JP2003501926A - Flat plate monopole antenna - Google Patents

Abstract

A monopole antenna includes a conductive ground plane, a conductive radiating plate, an antennae interface terminal, and a resonant network for defining operating characteristics of the antennae. The conductive radiating plate is spaced apart from the ground plane and, together with the ground plane, defines a cavity therebetween. The antennae interface terminal is in communication with the cavity and is electrically isolated from the ground plane and the radiating plate. The resonant network includes an inductive element electrically coupled between the interface terminal and the radiating plate. Preferably, the inductive element is disposed within the cavity and comprises a first air-core coiled wire inductor electrically coupled between the radiating plate and the interface terminal, and a second air-core coiled wire inductor electrically coupled between the interface terminal and the ground plane. Also, preferably each inductor has a number of wire turns, and the resonant network provides the antenna with a resonant frequency determined in accordance with the number of wire turns.

Description

Detailed Description of the Invention

FIELD OF THE INVENTION The present invention relates to flat-plate antennas. The invention particularly relates to a flat-plate monopole antenna suitable for use with mobile wireless communication devices.

BACKGROUND OF THE INVENTION Conventional wireless communication devices, such as cellular telephones, typically use monopole antennas to carry and receive electronic information. A conventional cellular monopole antenna comprises a tubular antenna element grounded to the casing of a cellular telephone and a metal rod provided in the grounded tubular antenna element.
In order to achieve the large gain and bandwidth characteristics required for cellular communications, monopole antennas typically must be much longer than the length of the cellular telephone casing. Long monopole antennas hinder the portability of cellular phones, so they typically allow the monopole antenna to be retracted into the phone casing when the cellular phone is not used. It is manufactured as a series of stretchable monopole antenna parts. However, monopole antennas must still be extended to obtain the gain and bandwidth characteristics required for cellular communication. Therefore, attempts have been made to reduce the size of monopole antennas without compromising antenna gain and bandwidth.

For example, Yokoyama (US Pat. No. 4,791,423) teaches a microstrip antenna suitable for use in mobile phones. The microstrip antenna includes a first grounding rectangular conductive sheet, a radiating rectangular conductive sheet parallel to the grounding conductive sheet, and a first grounding conductive sheet and a radiating conductive sheet. The supply pin provided on the substrate with the first
A second ground conductive sheet and a second ground conductive sheet facing the edge of the ground conductive sheet and perpendicular to the sleeve of the first ground conductive sheet and the radiative conductive sheet, thereby providing an antenna Improve the beam tilt characteristics of. The second ground conductive sheet is
It functions as a connecting conductive sheet that connects the first ground conductive sheet to the radiating conductive sheet. In one variation, shown in FIG. 4a of this patent, the patch antenna has a flat passive element located above and close to the radiating conductive sheet to achieve antenna impedance matching. is doing.

Nakase (US Pat. No. 5,061,939) teaches a flat plate antenna suitable for use with mobile phones. A flat plate antenna is provided between a rectangular conductive ground plate, an egg-shaped conductive top plate for radiation parallel to the ground plate, and between the ground plate and the top plate for connecting the top plate to the ground plate. A plurality of elongated connecting members and a strip line resonator (s) provided between the ground plate and the top plate.
tripline resonator). The strip line resonator has a feeder line and a capacitor electrode centrally provided below the top plate for adjusting the resonance frequency of the antenna.

Yokoyama (US Pat. No. 5,148,181) describes a user's head during operation of a communication device,
And / or teaches a mobile radio communication device having an antenna to prevent the antenna gain from being reduced by the hand. The antenna is provided on the upper surface of the casing of the communication device, and has a rectangular first conductive plate, a rectangular second conductive plate extending below and parallel to the first conductive plate, and A first conductive plate and a rectangular third conductive plate extending vertically from the second conductive plate. The first conductive plate is spaced apart from the top surface of the casing of the communication device. The antenna also has a short circuit plate extending vertically from the first conductive plate and is connected to the upper surface of the casing proximate to the location of the earpiece and mouthpiece.

Both Yokoyama and Nakase provide antennas that are significantly smaller in size than conventional stretchable monopole antennas. However, in each embodiment, the antenna bandwidth, resonance frequency, and input impedance characteristics are specified by fixed variables such as the dimensions of the conductive plates and by the spacing between the conductive plates. As a result, strict attention must be paid to manufacturing tolerances to achieve the proper operating characteristics of monopole antennas. Therefore, there remains a need for monopole antennas that are much smaller than conventional stretchable monopole antennas and whose operating characteristics are not compromised by changes due to manufacturing tolerances.

