EP1481444A2 - Multi-band pif antenna with meander structure - Google Patents

Multi-band pif antenna with meander structure

Info

Publication number
EP1481444A2
EP1481444A2 EP03743664A EP03743664A EP1481444A2 EP 1481444 A2 EP1481444 A2 EP 1481444A2 EP 03743664 A EP03743664 A EP 03743664A EP 03743664 A EP03743664 A EP 03743664A EP 1481444 A2 EP1481444 A2 EP 1481444A2
Authority
EP
European Patent Office
Prior art keywords
radiating element
area
antenna according
ground plane
antenna
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP03743664A
Other languages
German (de)
French (fr)
Other versions
EP1481444A4 (en
Inventor
Ulrich Bettin
Peter Nevermann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Siemens Communications Inc
Original Assignee
Siemens Information and Communication Mobile LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US10/091,619 external-priority patent/US6882318B2/en
Application filed by Siemens Information and Communication Mobile LLC filed Critical Siemens Information and Communication Mobile LLC
Publication of EP1481444A2 publication Critical patent/EP1481444A2/en
Publication of EP1481444A4 publication Critical patent/EP1481444A4/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q1/00—Details of, or arrangements associated with, antennas
    • H01Q1/12—Supports; Mounting means
    • H01Q1/22—Supports; Mounting means by structural association with other equipment or articles
    • H01Q1/24—Supports; Mounting means by structural association with other equipment or articles with receiving set
    • H01Q1/241—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM
    • H01Q1/242—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use
    • H01Q1/243—Supports; Mounting means by structural association with other equipment or articles with receiving set used in mobile communications, e.g. GSM specially adapted for hand-held use with built-in antennas
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q5/00—Arrangements for simultaneous operation of antennas on two or more different wavebands, e.g. dual-band or multi-band arrangements
    • H01Q5/30—Arrangements for providing operation on different wavebands
    • H01Q5/307—Individual or coupled radiating elements, each element being fed in an unspecified way
    • H01Q5/342—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes
    • H01Q5/357—Individual or coupled radiating elements, each element being fed in an unspecified way for different propagation modes using a single feed point
    • H01Q5/364—Creating multiple current paths
    • H01Q5/371—Branching current paths
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01Q—ANTENNAS, i.e. RADIO AERIALS
    • H01Q9/00—Electrically-short antennas having dimensions not more than twice the operating wavelength and consisting of conductive active radiating elements
    • H01Q9/04—Resonant antennas
    • H01Q9/0407—Substantially flat resonant element parallel to ground plane, e.g. patch antenna
    • H01Q9/0421—Substantially flat resonant element parallel to ground plane, e.g. patch antenna with a shorting wall or a shorting pin at one end of the element

