communications Services (PCS) phones, the need for suitably small antennas for such communication devices has increased. Recent advances in integrated circuit and battery technology have resulted in drastic reductions in the size and weight of such communication devices over the past few years. One area where size reduction is still desirable is communication device antennas. This is due to the fact that the size of the antenna can play an important role in reducing the size of the device. In addition, antenna size and shape affect the aesthetics and production cost of the device.

An important factor in considering antenna design for a wireless communication device is the antenna radiation pattern. In a particular application, a communication device must be able to communicate with another such device or a base station, center or satellite (which may be located in any number of directions from the device). As a result, there is a point that the antenna of such a wireless communication device has a substantially omnidirectional radiation pattern, or a pattern extending upward from the horizon.

Another important factor to consider in antenna design for a wireless communication device is the bandwidth of the antenna. For example, a wireless device such as a telephone used with a PCS communication system operates in the 1.85-1.99 GHz band, and thus requires 7.29 percent of the useful bandwidth. Phones used in typical cellular communication systems operate in the 824-894 MHz frequency band, which requires 8.14 percent of the bandwidth. Correspondingly, the antennas used on these types of wireless communication devices must be designed to meet the appropriate bandwidth requirements, otherwise, the communication signal is severely attenuated.

One type of antenna commonly used in wireless communication devices is the whip antenna, which is easily retracted into the device when not in use. However, this whip antenna has several disadvantages. Such whip antennas are often damaged by snagging on objects, people or surfaces when extended for use, or even when retracted. Even when the whip antenna is designed to be retractable to minimize such damage, it still extends across the full size of the device and interferes with the placement of advanced features and circuitry in certain parts of the device. It also requires a minimum size of the device enclosure when retracted, which is larger than desired.

Whip antennas are also often used in conjunction with short helical antennas, where the whip is energized when it is retracted into the phone. The helical antenna provides the same radiator length in a more compact space to maintain proper radiation coupling characteristics. While the helical antenna is shorter, it also creates a large distance from the surface of the wireless device, affecting aesthetics and hooking on other objects. In order to place such an antenna inside a wireless device, appropriate bulk would be required, which is not ideal.

Another antenna that may be suitable for use in a wireless communication device is a conformal antenna. In general, conformal antennas follow the shape of the surface they are mounted on and often exhibit a very low radiation profile. There are several different types of conformal antennas, such as patch antennas, microstrip antennas, and strip antennas. In particular, microstrip antennas have been used in personal communication devices in recent years.

For example, one type of antenna that may be suitable for use in a wireless communication device is a "reverse F" antenna. However, such antennas suffer from several disadvantages. They can be much larger than ideal and suffer from lower bandwidth and lack the ideal omnidirectional radiation pattern.

As the name implies, a microstrip antenna includes a patch or microstrip element, which is also known as a radiator patch. The length of the microstrip element is set relative to the wavelength λ, in relation to the resonant frequency f ₀ , wherein the resonant frequency is chosen to match the relevant frequency, such as 800 MHz or 1900 MHz. Typically the lengths used for microstrip elements are half wavelength (λ ₀ /2) and quarter wavelength (λ ₀ /4). Although, in recent years some types of microstrip antennas have been used in wireless communication devices, further improvements are still needed in several areas. One area in need of further improvement is overall size reduction. Another area that needs significant improvement is bandwidth. In practical dimensions, current patch or microstrip antenna designs do not appear to yield ideal bandwidth characteristics of the 7.29 to 8.14 percent or more required for use in most communication systems.

The traditional patch and strip antennas found in most wireless devices have other problems when placed near a broad ground plane. Additionally, "hand loading", ie placing the user's hand near the antenna, significantly changes the resonant frequency and performance of the antenna.

Radiation patterns are not only important for establishing a communication link as described above, but are also related to government radiation standards for wireless device users. The radiation pattern must be controlled and regulated so that a minimum amount of radiation can be absorbed by the device user. Government standards exist that establish the amount of radiation that can be allowed in the vicinity of wireless device users. One effect of these regulations is that internal antennas cannot be placed in many places in a wireless device due to the theoretical radiation exposure to the user. However, as noted above, ground planes and other structures often interfere with their effective use when currently existing antennas are used in other locations.

Accordingly, new antenna structures and techniques for fabricating antennas are needed to achieve internal wireless device antenna structures with radiation patterns more commensurate with the improved radiation needs of end users. At the same time, the antenna needs to meet the requirements of advanced communication systems in terms of bandwidth, coupling efficiency, and at the same time, it is more conducive to internal installation to provide more flexible component placement in the antenna device, greatly improved aesthetics and reduced antenna damage. .

Summary of the invention

In view of the above and other problems found in the prior art regarding the manufacture of internal antennas for wireless devices, it is an object of the present invention to provide an antenna with reduced size and increased flexibility for mounting to the inside of a wireless device.

