JP4296282B2 - Multi-frequency microstrip antenna - Google Patents

Description

  The present invention relates to a microstrip antenna (hereinafter abbreviated as “MSA”) having multi-frequency shared characteristics that operates at a plurality of frequencies, and in particular, can transmit and receive linearly polarized waves and circularly polarized waves at many frequencies. An antenna is realized.

  The MSA is an antenna that generates a magnetic current at the end of the radiation conductor by an electric field between the radiation conductor and the ground conductor (GND), and radiates radio waves using the magnetic current as a wave source. Conventionally, MSA has been used in many fields including mobile communication because it is small, lightweight, and can be configured to be thin. In addition, MSA elements are stacked two times and have dual frequency shared characteristics, An antenna with three-frequency sharing characteristics is made by overlapping three layers.

Non-Patent Document 1 below describes a multi-frequency shared MSA having a single layer structure. As shown in FIG. 40A, this antenna is formed on the same plane as the MSA radiating element 12 formed on the insulating substrate 11, the ground conductor 13 provided on the back surface of the insulating substrate 11, and the ground conductor 13. The radiating element 12 is fed from the feed line 14 by an electromagnetic coupling type feed method.
The ground conductor 13 has a size of 60 × 60 mm. Further, as shown in FIG. 40 (b), the radiating element 12 has two slits 15 and 16 in which a part of the quadrangle is opened inside a 22 × 22 mm (area 480 mm ² ) square. The two ring-shaped element portions 17 and 18 partitioned by the slits 15 and 16 and the central MSA element portion 19 function as an antenna.

FIG. 41 shows the return loss characteristics of the multi-frequency shared MSA, and shows the three-frequency shared characteristics having resonance points at the frequencies f _L , f _M, and f _H. In the figure, a solid line indicates an actual measurement value, and a dotted line indicates a simulation value.
FIG. 42 shows radiation patterns on the E plane and the H plane at the resonance frequencies of f _L , f _M, and f _H. In the figure, the solid line indicates the actual measurement value, the dotted line indicates the simulation value, and the alternate long and short dash line indicates the cross polarization level.
Cross polarization needs to be suppressed in order to avoid interference, but it is considered that there is no practical problem if it is −20 dB or less. In this three-frequency shared MSA, the cross polarization level in the boresight direction at each resonance frequency shows a value of −20 dB or less.

Patent Document 1 below describes an MSA that has dual-frequency characteristics and operates as a linearly polarized antenna at one frequency and as a circularly polarized antenna at the other frequency. As shown in FIG. 43 (a) (plan view) and FIG. 43 (b) (cross-sectional view at AA in FIG. 43 (a)), this linearly polarized wave / circularly polarized wave antenna is a Teflon made of double-sided copper foil. A circular patch 1 and an annular ring 2 are formed on one surface of a (registered trademark) glass substrate 9 by etching, and a ground conductor 4 is formed on the other surface. Then, the outer peripheral portion of the annular ring 2 is short-circuited to the ground conductor 4 by electroless copper plating, a hole is formed in the substrate 9, the feeder 7 is connected to the patch 1, and the feeder 8 is connected to the annular ring 2. Finally, a perturbation pattern (cut) 3 is formed in the annular ring 2 to adjust the characteristics.
In this antenna, the patch 1 exhibits linear polarization characteristics at a resonance frequency of 2.5 GHz band, and the annular ring 2 having the perturbation pattern 3 exhibits circular polarization characteristics at a resonance frequency of 1.5 GHz band. Therefore, this antenna can be mounted on an automobile, the patch 1 can be used as an antenna of an in-vehicle information communication system using a beacon, and the annular ring 2 can be used as an antenna of a positioning system (GPS) using a satellite.
Japanese Patent Laid-Open No. 5-291816 Suzuki, Haneishi "Folded slot loaded frequency sharing microstrip antenna" IEICE Transactions B, Vol. J85-B, no. 2, pp.207-215, February 2002

Recent automobiles are equipped with a large number of systems such as a GPS system, an in-vehicle information communication system, an ETC system, a cellular system, a satellite broadcast receiving system, and a wireless LAN, and require a large number of antennas.
The multi-frequency shared MSA can handle such a plurality of uses with one element.

  However, in the multi-frequency shared MSA described in Non-Patent Document 1, if the area of the radiating element is not changed, sharing of three frequencies is the limit, and if the number of sharing is further increased, the cross polarization level exceeds −20 dB. Accompanied by deterioration of the radiation pattern. In addition, this multi-frequency shared MSA can increase the frequency only for the linearly polarized wave, and cannot change the frequency of the circularly polarized wave.

  Further, in the linearly polarized wave / circularly polarized wave antenna described in Patent Document 1, an annular ring that operates as a circularly polarized wave antenna element needs to be connected to a ground conductor. It is not possible to increase the number of shared frequencies by adding in-plane, or to arbitrarily set the polarization characteristics of antenna elements not connected to the ground conductor.

  The present invention was devised to improve such a situation, and can share a large number of frequencies. The shared frequency can be arbitrarily set, or the polarization characteristics at the shared frequency. An object of the present invention is to provide a multi-frequency shared MSA that can be freely set.

The multi-frequency shared MSA of the present invention includes an annular antenna element formed on one surface of a substrate by an annular planar conductive path having a symmetrical shape with respect to a center line, and a conductive plane inside the annular antenna element. in formed, the annular antenna element and the center position and the center line coincides, a planar antenna element outline is similar, being formed by an annular planar conductive path outside of the loop antenna element, the annular antenna element One or a plurality of annular antenna elements whose center position and center line coincide with each other and whose shapes are similar to each other, and the annular antenna element is disposed on the other surface of the substrate via the substrate at the position of the center line. each and intersect at one point, and a straight portion opposed to the planar antenna element via the substrate at the position of the center line, at a position where the straight portion intersects with each of the annular antenna elements Along the serial linear portion to the annular antenna element comprises a L probe having a stub portion extending a predetermined length, each of said planar antenna element and the annular antenna elements are fed from the L probe electromagnetically coupled The length of the stub portion of the L probe is set so that matching can be achieved in a state where each of the annular antenna elements resonates at the one frequency. Features.
In this multi-frequency MSA, a current path is formed in each of the planar antenna element and each annular antenna element, and each current path resonates at a different resonance frequency because of its different length. Show properties.

In the multi-frequency shared MSA according to the present invention, the annular antenna element may have a quadrangular outer shape, and may be electromagnetically coupled to the L probe at a central portion of one side of the quadrangle.
In this rectangular annular antenna element, a uniform current distribution appears from the position of the L probe toward the symmetrical position on the square.

In the multi-frequency shared MSA of the present invention, the annular antenna element and the planar antenna element have two center lines orthogonal to each other, and the L probe is disposed at each position of the center line. It can also be configured.
This MSA can be used as a dual-polarized antenna that shares orthogonally polarized waves and horizontally polarized waves.

Moreover, in the multiband MSA of the present invention, the annular antenna element and the outer shape of the planar antenna element as well as the regular polygon or circular, perturbation elements located at point symmetry of the loop antenna element and the planar antenna elements Can be provided.
In this MSA, the operating frequency is determined by the current path formed in the planar antenna element and each annular antenna element, and the polarization characteristic of each annular antenna element is determined by the position and size of the perturbing element loaded thereon.

The multi-frequency shared MSA of the present invention can share a large number of frequencies, and can arbitrarily set the frequencies.
In addition, the polarization characteristic of the operating frequency can be freely set to left-handed polarized wave, right-handed polarized wave, or linearly polarized wave.