Definitions

  • the present invention relates generally to antennas and more particularly to a multi-band planar inverted F antenna.
  • Planar inverted F antennas are used in wireless communications, e.g., cellular telephones, wireless personal digital assistants (PDAs), wireless local area networks (LANs) - Bluetooth, etc.
  • the PIFA generally includes a planar radiating element having a first area, and a ground plane having a second area that is parallel to the radiating element first area.
  • An electrically conductive first line is coupled to the radiating element at a first contact located at an edge on a side of the radiating element. The first line is also coupled to the ground plane.
  • An electrically conductive second line is coupled to the radiating element along the same side as the first line, but at a different contact location on the edge than the first line.
  • the first and second lines are adapted to couple to a desired impedance, e.g., 50 ohms, at frequencies of operation of the PIFA.
  • the first and second lines are perpendicular to the edge of the radiating element to which they are coupled, thereby forming an inverted F shape (thus the descriptive name of planar inverted F antenna).
  • the resonance frequency of the PIFA is determined generally by the area of the radiating element and to a lesser extent the distance between the radiating element and the ground plane (thickness of the PIFA assembly).
  • the bandwidth of the PIFA is generally determined by thickness of the PIFA assembly and the electrical coupling between the radiating element and the ground plane.
  • a significant problem in designing a practical PIFA application is the trade off between obtaining a desired operating bandwidth and reducing the PIFA volume (area x thickness).
  • S AR value specific absorption rate
  • Prior known planar inverted F antennas have sacrificed bandwidth by requiring a reduction in the volume (thickness) of the PIFA for a given wireless application.
  • the physical dimensions need to be changed.
  • the dimensions of a PIFA designed for 900 MHz need to be scaled by multiplying it with a factor 900/850 to operate at 850 Mhz. Therefore, it is obvious, that the dimensions of the PIF antenna are bigger at 850 MHz.
  • redesigning a product for a different frequency can cause problems in the redesign of the respective antenna.
  • the invention overcomes the above-identified problems as well as other shortcomings and deficiencies of existing technologies by providing an apparatus and a system for increasing the useable bandwidth of a PIFA.
  • the invention provides an antenna including a ground plane and a radiating element.
  • the ground plan has a first planar surface and a first area
  • the radiating element has a second planar surface and a second area.
  • the second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective overall length of the radiating element.
  • FIG. 1 is a schematic diagram of a prior technology planar inverted F antenna
  • FIG. 2 is a schematic diagram of a first exemplary embodiment of a planar inverted F antenna (PIFA) according to the present invention
  • FIGs. 3 and 4 are top views of further exemplary embodiments of the radiation element of a PIFA according to the present invention.
  • FIGs. 5-7 are top views of different exemplary embodiments of PIF As showing various shapes of the elongating sub-sections according to the present invention. DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS
  • an antenna includes a ground plane and a radiating element.
  • the ground plan has a first planar surface and a first area
  • the radiating element has a second planar surface and a second area.
  • the second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area comprises a section having a meandering form elongating the effective over all length of the radiating element.
  • the antenna may further comprise a first connecting line and a second connecting line. The first connecting line is coupled to a first edge of the ground plane and to a second edge of the radiating element at a first contact location, and the second connecting line is coupled to the second edge of the radiating element at second and third contact locations.
  • the first area of the ground plane can be greater than the second area of the radiating element or can be substantially the same as the second area of the radiating element.
  • the first contact location can be between the second and third contact locations.
  • the second connecting line can be coupled to the second edge of the radiating element at a plurality of contact locations.
  • the first and second connecting lines can be adapted for a desired impedance, which can be, for example, about 50 ohms.
  • the second area of the radiating element can comprises a first and a second section, wherein one of the sections can comprise at least one sub-section elongating the effective electrical length of the section and the second section can have an L-shaped form.
  • the meandering form can be a sinusoidal, triangular, rectangular or any other suitable wave-like form.
  • the ground plane can be on one side of an insulating substrate and the radiating element can be on the other side of the insulating substrate. Furthermore, the ground plane, the insulating substrate and the radiating element can be flexible. The first area of the ground plane and the second area of the radiating element can be rectangular or non-rectangular.
  • FIG. 1 Another embodiment is a planar inverted F antenna which comprises a ground plane and a radiating element.
  • the ground plane has a first planar surface and a first area
  • the radiating element has a second planar surface and a second area.
  • the second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective over all length of the radiating element.
  • the antenna also includes a first connecting line coupled to an edge of the ground plan and to an edge of the radiating element, and a second connecting line coupled to the edge of the radiating element on either side of where the first connecting line is coupled thereto.
  • a planar inverted F antenna which includes a ground plane and a radiating element.
  • the ground plan has a first planar surface, a first circumference and a first plurality of edges on the first circumference
  • the radiating element has a second planar surface, a second circumference and a second plurality of edges on the second circumference.
  • the second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective overall length of the radiating element.
  • the antenna also has a first connecting line coupled to a first edge of the first plurality of edges and a first edge of the second plurality of edges, and a second connecting line coupled to the first edge of the second plurality of edges on either side of the first connecting line.
  • Another embodiment is a radio system having a planar inverted F antenna (PIFA).
  • the system includes a ground plane and a radiating element.
  • the ground plane has a first planar surface and a first area
  • the radiating element has a second planar surface and a second area.
  • the second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective overall length of the radiating element.
  • the system also includes a first connecting line coupled to a first edge of the ground plane and to a second edge of the radiating element at a first contact location, and a second connecting line coupled to the second edge of the radiating element at second and third contact locations.
  • the first and second connecting lines are adapted to couple to a radio at a desired impedance.
  • FIG. 1 illustrates a schematic diagram of a prior technology planar inverted F antenna (PIFA).
  • the prior technology PIFA is generally represented by the numeral 100.
  • the PIFA 100 comprises a radiating element 102, a ground plane 104, a first connecting line 110 coupled to the radiating element 102 at contact location 108, and a second connecting line 112 coupled to the radiating element 102 at contact location 106.
  • the first connecting line 110 is also coupled to the ground plane 104 via connection 116.
