EP0965152B1 - Resonant antenna - Google Patents

Abstract

An antenna for receiving and transmitting electromagnetic microwaves having lambd wavelengths consisting of a substrate layer (10) made of a low dielectric material which bears on one side a conductive ground plane (1) and whose opposite side is conductively structured as micro-strip circuits. The conductive structure (S) has an elongate conductor section (3, 3a, 3b, R, Ra, Rb) which acts as a resonator and whose length (LR) is shorter than lambdc/4. One end of said conductor section is conductively connected to the ground plane (8, 1) and its other end is conductively connected to at least another conductor section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K) used as an end capacitor to adjust resonance conditions. The conductor section (3, 3a, 3b, R, Ra, Rb) which acts as a resonator is connected to the inner conductor of a coaxial optical fiber and the outer conductor or the coaxial optical fiber is connected to the ground plane (1).

Description

The invention relates to an antenna for receiving and transmitting of electromagnetic microwaves of wavelengths λ from a substrate layer made of low dielectric Material that has a conductive ground plane on one side has and the opposite side conductive in the form of Microstrip lines is structured.

The scope of the invention extends ostensibly in the mobile and handheld technology sector within the spectral range between 890 MHz and 960 MHz or 1710 MHz and 1890 MHz by the component according to the invention into the corresponding end device and handheld technology is integrated.

Known antenna solutions for the field of mobile radio applications are based on linear antenna designs in form of monopole arrangements in a shortened or unabridged version. These linear antennas are both externally mountable On-board antennas as well as directly with the end device coupled components known, as well as with different Indicative factor and efficiency, where these components in the azimuthal plane are only round strands are. Known flat antenna solutions are based on two-dimensional, dipole-like configurations, whose directional diagram is irregular and in connection with the the respective antenna carrier or antenna body have a significant radiation field deformation. The radiation properties related to the area of application are clear from those of the classic linear antennas inferior. There are also targeted blanking properties of the radiation diagram undetectable. Farther no solutions are known whose electromagnetic or radiation properties based on asymmetrical and open waveguide technology, especially microstrip technology, using foil conductors or foil-like guide surfaces can be achieved.

The one shown in the patent DE 41 13 277 and azimuthal omnidirectional antenna configuration is only possible from a film as a mechanical structural support, said antenna component having an outside of the terminal equipment arranged head capacity is. In the same way. That in the patent DE 41 21 333 shown and azimuthal omnidirectional antenna configuration of an electrically non-conductive film as a mechanical structure support, the main radiation direction an inclination with respect to the elevation values of approx. (minus) -30 ° (angular degree), that is, a negative one Has elevation angle.

A disadvantage of the known antenna configurations is hence that they are either in the azimuthal plane exclusively are omnidirectional or only within the negative Radiate elevation angle range.

The object of the present invention is a system integrable Antenna component with the smallest possible area Expansion with azimuthal as possible one-sided Directionality, that is the preferred illumination of a Spatial hemisphere and a limited angular displacement of the elevation-related directivity within the positive To provide elevation angle range.

This object is achieved by the features of Characteristic part of claim 1 and suf the claim 1 related subclaims resolved.

The antenna according to the invention, which can also be referred to as a foil radiator, is a modified λ / 4 radiator which is short-circuited to ground on one side. In order to obtain the most compact possible design, the elongated conductor section, which serves as a resonator, is made shorter than λ _ε / 4. As a result, however, the resonator becomes inductive and the vibration condition is not met. In order that the resonance condition of the radiator element is met, an end capacitance is generated at the end of the resonator opposite the short-circuited side. This end capacitance is generated by at least one additional additional conductor section, one end of which connects to the end of the resonator opposite the short-circuited side and the other end of which forms an open circuit. The length of the additional further conductor sections determine the vibration condition and thus the resulting resonance frequency of the entire structure. Various embodiments of the conductor sections at the end of the resonator are conceivable for realizing a defined end capacitance for maintaining the vibration condition. The end capacitance can be realized by one or more lines of appropriate length, which do not necessarily have to run parallel to one another or to the resonator. All lines can also be designed in any curved shape and not just in a straight shape.