The figure which shows the structure of multifrequency shared MSA in the 1st Embodiment of this invention. The figure which shows the current pathway and current distribution of multifrequency shared MSA in the 1st Embodiment of this invention. The figure which shows the return loss characteristic of multi-frequency shared MSA in the 1st Embodiment of this invention The figure which shows the radiation pattern of multifrequency shared MSA in the 1st Embodiment of this invention The figure which shows the gain characteristic of multifrequency shared MSA in the 1st Embodiment of this invention The figure which shows the change of the resonant frequency and gain when changing the width | variety of the ring type MSA of 1st mode. The figure which shows the change of the resonant frequency and gain when changing the width | variety of 2nd mode ring type MSA The figure which shows the change of the resonant frequency and gain when changing the width | variety of the ring type MSA of 3rd mode The figure which shows multi-frequency common MSA which consists of four ring type MSAs and one square MSA in the 1st Embodiment of this invention. The figure which shows the return loss characteristic of the multi-frequency common use MSA of FIG. The figure which shows the current pathway and current distribution of multi-frequency common use MSA of FIG. The figure which shows the radiation pattern of multi-frequency common use MSA of FIG. The figure which shows the gain characteristic of MSA of FIG. The figure which shows multi-frequency common MSA which consists of six ring type MSAs and one square MSA in the 1st Embodiment of this invention. The figure which shows the return loss characteristic of the multi-frequency common use MSA of FIG. The figure which shows the electric current path and electric current distribution of multifrequency common use MSA of FIG. The figure which shows the radiation pattern of multi-frequency common use MSA of FIG. The figure which shows the structure and return loss characteristic of multi-frequency common use MSA which removed square MSA in the 1st Embodiment of this invention. The figure which shows multi-frequency shared MSA with the polarization sharing characteristic in the 1st Embodiment of this invention The figure which shows the return loss characteristic and isolation characteristic of multi-frequency common use MSA of FIG. The figure which shows the structure of multifrequency common use MSA (left-handed-left-handed) in the 2nd Embodiment of this invention. The figure which shows the return loss characteristic and current distribution of multi-frequency common use MSA of FIG. The figure which shows the radiation pattern of multi-frequency common use MSA of FIG. The figure which shows the axial ratio of multi-frequency common use MSA of FIG. The figure which shows the structure of multifrequency shared MSA (left-handed-left-handed-left-handed) in the 2nd Embodiment of this invention. The figure which shows the return loss characteristic and current distribution of multi-frequency common use MSA of FIG. The figure which shows the radiation pattern of MSA of FIG. The figure which shows the axial ratio of multi-frequency common use MSA of FIG. The figure which shows the structure of multi-frequency shared MSA (right rotation-left rotation-left rotation) in the 2nd Embodiment of this invention. The figure which shows the return loss characteristic and current distribution of multi-frequency common use MSA of FIG. The figure which shows the radiation pattern of multi-frequency common use MSA of FIG. The figure which shows the axial ratio of MSA of FIG. FIG. 25 is a diagram showing the configuration of a multi-frequency shared MSA (straight-right rotation-left rotation) in the second embodiment of the present invention (note, FIG. 25 is a structural parameter including ΔS1, ΔS2, ΔS3, ΔS4, ΔS5, ΔS6, etc.) (Dimensions are different.) The figure which shows the return loss characteristic of the multi-frequency common use MSA of FIG. The figure which shows the axial ratio of multi-frequency common use MSA of FIG. The figure which shows the form (a) which applied the L probe electric power feeding method to the linearly polarized wave MSA, and the form (b) which applied the individual electric power feeding method The figure which shows the return loss characteristic in each form of FIG. The figure which shows the form (a) which applied the L probe electric power feeding method to circularly polarized MSA, and the form (b) which applied the individual electric power feeding method The figure which shows the return loss characteristic in each form of FIG. The figure which shows the structure of the conventional multi-frequency common use MSA The figure which shows the return loss characteristic of the conventional multi-frequency common use MSA The figure which shows the radiation pattern of the conventional multi-frequency common use MSA The figure which shows the structure of the conventional multi-frequency common use MSA

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Patch 2 Annular ring 3 Perturbation pattern 4 Ground conductor 7 Feed line 8 Feed line 9 Substrate 11 Insulating substrate 12 Radiation element 13 Ground conductor 14 Feed line 15 Slit 16 Slit 17 Ring-shaped element part 18 Ring-shaped element part 19 MSA element part 21 First insulating substrate 22 Radiating element 23 Second insulating substrate 24 Power feeding unit (L probe)
25 Ground conductor 26 Coaxial connector 31 Slit 32 Slit 33 Slit 221 Ring type MSA
222 Ring type MSA
223 Ring type MSA
224 Ring type MSA
225 Ring type MSA
226 Ring type MSA
227 Square MSA
241 L probe 242 L probe 2211 Perturbing element 2212 Perturbing element 2213 Perturbing element 2214 Perturbing element 2215 Perturbing element 2216 Perturbing element 2218 Perturbing element 2223 Perturbing element 2223 Perturbing element 2225 MSA
2231 perturbing element 2232 perturbing element 2233 perturbing element 2234 perturbing element 2235 perturbing element 2236 perturbing element 2237 perturbing element 2238 perturbing element

(First embodiment)
In the first embodiment of the present invention, a multi-frequency shared MSA capable of transmitting and receiving linearly polarized waves at a large number of frequencies will be described.
FIG. 1 shows a configuration of a multi-frequency shared MSA in the first embodiment of the present invention. 1A is a perspective view, and FIG. 1B is a cross-sectional view. FIG. 1C is an enlarged view of the L probe, and FIG. 1D is an enlarged view of the radiating element.
This multi-frequency shared MSA includes a radiating element 22 formed of a ring-shaped and rectangular metal conductor layer formed on the first insulating substrate 21 and a skewer-shaped metal conductor layer formed on the second insulating substrate 23. And a ground conductor 25 provided on the back surface of the second insulating substrate 23, and a coaxial connector 26 having a center conductor and an outer conductor.

The radiating element 22 includes a ring-shaped MSA 221, 222, and 223 having a square shape and a square MSA 227 having a square shape, and these are formed on three metal conductor layers on the first insulating substrate 21 that is an antenna unit substrate. It is formed by providing slits 31, 32, and 33.
A skewer-shaped metal conductor layer of the power feeding unit 24 includes a linear part having a length P1 that extends from the center of one side of the ring type MSA 221, 222, 223 to the lower part of the square MSA 227, and a ring type from both sides of the linear part. And a stub portion extending along the length of Pt along each of the MSAs 221, 222, and 223.
The tip of the central conductor of the coaxial connector 26 passes through the second insulating substrate 23 and is connected to the straight portion of the power feeding unit 24, and the outer conductor of the coaxial connector 26 insulated from the central conductor is connected to the ground conductor 25. Connected.
This power supply unit 24 is provided with a stub portion in a conventional “L probe” capable of electromagnetic coupling type power supply in a wide band, and by adjusting the length Pt of the stub portion, an eigenmode based on each resonance frequency is provided. Is consistent.
The second insulating substrate 23 serves as a power supply substrate constituting the L probe 24 and is laminated with the first insulating substrate 21 serving as an antenna portion substrate and the L probe 24 sandwiched therebetween.

In the radiating element 22 having the ring type MSA 221, 222, 223 and the rectangular MSA 227, four current paths shown in FIGS. 2 (a), (b), (c), and (d) are formed and supplied with power from the L probe 24. In some cases, a resonance phenomenon due to each current path appears. In FIG. 2, the current distribution of each current path obtained by the electromagnetic field simulator (electromagnetic field simulator (IE3D) using the moment method) is schematically shown by arrows. As shown in FIGS. 2A, 2B, 2C, and 2D, a uniform current distribution from the position of the L probe 24 toward the symmetrical position appears in each current path.
Here, the phenomenon based on the current distribution of the longest current path appearing in the ring type MSA 221 (FIG. 2A) is referred to as “1st mode”, and the second longest current path appearing in the ring type MSA 222 (FIG. 2B). The phenomenon based on the current distribution is “2nd mode”, the phenomenon based on the current distribution of the third longest current path appearing in the ring type MSA 223 (FIG. 2C) is “3rd mode”, and the shortest current path appearing in the square MSA 227 ( The phenomenon based on the current distribution in FIG. 2D is referred to as “4th mode”.