  • the connecting lines 110 and 112 are adapted for coupling to a radio system (not shown) through connections 114 and 116.
  • connections 114 and 116 generally are adapted for a desired impedance, e.g., 50 ohms, at frequencies of operation of the PIFA.
  • the connection 114 is generally the "hot" connection, and the connection 116 is generally the ground connection.
  • FIG. 2 depicted is a schematic diagram of an exemplary embodiment of a planar inverted F antenna (PIFA), according to the present invention. This specific exemplary embodiment of a PIFA is generally represented by the numeral 200.
  • the PIFA 200 comprises a radiating element 202, a ground plane 204, a first connecting line 210 coupled to the radiating element 202 at contact location 208, and a second connecting line 212 coupled to a third connecting line 220 which is coupled to the radiating element 202 at contact locations 206 and 218.
  • the first connecting line 210 is also coupled to the ground plane 204 through coupling line 211.
  • the connecting lines 210 and 212 are adapted to be coupled to a radio system (not shown) through connections 214 and 216.
  • the connections 214 and 216 generally are adapted for a desired impedance, e.g., 20 ohms, 50 ohms, 75 ohms, or from about 20 to 300 ohms at frequencies of operation of the PIFA 200.
  • the connection 214 is generally the "hot" connection, and the connection 216 is generally the ground connection.
  • Coupling to the radiating element 202 at multiple contact locations (206, 218) increases the bandwidth of the PIFA 200.
  • the radiating element 202 includes two sections 240 and 250.
  • Section 250 includes a sub-section 230 comprising a meander structure to elongate section 250.
  • the area of the radiating element 202 determines the resonance frequency; whereas, the thickness, namely the distance between the radiating element 202 and the ground plane 204, determines the bandwidth of the PIF antenna. Further, the lower the resonance frequency is, the longer the antenna is or in other words the bigger the size or profile of the antenna.
  • the type of multi-band PIF antenna shown in Fig. 2 comprises substantially two different sections, namely a rectangular section 240 and a L-shaped section 250. Each section has its own resonance frequency. Thus, two frequency bands can be supported by such an antenna.
  • the coupling 220 which connects the "hot" connection 214 with radiating element 202 further enhances the two antenna elements. By means of this connection, both antenna elements are switched in parallel.
  • sub-section 230 within antenna section 250 effectively elongates the length of section 250 and thus decreases the resonance frequency without changing the overall size of the antenna.
  • FIG. 3 shows a top view of a radiating element of another embodiment according to the present invention.
  • the radiating element includes two separate antenna elements 340 and 350 instead of a single element.
  • the first antenna element 340 has a substantially rectangular shape and the second element 350 has a substantially L-type shape. Both elements 340 and 350 can be placed as shown whereby the second L-shaped element 350 partially frames element 340.
  • the ground connection 315 is coupled with connection points of both antenna elements 340 and 350 through a bridge connector 310.
  • the "hot" connection 325 is coupled at connection points to each antenna element 340, 350 through respective wires or transmission lines 300 and 320.
  • the design of the L-shaped antenna element 350 comprises a sub-section 330 to increase the effective length of the antenna element 350. This sub-section 330 has a meandering form.
  • the L- shaped antenna element 350 has an effective partial length d for sub-section 330. Through the use of a meandering shape, the effective electrical length will become some multiple of length d, thus elongating the respective antenna element 350.
  • FIG. 4 shows yet another embodiment of the radiating element according to the present invention.
  • a single sheet metal is used and, for example, is stamped to provide substantially two sections 440 and 450.
  • Section 450 has a sub-section 430 with a meandering structure or shape. Only a single ground connection 425 is needed. This connection is positioned, preferably, at the joint point where both antenna elements are connected.
  • the "hot" connection 415 is placed in a similar manner as shown in FIGs. 2 and 3.
  • the sub-section of the antenna element comprising a meandering structure or form can have a plurality of different shapes. It is essential, however, that the effective length of the sub-section is longer than the physical length d of this subsection to elongate the effective overall electrical length of the antenna element. Also, no additional manufacture steps are necessary, as the meander-like structure is formed within the surface plane of the radiating element.
  • FIGs. 5-7 show various different embodiments of the radiating element of multi-band PIF antennas according to the present invention. For example, Figs. 5A- D, 6C and 6E use a meandering form having a sinusoidal waveform shape placed in different parts of the L-shaped antenna element. Figs.
  • 5E and 5F use elongating subsections providing a triangular waveform shape placed in different parts of the L- shaped antenna element.
  • Figs. 6A, 6B and 6D show elongating meander subsections having a rectangular waveform shape.
  • Figs. 6F, 7A and 7B each show two elongating meander sub-sections in the radiating element using combinations of differently shaped meandering sub-sections. More than one sub-section can be provided, as shown in Figs. 6F, 7A and 7B. Multiple sub-sections can have the same or similar shapes or different shapes depending on the desired resonance frequency.
  • FIG. 7C shows yet another embodiment of the present invention.
  • the meander-like sub-section is provided within the substantially rectangular antenna element.
  • the ground connection either the L-shaped element is elongated or the rectangular element is elongated.
  • the ground plane and/or the radiating element may have openings, e.g., holes or cutouts, therein for reduction of weight and/or attachment of mechanical support(s), e.g., dielectric insulating supports (not illustrated) holding the ground plane and/or the radiating element.
  • the present invention is not restricted to any one shape, size and/or form as shown in FIGs. 5-7.
  • the ground plane and radiating element may be made of any type of conducting material, e.g., metal, metal alloys, graphite impregnated cloth, film having a conductive coating thereon, etc.
  • the distance between the radiating element and the ground plane need not be constant.
  • the multiple contact location embodiments of the present invention may also be used effectively in planar structures for push bend antenna configurations without an increase in fabrication costs.
  • the application of the elongating meandering sub-section is of course not limited to multi-band antennas but can also be used in any type of single-band antenna.
  • the antenna shown in FIG. 7C can be used, for example, as a single band antenna.
  • Any other single band antenna using an antenna type similar to the above shown multi- band antennas can be modified according to the principles of the present invention.
  • the combination of different contact locations on the radiating element in multi-band antennas results in a multiple resonance, closely coupled, "stagger tuned" PIFA structure.
  • the physical size or profile of the PIF antenna can stay the same while the resonance frequency can be lowered.
  • a lower frequency range can be provided by the PIFA according to the invention without changing mechanical parts or making the phone size bigger in order to accommodate an otherwise larger antenna profile that would result if the invention were not used.
  • existing phones can be built with an even smaller profile since the PIF antenna at a given operating frequency band with the meander structure requires a smaller volume than a PIF antenna without a meandering structure for the same operating frequency band.