By covering the antenna or the foil radiator by an additional dielectric layer, which in the Design process is taken into account can be extensive Insensitivity to others near the Dielectric located radiator can be achieved. This is important so that by installing the foil spotlight in Radio equipment (dielectric interference) and by Influencing yourself by holding the radio in the hand results, the functionality is retained and the Strahier is not out of tune.

Because with this type of spotlights one side is short-circuited there is only one radiating or receiving end. This leads to an asymmetry in the directional characteristic in the vibration plane of the electric field vector (E plane) and thus to an angular offset of the main radiation direction in this plane by approx. 30 ° in the viewing direction short-circuited spotlight side - radiant end.

The electrical properties of this antenna, e.g. Quality, Impedance bandwidth, efficiency and gain depend on the size of the mechanical reduction (reduction) achieved, the width of the resonator, the distance between the resonator and the end capacitance sections, the effective permittivity constant, the substrate thickness or of the dielectric loss angle.

By means of the presented invention, it is possible to accommodate two or more antennas for different wavelengths in a relatively small space. An essential feature of the invention is that the resonators implemented in microstrip technology for receiving the microwaves are shorter than λ _ε / 4, which enables a particularly compact and small construction to be achieved. Because the resonator length is chosen to be shorter than λ _ε / 4, the oscillation condition is no longer met, as already explained. The required end capacities are realized by further line sections. An increase in the frequency bandwidth can be achieved by additional radiator elements through electromagnetic coupling. This is done by additional microstrip lines, which are arranged at certain distances from the resonator and its end capacitors. It is possible to receive several wave ranges with two or more resonators on a substrate, wherein the resonators can be arranged spatially nested in one another and matched to the required frequency bands. The individual antennas do not have to be in one plane but can also be arranged in layers one above the other. It is also possible that several antenna arrangements are provided per layer, so that more than two different frequency bands can be operated. This makes it possible for a mobile radio telephone to be able to communicate with different mobile radio networks.

Below are some embodiments of the invention explained in more detail with reference to drawings.

Figur 1:

Erfindungsgemäße Antenne mit einem mit der Masseebene verbundenen Resonator und zwei die Endkapazitäten darstellenden beidseitig an den Resonator angrenzenden Leiterabschnitten;

Figur 2:

Querschnittsdarstellung der Antenne gem. Figur 1;

Figur 3:

Antenne gem. Figur 1 mit nur einem die Endkapazitat bildenden Leiterabschnitt;

Figur 4:

Antenne gem. Figur 1, bei der die Leiterabschnitte auf einer Seite des Resonators angeordnet sind;

Figur 5 und 6:

Antenne mit 4 bzw. 3 die Endkapazitäten bildenden Leiterabschnitten;

Figur 7:

Antenne, deren Endkapazitätsleiterabschnitte nicht gerade, sondern rechteckförmig gestaltet sind;

Figur 8 bis 10:

Erfindungsgemäße Antenne gemäß Figur 2, bei der mehrere ineinander verschachtelt angeordnete Resonatoren zur Vergrößerung der Frequenzbandbreite vorgesehen sind;

Figur 11:

Zwei erfindungsgemäße ineinander verschachtelte Antennen, für den Empfang von zwei Frequenzbändern;

Figur 12:

Zwei auf einem Substrat angeordnete erfindungsgemäße Antennen zum Empfang von zwei Frequenzbänder mit jeweils zusätzlicher Verkopplung zur Vergrößerung der jeweiligen Frequenzbandbreite;

Figur 13:

Draufsicht auf eine Schicht-Antenne zum Empfang von zwei Frequenzbändern;

Figur 14:

Querschnittsdarstellung einer Antenne gem. Figur 13.