FIG. 3 shows the return loss characteristic of the multi-frequency shared MSA. However, various dimensions of the multi-frequency shared MSA indicated by reference numerals in FIG. 1 were set as follows (unit: mm).
a1 = b1 = 22.1, w1 = w2 = 1.6, w3 = 1.2, d1 = d2 = d3 = 0.4, Pl = 10.3, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 2.25, t1 = t2 = 1.2
The first and second insulating substrates 21 and 23 are Teflon (registered trademark) glass fiber substrates (PTFE substrates, relative dielectric constant εr = 2.6, tan δ = 1.8 × 10 ⁻³ ). The printed circuit board with the copper thin film deposited on the substrate was etched to form the radiating element 22 and the L probe 24.
In FIG. 3, the vertical axis represents the return loss value (dB) and the horizontal axis represents the frequency (GHz). In the figure, the solid line indicates the actual measurement value (Exp), and the dotted line indicates the simulation value (Sim).

In FIG. 3, (a) the resonance phenomenon observed at 2.69 GHz (Exp) (2.68 GHz (Sim)) corresponds to the current distribution of the 1st mode. Also, (b) 3.35 GHz (Exp) (3.36 GHz (Sim)), (c) 4.32 GHz (Exp) (4.33 GHz (Sim)) and (d) 6.62 GHz (Exp) (6. The resonance phenomenon at 59 GHz (Sim) corresponds to the current distribution in the 2nd mode, 3rd mode, and 4th mode, respectively.
As is apparent from FIG. 2, as the mode order increases, the path length of the current path corresponding to each mode is shortened, and as shown in FIG. 3, the resonance frequency of each mode increases. Yes.
As described above, this multi-frequency shared MSA realizes multiband characteristics having four different frequencies as operating frequencies. In addition, as can be seen from FIG. 3, the actual measurement value of the return loss characteristic agrees well with the simulation value within a design-significant range.

FIG. 4 shows radiation patterns in the 1st mode, 2nd mode, 3rd mode and 4th mode of this multi-frequency shared MSA in (a), (b), (c) and (d). In this figure, at each resonance frequency, not only the radiation pattern on the E plane, but also the radiation pattern on the H plane is shown for reference. In the figure, the solid line indicates the radiation pattern, and the dotted line indicates the cross polarization level.
As is clear from FIG. 4, the radiation patterns in the 1st mode, 2nd mode, 3rd mode, and 4th mode show good unidirectional patterns on both the E plane and the H plane, and the cross polarization component is also in the zenith direction (θ = 0 °), the worst value is suppressed to −20 dB or less.
FIG. 5 shows gain values in the respective modes. In this figure, the horizontal axis represents frequency and the vertical axis represents gain. A gain of 4.0 dBi or more is obtained in all of the 1st mode, 2nd mode, 3rd mode, and 4th mode.

As described above, this multi-frequency shared MSA can hold more resonance frequencies even though the area of the radiating element 22 is the same as that of the radiating element 12 in FIG. The characteristics of the radiation pattern are not inferior to those of the MSA in FIG.
Since the L probe 24 formed into the multi-frequency shared MSA skewer is set so that the length of the stub can be matched in each mode, the resonance frequency of each mode extends over a wide range. Therefore, it is possible to efficiently supply a power supply signal that covers the entire range, which contributes to the realization of excellent multi-frequency sharing characteristics.

Next, a method for controlling the resonance frequency of the multi-frequency shared MSA will be described.
In this multi-frequency shared MSA, the resonance frequency can be changed by changing the position of the slit formed in the metal conductor layer on the antenna part substrate and changing the length of the current path in each mode.
In FIG. 6, in order to change the length of the current path in the 2nd mode, as shown in FIG. 6A, the width W1 of the ring-type MSA 221 in the 1st mode is changed (that is, the position of the slit 31 is changed). The change of the resonance frequency of the 1st mode and 2nd mode in the case is shown (the width d of the slit 31 is fixed to 0.4 mm). FIG. 6B shows current paths in the 1st mode and the 2nd mode at this time, and FIG. 6C shows a graph of the change in the resonance frequency according to the width W1. In this figure, the horizontal axis represents W1 (mm) and the vertical axis represents the resonance frequency (GHz). FIG. 6D is a graph showing changes in the gain value accompanying changes in the width W1. In this figure, the horizontal axis represents W1 (mm), and the vertical axis represents gain (dBi).

  Further, in FIG. 7, in order to change the length of the current path in the 3rd mode, as shown in FIG. 7A, the width W1 of the ring MSA 221 in the 1st mode is fixed and the ring MSA 222 in the 2nd mode is fixed. The change of the resonance frequency of the 1st mode, 2nd mode, and 3rd mode when the width W2 is changed is shown (the width d of the slits 31 and 32 is fixed to 0.4 mm, and W1 is fixed to 1.6 mm). FIG. 7B shows the current paths of the 1st mode, 2nd mode, and 3rd mode at this time, and FIG. 7C shows the change of the resonance frequency according to the width W2 in a graph. d) is a graph showing the change of the gain value accompanying the change of the width W2.

  Further, in FIG. 8, in order to change the length of the 4th mode current path, as shown in FIG. 8A, the width W1 of the 1st mode ring type MSA 221 and the width W2 of the 2nd mode ring type MSA 222 are Fig. 5 shows changes in the resonance frequency of the 1st mode, 2nd mode, 3rd mode, and 4th mode when the width W3 of the ring-type MSA 223 in the 3rd mode is changed and the width d of the slits 31, 32, and 33 is 0. 4mm, W1 and W2 are fixed at 1.6mm). The current paths in the 1st mode, 2nd mode, 3rd mode, and 4th mode at this time are as shown in FIG. FIG. 8B is a graph showing a change in the resonance frequency according to the width W3, and FIG. 8C is a graph showing a change in the gain value accompanying the change in the width W3.

  As apparent from FIGS. 6 to 8, the resonance frequency can be changed by changing the length of the current path in each mode. Even if the width of the ring type MSA increases, the resonance frequency of the ring type MSA hardly changes. This indicates that the current path is formed in the vicinity of the outermost periphery of the ring type MSA or the rectangular MSA. The value of the gain greatly affects the width of the ring-type MSA. If the width is narrow, the gain decreases.

This multi-frequency shared MSA can further increase the number of modes.
FIG. 9 shows a multi-frequency shared MSA in which the radiating element 22 includes four ring MSAs 221, 222, 223, 224 and one rectangular MSA 227. 9A is a perspective view, FIG. 9B is a cross-sectional view, and FIG. 9C is an enlarged view of the radiating element.
Various dimensions of the multi-frequency shared MSA are set as follows (unit: mm).
a = b = 22.1, w1 = w2 = w3 = w4 = 0.8, d1 = d2 = d3 = d4 = 0.4, Pl = 10.8, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 1.25, t1 = t2 = 1.2
The first and second insulating substrates 21 and 23 were the same as those shown in FIG.
The L probe 24 is provided with a stub portion corresponding to each of the ring type MSAs 221, 222, 223, and 224.

  FIG. 10 shows the return loss characteristics (simulated values) of this multi-frequency shared MSA. In FIG. 10, (a) 2.58 GHz is 1st mode, (b) 2.95 GHz is 2nd mode, (c) 3.39 GHz is 3rd mode, (d) 3.99 GHz is 4th mode, (e) 5.20 GHz. Is the first higher-order mode of the 1st mode, (f) 5.91 GHz corresponds to the first higher-order mode of the 2nd mode, and (g) 6.42 GHz corresponds to the 5th mode.

  FIGS. 11A to 11G show current paths and current distributions in the respective modes of FIG. In each of the current paths of (a) 1st mode, (b) 2nd mode, (c) 3rd mode, (d) 4th mode, and (g) 5th mode, one is directed from the position of the L probe 24 toward its symmetrical position. Various current distributions appear. On the other hand, in (e) the first higher-order mode in the 1st mode and (f) the first higher-order mode in the 2nd mode, a current distribution in which the current direction is reversed in the middle of the current path appears.