Abstract

A mono-band or multi-band planar inverted F antenna (PIFA) structure (200) comprises a planar radiating element (202) having a first area, a ground plane (204) having a second area that is substantially parallel to the radiating element first area. The first area further comprises a section (230) having a meandering form elongating the effective overall length of the radiating element.

Description

MULTI-BAND PIF ANTENNA WITH MEANDER STRUCTURE
BACKGROUND OF THE INVENTION
The present invention relates generally to antennas and more particularly to a multi-band planar inverted F antenna. Planar inverted F antennas (PIF As) are used in wireless communications, e.g., cellular telephones, wireless personal digital assistants (PDAs), wireless local area networks (LANs) - Bluetooth, etc. The PIFA generally includes a planar radiating element having a first area, and a ground plane having a second area that is parallel to the radiating element first area. An electrically conductive first line is coupled to the radiating element at a first contact located at an edge on a side of the radiating element. The first line is also coupled to the ground plane. An electrically conductive second line is coupled to the radiating element along the same side as the first line, but at a different contact location on the edge than the first line. The first and second lines are adapted to couple to a desired impedance, e.g., 50 ohms, at frequencies of operation of the PIFA. In the PIFA, the first and second lines are perpendicular to the edge of the radiating element to which they are coupled, thereby forming an inverted F shape (thus the descriptive name of planar inverted F antenna).
The resonance frequency of the PIFA is determined generally by the area of the radiating element and to a lesser extent the distance between the radiating element and the ground plane (thickness of the PIFA assembly). The bandwidth of the PIFA is generally determined by thickness of the PIFA assembly and the electrical coupling between the radiating element and the ground plane. A significant problem in designing a practical PIFA application is the trade off between obtaining a desired operating bandwidth and reducing the PIFA volume (area x thickness). Furthermore, it is preferably that a larger ground plane area (shield) helps in reducing radio frequency energy that may enter into a user's head (S AR value = specific absorption rate), e.g., from a mobile cellular telephone. However, the volume of the PIFA increases with a larger ground plane area unless the thickness (distance between the radiating element and ground plane areas) is reduced.
As the number of wireless communications applications increases and the physical size of wireless devices decreases, antennas for these applications and devices are needed. Prior known planar inverted F antennas have sacrificed bandwidth by requiring a reduction in the volume (thickness) of the PIFA for a given wireless application.
In addition different markets use different operating frequencies. For example, a new GSM band at 850 MHz was assigned recently in North America. Existing PIF antenna solutions from the European GSM 900 MHz band need to be adapted properly, i.e., the resonance frequency needs to be shifted from 900 MHz to 850 MHz band. It is thus desirable to be able to redesign a wireless communication product for different frequencies with a minimum of design changes.
However, in order to use the same sort of antenna at a lower resonance frequency the physical dimensions need to be changed. As an example, the dimensions of a PIFA designed for 900 MHz need to be scaled by multiplying it with a factor 900/850 to operate at 850 Mhz. Therefore, it is obvious, that the dimensions of the PIF antenna are bigger at 850 MHz. Thus, redesigning a product for a different frequency can cause problems in the redesign of the respective antenna.
Therefore, there is a need for a PIFA design able to operate at a different resonance frequency without having to increase the dimensions thereof. SUMMARY OF THE INVENTION
The present invention overcomes the above-identified problems as well as other shortcomings and deficiencies of existing technologies by providing an apparatus and a system for increasing the useable bandwidth of a PIFA. According to an exemplary embodiment, the invention provides an antenna including a ground plane and a radiating element. The ground plan has a first planar surface and a first area, and the radiating element has a second planar surface and a second area. The second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective overall length of the radiating element.
A more complete understanding of the specific embodiments of the present invention and advantages thereof may be acquired by referring to the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a prior technology planar inverted F antenna
(PIFA);
FIG. 2 is a schematic diagram of a first exemplary embodiment of a planar inverted F antenna (PIFA) according to the present invention; FIGs. 3 and 4 are top views of further exemplary embodiments of the radiation element of a PIFA according to the present invention; and
FIGs. 5-7 are top views of different exemplary embodiments of PIF As showing various shapes of the elongating sub-sections according to the present invention. DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENTS
According to an exemplary embodiment of the invention, an antenna includes a ground plane and a radiating element. The ground plan has a first planar surface and a first area, and the radiating element has a second planar surface and a second area. The second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area comprises a section having a meandering form elongating the effective over all length of the radiating element. The antenna may further comprise a first connecting line and a second connecting line. The first connecting line is coupled to a first edge of the ground plane and to a second edge of the radiating element at a first contact location, and the second connecting line is coupled to the second edge of the radiating element at second and third contact locations. The first area of the ground plane can be greater than the second area of the radiating element or can be substantially the same as the second area of the radiating element. The first contact location can be between the second and third contact locations. Furthermore, the second connecting line can be coupled to the second edge of the radiating element at a plurality of contact locations. The first and second connecting lines can be adapted for a desired impedance, which can be, for example, about 50 ohms. The second area of the radiating element can comprises a first and a second section, wherein one of the sections can comprise at least one sub-section elongating the effective electrical length of the section and the second section can have an L-shaped form. The meandering form can be a sinusoidal, triangular, rectangular or any other suitable wave-like form. The ground plane can be on one side of an insulating substrate and the radiating element can be on the other side of the insulating substrate. Furthermore, the ground plane, the insulating substrate and the radiating element can be flexible. The first area of the ground plane and the second area of the radiating element can be rectangular or non-rectangular.