Show it:

Figure 1:

Antenna according to the invention with a resonator connected to the ground plane and two conductor sections which represent the end capacitors and which adjoin the resonator on both sides;

Figure 2:

Cross-sectional representation of the antenna acc. Figure 1;

Figure 3:

Antenna acc. 1 with only one conductor section forming the final capacitance;

Figure 4:

Antenna acc. Figure 1, in which the conductor sections are arranged on one side of the resonator;

Figure 5 and 6:

Antenna with 4 or 3 conductor sections forming the end capacities;

Figure 7:

Antenna, the end capacitance sections of which are not straight, but rather rectangular in shape;

Figure 8 to 10:

Antenna according to the invention according to FIG. 2, in which a plurality of resonators arranged nested one inside the other are provided in order to enlarge the frequency bandwidth;

Figure 11:

Two antennas interleaved according to the invention for the reception of two frequency bands;

Figure 12:

Two antennas according to the invention arranged on a substrate for receiving two frequency bands, each with additional coupling to enlarge the respective frequency bandwidth;

Figure 13:

Top view of a layer antenna for receiving two frequency bands;

Figure 14:

Cross-sectional representation of an antenna acc. Figure 13.

FIG. 1 shows an antenna according to the invention with a film-like low dielectric carrier 10, which is one-sided with a conductive structure S consisting of parallel to each other and rectilinear conductor sections 2, 3 and 4 of different lengths coated is, the conductor section 3 is conductive and one-sided is connected to a ground plane 8, which in turn, as shown in Figure 2, via a conductive coating the cross-sectional area of the carrier substrate 10 is connected to ground level 1. Instead of the capable Coating 12 can be in a not shown Embodiment, the ground surface 8 by means of or a plurality of contact pins covering the dielectric substrate layer 10 reach through, with the ground level 1 in connection his. The conductive coating of the Cross-sectional area of the carrier substrate 10 does not have to have the entire width of the antenna, but it can be a partial coating of the film cross-sectional area made become. The conductor sections 2, 3 and 4 are each by a gap 5.6 of defined spa width from one another arranged separately, the conductor sections 2, 3 and 4 in each case by a strip-shaped strip running in the transverse direction Conductor section 7 of defined section length and -Width are conductively interconnected, the in Conductor section running transversely on that of the ground contact 8 opposite end of the conductor section Antenna is arranged. The conductor section 3, the one Conductor section end connected to the ground surface 8 and on opposite conductor section end with the transverse one strip-shaped conductor section 7 is connected, is coupled to a signal waveguide at location 9 by the inner conductor 13 of a coaxial waveguide through a Aperture 15, which is arranged in the rear ground plane 1 is guided toe and with the conductor section 3 in place 9 coupled on the longitudinal line of symmetry of the conductor section and the outer conductor of the coaxial waveguide with the rear ground plane 1 conductive at the bezel edge 15 is connected.

The vibration condition of the open and unbalanced Waveguide structure in the form of microstrip technology about the geometric length and width of the conductor sections 2, 3 and 4 set. The input impedance of the microstrip array is along the location of the coupling 9 the line of symmetry of the conductor section 3 determines the again from the resulting length of the conductor sections 2 and 4 depends, the signal coupling in and out on Location 9 via a circular coaxial orifice slit or rectangular aperture.

The detuning of the radiator due to dielectric environmental influences over the length of the conductor sections 2 and / or 4 compensated, the degree of detuning of

Due to dielectric environmental influences the overlay of a dielectric layer 11 defined Dielectric constant as well as defined geometry is influenced or minimized.

The dielectric carrier layer 10 is in particular one Polystyrene film with a layer thickness of 1 mm, which is one-sided and all over with a copper or aluminum foil Layer thickness between 0.01 mm and 0.5 mm is provided forms the ground plane. According to Figure 2, the same Polystyrene support with a foil-like and made of copper or aluminum existing structure S of the layer thickness between 0.01 mm and 0.5 mm, consisting of the parallel to each other running and each separated by a longitudinal gap, rectilinear conductor sections 2, 3, 4 Mistake. The dielectric layer 11 also has one Layer thickness of approx. 1 mm.