  12A to 12G show radiation patterns in each mode of FIG. (E) The first higher-order mode in 1st mode and the first higher-order mode in (f) 2nd mode show high cross polarization levels, but (a) 1st mode, (b) 2nd mode, ( In each of the c) 3rd mode, (d) 4th mode, and (g) 5th mode, the radiation pattern has a good unidirectional property and the cross polarization level is extremely low.

FIG. 13 shows gain values in (a) 1st mode, (b) 2nd mode, (c) 3rd mode, (d) 4th mode, and (g) 5th mode.
As described above, this multi-frequency shared MSA removes the higher-order modes (e) and (f) from the object of use, so that (a) 1st mode, (b) 2nd mode, (c) 3rd mode, ( d) It can be used as a multi-frequency shared antenna exhibiting excellent characteristics in each mode of 4th mode and (g) 5th mode.

FIG. 14 shows a multi-frequency shared MSA in which the radiating element 22 includes six ring-type MSAs 221, 222, 223, 224, 225, and 226 and one rectangular MSA 227. FIG. 14A is a perspective view, FIG. 14B is a cross-sectional view, and FIG. 14C is an enlarged view of a radiating element.
Various dimensions of the multi-frequency shared MSA are set as follows (unit: mm).
a = b = 22.1, w1-w6 = 0.4, d1-d6 = 0.4, Pl = 10.8, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 3.75, t1 = t2 = 1.2
The first and second insulating substrates 21 and 23 were the same as those shown in FIG.
The L probe 24 is provided with a stub portion corresponding to each of the ring type MSAs 221, 222, 223, 224, 225, and 226.

FIG. 15 shows the return loss characteristic (simulation value) of this multi-frequency shared MSA. In FIG. 15, (a) 2.53 GHz is 1st mode, (b) 2.77 GHz is 2nd mode, (c) 3.01 GHz is 3rd mode, (d) 3.30 GHz is 4th mode, (e) 3.65 GHz. Corresponds to the 5th mode, (f) 4.09 GHz corresponds to the 6th mode, and (g) 6.69 GHz corresponds to the 7th mode.
FIGS. 16A to 16G show current paths and current distributions in the respective modes of FIG. In each current path of each mode, a uniform current distribution appears from the position of the L probe 24 toward its symmetrical position.
FIGS. 17A to 17G show the radiation patterns in each mode of FIG. Each mode shows a radiation pattern with good unidirectionality, and the cross polarization level is extremely low.

  Thus, the multi-frequency shared MSA includes (a) 1st mode, (b) 2nd mode, (c) 3rd mode, (d) 4th mode, (e) 5th mode, (f) 6th mode, and (g ) It can be used as a multi-frequency shared antenna exhibiting excellent characteristics in each mode of the 7th mode.

In these multi-frequency shared MSAs, only the ring type MSA can be used as a radiating element except for the square MSA. FIG. 18 shows, as an example, the shape of a radiating element (FIG. 18 (a)) and the return loss characteristic (FIG. 18 (b)) of a multi-frequency shared MSA composed of only ring-type MSAs 221, 222, and 223. .
Various dimensions of the multi-frequency shared MSA were set as follows (unit: mm).
a = b = 22.1, w1 = w2 = 1.6, w3 = 1.2, d1 = d2 = 0.4, Pl = 5.2, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 0.25, t1 = t2 = 1.2
When the square MSA is removed in this way, the central portion of the radiating element can be used as the installation location of the attached circuit element, and the antenna device can be downsized.

In addition, as shown in FIG. 19, this multi-frequency shared MSA is provided with two L probes 241 and 242 at orthogonal positions so that the linearly polarized waves that are perpendicular to each other and vertically polarized waves are shared. It can be used as a wave sharing antenna. FIG. 19A is a perspective view thereof, and FIG. 19B is an enlarged view of the radiating element.
In the polarization sharing characteristic, it is necessary to transmit and receive two orthogonal polarized waves independently without interfering with each other, the cross polarization level is low, and the isolation characteristic is good. The amount of energy supplied from one port to the other port is required to be small.
Various dimensions of the multi-frequency shared MSA are set as follows (unit: mm).
a = b = 22.1, w1 = w2 = 1.6, w3 = 1.2, d1 = d2 = 0.4, P1l = P12 = 5.8, Pw1 = Pw2 = 1.5, Ps1 = Ps2 = 0.8, Pd1 = Pd2 = 0.8

FIG. 20 shows the return loss characteristic and isolation characteristic of this multi-frequency shared MSA. In the figure, the solid line shows the return loss characteristic, and the scale is shown on the left side. The dotted line indicates the isolation characteristic, and the scale is shown on the right side.
The isolation at each resonance frequency shows a value of −30 dB or less, and good characteristics are obtained.
As described above, in this multi-frequency shared MSA, the polarization sharing characteristic can be easily realized by adding another L probe.

Although the radiation characteristics of the multi-frequency shared MSA have been described so far, it is obvious from the “reciprocity” of the antenna that the same characteristics can be obtained when the multi-frequency shared MSA is used as a receiving antenna. .
As described above, the multi-frequency shared MSA has utility as a multi-band antenna having a planar structure that transmits and receives linearly polarized radio waves. This multi-frequency shared MSA is used, for example, as a 3-frequency shared multi-band antenna for cellular phones that receive GSM, DCS and PCS systems, and for wireless LAN (2.4 GHz band and 5.0 GHz band) and VICS. An application as a (2.5 GHz band) multiband antenna can be assumed. Further, mobile communication (vertical polarization) and television reception (horizontal polarization) can be shared, and polarization diversity reception can be performed. Moreover, it can also be used as an antenna that can handle any frequency band.

  Here, the case where the ring type MSA is formed in a square shape and the square MSA is formed (or not formed) in the center has been described, but the shapes of the ring type MSA and the central MSA are square, rectangular, regular six Any shape that is symmetrical with respect to the center line, such as a square, equilateral triangle, or circle, may be used. At this time, the L probe is arranged at the position of the center line.

  Further, here, a case where a Teflon (registered trademark) glass fiber substrate is used as a substrate and the copper thin film formed on the substrate is etched to form the radiation element 22 and the L probe 24 has been described. However, the present invention is not limited to this, and for example, a conductive pattern such as a radiating element or an L probe may be printed on a ceramic green sheet with a metallized paste containing metal powder, and then stacked and fired.

(Second Embodiment)
In the second embodiment of the present invention, a multi-frequency shared MSA that can freely set polarization characteristics at a plurality of operating frequencies will be described.
FIG. 21 shows the configuration of the multi-frequency shared MSA in the second embodiment of the present invention. FIG. 21A is a perspective view, and FIG. 21B is a cross-sectional view. FIG. 21C is an enlarged view of the L probe, and FIG. 21D is an enlarged view of the radiating element.
This multi-frequency shared MSA includes a radiating element 22 formed of a ring-shaped and rectangular metal conductor layer formed on the first insulating substrate 21 and a skewer-shaped metal conductor layer formed on the second insulating substrate 23. And a ground conductor 25 provided on the back surface of the second insulating substrate 23, and a coaxial connector 26 having a center conductor and an outer conductor.

The radiating element 22 includes a square frame-shaped ring type MSA 221 and a square square MSA 2230, which are provided with one slit 31 in the metal conductor layer on the first insulating substrate 21 which is an antenna portion substrate. It is formed by. The ring type MSA 221 has perturbation elements 2211 and 2122, which are formed by cutting the metal conductor layer in a triangular shape at two corners on the diagonal line, and the square MSA 2230 has two corners on the diagonal line intersecting with the diagonal line. The same perturbation elements 2231 and 2232 are formed.
The skewer-shaped metal conductor layer of the power feeding section 24 has a straight line portion having a length P1 that crosses the center of one side of the ring type MSA 221 to reach the square MSA 2230, and a length along the ring type MSA 221 from both sides of the straight line portion. And a stub portion extending by Pt.