A second object of the invention is to reduce the interaction between the user of the wireless device and the antenna, which would otherwise affect performance.

An advantage of the present invention is that it provides a physically deformable support substrate that allows conformal mounting in wireless devices.

Another advantage includes a reduction in manual labor and time taken to connect and install an antenna into a wireless device, as well as a reduction in the number of cables and connectors required for these purposes.

These and other intentions, objects and advantages are achieved in a substrate antenna for use in a wireless device comprising one or more conductive traces supported on a dielectric substrate having a predetermined thickness. Appropriate dimensions for the length and width of the lines are selected according to the relevant wavelength and spatial allocation of the wireless device. The support substrate is mounted offset and generally perpendicular to the ground plane associated with the circuitry and components in the device through which the antenna is used. That is, the substrate is mounted adjacent to the edge of the ground plane and has a plane that is less than 90 degrees from the plane of the ground plane. Place the substrate not directly above and below the ground plane.

Electrically connect the wire to the conductive pad on the end that is connected to the antenna's signal feed. Due to the use of conductive pads, the signal feed consists of a conductive spring-loaded, spring or clip-type device that makes electrical contact by pressing on the conductive pad. This allows automatic connection to the antenna when the board is installed into the wireless device and requires manual installation such as cables or connectors.

Substrate antennas use very thin and compact structures, which provide adequate bandwidth. The compactness of the antenna and the greater variety of useful shapes allow the substrate antenna to be used very effectively as the internal antenna of the wireless device. It can advantageously be placed in the device housing to take advantage of the space available despite the many possible interfering characteristics or structures in the housing.

Figure overview

The present invention is described below with reference to the accompanying drawings, wherein like parameters generally indicate identical electrically, functionally similar, and/or structurally similar elements, the drawing in which the element first appears is indicated by the leftmost numeral in the parameter, wherein

Figures 1a and 1b illustrate perspective and side views of a portable radiotelephone with a whip and an external helical antenna;

Figures 2a and 2b illustrate perspective and side views of another portable radiotelephone having a whip and an external helical antenna;

3a and 3b illustrate side and rear cross-sectional views of the phone of FIG. 1b with exemplary internal circuitry;

Figure 3c illustrates a cross-sectional view of the side of the phone of Figure 2b with exemplary internal circuitry;

4a-4c illustrate a substrate antenna according to one embodiment of the present invention;

Figures 5a and 5b illustrate side sectional and rear views of the phone of Figure 1b using the present invention;

Figure 5c illustrates a side plan view of the phone of Figure 1b using the present invention;

Figure 6 illustrates a cross-sectional side view of the phone of Figure 5a having another embodiment of the present invention; and

Figures 7a-7h illustrate other embodiments of the present invention

Detailed description of the preferred embodiment

While conventional microstrip antennas such as the inverted F antenna have properties that make them potentially useful in personal communication devices, further improvements are still needed in other areas to enable this type of antenna Useful in wireless communication devices such as PCS phones. One area that needs further improvement is bandwidth. In general, to operate satisfactorily, PCS and cellular telephones require bandwidths greater than currently available through practical size microstrip antennas.

Another area that needs further improvement is the size of the microstrip antenna. For example, a reduction in the size of a microstrip antenna will make the wireless communication device in which it is applied more compact and aesthetically pleasing. In fact, this may even determine whether such an antenna can be used in a wireless communication device. The size reduction of the conventional microstrip antenna is made possible by reducing the thickness of the dielectric substrate used, or increasing the value of the dielectric constant, thereby shortening the necessary length. However, this has the undesirable effect of reducing the bandwidth of the antenna, thereby making it unsuitable for wireless communication devices.

Additionally, the field pattern of conventional microstrip antennas such as pad radiators is usually directional. Most pad radiators radiate only in the upper hemisphere relative to the antenna horizon. This pattern shifts or rotates as the device is moved and can create undesirable nulls in the coverage area. Thus, microstrip antennas are not very ideal for use in many wireless communication devices.

The present invention provides solutions to the above and other problems. The present invention is directed to a substrate antenna that provides adequate bandwidth and is reduced in size compared to other antenna designs, but maintains other characteristics required for use in wireless communication devices. The chip antenna of the present invention can be built near the top surface of a wireless or personal communication device such as a cellular phone, or can be mounted adjacent to or on a surface in a wireless device such as a post, I/O circuit, keypad, etc. other components or behind them. It is also possible to build the substrate antenna directly into, for example, the plastic interior forming the housing or onto the surface of the wireless device.

Unlike whip or external helical antennas, the substrate antenna of the present invention is not affected by snagging on objects or surfaces. The antenna also does not consume the interior space required by the advanced features and circuitry, nor does it require large housing dimensions to accommodate it when retracted. The substrate antenna of the present invention can be automated with a minimum of manual labor, which reduces cost and increases reliability. In addition, the substrate antenna radiates an almost omnidirectional pattern, which makes it suitable for use in many wireless communication devices.