SUMMARY OF THE INVENTION In accordance with the present invention, a wireless communication device and monopole antenna are provided that address the shortcomings of conventional monopole antennas. The monopole antenna according to the present invention includes a conductive ground plane, a conductive radiating plate, and an antenna interfering terminal.
e terminal) and a resonant network (
resonant network). The conductive radiating plate is spaced from the ground plane and together with the ground plane defines a cavity between them. The antenna interference terminal communicates with the cavity and is electrically isolated from the ground plane and the radiation plate. The resonant network has an inductor member electrically coupled between the interference terminal and the radiation plate.

A wireless communication device according to the present invention includes a conductive casing for receiving a wireless communication handset therein, a conductive radiating plate spaced apart from the casing and defining an antenna with a ground plane, and A resonant network for defining operating characteristics. The conductive casing has an antenna communication port for interfering with communication hardware. The resonant network has an inductor member electrically coupled between the communication port and the radiation plate.

In a preferred apparatus of the present invention, the inductor member is provided in the cavity and is electrically coupled between the radiation plate and the interference terminal as a first air-core coiled wire inductor. ) And a second air core wound inductor electrically coupled between the interference terminal and the ground plane. Each inductor has a plurality of winding turns and the resonant network provides an antenna having a resonant frequency determined according to the number of winding turns.

Detailed Description of the Preferred Embodiments The preferred embodiments of the present invention will now be described, by way of example only, with reference to the drawings. Referring to FIG. 1, a wireless communication device, generally indicated at 100, is shown that includes a conductive casing 102, a conductive radiating plate 104 spaced from the casing 102, and a casing 102 and a radiating plate. And a cavity 106 defined between the cavities 104 and 104. Preferably the casing 102
Has a substantially rectangular parallelopiped shape and is configured to receive a wireless communication circuit and includes a pair of opposed surfaces 108a, 108b, a pair of opposed sides 110a, 110b, And a pair of opposite ends 112a, 112
b. Also, the casing 102 is preferably formed as a handset of a wireless telephone housed within the casing 102 operating as a wireless telephone and a wireless communication circuit. However, it should be understood that the casing 102 may take other shapes and the wireless communication circuitry may function other than as a wireless telephone, depending on the needs of the application.

As shown more clearly in FIG. 2, the casing 102 has an antenna communication port 114 and an antenna interference terminal 116 extending through the communication port 114. The interference terminal 116 extends into the cavity 106, and
02 and the radiation plate 104 are electrically insulated. Furthermore, the interference terminal 1
16 interferes with the communication hardware provided within the casing 102 and enables the communication hardware to carry and receive data as electromagnetic waves.

The radiating plate 104 serves to define the monopole antenna in the casing 10.
In cooperation with 2, the casing 102 acts as a conductive ground plane for the antenna. Preferably, the radiating plate 104 comprises a rectangular flat conductive plate made of copper or aluminum. However, the radiation plate 104
May have any other suitable shape suitable for antenna operation. For example, in one variation, the radiating plate is manufactured with an arcuate shape, as shown in FIG. Further, the radiating plate 104 may have the same or different dimensions as the casing 102.

As shown in FIG. 1, the radiating plate 104 is preferably oriented substantially parallel to the casing end 112 and at a right angle to the casing surface 108. However, the radiating plate 104 can also be provided at other angles with respect to the casing surface 108 so as to modify the antenna pattern of the monopole antenna. For example, in FIG. 4, a wireless communication device 100 ′ is shown with the end 112 a ′ and the radiating plate 104 tilted with respect to the casing surface 108. Alternatively, the radiating plate 104 may be slightly tilted with respect to the casing end 112a.

As shown in FIGS. 1 and 2, the wireless communication device 100 also includes a resonant network 118, which, along with the dimensions of the radiating plate 104 and the cavity 106, provides operational characteristics of the monopole antenna. Stipulate. Resonant network 1
Reference numeral 18 is provided in the cavity 106 and has an inductor antenna member electrically coupled to the interference terminal 116, the radiation plate 104 and the casing 102. However, it should be understood that the resonant network 118 is not limited to having only a single inductor antenna member. For example, in one variation (not shown), in order to increase the bandwidth of the antenna, the resonant network 118 has a plurality of separate inductor antenna members, each of which is connected to the interference terminal 116 at each electrical terminal. Is also connected to the radiation plate 104.
And each position of the casing 102.