In a special embodiment, the antenna has a length L _A of 119 mm and a width B _A of 40 mm. The length L _{8 of} the ground surface 8 is 20 mm. The distance L ₅ from the ground surface 8 to the feed point of the antenna 9 is also 20 mm. The diameter of the aperture 15 is 4.1 mm. The length of the conductor sections K ₁ and K ₂ forming the final capacitance are 82.6 mm and 56.7 mm. The length L _A of the conductor section 3 or R forming the resonator is 85.7 mm. The width of the conductor section 2 is 11.5 mm and the width of the conductor section 4 is 9.5 mm. The width of the resonator conductor section is 12 mm.

FIG. 3 shows a radiator according to the invention, in which only one parallel to the resonator conductor section 3 or R arranged conductor section K forms the final capacitance.

FIG. 4 shows an emitter according to the invention, in which the. Sndcapacitance is formed by two parallel conductor sections K ₁ and K ₂ , which are arranged on one side of the resonator conductor section R. Likewise, as shown in FIGS. 5 and 6, an antenna can be configured in which the resulting end capacitance is realized by three or four conductor sections K ₁ to K ₄ .

FIG. 7 shows a further embodiment of the invention Antenna where the end capacitance is Conductor sections 16 and 17 are not rectilinear, but have a rectangular shape.

Figures 8 to 10 show antennas in which the frequency bandwidth the antenna through electromagnetic coupling with additional conductor elements, which on the same dielectric carrier substrate are arranged, is adjusted or enlarged. The antenna according to FIG. 8 corresponds in its basic structure to the antenna according to FIG. 3, a U-shaped conductor section 19, 20, 21 with its one leg 21 in the gap between the resonator conductor section 3 and the final capacity. Head section 2 engages. The other leg 19 is with an additional ground surface 18 in connection, which in turn corresponding to the ground plane 9 with the ground plane i is connected. The basic structure of FIG. 9 corresponds of Figure 1, with two additional U-shaped Conductor sections 23 to 28 are provided, which each with its one leg 27, 28 in the through the Intervene conductor sections 2, R, 4 formed column.

FIGS. 9 and 10 show further possible configurations the antenna according to the invention, the arrangement of the additional, the coupling to increase the frequency bandwidths influencing conductor sections 30 to 38 is in principle arbitrary. It is also conceivable that the Interconnect conductor sections spirally so that on relatively small space a long parallel routing of conductor sections is produced.

FIGS. 11 to 14 show antennas in which two antenna signals can be coupled in or out, as a result of which two frequency bands can be received or operated simultaneously using only one film antenna. Due to the different design of the resonator conductor sections R _a and R _b , the resonance conditions in connection with the conductor sections 41a, b and 42a, b and the locations 43a, 43b of the coupling-out of the electromagnetic waves are determined. Due to the nesting of the two radiator arrangements, they can be arranged in a confined space.

FIG. 12 shows a further embodiment of an antenna with two connections 51a, 51b for dielectric waveguides, only that shown in Figure 8 Spotlight arrangement in different dimensions arranged side by side on a substrate carrier are.

Figures 13 and 14 show a multi-layer antenna, at which the antennas according to the invention one above the other in several layers are sandwiched, one each Antenna the vibration conditions for the frequencies of a corresponds to certain cellular network. Because of the different Resonance frequencies interfere with one another arranged strahiunas structures only insignificantly. Compared to the arrangement according to FIG. 2, the Layering the radiator structures less space needed, whereby the antenna according to Figure 13 more compact and thus the housing of a mobile phone that encloses it can be made relatively small.