Broadly, the present invention may be implemented in any wireless device, such as a personal communication device, wireless telephone, wireless modem, facsimile device, portable computer, search machine, information broadcast receiver, and the like. One such environment is a portable or portable radiotelephone, such as for cellular, PCS or other commercial communication services. A variety of such radiotelephones are known in the art with correspondingly different housing shapes and styles.

Figures 1 and 2 illustrate typical radiotelephones as they are used in radiocommunication systems such as the cellular and PCS systems described above. The phones illustrated in Figures 1 (1a and 1b) are "clam shell" or fold-out phones, while the phones illustrated in Figure 2 (2a and 2b) are typically rectangular or "stick" shaped phones. These telephones are typical radiotelephones used in wireless communication systems such as the cellular and PCS systems described above. Since there are a variety of wireless devices and phones, and associated physical configurations, including these and other types and styles with which the present invention may be used (as will become apparent from the discussion below), these phones are used for purposes of illustration only.

In FIGS. 1 a and 1 b , a phone 100 is shown having a main housing or body 102 that supports a whip antenna 104 and a helical antenna 106 . Antenna 104 is typically mounted to share a common central axis with antenna 106 so that when extended it stretches or protrudes through helical antenna 106, although this is not required for proper operation. These antennas are manufactured to be of appropriate length for the frequency concerned, or useful for the particular wireless device in which they are used. Their specific design is known in the related art.

The front of housing 102 is also shown supporting a speaker 110 , display panel or screen 112 , keypad 114 , microphone or microphone hole 116 , and connector 118 . In FIG. 1 b , the antenna 104 is shown in the extended position normally used by the wireless device, while in FIG. 1 a the antenna 104 is shown retracted into the housing 102 .

In FIGS. 2a and 2b , a phone 200 is shown having a main housing or body 202 that supports a whip antenna 204 and a helical antenna 206 in the same manner as phone 100 . The front of the housing 200 is also shown supporting a speaker 210 , a display panel or screen 212 , a keypad 214 and a microphone or microphone hole 216 . In FIG. 2a the antenna 204 is shown in the extended position, while in FIG. 2b the antenna 204 is shown retracted into the housing 202 .

As mentioned above, whip antennas 104 and 204 have several disadvantages. One is that when stretched during use, they suffer damage caused by snagging on other things or surfaces. The antennas 104 and 204 also consume the internal space of the phone in such a way that the placement of advanced feature components and circuits (including power sources such as batteries) is more limited and less flexible. Additionally, when retracted, the antennas 104 and 204 may require a minimum housing size that is unacceptably large. Alternatively, antennas 104 and 204 may be configured from further compressed sections to reduce size when retracted, but generally feel less aesthetically pleasing, more fragile or unstable, or less maneuverable to the user. Antennas 106 and 206 are also on other objects or surfaces when in use and cannot be retracted into phone housings 102 and 202, respectively.

For clarity and convenience only, the use of the present invention is described in terms of an exemplary radiotelephone. The present invention is not limited to application in this exemplary environment. How to implement the invention in alternative environments will become apparent to those skilled in the art after reading the following description. In fact, it will be clear that the present invention can be applied to other wireless communication devices such as (but not limited to) search machines, portable computers, small portable facsimile machines with wireless communication capabilities.

Each of these phones has various internal components, typically supported on one or more circuit boards, for performing the various functions required. Figures 3a, 3b and 3c are used to illustrate the general internal structure of a typical radiotelephone. FIG. 3 a illustrates a cross-section of the phone when viewed from one side to see how circuits or components are supported within the housing 102 . FIG. 3b illustrates a cutaway view of the same phone when viewed from the back on the side opposite the keypad, to understand the relationship of circuits or components typically found in housing 102. FIG. Figure 3c illustrates a cross-sectional view of the phone shown in Figure 2b when viewed from one side.

In FIGS. 3a and 3b, a circuit board 302 is shown inside the housing 102 supporting various components such as integrated circuits or chips 304, discrete components 306 such as resistors and capacitors, and various connectors 308. . A flat panel display and keyboard are typically mounted on the back of circuit board 302 with wiring and connectors (not shown) that interface speakers, microphones or other similar components to circuitry on circuit board 302 . The antennas 104 and 106 are placed on one side and connected to the circuit board 302 using special wire connectors and binding posts (clips) for this purpose.

Typically, a predetermined number of posts or brackets 310 are used in the housing 102 to mount circuit boards or other components within the housing. One or more support ridges or small shelves 311 may also be used to support the circuit board. These struts may be formed as part of the housing (such as when it is formed by injection molding plastic), or fixed in place (such as with adhesive or other known mechanisms). In addition, there are typically one or more additional snap posts 312 for receiving screw holes, screws or similar fasteners 313 to secure portions of the housing 102 to each other. That is, housing 102 is fabricated using multiple parts or a body and a cover over the electronic circuit. Fastening posts 312 are then used to receive elements 313 to secure parts of the housing together. The present invention easily accommodates or resolves various posts 310 or 312 while still providing a very efficient internal antenna design.