The tip of the central conductor of the coaxial connector 26 passes through the second insulating substrate 23 and is connected to the straight portion of the power feeding unit 24, and the outer conductor of the coaxial connector 26 insulated from the central conductor is connected to the ground conductor 25. Connected.
This power supply unit 24 is provided with a stub portion in a conventional “L probe” capable of electromagnetically coupling type power supply in a wide band, and the length Pt of this stub portion is adjusted so that the ring type MSA 221 is involved. The mode is consistent.
The second insulating substrate 23 serves as a power supply substrate constituting the L probe 24 and is laminated with the first insulating substrate 21 serving as an antenna portion substrate and the L probe 24 sandwiched therebetween.

In this multi-frequency shared MSA, various dimensions indicated by symbols in FIG. 21 are set as follows.
a = b = 22.1, w1 = 1.6, d1 = 0.4, Pl = 9.8, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 2.25, t1 = t2 = 1.2 (above, the unit is mm).
Further, when the area of the perturbation element 2231 of the square MSA 2230 is ΔS1 and the area of the perturbation element 2232 is ΔS2, ΔS1 = ΔS2, and the total area when the perturbation element of the square MSA2230 is not loaded (the area including the area of the perturbation element) ) Is set to 2.63% (represented as “ΔS1 + ΔS2 = 2.63%”), the area of the perturbation element 2211 of the ring type MSA 221 is ΔS3, and the area of the perturbation element 2212 is When ΔS4, ΔS3 = ΔS4, and the ratio of (ΔS3 + ΔS4) to the total area when the perturbation element of the ring type MSA 221 is not loaded is set to ΔS3 + ΔS4 = 0.95%.
The first and second insulating substrates 21 and 23 are Teflon (registered trademark) glass fiber substrates (PTFE substrates, relative dielectric constant εr = 2.6, tan δ = 1.8 × 10 ⁻³ ). The printed circuit board with the copper thin film deposited on the substrate is etched to form the radiating element 22 and the L probe 24.

When receiving power, the ring type MSA 221 of the radiating element 22 is formed with a first current path starting at a point on the L probe 24 and ending at a point facing the starting point. By the action of the perturbation elements 2211 and 2122, a second current path in a direction orthogonal to the first current path is formed. Therefore, in the ring-type MSA 221 that has received power supply, as schematically shown in FIG. 22A, the current distribution flowing in the first current path (white arrow) and the current distribution flowing in the second current path (Black arrows) occur, and these currents are orthogonal.
The magnitudes ΔS3 and ΔS4 of the perturbation elements 2211 and 2122 are set so that the phase difference between the orthogonal currents is ± 90 °. Therefore, the circular MSA 221 emits circularly polarized radio waves.

  When the ring type MSA 221 exists alone, as shown in FIG. 22A, when the perturbation elements 2211 and 2122 are loaded on the left side of the side where the L probe 24 is located and the diagonal position thereof, When right-handed polarized waves (circularly polarized waves turning rightward with respect to the traveling direction of the radio wave) are generated, and conversely, when a perturbation element is loaded on the right side of the side where the L probe 24 is located and the diagonal position thereof, , Left-handed polarization occurs. However, when other MSAs are adjacent to each other, the turning direction of the circularly polarized wave changes due to the interaction with the other MSA.

Similarly, the square MSA 2230 that has been supplied with power also has a first current path starting from a point on the L probe 24 and ending at a point facing the starting point, and the first MS 2230 caused by the perturbation elements 2231 and 2232. The first current path and the second current path in the direction orthogonal to the first current path are formed (note that the first current path and the second current path are formed near the periphery of the square MSA 2230). Therefore, in the square MSA 2230 that has received power supply, as schematically shown in FIG. 22 (b), the current distribution (white arrow) flowing in the first current path and the second current path orthogonal thereto are shown. A flowing current distribution (black arrow) occurs.
The magnitudes ΔS1 and ΔS2 of the perturbation elements 2231 and 2232 are adjusted so that the phase difference between the orthogonal currents is ± 90 °, and therefore circularly polarized radio waves are also radiated from the square MSA 2230.

FIG. 22C shows the return loss characteristic of the multi-frequency shared MSA. The vertical axis represents the return loss value (dB), and the horizontal axis represents the frequency (GHz).
The return loss value (dB) is usually considered to be less than −10 dB for an antenna, but in this multi-frequency shared MSA, (a) 2.75 GHz and (b) 4.68 GHz, The value greatly exceeds -10 dB. (A) The 2.75 GHz resonance phenomenon is distorted by the current distribution of the ring type MSA 221, and this will be referred to as “1st mode”. Further, (b) the resonance phenomenon of 4.68 GHz is suppressed by the square MSA 2230, and this is referred to as “2nd mode”.

  FIG. 23A shows a radiation pattern in the 1st mode, and FIG. 23B shows a radiation pattern in the 2nd mode. In FIGS. 23 (a) and 23 (b), the outer solid line and the dotted line (the solid line and the dotted line substantially overlap) are referred to as a plane including the width direction of the L probe and the zenith direction (hereinafter referred to as “φ = 0 ° plane”). )) And the radiation level of the left-handed polarized wave in a plane including the length direction and the zenith direction of the L probe (hereinafter referred to as “φ = 90 ° plane”), and the inner solid line and dotted line indicate φ = 0 ° The radiation level of right-handed polarization in the plane and the φ = 90 ° plane is shown. From this radiation pattern, it can be seen that the multi-frequency shared MSA generates a left-handed polarized wave in both the 1st mode and the 2nd mode.

FIG. 24 shows the axial ratio of circularly polarized light radiated in the zenith direction (θ = 0). The value (dB) of the axial ratio is calculated by 20 × log (a / b), where a is the major axis of the ellipse and b is the minor axis. Therefore, with perfect circular polarization, the axial ratio value is 0 dB. Generally, if it is 3 dB or less, it is regarded as circular polarization.
24C shows the axial ratio at each frequency, FIG. 24A is an enlarged view of the axial ratio in the 1st mode (2.75 GHz), and FIG. 24B shows the 2nd mode (4 .68 GHz) is an enlarged view of the axial ratio. The axial ratio of the 1st mode and the 2nd mode is about 0.5 dB, indicating that a good circularly polarized wave is generated.
Thus, this multi-frequency shared MSA can generate a left-handed circularly polarized wave at each of two different frequencies.

The installation positions and sizes of the perturbation elements 2211, 2122, 2231, and 2232 need to be adjusted so that a desired polarization characteristic is obtained in each mode. In this multi-frequency shared MSA, first, the positions and sizes of the perturbation elements 2231 and 2232 are set so that the square MSA 2230 generates a left-handed polarized wave at the frequency of the 2nd mode, and then the ring-type MSA 221 is connected to the square MSA 2230. The positions and sizes of the perturbation elements 2211 and 2122 are set so as to generate the left-handed polarized wave at the frequency of the 1st mode while receiving the above interaction.
The positions and sizes of the perturbation elements 2211, 2122, 2231, and 2232 thus obtained are shown in FIG. In this case, the positions and sizes of the perturbation elements 2211 and 2212 of the ring type MSA 221 may be determined first, and the positions and sizes of the perturbation elements 2231 and 2232 of the square MSA 2230 may be determined later. Further, it is possible to set one or both of the rectangular MSA 2230 and the ring type MSA 221 to the right-handed polarized wave by the same procedure.
The length of the stub of the L probe 24 is set so as to be matched with the ring type MSA 221 in the 1st mode.

  In the multi-frequency shared MSA, the resonance frequency can be changed by changing the length of the current path in each mode. Even when the outer shape of the radiating element 22 is kept constant, the length of the current path of the rectangular MSA 2230 is changed by moving the position of the slit 31 formed in the metal conductor layer on the antenna unit substrate 21, and the resonance thereof. The frequency can be changed. Since the current path of the ring type MSA 221 is formed near the outer periphery of the ring, the resonance frequency does not change to the left even if the position of the slit 31 is moved.