FIG. 14 shows the antenna according to FIG. 13 in cross section. The conductive coating 12a, b of the cross-sectional area of the carrier substrates 10a and 10b is conductively connected to the structured layers S _A and S _B. Such a conductive cross-sectional coating can also be provided on the opposite side, depending on the antenna design.

It goes without saying that depending on the desired resonance frequency, Coupling and detuning the respective Geometries of the individual conductor sections selected accordingly must be used to achieve predetermined frequency values the geometries of the conductor structures partially have to be determined empirically.

LIST OF REFERENCE NUMBERS

1

ground plane

2, 2 _{a / b} , 4, 4 _{a / b} , 6 _{a / b} , K, K _i

Conductor section as final capacity

3, R, R _i

Resonatorleiterabschnitt

5.6

Clearance gap between the end capacitance sections and the resonator conductor sections

7.7 _{a / b} , 41 _{a / b} , 45 _{a / b}

Resonator conductor section with end capacitance conductor sections connecting transverse conductor section

8th

Ground surface; in connection with the ground plane 1

9

Feed point of the antenna

10

Dielectric carrier layer;

11

Dielectric layer

12

Conductive coating of the cross-sectional area of the carrier substrate

13,13a, 13b

Inner conductor of a coaxial waveguide

14,14a, 14b

soldered point

15,15a, 15b

cover

16.17

Conductor section as end capacity in square waveform

18,22,29,40b, 47

additional ground area; with the ground plane 1 in connection

19-21; 23-28; 30-35; 31 ', 33' 35 ', 48a / b-50a / b

Additional substantially U-shaped conductor section

36,37,38,36 ' 37 ', 38', 40b

Head section for setting the detuning the antenna

B _A

Antenna width

L ₈

Length of the ground plane 8

L _A

Antenna length

L _B

Distance of the coupling point from the Ground area 8

L _R

Length of the resonator conductor section

L _Ki

Length of the end capacitance sections

L _Sp , L _Sp1

Width of the spacing column

S, S _a , S _b

Conductive structured in microstrip lines layer

Claims (15)