Another embodiment is a planar inverted F antenna which comprises a ground plane and a radiating element. The ground plane has a first planar surface and a first area, and the radiating element has a second planar surface and a second area. The second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective over all length of the radiating element. The antenna also includes a first connecting line coupled to an edge of the ground plan and to an edge of the radiating element, and a second connecting line coupled to the edge of the radiating element on either side of where the first connecting line is coupled thereto.
Yet another embodiment is a planar inverted F antenna which includes a ground plane and a radiating element. The ground plan has a first planar surface, a first circumference and a first plurality of edges on the first circumference, and the radiating element has a second planar surface, a second circumference and a second plurality of edges on the second circumference. The second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective overall length of the radiating element. The antenna also has a first connecting line coupled to a first edge of the first plurality of edges and a first edge of the second plurality of edges, and a second connecting line coupled to the first edge of the second plurality of edges on either side of the first connecting line. Another embodiment is a radio system having a planar inverted F antenna (PIFA). The system includes a ground plane and a radiating element. The ground plane has a first planar surface and a first area, and the radiating element has a second planar surface and a second area. The second planar surface of the radiating element is substantially coplanar with the first planar surface of the ground plane, and the second area includes a section having a meandering form elongating the effective overall length of the radiating element. The system also includes a first connecting line coupled to a first edge of the ground plane and to a second edge of the radiating element at a first contact location, and a second connecting line coupled to the second edge of the radiating element at second and third contact locations. The first and second connecting lines are adapted to couple to a radio at a desired impedance.
Referring now to the drawings, the details of an exemplary specific embodiment of the invention are schematically illustrated. FIG. 1 illustrates a schematic diagram of a prior technology planar inverted F antenna (PIFA). The prior technology PIFA is generally represented by the numeral 100. The PIFA 100 comprises a radiating element 102, a ground plane 104, a first connecting line 110 coupled to the radiating element 102 at contact location 108, and a second connecting line 112 coupled to the radiating element 102 at contact location 106. The first connecting line 110 is also coupled to the ground plane 104 via connection 116. The connecting lines 110 and 112 are adapted for coupling to a radio system (not shown) through connections 114 and 116. The connections 114 and 116 generally are adapted for a desired impedance, e.g., 50 ohms, at frequencies of operation of the PIFA. The connection 114 is generally the "hot" connection, and the connection 116 is generally the ground connection. Referring to FIG. 2, depicted is a schematic diagram of an exemplary embodiment of a planar inverted F antenna (PIFA), according to the present invention. This specific exemplary embodiment of a PIFA is generally represented by the numeral 200. The PIFA 200 comprises a radiating element 202, a ground plane 204, a first connecting line 210 coupled to the radiating element 202 at contact location 208, and a second connecting line 212 coupled to a third connecting line 220 which is coupled to the radiating element 202 at contact locations 206 and 218. The first connecting line 210 is also coupled to the ground plane 204 through coupling line 211. The connecting lines 210 and 212 are adapted to be coupled to a radio system (not shown) through connections 214 and 216. The connections 214 and 216 generally are adapted for a desired impedance, e.g., 20 ohms, 50 ohms, 75 ohms, or from about 20 to 300 ohms at frequencies of operation of the PIFA 200. The connection 214 is generally the "hot" connection, and the connection 216 is generally the ground connection. Coupling to the radiating element 202 at multiple contact locations (206, 218) increases the bandwidth of the PIFA 200. According to the shown embodiment, the radiating element 202 includes two sections 240 and 250. Section 250 includes a sub-section 230 comprising a meander structure to elongate section 250.
Generally, the area of the radiating element 202 determines the resonance frequency; whereas, the thickness, namely the distance between the radiating element 202 and the ground plane 204, determines the bandwidth of the PIF antenna. Further, the lower the resonance frequency is, the longer the antenna is or in other words the bigger the size or profile of the antenna. The type of multi-band PIF antenna shown in Fig. 2 comprises substantially two different sections, namely a rectangular section 240 and a L-shaped section 250. Each section has its own resonance frequency. Thus, two frequency bands can be supported by such an antenna. The coupling 220 which connects the "hot" connection 214 with radiating element 202 further enhances the two antenna elements. By means of this connection, both antenna elements are switched in parallel.
According to the present invention, sub-section 230 within antenna section 250 effectively elongates the length of section 250 and thus decreases the resonance frequency without changing the overall size of the antenna.