This multi-frequency shared MSA can further increase the number of modes and arbitrarily set the polarization characteristics.
FIG. 25 shows a multi-frequency shared MSA in which the radiating element 22 includes two ring MSAs 221, 222 having a perturbing element and a rectangular MSA 2230, and each MSA 221, 222, 223 generates a left-handed circularly polarized wave. Yes. 25A is a perspective view, FIG. 25B is a cross-sectional view, FIG. 25C is an enlarged view of an L probe, and FIG. 25D is an enlarged view of a radiating element. The L probe 24 is provided with a stub portion corresponding to each of the ring type MSAs 221 and 222.

Various dimensions of the multi-frequency shared MSA are set as follows.
a1 = b1 = 22.1, w1 = w2 = 1.6, d1 = d2 = 0.4, Pl = 10.8, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 2.25, t1 = t2 = 1.2 (above, unit is mm).
Further, the area of the perturbation element 2233 of the square MSA 2230 is ΔS1, the area of the perturbation element 2234 is ΔS2, the area of the perturbation element 2221 of the ring MSA 222 is ΔS3, the area of the perturbation element 2222 is ΔS4, and the area of the perturbation element 2213 of the ring MSA 221 Is ΔS5 and the area of the perturbation element 2214 is ΔS6, ΔS1 = ΔS2, ΔS3 = ΔS4, ΔS5 = ΔS6, and ΔS1 + ΔS2 = 3.65%, ΔS3 + ΔS4 = 0.71%, ΔS5 + ΔS6 = 0.51% is doing.
The first and second insulating substrates 21 and 23 are the same as those shown in FIG.

  FIG. 26 (d) shows the return loss characteristic of the multi-frequency shared MSA. In the figure, resonance phenomena appearing in (a) 2.73 GHz, (b) 3.43 GHz, and (c) 5.87 GHz are generated based on the current distribution of the ring type MSA 221, the ring type MSA 222, and the square MSA 2230, respectively. These are referred to as “1st mode”, “2nd mode”, and “3rd mode”. FIG. 26A, FIG. 26B, and FIG. 26C schematically show current distributions in the 1st mode, the 2nd mode, and the 3rd mode, respectively. Note that the resonance phenomenon appearing in the vicinity of 5.3 GHz in FIG. 26D is a high-order mode of the 1st mode, which needs to be excluded from the frequency to be shared.

  FIG. 27A shows a radiation pattern in the 1st mode, FIG. 27B shows a radiation pattern in the 2nd mode, and FIG. 27C shows a radiation pattern in the 3rd mode. 27A, 27B, and 27C, the outer solid line and the dotted line (the solid line and the dotted line almost overlap each other) indicate the radiation levels of the left-handed polarized wave in the φ = 0 ° plane and the φ = 90 ° plane. The inner solid line and dotted line indicate the radiation level of right-handed polarized waves in the φ = 0 ° plane and the φ = 90 ° plane. From this radiation pattern, it can be seen that the multi-frequency shared MSA generates a left-handed polarized wave in any of the 1st mode, the 2nd mode, and the 3rd mode.

  FIG. 28 (d) shows the axial ratio at each frequency, FIG. 28 (a) is an enlarged view of the axial ratio in the 1st mode (2.73 GHz), and FIG. 28 (b) shows the 2nd mode (3 FIG. 28C is an enlarged view of the axial ratio in the 3rd mode (5.87 GHz). The axial ratio of the 1st mode is 0.5 dB, the axial ratio of the 2nd mode and the 3rd mode is about 1 dB, indicating that good circular polarization is generated in any mode.

  In this multi-frequency shared MSA, first, the positions and sizes of the perturbation elements 2233 and 2234 are set so that the square MSA 2230 generates a left-handed polarized wave at the frequency of the 3rd mode, and then the ring type MSA 222 is connected to the square MSA 2230. The positions and sizes of the perturbation elements 2221 and 2222 are set so as to generate left-handed polarization at the frequency of the 2nd mode while receiving the interaction of the ring MSA 2230 and the ring MSA 222. The positions and sizes of the perturbation elements 2213 and 2214 are set so that the left-handed polarized wave is generated at the frequency of the 1st mode while receiving the above interaction.

  The positions and sizes of the perturbation elements 2213, 2214, 2221, 2222, 2233, and 2234 thus obtained are shown in FIG. In this case, the position and size of the perturbation element of the ring type MSA 221 or the ring type MSA 222 may be determined first, and the position and size of the perturbation element of the square MSA 2230 may be determined later. Further, in the same procedure, one or more of the square MSA 2230, the ring type MSA 222, and the ring type MSA 221 can be set to the right-handed polarization.

The length of the stub of the L probe 24 is set so as to be matched with the ring type MSA 221 in the 1st mode and matched with the ring type MSA 222 in the 2nd mode. Thus, by setting the length of the stub of the L probe 24 formed into a skewer shape so that matching can be achieved in each mode, the range for the current path of each mode in which the resonance frequency extends over a wide range. It is possible to efficiently supply a power supply signal that covers all of the above.
Further, in this multi-frequency shared MSA, the length of the current path of the ring type MSA 222 or the rectangular MSA 2230 is changed by moving the positions of the slits 31 and 32 formed in the metal conductor layer on the first insulating substrate 21. Their resonant frequency can be changed.

  29, the radiating element 22 includes two ring MSAs 221, 222 having a perturbing element and a rectangular MSA 2230. The ring MSA 221 is a clockwise circular polarization, and the ring MSA 222 and the rectangular MSA 2230 are counterclockwise circularly polarized. A multi-frequency shared MSA that generates waves is shown. 29A is a perspective view, FIG. 29B is a cross-sectional view, FIG. 29C is an enlarged view of an L probe, and FIG. 29D is an enlarged view of a radiating element. The L probe 24 is provided with a stub portion corresponding to each of the ring type MSAs 221 and 222.

Various dimensions of the multi-frequency shared MSA are set as follows.
a1 = b1 = 22.1, w1 = w2 = 1.6, d1 = d2 = 0.4, Pl = 10.8, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 2.25, t1 = t2 = 1.2 (above, unit is mm).
Further, the area of the perturbation element 2235 of the square MSA 2230 is ΔS1, the area of the perturbation element 2236 is ΔS2, the area of the perturbation element 2223 of the ring MSA 222 is ΔS3, the area of the perturbation element 2224 is ΔS4, and the area of the perturbation element 2215 of the ring MSA 221 Is ΔS5, and the area of the perturbation element 2216 is ΔS6, ΔS1 = ΔS2, ΔS3 = ΔS4, ΔS5 = ΔS6, and ΔS1 + ΔS2 = 3.65%, ΔS3 + ΔS4 = 0.66%, ΔS5 + ΔS6 = 0.03% is doing.
The first and second insulating substrates 21 and 23 are the same as those shown in FIG.

  FIG. 30 (d) shows the return loss characteristics of the multi-frequency shared MSA. In the figure, the resonance phenomena appearing in (a) 2.71 GHz, (b) 3.43 GHz, and (c) 5.87 GHz are generated based on the current distributions of the ring type MSA 221, the ring type MSA 222, and the square MSA 2230, respectively. These are referred to as “1st mode”, “2nd mode”, and “3rd mode”. FIG. 30A, FIG. 30B, and FIG. 30C schematically show current distributions in the 1st mode, the 2nd mode, and the 3rd mode, respectively.

  FIG. 31A shows a radiation pattern in the 1st mode, FIG. 31B shows a radiation pattern in the 2nd mode, and FIG. 31C shows a radiation pattern in the 3rd mode. In FIG. 31 (a), the outer solid line and the dotted line (the solid line and the dotted line substantially overlap) indicate the radiation levels of right-handed polarized waves in the φ = 0 ° plane and the φ = 90 ° plane, and the inner solid line and The dotted lines indicate the radiation level of the left-handed polarized wave in the φ = 0 ° plane and the φ = 90 ° plane. Further, in FIGS. 31 (b) and 31 (c), the outer solid line and the dotted line (the solid line and the dotted line substantially overlap) indicate the radiation level of the left-handed polarized wave in the φ = 0 ° plane and the φ = 90 ° plane, The inner solid line and dotted line indicate the radiation levels of right-handed polarized waves in the φ = 0 ° plane and the φ = 90 ° plane. From this radiation pattern, it can be seen that in this multi-frequency shared MSA, a right-handed polarized wave is generated in the 1st mode and a left-handed polarized wave is generated in the 2nd mode and the 3rd mode.