1. An antenna for receiving and transmitting of electromagnetic microwaves of wavelength λ, consisting of a substrate layer (10) made of low-dielectric material, which on one side is provided with a conductive ground plane (1) and whose opposite side is conductive and structured in the form of micro-strip circuits, and characterized by the fact that the conductive structure (S) has a longitudinal conductor section (3, 3a, 3b, R, Ra, Rb) as resonator, whose length (L_R) is shorter than λ_g/4, and which is conductively connected with the ground plane (8, 1) at its end, and whose other end is conductively connected with at least one other conductor section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K), which serves as end capacitance for the purpose of adjusting the resonance condition, whereby the resonator conductor section (3, 3a, 3b, R, Ra, Rb) is in connection with an internal conductor of a coaxial wave guide and the external conductor of the coaxial wave guide is in connection with the ground plane (1).
2. An antenna as described in Claim 1 and characterized by the fact that the at least one additional conductor section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K) likewise is constructed as a micro-strip circuit and arranged parallel to the resonator conductor section (3, 3a, 3b, R, Ra, Rb).
3. An antenna as described in the foregoing Claim 1 or Claim 2 and characterized by the fact that the resonator conductor section (3, 3a, 3b, R. Ra, Rb) is conductively connected with the additional conductor section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K) in such manner that the two conductor sections section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K; 3, 3a, 3b, R. Ra, Rb) together with the connection conductor section (17, 41a, 45a, 45b, 49a, 49b) connected to them form a U with arms of equal or different lengths.
4. An antenna as described in Claim 1 or Claim 3 and characterized by the fact that at least two additional conductor sections (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K), which are particularly arranged parallel to the resonator conductor section (3, 3a, 3b, R, Ra, Rb), each connected by its one end with the end of the resonator conductor section (3, 3a, 3b, R. Ra, Rb) via a connection circuit (7, 41a, 41b, 45a, 45b, 49a, 49b) running transversely to the longitudinal line of symmetry of the resonator conductor section (3, 3a, 3b, R. Ra, Rb), whereby the other conductor sections (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K) are distributed either on one side or on both sides, whereby particularly the length (L_k) of the other conductor section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K) is different.
5. An antenna as described in one of the foregoing Claims and characterized by the fact that the one end of the resonator conductor section (3, 3a, 3b, R, Ra, Rb) is connected to the ground plane (1) by at least one terminal pin passing through the substrate layer (10, 10a, 10b).
6. An antenna as described in the foregoing Claims 1 to 4 and characterized by the fact that the one end of the resonator conductor section (3, 3a, 3b, R, Ra, Rb) is connected via a conductive coating (12, 12ab) to the [or: of] the transverse surface of the substrate layer (10, 10a, 10b).
7. An antenna as described in one of the foregoing Claims and characterized by the fact that at least on additional conductor section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K) is formed as straight linear, angular, bent/curved, wavelike, zigzag, or right-angular.
8. An antenna as described in one of the foregoing Claims and characterized by the fact that that for the purpose of adjustment of the resonator condition, at least one additional, essentially U-shaped conductor section (19, 20, 21; 23-28; 30-35; 31', 33', 35'; 48a/b-50a/b) is arranged on the substrate layer (10), whereby one arm (21, 27, 28, 34, 35, 35', 50a, 50b) of said U-shaped additional conductor section impinges into the opening formed by the resonator section (3, 3a, 3b, R, Ra, Rb) and the additional conductor section (2, 2a, 2b, 4, 42a, 42b, 46a, 46b, K) and the end of the other arm (19, 23, 24, 30, 31, 48a, 48b) of the additional conductor section is connected to the ground plane (1, 18, 22, 29, 47, 47').
9. An antenna as described in Claim 8 and characterized by the fact that the additional U-shaped conductor section (Rb, 41b, 42b) is likewise an antenna for transmitting and receiving electromagnetic waves, whereby the waves are coupled in or coupled out from the conductor section (Rb) connected to the ground plane (1, 40b) in such a way that the interleaving structures of the antennas affect the resonance conditions and/or [de]tuning of the individual resonators by reciprocal electromagnetic coupling and an expanded frequency range is achieved.
10. An antenna as described in one of the foregoing Claims and characterized by the fact that several antennas for transmitting and/or receiving different wavelengths are arranged on the substrate layer 10, 10a, 10b) alongside each other and which are each coupled with a coaxial wave guide.
11. An antenna as described in one of the foregoing Claims and characterized by the fact that several antennas each separated by at least one substrate layer (10a) are arranged on top of one another.
12. An antenna as described in one of the foregoing Claims and characterized by the fact that that the internal conductor (13, 13a, 13b) of the coaxial wave guide is lead through an aperture (15, 15a, 15b) in the ground plane (1) and a recess in the layer (10, 10a, 10b) and connected to the resonator conductor section (3, 3a, 3b, R, Ra, Rb), whereby the input impedance of the antenna is determined over the point (9) of the in-coupling along the longitudinal line of symmetry of the resonator conductor section (3, 3a, 3b, R, Ra, Rb).
13. An antenna as described in the foregoing Claim 12 and characterized by the fact that the aperture (15, 15a, 15b) is circular, slit-like, or rectangular.
14. An antenna as described in one of the foregoing Claims and characterized by the fact that the [de]tuning of the antenna as a result of dielectric environmental factors is compensated over the length of the additional conductor sections (19, 20, 21; 23-28; 30-35; 31', 33', 35'; 48a/b-50a/b) and/or by the antennas arranged additionally on the substrate.
15. An antenna as described in one of the foregoing Claims and characterized by the fact that that the degree of [de]tuning of the antenna as a consequence of dielectric environmental factors is affected or minimized by the application of a dielectric layer (11) of a defined dielectric number and of a defined geometry, in particular thickness.

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