As seen in the enlarged view of FIG. 3b, circuit board 302 is typically fabricated as a multilayer circuit board having several alternately stacked conductor layers and dielectric substrates that are bonded together to form complex circuit interconnections structure. Such circuit boards are known and understood in the art. As part of the overall structure, the circuit board 302 has at least one, and sometimes more, ground planes or planes, either on the bottom surface or mounted at intermediate locations within the circuit board.

Applicants have recognized that it is the interaction of the antenna of 104, 106, 204 or 206 with this ground plane that forms the radiation pattern of the wireless device. The antenna effectively excites the ground plane. That is, there is an electric current between the conductive material in the whip or helical antenna and the ground plane, which generates electromagnetic waves that enter the air to form communication signals. It is also the combination that receives the input signal received by the wireless device. For this and other reasons, applicants have realized that a larger but less useful antenna can be replaced by a smaller more compact antenna element if it is properly placed with respect to the ground plane of the wireless device.

It has also been noted that some other attempts at creating internal antennas place the antenna radiator element on the ground plane, especially where some amount of radiation shielding is required. Unfortunately, this makes it impossible to produce a low-loss match to the antenna with sufficient operating bandwidth for normal cellular and PCS use. As a result, such antennas are much less efficient and have lower gain, often reducing gain by about 6dB.

A chip antenna 400 constructed and operative in accordance with one embodiment of the present invention is shown beginning in FIGS. 4a-4c. In FIGS. 4 a and 4 b , a chip antenna 400 comprises conductive traces 402 (also referred to as strips or elongated conductors), a dielectric support substrate 404 and a signal feed area 406 . The conductive trace 402 can be fabricated as more than one trace, which are electrically connected in series to form a desired antenna radiator structure. Trace 402 is electrically connected to conductive pad 408 in signal feed area 406 at or near one end of substrate 404 .

Substrate 404 is fabricated from known dielectric materials or substrates for such purposes, such as circuit boards or flexible materials. For example, small fiberglass based printed circuit boards (PCBs) may be used. Various materials are commercially available for the manufacture of the substrate. Typical commercially available fiberglass, phenolic, plastic or other printed circuit board or substrate materials can be used. The use of a thin substrate is not necessary, however, it provides the convenience of being deformable and easy to fit into place. Very thin sheets of fiberglass reinforced Teflon can be used for very thin substrates where large flex and flex is desired. However, this thin material may not provide rigid enough support to prevent the antenna characteristics from changing as the phone is moved. Those familiar with the art of electronics and antenna design are well familiar with the variety of commercially available products from which suitable antenna substrates can be fabricated, depending on desired dielectric properties or antenna bandwidth characteristics.

The substrate acts to support the antenna radiator elements (here lines) and to space them from other conductive surfaces, or to provide minimal spacing from hands or other radiation absorbing or interacting materials such as fabrics.

The wires are made of a conductive material such as copper, brass, aluminum, silver or gold or other conductive materials known to be useful in making antenna elements, or compounds. This can involve conductive material embedded in plastic or conductive epoxy, which can also be used as a substrate.

The lines may be deposited using one of several known techniques such as, but not limited to, standard photoetching of conductive material onto dielectric or insulating substrates; electroplating or deposition of conductive material onto substrates ; Or use an adhesive or the like to place a conductive material such as a metal sheet on a support base. Additionally, known coating or deposition techniques may be used to deposit metallic or conductive materials on the formable plastic support element or substrate.

The length of the line 402 mainly determines the resonant frequency of the substrate antenna 400 . Line 402, or a group or series of connected lines, is appropriately set for a particular operating frequency. The lines used to make up the antenna are deposited to provide a conductive element which is 1/4 of the effective wavelength for the frequency concerned. Those skilled in the art will readily recognize the benefit of making the length slightly greater or less than λ/4 to match the impedance to the corresponding transmit or receive circuit. Additionally, connecting elements such as exposed cables, wires or posts, as will be discussed below, contribute to the overall length of the antenna and are considered when selecting the dimensions of the lines.

Substrate antenna 400 is used with a wireless device capable of communicating at more than one frequency, and the length of line 402 is established in relation to the frequency. That is, multiple frequencies can be accommodated, assuming they are relative to wavelength percentages. For example, a length of λ/4 at one frequency corresponds to 3λ/4 or λ/2 at a second frequency. This relationship of using a single radiator for multiple frequencies is well known in the prior art.