FIG. 3 shows a top view of a radiating element of another embodiment according to the present invention. In this embodiment, the radiating element includes two separate antenna elements 340 and 350 instead of a single element. The first antenna element 340 has a substantially rectangular shape and the second element 350 has a substantially L-type shape. Both elements 340 and 350 can be placed as shown whereby the second L-shaped element 350 partially frames element 340. The ground connection 315 is coupled with connection points of both antenna elements 340 and 350 through a bridge connector 310. The "hot" connection 325 is coupled at connection points to each antenna element 340, 350 through respective wires or transmission lines 300 and 320. According to the present invention, the design of the L-shaped antenna element 350 comprises a sub-section 330 to increase the effective length of the antenna element 350. This sub-section 330 has a meandering form.
Manufacture of such an antenna element can achieved by either a stamping procedure, etching process, or any other suitable method using, for example, sheet metal. The L- shaped antenna element 350 has an effective partial length d for sub-section 330. Through the use of a meandering shape, the effective electrical length will become some multiple of length d, thus elongating the respective antenna element 350.
FIG. 4 shows yet another embodiment of the radiating element according to the present invention. In this embodiment, a single sheet metal is used and, for example, is stamped to provide substantially two sections 440 and 450. Section 450 has a sub-section 430 with a meandering structure or shape. Only a single ground connection 425 is needed. This connection is positioned, preferably, at the joint point where both antenna elements are connected. The "hot" connection 415 is placed in a similar manner as shown in FIGs. 2 and 3.
The sub-section of the antenna element comprising a meandering structure or form can have a plurality of different shapes. It is essential, however, that the effective length of the sub-section is longer than the physical length d of this subsection to elongate the effective overall electrical length of the antenna element. Also, no additional manufacture steps are necessary, as the meander-like structure is formed within the surface plane of the radiating element. FIGs. 5-7 show various different embodiments of the radiating element of multi-band PIF antennas according to the present invention. For example, Figs. 5A- D, 6C and 6E use a meandering form having a sinusoidal waveform shape placed in different parts of the L-shaped antenna element. Figs. 5E and 5F use elongating subsections providing a triangular waveform shape placed in different parts of the L- shaped antenna element. Also, Figs. 6A, 6B and 6D show elongating meander subsections having a rectangular waveform shape. Figs. 6F, 7A and 7B each show two elongating meander sub-sections in the radiating element using combinations of differently shaped meandering sub-sections. More than one sub-section can be provided, as shown in Figs. 6F, 7A and 7B. Multiple sub-sections can have the same or similar shapes or different shapes depending on the desired resonance frequency.
FIG. 7C shows yet another embodiment of the present invention. In this embodiment, the meander-like sub-section is provided within the substantially rectangular antenna element. Thus, depending on the placement of the ground connection, either the L-shaped element is elongated or the rectangular element is elongated.
It is contemplated and within the scope of the present invention that coupling to the radiating element at more than two contact locations may be utilized for increased bandwidth of the PIFA, according to the present invention. The ground plane and/or the radiating element may have openings, e.g., holes or cutouts, therein for reduction of weight and/or attachment of mechanical support(s), e.g., dielectric insulating supports (not illustrated) holding the ground plane and/or the radiating element.
The present invention is not restricted to any one shape, size and/or form as shown in FIGs. 5-7. The ground plane and radiating element may be made of any type of conducting material, e.g., metal, metal alloys, graphite impregnated cloth, film having a conductive coating thereon, etc. The distance between the radiating element and the ground plane need not be constant. The multiple contact location embodiments of the present invention may also be used effectively in planar structures for push bend antenna configurations without an increase in fabrication costs.
The application of the elongating meandering sub-section is of course not limited to multi-band antennas but can also be used in any type of single-band antenna. Depending on the connection of the ground and "hot" connections, the antenna shown in FIG. 7C can be used, for example, as a single band antenna. Any other single band antenna using an antenna type similar to the above shown multi- band antennas can be modified according to the principles of the present invention. As described above, the combination of different contact locations on the radiating element in multi-band antennas results in a multiple resonance, closely coupled, "stagger tuned" PIFA structure.
With the use of the meandering structure in the radiating element of the PIFA, the physical size or profile of the PIF antenna can stay the same while the resonance frequency can be lowered. Thus, a lower frequency range can be provided by the PIFA according to the invention without changing mechanical parts or making the phone size bigger in order to accommodate an otherwise larger antenna profile that would result if the invention were not used. Further, when a frequency change is not desired, existing phones can be built with an even smaller profile since the PIF antenna at a given operating frequency band with the meander structure requires a smaller volume than a PIF antenna without a meandering structure for the same operating frequency band.
The present invention has been described in terms of specific exemplary embodiments. In accordance with the present invention, the parameters for a system may be varied, typically with a design engineer specifying and selecting them for the desired application. Further, it is contemplated that other embodiments, which may be devised readily by persons of ordinary skill in the art based on the teachings set forth herein, may be within the scope of the invention, which is defined by the appended claims. The present invention may be modified and practiced in different but equivalent manners that will be apparent to those skilled in the art and having the benefit of the teachings set forth herein.