  FIG. 32 (d) shows the axial ratio at each frequency, FIG. 32 (a) is an enlarged view of the axial ratio in the 1st mode (2.71 GHz), and FIG. 32 (b) shows the 2nd mode (3 FIG. 32C is an enlarged view of the axial ratio in the 3rd mode (5.87 GHz). The axial ratio of the 1st mode and the 2nd mode is 0.5 dB or less, and the axial ratio of the 3rd mode is about 1 dB, indicating that a good circularly polarized wave is generated in any mode.

  In this multi-frequency shared MSA, first, the positions and sizes of the perturbation elements 2235 and 2236 are set so that the square MSA 2230 generates a left-handed polarized wave at the frequency of the 3rd mode, and then the ring type MSA 222 is connected to the square MSA 2230. The positions and sizes of the perturbation elements 2223 and 2224 are set so as to generate left-handed polarization at the frequency of the 2nd mode while receiving the interaction of the ring MSA 2230 and the ring MSA 222. The positions and sizes of the perturbation elements 2225 and 2226 are set so as to generate right-handed polarization at the frequency of the 1st mode while receiving the above interaction.

  The positions and sizes of the perturbation elements 2215, 2216, 2223, 2224, 2235, and 2236 thus obtained are shown in FIG. In this case, the position and size of the perturbation element of the ring type MSA 221 or the ring type MSA 222 may be determined first, and the position and size of the perturbation element of the square MSA 2230 may be determined later.

  33, the radiating element 22 includes two ring MSAs 221, 222 having a perturbing element and a rectangular MSA 2230. The ring MSA 221 is linearly polarized and the ring MSA 222 is right-handed circularly polarized, square. The MSA 2230 shows a multi-frequency shared MSA that generates a left-handed circularly polarized wave. 33 (a) is a perspective view, FIG. 33 (b) is a cross-sectional view, FIG. 33 (c) is an enlarged view of an L probe, and FIG. 33 (d) is an enlarged view of a radiating element. The L probe 24 is provided with a stub portion corresponding to each of the ring type MSAs 221 and 222.

Various dimensions of the multi-frequency shared MSA are set as follows.
a1 = b1 = 22.1, w1 = w2 = 1.6, d1 = d2 = 0.4, Pl = 10.8, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 2.25, t1 = t2 = 1.2 (above, unit is mm).
Further, the area of the perturbation element 2237 of the square MSA 2230 is ΔS1, the area of the perturbation element 2238 is ΔS2, the area of the perturbation element 2225 of the ring MSA 222 is ΔS3, the area of the perturbation element 2226 is ΔS4, and the area of the perturbation element 2217 of the ring MSA 221 Is ΔS5 and the area of the perturbing element 2218 is ΔS6, ΔS1 = ΔS2, ΔS3 = ΔS4, ΔS5 = ΔS6, and ΔS1 + ΔS2 = 3.65%, ΔS3 + ΔS4 = 1.21%, ΔS5 + ΔS6 = 0.41% is doing.
The first and second insulating substrates 21 and 23 are the same as those shown in FIG.

FIG. 34 shows the return loss characteristics of this multi-frequency shared MSA. The resonance phenomena appearing in (a), (b), and (c) in the figure are generated based on the current distribution of the ring type MSA 221, the ring type MSA 222, and the square MSA 2230, respectively, and these are referred to as “1st mode” “2nd”. The mode is called “3rd mode”.
FIG. 35D shows the axial ratio at each frequency, FIG. 35A is an enlarged view of the axial ratio in the 1st mode, and FIG. 35B is an enlarged view of the axial ratio in the 2nd mode. FIG. 35C is an enlarged view of the axial ratio in the 3rd mode. The axial ratio of the 1st mode is about 30 dB, and can be regarded as a linearly polarized wave. The axial ratio of the 2nd mode and the 3rd mode is 1 dB or less, indicating that a good circularly polarized wave is generated.

  In this multi-frequency shared MSA, first, the position and size of the perturbation elements 2237 and 2238 are set so that the square MSA 2230 generates a left-handed polarized wave at the frequency of the 3rd mode, and then the ring type MSA 222 is connected to the square MSA 2230. The position and size of the perturbation elements 2225 and 2226 are set so as to generate right-handed polarization at the frequency of the 2nd mode while receiving the interaction of the ring MSA 2221 and the ring MSA 2230. The positions and sizes of the perturbation elements 2217 and 2218 are set so as to generate linearly polarized waves at the frequency of the 1st mode while receiving the interaction with the.

  The positions and sizes of the perturbation elements 2217, 2218, 2225, 2226, 2237, and 2238 thus obtained are shown in FIG. In this case, the position and size of the perturbation element of the ring type MSA 221 or the ring type MSA 222 may be determined first, and the position and size of the perturbation element of the square MSA 2230 may be determined later.

  In this way, this multi-frequency shared MSA can increase the number of ring type MSAs to diversify the operating frequency, and the polarization characteristics of these operating frequencies can be represented by left-handed polarization and right-handed rotation. It can be freely set to polarization or linear polarization.

  Further, in this multi-frequency shared MSA, a radiating element can be constituted by only a ring type MSA except for a square MSA. By doing so, the central portion of the radiating element can be used as an installation location of the attached circuit element or used as an electrical connection location to the L probe, so that the antenna device can be downsized.

Although the radiation characteristics of the multi-frequency shared MSA have been described so far, it is obvious from the “reciprocity” of the antenna that the same characteristics can be obtained when the multi-frequency shared MSA is used as a receiving antenna. .
Therefore, the multi-frequency shared MSA of the present invention is a single device, for example, GPS (right-handed), satellite digital audio broadcasting (left-handed), ETC (right-handed), mobile communication (straight line), wireless LAN (straight line), etc. It can be used as an antenna capable of receiving.

  Here, the radiating element has a square outer shape, but the outer shape may be a regular polygon such as a regular triangle or a regular hexagon, or a shape such as a circle or an ellipse close to a circle.

  Further, here, a case where a Teflon (registered trademark) glass fiber substrate is used as a substrate and the copper thin film formed on the substrate is etched to form the radiation element 22 and the L probe 24 has been described. However, the present invention is not limited to this, and for example, a conductive pattern such as a radiating element or an L probe may be printed on a ceramic green sheet with a metallized paste containing metal powder, and then stacked and fired.

  In the multi-frequency shared MSA of the present invention, power is supplied to each radiating element by electromagnetic coupling using an L probe having a linear portion and a stub portion. The electromagnetic power feeding method (L probe power feeding method) using the L probe having this shape has the following advantages compared to the “individual power feeding method” in which power is fed by directly connecting a connector to each radiating element.

  In the L-probe power feeding method, multiband signals (signals having a plurality of frequencies) are transmitted and received by a single power feeding line, and the power feeding system can be configured simply. Therefore, the entire apparatus can be reduced in size. On the other hand, the individual power supply method requires a plurality of power supply lines corresponding to the number of radiating elements, and the entire apparatus cannot be configured compactly. When a large number of radiating elements are provided at a narrow interval, it becomes impossible to physically arrange the connector and the coaxial line connected thereto.

  In the L probe feeding method in which a single L probe feeds a plurality of radiating elements, a signal from an antenna system is processed, and then a distributor that divides the signal into a plurality of output ends, or each frequency component is separated / Although it is necessary to output to the transmission system through the duplexer to be selected, at present, distributors and duplexers are inexpensive, small, and lightweight and can be easily obtained, so there is no disadvantage. Rather, the advantage is that the multiband signal can be integrated and processed in one place. It is also possible to form a microwave integrated circuit (MMIC) by integrating the antenna system and the signal processing system.