The thickness of the lines, 402, often corresponds to a fraction of a wavelength, to minimize miniaturization, or to prevent cross-flow modes, and to keep the antenna size (thickness) to a minimum. As is known in the art of antenna design, the selected value is based on the bandwidth over which the antenna must operate. The width of the lines, 402 is also smaller than the wavelength in the dielectric substrate material so that higher order modes will not be excited.

The overall length of the line 402 is approximately λ/4, but it should be noted that the line can be folded, bent or reoriented to extend back in the direction it came from such that the overall antenna structure is less than λ/4 in length. The thin conductor size (combined with a relatively thin support substrate and less than λ/4 in length) allows a significant reduction in the overall size of the antenna compared to conventional ribbon or patch antennas, thereby making it ideal for use in personal communication Ideal for use in installations. For example, compare these dimensions to the ground plane of a conventional microstrip antenna (typically at least λ/4 in size to work properly).

As shown in FIGS. 4 a and 4 c , conductive pads 408 are located in the signal feed area 406 and are electrically coupled or connected to the lines 402 . Typically, spacers 408 and lines 402 are made of the same material, possibly as a single unitary body or structure (although not required, the same fabrication techniques can be used). The spacers 408 simply need to make good electrical contact with the lines 402 in order to transmit the signal without negatively affecting the impedance and performance of the antenna.

In some configurations the line will face the circuit board and the signal source or receiver, in other configurations it can be away from the circuit board and opposite it. In this latter state, the substrate is located between the lines and the circuit board. In this state, conductive pads 408 may be on the opposite side of the substrate to easily receive signals directly from the circuit board without requiring wires or other conductors to run around the substrate. In many applications, more complicated connection and installation steps are not desired. Thus, as shown in Figure 4c, a second contact pad 410 can be used on the opposite side of the substrate as shown in Figure 5a, and conductive vias are used to send signals through the substrate.

The signal transmit feed is coupled to the substrate antenna 400 using spacers 408 (and 410). The use of conductive spacers 408 (and 410) allows the antenna to be installed and operated in such a way that a convenient electrical connection and signal transmission is provided through what is known in the art as a "spring" type, or spring loaded, connector or terminal post . This simplifies the construction and manufacture of the wireless device by eliminating the need for manual installation of specialized connectors, or having to manually insert the antenna into the connection structure. This type of electrical connection also means that the antenna can be easily replaced when needed, for repairs or upgrades, or to change the radio to another frequency without having to solder or work with specialized connectors, etc. As mentioned above, spring contacts contribute to the overall length of the antenna or antenna radiator (line) and are taken into account when selecting the size of the line.

A signal feed couples a signal from a signal processing unit or circuit (not shown) on the circuit board 302 to the substrate antenna 400 . Note that "circuitry" is used to collectively refer to the functions provided by known signal processing circuits (including receivers, transmitters, amplifiers, filters, transceivers, etc., and all known in the art).

In FIGS. 5a and 5b, antennas 104 and 106 have been replaced by chip antenna 400. In FIG. A circuit board 302 is shown in Figure 5a and comprises layers of conductive and dielectric materials, such as copper and fiberglass, forming what is known in the art as a multilayer board or printed circuit board (PCB). This represents a layer of dielectric material 502, which is on top of or immediately following a layer of metal conductor 504, which is next to a layer of dielectric material 506, which is next to or supports a layer of metal conductor 508. Conductive vias (not shown) are used to interconnect various conductors on different layers or levels to components on the exterior surface. The pattern of etching on any given layer determines the pattern of interconnections for that layer. In this configuration, layer 504 or 508 can form a ground plane or plane for board 302, as may be known in the art.

The antenna 400 is mounted close to the circuit board 302, but offset from the ground plane, and positioned so that the base 404 is substantially perpendicular to the ground plane. This arrangement provides antenna 400 with a very thin profile, allowing it to be placed in very confined spaces and close to the surface of housing 102 . For example, the antenna 400 can be placed between a fastener or mounting post and the side (top) of the housing 102, some not accessible using conventional microstrip antenna designs.

As an option, such posts can now be used to automatically place and support the antenna 400 without the need for additional support devices and accessories. Some support means are not required to hold the substrate in place, and this provides for a very simple installation mechanism, reducing labor costs for antenna installation and potentially allowing automated assembly. The nature of how the base is mounted in place allows it to simply rest on the enclosure. The circuit board can also simply rest on the housing using a press fit of the display panel or connectors 118 that fit through small holes or channels in the housing.

Alternatively, small brackets, posts, flanges, ridges, slots, channels, support extrusions, protrusions, etc. can be used to place the base 404 in place inside the wireless device, or during the manufacture of the housing 102. The same thing that is formed in the material of the wall can be used to let the boards go up. That is, such a support is molded or formed into the wall of the device housing during manufacture, such as by injection moulding. These supports hold the base 404 in place when the phone is assembled, inserted between or within them, or using fasteners attached to them. Ridges or tabs (or support posts) formed in the housing walls can "bite" the edges of the plates to help hold them in place.