The inductor antenna member includes a first inductor 120 electrically connected between the radiation plate 104 and the interference terminal 116, the interference terminal 116, and the casing 10.
And a second inductor 122 electrically connected to the second inductor 122. Preferably, the first inductor 120 and the second inductor 122 are integrally connected by a common core. Resonant network 118 also includes a capacitor antenna member defined by the dimensions of casing 102, radiating plate 104 and cavity 106. The inductor antenna member is provided in parallel with the capacitor antenna member, and the capacitor antenna member and the inductor antenna member are integrated to achieve a parallel resonant circuit. As is apparent, the resonance frequency of the monopole antenna is determined by the capacitance of the capacitor antenna member and the inductance of the inductor antenna member.

Preferably, the cavity 106 comprises an air cavity and the inductors 120, 122 have a monopole antenna resonant frequency of each inductor 120, 12.
An air core coil winding inductor having a plurality of winding turns is provided, as defined by the number of two winding turns. Instead, the cavity 106
May have a support structure that supports the dielectric or radiation plate 104. Also, the windings preferably used in the winding inductors 120, 122 allow the distance between the radiating plate 104 and the end 112a (and hence the capacitance of the capacitor antenna member) to be adjusted. It has a flexible winding. In this way, the resonant frequency of the monopole antenna can be adjusted to calculate the change in manufacturing tolerances.

The input impedance of the monopole antenna depends on the winding inductors 120 and 122.
Understand that it is specified by the number of winding turns (and hence the inductance) of the. On the other hand, the capacitance of the capacitor antenna member is
4 and the size and shape of the casing 102. Thus, the present invention enables the input impedance of the monopole antenna to be matched to the impedance of the wireless communication circuit by adjusting the number of winding turns, changing the dimensions of the radiating plate 104 and / or the casing 102. This provides many advantages that allow the resonant frequency and bandwidth of the antenna to be tailored as desired. However, in each case, the length and width of the radiation plate 104 and the end 112a are preferably 10% of the operating wavelength of the antenna at the resonant frequency.
Keep below.

Table 1 presents samples of resonant frequencies obtained using several different dimensional changes of the present invention. For reference, the symbols W, L, used below
H, D, N1 and N2 are shown in Figures 5a, 5b. 77 mm (operating in the GSM band) was given to the antenna length of a conventional cellular telephone, and Table 1
Demonstrates a substantial height reduction achievable with the present invention as well.

[0019]

[Table 1]

The invention is defined by the claims, and the above description is merely illustrative of the preferred embodiments of the invention. Although not expressly stated herein, one of ordinary skill in the art, without departing from the spirit and scope of the invention as defined by the claims,
Appropriate additions, deletions and / or changes may be foreseen for the desired embodiment.

[Brief description of drawings]

1 is a perspective view of a wireless communication device according to the present invention showing a conductive casing (antenna ground plane), a radiating plate and a resonant network.

FIG. 2 is an enlarged view of the top end of the wireless communication device shown in FIG. 1 showing an air core wound inductor of a resonant network.

FIG. 3 is a longitudinal cross-sectional view of one variation of a wireless communication device having an arched radiating plate.

FIG. 4 is a side view of another variation of a wireless communication device having a radiating plate tilted with respect to a conductive casing.

FIG. 5a   FIG. 6 is a schematic diagram of a wireless communication device having the dimension codes used herein.

FIG. 5b is an enlarged schematic view of a top end of a wireless communication device with additional dimension codes used herein.

[Procedure for Amendment] Submission for translation of Article 34 Amendment of Patent Cooperation Treaty

[Submission date] August 21, 2001 (2001.8.21)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Contents of correction]

Yokoyama (US Pat. No. 5,148,181) describes a user's head during operation of a communication device,
And / or teaches a mobile radio communication device having an antenna to prevent the antenna gain from being reduced by the hand. The antenna is provided on the upper surface of the casing of the communication device, and has a rectangular first conductive plate, a rectangular second conductive plate extending below and parallel to the first conductive plate, and A first conductive plate and a rectangular third conductive plate extending vertically from the second conductive plate. The first conductive plate is spaced apart from the top surface of the casing of the communication device. The antenna also has a short circuit plate extending vertically from the first conductive plate and is connected to the upper surface of the casing proximate to the location of the earpiece and mouthpiece. Boubouleix (U.S. Pat. No. 4,491,843) discloses a metal box in the form of a parallel tube, an amplifier mounted in the metal box, a metal plate mounted adjacent to the top face of the metal box, and a top plate. It teaches a dipole antenna with an inductor extending through the end face. The inductor is connected to the metal plate at one end and to the amplifier at the opposite end. Delaveaud ("Small and low profile antennas replacing monopole antennas", Electronics Letter, Volume 34, No. 8,
British Empire (GB), April 16, 1998, IEEE Steven Age
ge)) teaches a monopole antenna with a parallel tube shaped metal box, metal plate and coaxial feed probe. The metal box has an upper flat ground plane, and the metal plate is provided close to the ground plane. The coaxial feed probe extends through the ground plane of the metal box. The center conductor of the probe has one end connected to the center of the metal plate and the other end connected to the ground plane.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Contents of correction]