Claims

What is claimed is:
1. An antenna comprising: a ground plane having a first planar surface and a first area; a radiating element having a second planar surface and a second area, wherein said second planar surface of said radiating element is substantially coplanar with the first planar surface of said ground plane and said second area comprises a section having a meandering form elongating the effective overall length of the radiating element.
2. The antenna according to claim 1, further comprising: a first connecting line coupled to a first edge of said ground plane and to a second edge of said radiating element at a first contact location; and a second connecting line coupled to the second edge of said radiating element at second and third contact locations.
3. The antenna according to claim 1, wherein the first area of said ground plane is greater than the second area of said radiating element.
4. The antenna according to claim 1, wherein the first area of said ground plane area is substantially the same as the second area of said radiating element.
5. The antenna according to claim 2, wherein the first contact location is between the second and third contact locations.
6. The antenna according to claim 2, further comprising the second connecting line being coupled to the second edge of said radiating element at a plurality of contact locations.
7. The antenna according to claim 1, wherein the first and second connecting lines are adapted for a desired impedance.
8. The antenna according to claim 7, wherein the desired impedance is about 50 ohms.
9. The antenna according to claim 1, wherein the second area of the radiating element comprises a first and a second section.
10. The antenna according to claim 9, wherein one of the sections comprises at least one sub-section elongating the effective length of the section.
11. The antenna according to claim 9, wherein the second section has a L- shaped form.
12. The antenna according to claim 1, wherein said section comprises a sinusoidal waveform shape.
11. The antenna according to claim 1, wherein said section comprises a triangular waveform shape.
12. The antenna according to claim 1, wherein said section comprises a rectangular waveform shape.
13. The antenna according to claim 1, wherein said ground plane is on one side of an insulating substrate and said radiating element is on the other side of the insulating substrate.
14. The antenna according to claim 13, wherein said ground plane, the insulating substrate and said radiating element are flexible.
<
15. The antenna according to claim 1, wherein the first area of said ground plane and the second area of said radiating element are rectangular.
16. The antenna according to claim 1, wherein the first area of said ground plane and the second area of said radiating element are non-rectangular.
17. A planar inverted F antenna, comprising: a ground plane having a first planar surface and a first area; a radiating element having a second planar surface and a second area, wherein the second planar surface of said radiating element is substantially coplanar with the first planar surface of said ground plane and the second area comprises a section having a meandering form elongating the effective overall length of the radiating element; a first connecting line coupled to an edge of said ground plan and to an edge of said radiating element; and a second connecting line coupled to the edge of said radiating element on either side of where the first connecting line is coupled thereto.
18. A planar inverted F antenna, comprising: a ground plane having a first planar surface, a first circumference and a first plurality of edges on the first circumference; a radiating element having a second planar surface, a second circumference and a second plurality of edges on the second circumference, the second planar surface of said radiating element being substantially coplanar with the first planar surface of said ground plane and the second area comprises a section having a meandering form elongating the effective overall length of the radiating element; a first connecting line coupled to a first edge of the first plurality of edges and a first edge of the second plurality of edges; and a second connecting line coupled to the first edge of the second plurality of edges on either side of the first connecting line.
19. A radio system having a planar inverted F antenna (PIFA), said system comprising: a ground plane having a first planar surface and a first area; a radiating element having a second planar surface and a second area, wherein the second planar surface of said radiating element is substantially coplanar with the first planar surface of said ground plane and the second area comprises a section having a meandering form elongating the effective overall length of the radiating element; a first connecting line coupled to a first edge of said ground plane and to a second edge of said radiating element at a first contact location; and a second connecting line coupled to the second edge of said radiating element at second and third contact locations, and first and second connecting lines are adapted to couple to a radio at a desired impedance.
20. The antenna according to claim 1, wherein said effective overall length comprises an effective overall electrical length.
21. The antenna according to claim 2, wherein said effective overall length comprises an effective overall electrical length.
22. The antenna according to claim 10, wherein said effective overall length comprises an effective overall electrical length.
23. The planar inverted F antenna according to claim 17, wherein said effective overall length comprises an effective overall electrical length.
24. The planar inverted F antenna according to claim 17, wherein said meandering form comprises a triangular waveform shape, a rectangular waveform shape, or a sinusoidal waveform shape.
25. The planar inverted F antenna according to claim 18, wherein said effective overall length comprises an effective overall electrical length.
26. The planar inverted F antenna according to claim 18, wherein said meandering form comprises a triangular waveform shape, a rectangular waveform shape, or a sinusoidal waveform shape.
27. The radio system according to claim 19, wherein said effective overall length comprises an effective overall electrical length.
28. The radio system according to claim 19, wherein said meandering form comprises a triangular waveform shape, a rectangular waveform shape, or a sinusoidal waveform shape.
EP03743664A 2002-03-04 2003-01-31 Multi-band pif antenna with meander structure Withdrawn EP1481444A4 (en)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
US91619 2002-03-04
US10/091,619 US6882318B2 (en) 2002-03-04 2002-03-04 Broadband planar inverted F antenna
US108059 2002-03-27
US10/108,059 US6856285B2 (en) 2002-03-04 2002-03-27 Multi-band PIF antenna with meander structure
PCT/US2003/002883 WO2003075395A2 (en) 2002-03-04 2003-01-31 Multi-band pif antenna with meander structure

Publications (2)

Publication Number Publication Date
EP1481444A2 true EP1481444A2 (en) 2004-12-01
EP1481444A4 EP1481444A4 (en) 2009-06-17

Family

ID=27791188

Family Applications (1)

Application Number Title Priority Date Filing Date
EP03743664A Withdrawn EP1481444A4 (en) 2002-03-04 2003-01-31 Multi-band pif antenna with meander structure

Country Status (5)

Country Link
EP (1) EP1481444A4 (en)
JP (1) JP2005519509A (en)
CN (1) CN1650473B (en)
RU (1) RU2004129327A (en)
WO (1) WO2003075395A2 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7388543B2 (en) 2005-11-15 2008-06-17 Sony Ericsson Mobile Communications Ab Multi-frequency band antenna device for radio communication terminal having wide high-band bandwidth
US8618988B2 (en) * 2007-10-05 2013-12-31 Kyocera Corporation Co-location insensitive multi-band antenna
TWI347034B (en) 2007-11-21 2011-08-11 Arcadyan Technology Corp Dual-band antenna
CN101453053B (en) * 2007-11-28 2012-09-26 智易科技股份有限公司 Dual-frequency antenna
CN102570059A (en) 2010-12-31 2012-07-11 旭丽电子(广州)有限公司 Independent multi-frequency antenna
CN202019051U (en) * 2011-03-02 2011-10-26 中兴通讯股份有限公司 Inverted-F antenna
CN103531908B (en) * 2013-10-30 2016-02-03 电子科技大学 Multi-band planar printed antenna
EP2937933B1 (en) * 2014-04-24 2016-12-28 Alcatel Lucent Low-profile wideband antenna element and antenna
CN105470636B (en) * 2015-12-30 2018-09-07 福建省汇创新高电子科技有限公司 Applied to WLAN double frequency high-isolation MIMO directional aerials
CN107026315A (en) * 2016-01-29 2017-08-08 佛山市顺德区顺达电脑厂有限公司 Dual-band antenna