Other methods for mounting are to use adhesive or tape to support the substrate on a side wall or other part or element of the wireless device.

As shown in FIG. 5b, the base 404 may be curved, or curved to closely match the shape of the housing, or accommodate other elements, features, or components in the wireless device. The substrate can be fabricated into this shape, or deformed during installation. Using a thin substrate allows the substrate to flex during installation, and this allows tension or pressure on one substrate to be applied to adjacent surfaces. This pressure generally secures the substrate in place without the need for screws or other types of fasteners.

However, those skilled in the art will readily recognize that the substrate need not be deformed or bent during fabrication or installation for the invention to function properly. Straight planar substrates work very well as a substrate configuration. Other shapes have the advantage of allowing for various installation conditions without changing the working of the invention.

When everything is in place, the back shell or panel of the enclosure is screwed, latched, or snapped in place. This enables "trapping" of the antenna or substrate in the housing by mounting in place the adjacent circuit board and the cover or housing parts snapped into place. Also in this approach, the antenna no longer requires additional posts or fixing elements. A set of tabs, or similar protrusions, may be used to connect the cover at some portions to reduce the number of screws required to hold it in place.

Conductive pad 408 is placed proximate to and electrically coupled or connected to circuit board 302 using springs, spring contacts or clips 510 . The spring contacts 510 or clips 510 are mounted to the circuit board 302 using known techniques such as injection soldering or conductive adhesive. One end of the clip 510 is electrically connected to a suitable conductor or conductive hole to transmit signals to the desired transmit and receive circuitry coupled to the antenna 400 in one or more wireless devices. The other end of the clip 510 is generally free floating and extends from the circuit board 302 towards where the antenna 400 is placed. More specifically, the clip 510 is placed proximate to the end of the wire 402 having the contact pad 408 . As shown, the clip 510 is bent away from the antenna in a circle, then called an arch, until it faces away from the antenna. This rounded arch provides the structure with greater flexibility and ease of working. However, other types of clips, such as that shown in Figure 6, are also useful, and the invention is not limited thereto. The spring contact or clip 510 is typically made of a metallic material such as copper or brass, however, any deformable conductive material known for this application, subject to signal attenuation or other desired contact characteristics may also be used , as known in the prior art.

Because the antenna 400 is not on a ground plane such as layer 504, or is parallel to it and immediately adjacent, the antenna has or maintains a sufficiently large radiation resistance. This means that it is possible to provide proper matching to the antenna 400 without significant loss, ie the antenna has a good matching impedance. Even if the antenna 400 is moved to various positions offset to one side of the circuit board 302 , efficiency can still be maintained, ie, it moves laterally without getting closer to the board 302 . This antenna design acts very efficiently to excite the ground plane without compromising its performance.

The substrate does not need to be perpendicular to the ground plane, but the main features of the invention are small size and enable minimal space. If the substrate is placed in the same plane, parallel to the ground plane, it will clearly take up more space between the case and the ground plane. This is less than ideal. However, the orientation of the substrate does not prevent the antenna from working. Conventional patch antennas must be used in this case, and this is one reason why they consume too much space. The present invention is different in that it can use a small amount of lateral space in the wireless device.

By placing the antenna close to the edge of the ground plane and above it, or at a distance relative to the housing, the antenna provides a more omnidirectional pattern than conventional whip antennas. The device placement of the antenna also means that the resulting radiation pattern is substantially vertically polarized, as is required for most wireless communication devices.

For electronics in wireless devices, the substrate is not located "above" or "below" the ground plane because being in that position, as stated earlier, would negatively affect impedance and performance. It is important to keep the antenna off the ground plane. This can be expressed in several ways. For example, there is a volume or space, above the surface of the ground plane, which occupies the entire ground plane up to (limited by) its edge. This volume is the exclusion zone for the base. Placing the lines in this volume means above the ground plane. From another point of view, any elevation or declination angle between the plane of the ground plane and the location of the substrate antenna may not be 90 degrees. In fact, it should basically be less than 90 degrees to ensure proper or sufficient separation from the ground plane.

Another way of thinking about the antenna, the placement of the substrate, considers the advantages that result from this design. Such an antenna may be mounted near the top of the wireless device between the ground plane and a side wall (or top or bottom, depending on the viewpoint). In the case of a foldable phone, the antenna could be mounted near the hinge or pivot or fulcrum between the two m-parts. This provides a location for the antenna which in use is farther away from the user, such as the user's head, due to the way the phone is opened, and places the spot well. This is a clear advantage for head absorption and the like. For a "stick" shaped phone or wireless device, the chip antenna can be mounted near the top or side surface as desired.