In the individual power feeding method, when the multi-frequency shared MSA is miniaturized, the intervals between the plurality of connectors approach each other, electromagnetic coupling occurs between the central conductors of the connectors, and unnecessary radiation occurs. Therefore, good characteristics cannot be obtained.
36, FIG. 37, FIG. 38, and FIG. 39 show the difference in characteristics when the L-probe feeding method and the individual feeding method are applied to the multi-frequency shared MSA, and the results are shown.

FIG. 36 (a) shows the configuration of the present invention in which a linearly polarized MSA having three ring-type MSAs is electromagnetically fed by an L probe, and FIG. 36 (b) shows the same linearly polarized MSA individually. The structure in the case of supplying power directly by applying the power supply method is shown. Various dimensions of the multi-frequency shared MSA are as follows (unit: mm).
a1 = b1 = 22.1, w1 = w2 = 1.6, w3 = 1.2, d1 = d2 = 0.4, Pl = 5.2, Pw = 1.5, Ps = 0.8, Pd = 0.8, Pt = 2.25, t1 = t2 = 1.2
The relative dielectric constant of the insulating substrate is εr = 2.6.
In the individual power feeding method of FIG. 36 (b), pins (Port-1, Port-2, Port-3) are arranged at positions on the center line of each link type MSA to directly feed power. Port-1 is at position ρ1 from the end of the inner MSA conduction path (width w3), Port-2 is at position ρ2 from the end of the middle MSA conduction path (width w2), and Port-3 is It arrange | positions in the position of (rho) 3 from the end of the conductive path (width w1) of outside MSA.

FIG. 37 (a) shows the return loss characteristic in the case of the L-probe power supply method, and resonances (a), (b), and (c) appear.
In FIG. 37 (b-1), the individual feeding method is applied by setting ρ1 = w3 / 2, ρ2 = w2 / 2, and ρ3 = w1 / 2 (that is, the pin is set at the center of the conductive path). FIG. 37 (b-2) shows the return loss characteristics at the time when ρ1 = w3 / 3, ρ2 = w2 / 4, and ρ3 = w1 / 4 (that is, the pin is set to 0. 0 from the end of the conductive path). FIG. 37 (b-3) shows the return loss characteristics when the individual power feeding method is applied (set at a position of 4 mm), and FIG. 37 (b-3) shows ρ1 = w3 / 4.8, ρ2 = w2 / 6.4, ρ3 The return loss characteristic is shown when the individual power feeding method is applied by setting = w1 / 6.4 (that is, the pin is set near the end of the conductive path). The solid line (S11) indicates the return loss characteristic of Port-1, the dotted line (S22) indicates the return loss characteristic of Port-2, and the alternate long and short dash line (S33) indicates the return loss characteristic of Port-3.
From this result, it can be seen that in the case of the individual feeding method, matching with the resonance frequency cannot be achieved.

FIG. 38A shows the configuration of the present invention in which a circularly polarized MSA including two ring MSAs having a perturbation element and a square MSA is electromagnetically fed by an L probe, and FIG. 3 shows a configuration in the case where direct power feeding is applied to the same circularly polarized MSA by applying the individual power feeding method. Various dimensions of the multi-frequency shared MSA are as follows (unit: mm).
a1 = b1 = 22.1, a ′ = b ′ = 14.1, w1 = w2 = 1.6, d1 = d2 = 0.4, Pl = 10.8, Pw = 1.5, Ps = 0. 8, Pd = 0.8, Pt = 2.25, t1 = t2 = 1.2
The relative dielectric constant of the insulating substrate is εr = 2.6. The area of the perturbation element is set to ΔS1 + ΔS2 = 3.65%, ΔS3 + ΔS4 = 0.66%, and ΔS5 + ΔS6 = 0.03%.

  In the individual power feeding method of FIG. 38 (b), pins (Port-1, Port-2, Port-3) are arranged at positions on the center line of the square MSA and the two ring type MSAs to directly feed power. Port-1 is located at the position of ρ0 from the center position of the rectangular MSA, Port-2 is located at the position of ρ1 from the end of the inner ring type MSA conduction path (width w2), and Port-3 is the conductivity of the outer MSA. It arrange | positions in the position of (rho) 3 from the edge of a path | route (width w1).

FIG. 39A shows the return loss characteristic in the case of the L-probe power supply method, and resonances of (a), (b), and (c) appear.
In FIG. 39 (b-1), ρ0 = 0.40 (a ′ / 2), ρ1 = w2 / 2, ρ2 = w1 / 2 are set (that is, the pin is set at the center of the ring conductive path). ) Shows the return loss characteristics when the individual power feeding method is applied, and FIG. 39B-2 sets ρ0 = 0.40 (a ′ / 2), ρ1 = w2 / 4, and ρ2 = w1 / 4. (I.e., the pin is set at a position of 0.4 mm from the end of the ring conductive path) and the return loss characteristic when the individual feeding method is applied is shown, and FIG. 39 (b-3) shows ρ0 = 0. .40 (a ′ / 2), ρ1 = w2 / 6.4, ρ2 = w1 / 6.4 (ie, the pin is set near the end of the ring conductive path) and the individual feeding method is applied The return loss characteristics are shown. The solid line (S11) indicates the return loss characteristic of Port-1, the dotted line (S22) indicates the return loss characteristic of Port-2, and the alternate long and short dash line (S33) indicates the return loss characteristic of Port-3.

From this result, it can be seen that in the case of the individual power feeding method, matching can be achieved with respect to a part of the resonance frequency obtained by the L probe power feeding method, but matching with all the resonance frequencies is not possible.
As described above, in the multi-frequency shared MSA of the present invention, multi-frequency sharing becomes possible only by using the L probe power feeding method.

The multi-frequency shared MSA of the present invention can be widely used as a multi-frequency shared antenna in various fields including mobile communication, and can be used in any frequency band in an existing field using an antenna. Can be widely used.
In addition, the circularly polarized multi-frequency shared MSA can be widely used as an antenna that requires a large number of antennas, for example, an automobile in which the operating frequency is switched, and various fields require various fields. As an antenna that can handle any of the various antenna characteristics, it can be widely used in various fields.

Claims (4)

On one side of the board,
An annular antenna element formed of an annular planar conductive path having a symmetrical shape with respect to the center line;
A planar antenna element formed in a conductive plane inside the annular antenna element, the center position and the center line of the annular antenna element coincide with each other, and the outer shape is similar.
Wherein the outer annular antenna element formed by an annular planar conductive path, the loop antenna element and the center position and the center line coincides, comprising a one or a plurality of loop antenna elements whose shape similar,
On the other side of the substrate,
A linear portion that intersects each of the annular antenna elements at one position via the substrate at the position of the center line and faces the planar antenna element via the substrate at the position of the center line; An L probe having a stub portion extending from the linear portion along the annular antenna element by a predetermined length at a position where the annular portion intersects each of the annular antenna elements;
Each of the planar antenna element and the annular antenna element is fed from the electromagnetically coupled L probe and resonates at a different frequency, respectively.
The multi-frequency shared microstrip is characterized in that the length of the stub portion of the L probe is set so as to be matched in a state where each of the annular antenna elements resonates with the one frequency. antenna. 2. The multi-frequency shared microstrip antenna according to claim 1 , wherein the annular antenna element has a quadrangular outer shape and is electromagnetically coupled to the L probe at a central portion of one side of the quadrilateral. Multi-frequency shared microstrip antenna. 3. The multi-frequency shared microstrip antenna according to claim 1, wherein the annular antenna element and the planar antenna element have two center lines orthogonal to each other, and the L probe is positioned at each of the center lines. A multi-strip microstrip antenna characterized by being arranged in 2. The multi-frequency shared microstrip antenna according to claim 1, wherein the annular antenna element and the planar antenna element have outer shapes that are regular polygons or circles, and the annular antenna element and the planar antenna element are point-symmetric. A multi-frequency microstrip antenna having a perturbation element at a position .