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1999003168A1 (en) * 1997-07-09 1999-01-21 Allgon Ab Trap microstrip pifa
US5926139A (en) * 1997-07-02 1999-07-20 Lucent Technologies Inc. Planar dual frequency band antenna
EP1011167A1 (en) * 1998-07-02 2000-06-21 Matsushita Electric Industrial Co., Ltd. Antenna unit, communication system and digital television receiver
DE19929689A1 (en) * 1999-06-29 2001-01-11 Siemens Ag Integrable dual band antenna
WO2001029927A1 (en) * 1999-10-15 2001-04-26 Siemens Aktiengesellschaft Switchable antenna

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6281850B1 (en) * 1996-02-16 2001-08-28 Intermec Ip Corp. Broadband multiple element antenna system
US6140967A (en) * 1998-08-27 2000-10-31 Lucent Technologies Inc. Electronically variable power control in microstrip line fed antenna systems
US6204826B1 (en) * 1999-07-22 2001-03-20 Ericsson Inc. Flat dual frequency band antennas for wireless communicators
JP2001185938A (en) * 1999-12-27 2001-07-06 Mitsubishi Electric Corp Two-frequency common antenna, multifrequency common antenna, and two-frequency and multifrequency common array antenna
US6459413B1 (en) * 2001-01-10 2002-10-01 Industrial Technology Research Institute Multi-frequency band antenna

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5926139A (en) * 1997-07-02 1999-07-20 Lucent Technologies Inc. Planar dual frequency band antenna
WO1999003168A1 (en) * 1997-07-09 1999-01-21 Allgon Ab Trap microstrip pifa
EP1011167A1 (en) * 1998-07-02 2000-06-21 Matsushita Electric Industrial Co., Ltd. Antenna unit, communication system and digital television receiver
DE19929689A1 (en) * 1999-06-29 2001-01-11 Siemens Ag Integrable dual band antenna
WO2001029927A1 (en) * 1999-10-15 2001-04-26 Siemens Aktiengesellschaft Switchable antenna

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO03075395A2 *

Also Published As

Publication number Publication date
EP1481444A4 (en) 2009-06-17
WO2003075395A2 (en) 2003-09-12
WO2003075395A3 (en) 2004-03-18
RU2004129327A (en) 2006-03-27
JP2005519509A (en) 2005-06-30
CN1650473B (en) 2012-05-30
CN1650473A (en) 2005-08-03

Similar Documents

Publication Publication Date Title
US6856285B2 (en) Multi-band PIF antenna with meander structure
US7907092B2 (en) Antenna with one or more holes
US6429819B1 (en) Dual band patch bowtie slot antenna structure
US20060077101A1 (en) Loaded antenna
JP4171875B2 (en) Multiband patch antenna and skeleton slot radiator
KR20060123188A (en) Modified printed dipole antenna for wireless multi-band communication systems
WO2003077360A1 (en) Multiband planar built-in radio antenna with inverted-l main and parasitic radiators
CN101297440A (en) Multiband antenna device and communication terminal device
US20120154231A1 (en) Loaded antenna
WO2001080355A1 (en) A multi-band antenna for use in a portable telecommunication apparatus
KR20050106533A (en) Multi-band laminated chip antenna using double coupling feeding
WO2003075395A2 (en) Multi-band pif antenna with meander structure
US7375689B2 (en) Multi-band antenna of compact size
CN111710982B (en) Novel broadband magnetic dipole antenna
WO2001089031A1 (en) Antenna arrangement
EP1933413B1 (en) Multi-band antenna of compact size
TWI223470B (en) Multi-band PIF antenna with meander structure
CN212848852U (en) Ultra-wideband microstrip omnidirectional antenna
SE522829C2 (en) Multiple-band antenna for use in portable telecommunication apparatus to establish and maintain wireless radio links using continuous trace with portions in different planes
EP1732162A1 (en) Loaded antenna
CN116613506A (en) Medium-sized indoor distributed directional antenna
KR20050033074A (en) Antenna element and mobile telephone device

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20040524

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT SE SI SK TR

RIN1 Information on inventor provided before grant (corrected)

Inventor name: BETTIN, ULRICH

Inventor name: NEVERMANN, PETER

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: SIEMENS COMMUNICATIONS, INC.

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: SIEMENS COMMUNICATIONS, INC.

A4 Supplementary search report drawn up and despatched

Effective date: 20090514

RIC1 Information provided on ipc code assigned before grant

Ipc: H01Q 9/04 20060101ALI20090508BHEP

Ipc: H01Q 1/38 20060101AFI20040618BHEP

Ipc: H01Q 1/24 20060101ALI20090508BHEP

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN WITHDRAWN

18W Application withdrawn

Effective date: 20090716