The present invention is the first to have a configuration that allows the use of these spaces or areas. The present invention is a novel approach to utilize the space, volume or area of the wireless device adjacent to the circuit board and close to the housing, separated from the ground plane. A new type of internal antenna can be installed in the area just laterally close to the ground plane.

One advantage of the present invention is that it requires no moving parts of the substrate to install or place into place. Large patch antennas or components require so much space or area that they require part of the circuit board to be removed, or the circuit moved, to make room for installation. Another aspect of such antennas is that they are usually mounted so that they are arranged in the plane of a circular plane. That is, the antenna radiators are formed in a planar configuration (even if they are curved) and their planar axes are aligned in line with the ground plane, which leads to excessive use of space by the antenna, failed parts of the target using internal antennas, loss of space .

It should be appreciated that a portion of the line 402 shown in Figures 4 and 5 is considered more sensitive to changes in the effective resonant length. This portion most likely shows a change in antenna resonance from the presence of the wireless device user's hand or head. There are three main energy losses affecting the operation of the antenna 400 in a wireless device. These are impedance mismatch losses due to dielectric loading of the user's hand, user's head absorption, and user's hand absorption. What kind of energy absorption or mismatch loss can degrade the performance. For example, hand or head absorption can significantly attenuate the signal used by the wireless device, thereby degrading performance.

The parts of the antenna 400 most sensitive to these effects are the open end, the non-feed end and the adjacent curved portion of the line 402 . This part of the antenna can be placed or placed in the housing of the phone so that the user's hand will have minimal contact, or maintain a large space with the hand. The antenna design allows for flexible placement in the radio, minimizes hand absorption, and more importantly reduces mismatch losses that may be caused by hands or other objects adjacent to the antenna (unless such movement is required) .

Another aspect of the small antenna size and flexible placement is that it may have an impact on the energy levels in the vicinity of the device user. The smaller size and convenient configuration of the antenna affects the placement of the antenna in the housing, which can greatly affect the radiation level at specific locations outside the device.

To further reduce the size of the antenna or to allow for flexible placement within the housing 102, the antenna may also be formed by disposing or depositing conductive material on the housing or on an interior surface of the wireless device. That is, for applications where there is a clear path along the side walls of the housing, the lines can be deposited or formed on the walls. This is shown in the cross-sectional side view of FIG. 6 . In Fig. 6, the line or lines 402 are placed directly on the housing which together supports the substrate function. This provides a limit in terms of using the minimum amount of space.

An intermediate layer of insulating material may be used between the housing and the lines 402 when the housing wall portion to be used is metallized or manufactured from metal or other conductive material. In this configuration, by simply pressing the sides of the housing, a metal layer with the desired line configuration can be formed on a thin layer with an adhesive backing that allows easy placement in the wireless device. This step can be automated using component extraction machines known in the art. The lines in this or any embodiment may use further coatings (known in the art) to protect the surface.

However, it will be clear to those skilled in the art that the relative position of the antenna or conductive material with respect to the ground plane should be the same as described above when not above the ground plane.

Figures 7a to 7h illustrate several alternative embodiments of the lines used to form the antenna of the invention. In Figure 7a, line 402 is shown as a single thin conductive strip running the length of substrate 404 (not shown) and connected at one end to or formed with a round contact pad 408. In Figure 7b, the line 402 is shown as a single thin conductive strip connected to the contact pad 408 and formed with an enlarged or rounded portion on the non-contacting end. The line has a "dog bone" profile. In Figure 7c, the lines 402 are longer thin conductive strips connected to, or formed with, the more square contact pads 408. Here, the strap runs the length of the base 404 and is folded or bent at the non-contacting end so that it is reoriented towards the contact pad. This allows the antenna to have a shorter overall length of the lines used to form the λ/4 length elements. As described below, it should be appreciated that various patterns and shapes can be used to reorient or fold the lines in different directions. For example, square corners, circular strips, or other shapes could be used for this function without changing the technology of the present invention. The width of the line is wider at the folded part than at the other part. As shown in Figure 4b, the increased width provides the antenna with a "max load" or improved bandwidth, which is useful for some applications. However, the present invention does not require this extra width.

In FIG. 7d , the lines 402 are again shown as conductive strips, connected to contact pads 408 , which run the length of the substrate 404 . In this embodiment, the lines assume a more complex shape following the edge of the base made of tabs or protrusions along one edge, and corresponding insets or depressions on the opposite edge. Before the line reaches the far end of the substrate in the direction of its folded-back contact, it undergoes two changes in angle. The last part after the line is folded is slightly larger than the original length of the line.

Tabs and other angles and recesses along the length of the substrate are used to interface with the sides or features of the enclosures of the wireless device and various fabrication components. The edge of the base 404 can be shaped, or shaped, to suit the shape of the inner edge of the housing, which can be matched to, or placed around, corresponding changes in the walls of the housing, and surround various bumps, protrusions, Regular portions or known portions that protrude from the housing wall surface, or even leave gaps for wiring, conductors and cables that need to be placed in the wireless device. To this end, various round, square or other shapes can be used for the sides or edges of the substrate. This edge allows the antenna to be installed in spaces hitherto unsuitable for microstrip antennas.