Yokoyama, Nakase, Beau Beaurex and DeLaVue all provide antennas that are significantly smaller than conventional stretchable monopole antennas. However, in each embodiment, the antenna bandwidth, resonant frequency, and input impedance characteristics are specified by fixed variables such as the dimensions of the conductive plates and by the distance between the conductive plates. As a result, strict attention must be paid to manufacturing tolerances to achieve the proper operating characteristics of monopole antennas. Therefore, it is much smaller than the conventional stretchable monopole antenna,
There remains a need for monopole antennas whose operating characteristics are not compromised by changes due to manufacturing tolerances.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE), OA (BF, BJ , CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, K E, LS, MW, MZ, SD, SL, SZ, TZ, UG , ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, CA, C H, CN, CU, CZ, DE, DK, DZ, EE, ES , FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP, KE, KG, KP, K R, KZ, LC, LK, LR, LS, LT, LU, LV , MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, S K, SL, TJ, TM, TR, TT, UA, UG, US , UZ, VN, YU, ZA, ZW

Claims (17)

[Claims] 1. A flat plate monopole antenna comprising: a conductive ground plane; a conductive radiating plate spaced from the ground plane and defining a cavity between the ground plane; and in communication with the cavity. An antenna interference terminal electrically isolated from the ground plane and the radiation plate; and a resonant network for defining the operating characteristics of the antenna, the resonant network electrically coupled to the interference terminal and the radiation plate. Monopole antenna with integrated inductor member. 2. The monopole antenna according to claim 1, wherein the ground plane, the radiation plate and the cavity define a capacitor member, and the inductor member is provided in parallel with the capacitor member. 3. The inductor member is provided in the cavity.
Or the monopole antenna described in 2. 4. The inductor member includes a first inductor electrically coupled between the radiation plate and the interference terminal, and a second inductor electrically coupled between the interference terminal and the ground plane. The monopole antenna according to any one of claims 1 to 3, further comprising: 5. The monopole antenna of claim 4, wherein at least one inductor comprises an air core inductor. 6. The inductor comprises a coil winding inductor, each coil winding inductor having a plurality of winding turns, and the resonant network is winding turns of the coil winding inductor. The monopole antenna of claim 4, which provides an antenna having a resonant frequency determined according to the number of 7. The monopole antenna according to claim 1, wherein the resonant network has a plurality of individual inductor members each electrically coupled to the interference terminal and each disposed on the radiation plate. 8. The radiating plate comprises an arcuate radiating plate.
7. The monopole antenna according to any one of 1 to 7. 9. A wireless communication device comprising: a conductive casing for receiving a wireless communication handset therein.
The conductive casing has an antenna communication port for interfering with communication hardware; comprises a conductive radiating plate spaced apart from the casing and defining the antenna with a ground plane; A wireless communication device comprising a resonant network for defining, the resonant network having an inductor member electrically coupled between a communication port and a radiating plate. 10. The wireless communication device according to claim 9, wherein the casing and the radiation plate define a capacitor member between them, and the inductor member is provided in parallel with the capacitor member. 11. The wireless communication device according to claim 9, wherein the radiation plate and the ground plane integrally define a cavity between them, and the inductor member is provided in the cavity. 12. The inductor member includes a first inductor electrically coupled between the radiation plate and the communication port, and a second inductor electrically coupled between the communication port and the casing. The wireless communication device according to claim 9, further comprising: 13. The wireless communication device of claim 12, wherein at least one inductor comprises an air core inductor. 14. The inductor comprises a coil winding inductor, each coil winding inductor having a plurality of winding turns, and the antenna comprises winding turns of the coil winding inductor. 13. The wireless communication device of claim 12, having a resonant frequency determined according to a number. 15. A resonant network having a plurality of individual inductor members electrically coupled at respective locations with a communication port of a radiating plate.
4. The wireless communication device according to any one of 4 above. 16. The wireless communication device according to claim 9, wherein the casing has at least one surface, and the radiation plate is inclined with respect to the at least one surface. 17. The wireless communication device according to claim 9, wherein the radiation plate includes an arch-shaped radiation plate.