In addition, the shape of the line 402 or the chip antenna 400 can also be varied in three dimensions. That is, while the lines are formed as generally flat surfaces, the base or surface of the base supporting the lines may be curved to allow for various mounting configurations. That is, due to the thin but strong nature of the substrate, the substrate can be fabricated with curved structures, altered surfaces, or simply deformed upon installation. This is shown in FIG. 7e , which is a top view of the substrate, transverse to length, showing the curved substrate 404 . It will be apparent to those skilled in the art that various curves or bends may be used in this dimension. For example, the surface of the substrate may form a certain "curved" pattern.

A preferred embodiment of the invention constructed and tested is shown in side and front views in Figures 7f to 7h. Here, the overall length of the substrate 402 is approximately 52 mm, and the width of the lines is approximately 1 mm. When the line widens at the end of the folded portion 702, the width is close to 1.5 mm. Contact pads 408 and 410 are both 6.75 mm square with a suitable set of conductive holes extending through the substrate to contact both of them. Use a fiberglass base approximately 1mm thick, and lines and spacers approximately 0.01mm thick. Note the space 704, which is between the folded end of the line and the edge of the base. This optional space or gap with the edge is used to set the line return and reduce the effect of a hand near or in contact with the edge of the antenna.

It will be apparent to those skilled in the art that various shapes such as, but not limited to, circular, oval, parabolic, angular, and square, C-, L-, or V-shaped folds, joints, and edges Both can be used for lines and substrates. The width of the conductors may vary along the length so that they taper, bend, or step narrower or wider towards the outer end (non-feed portion). As will be clear to those skilled in the art, these several effects or shapes can be combined into a single antenna structure. For example, angled graded tapes that bend in another dimension are possible.

The result of removing whip antenna 104 and helical antenna 106 can be easily seen from the side view of Figure 5c, which shows the telephone of Figure 1b using the present invention.

The foregoing description of the preferred embodiment will enable any person skilled in the art to make or use the invention. Various modifications to these embodiments, such as the type of wireless device used, will be apparent, and the general principles defined herein can be used in other embodiments without resorting to inventive efforts. Thus, the present invention is not limited to the embodiments shown here, but has the widest scope consistent with the principles and novel features disclosed herein.

Claims (15)

1. A substrate antenna used in a wireless communication device, the substrate antenna having a ground plane for incorporating a circuit inside it, characterized in that the substrate antenna comprises: a non-conductive support substrate of preselected thickness and length; which is a separate structure compared to said ground plane; An antenna radiator constructed in the form of a conductive line formed on said support substrate, said conductive line having a feed end and an open end, and having a length selected such that it contributes electromagnetic energy at least at a preselected frequency the action of a source radiator; and the length of said conductive line is about 1/4 wavelength of said electromagnetic energy; and The support substrate is disposed in the wireless device adjacent to and beyond an edge of the ground plane. 2. The chip antenna according to claim 1, wherein said lines are formed by depositing a metal material on said dielectric material. 3. The chip antenna of claim 1, further comprising a conductive spacer coupled to the feed end of the trace, configured to transmit signals between the radiator and other circuitry. 4. The chip antenna according to claim 3, wherein said conductive spacer is connected to a spring-type signal feed. 5. The chip antenna according to claim 1, wherein the length and width of said lines are so large that said chip antenna can receive and transmit signals having a frequency range of 824 to 894 MHz. 6. The chip antenna according to claim 1, wherein the length and width of the lines are so large that the chip antenna can receive and transmit signals in the frequency range of 1.85-1.99 GHz. 7. The chip antenna of claim 1, wherein said substrate is located near an edge of said ground plane and has a center plane axis offset from said ground plane by less than 90 degrees. 8. The chip antenna of claim 1, wherein said substrate has a center plane axis parallel to an edge of said ground plane. 9. The chip antenna of claim 8, wherein said substrate resides in a plane substantially perpendicular to said ground plane plane. 10. The chip antenna of claim 1, wherein said substrate is not directly above or below a planar area occupied by said ground plane. 11. The chip antenna of claim 1, wherein said substrate is disposed between an edge of said ground plane and a housing wall of said wireless device. 12. The chip antenna of claim 1, wherein said radiator extends along a linear path between said first and second ends of said substrate. 13. The chip antenna according to claim 12, wherein said radiator is further bent adjacent to one end of said substrate, and extends backward toward the opposite end. 14. The chip antenna of claim 1, wherein said support substrate comprises a main part of a housing for said wireless device. 15. The chip antenna of claim 1, wherein said support base comprises a support member secured at a preselected location on said wireless device housing.

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