JPH0555609U - Microstrip antenna - Google Patents

Abstract

(57) [Summary] (Modified) [Purpose] To obtain a compact and highly reliable microstrip antenna. A radiation electrode 11 and a ground electrode 12 are formed inside a dielectric laminated body 10 in which dielectric ceramic sheets are laminated, and the radiation electrode 11 is drawn out to the back surface by a conductor 16 filled in a through hole. Further, the radiation electrode and these circuit elements are connected to each other by being integrated with the ceramic laminated body containing the circuit elements. An active element or the like can be mounted on the back surface of the laminated body.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to the structure of a microstrip antenna used in a navigation system or the like, and relates to the structure of a microstrip antenna formed by stacking a dielectric and a conductor.

[0002]

[Prior Art]

 In GPS navigation systems and the like, a small antenna that receives signals from satellites is required, and the use of a microstrip antenna is considered as one of them.

This microstrip antenna has a radiation electrode having a size of ½ of the wavelength to be received on the front surface of a dielectric substrate, and a ground electrode on the entire back surface. There are square and circular radiating electrodes, and by devising their shape, the reception frequency can be broadened.

FIG. 3 is a front sectional view showing an example of the structure of such a conventional microstrip antenna. A radiation electrode 31 is formed on the front surface of a dielectric substrate 30 which is a sintered body of a dielectric ceramic, and a ground electrode 32 is formed on the back surface. From the 50Ω point of the radiation electrode 31, a conductor is drawn out to the back surface of the dielectric substrate 30 through the through hole. From here, it is connected to the receiving circuit by a coaxial line.

[0005]

[Problems to be solved by the device]

 There is an increasing demand for miniaturization and weight reduction of the above microstrip antenna.

Further, since it is mounted on an automobile, a structure and strength capable of withstanding a harsh environment are required, and a structure that does not cause deterioration of characteristics is desired.

The present invention is intended to obtain a highly reliable microstrip antenna that can be reduced in size and weight. Furthermore, it is intended to obtain a microstrip antenna having a good gain and capable of adjusting the resonance frequency.

[0008]

[Means for Solving the Problems]

 The present invention solves the above problems by forming a microstrip antenna with a laminated structure of a dielectric and a conductor and integrally forming electrodes and circuit elements therein.

That is, in a microstrip antenna having a radiation electrode on the front side and a ground electrode on the back side across the ceramic dielectric, the ceramic dielectric is a sintered body obtained by laminating ceramic dielectric sheets, and the radiation electrode and the ground electrode are grounded. The electrode is characterized in that it is sandwiched between ceramic dielectrics and formed inside the laminate.

Further, the passive element and the like are integrally formed in the laminated body, or the active element is mounted on the back surface so that the circuits of the antenna and the receiver can be integrally formed.

[0011]

[Action]

 With the above laminated structure, since the radiation electrode is in the dielectric, the leakage is reduced and the gain is improved. Further, since both the radiation electrode and the ground electrode are formed inside the dielectric body, it is easy to prevent deterioration due to changes in the external environment, and stable characteristics can be obtained. In addition, miniaturization is facilitated by integration with other circuit elements.

[0012]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a front sectional view showing an embodiment of the present invention. The dielectric laminate 10 is a sheet made of a dielectric ceramic material such as Mg—Ca—Ti system having a dielectric constant of about 20 by a doctor blade method, etc., laminated, pressure-bonded and fired. A radiation electrode 11 and a ground electrode 12 are provided inside the dielectric laminate 10. These electrodes are obtained by printing a paste of silver or the like on the surface of a laminated sheet and firing it at the same time as the dielectric.

A through hole is formed in the sheet corresponding to the 50 Ω point of the radiation electrode 11, and the conductor 16 is filled in the through hole. By this conductor 16, the radiation electrode 11 is led out to the radiation electrode 12 side, that is, the back surface, and connected to a coaxial line (not shown). The ground electrode is also drawn to the back surface in the same manner.

Since the distance between the radiation electrode 11 and the ground electrode 12 is relatively large, such as several mm, it is possible to stack and use sheets having large thickness. Alternatively, materials obtained by other molding methods can be integrated as long as shrinkage matching is possible.

The resonance frequency can be adjusted by changing the thickness and the dielectric constant of the dielectric layer on the surface of the radiation electrode 11. Since the size of the electrodes cannot be adjusted with the microstrip antenna according to the present invention, the resonance frequency is adjusted by changing the effective dielectric constant of the dielectric substrate. In order to increase the effective dielectric constant, the thickness of the dielectric layer can be increased to lower the resonance frequency, and conversely, the thickness can be decreased to increase the resonance frequency.

FIG. 2 is a front sectional view showing another embodiment of the present invention. Forming the radiation electrode 21 and the ground electrode 22 in the dielectric laminate 20 is the same as in the above example. In this example, the conductor pattern 23 is formed between the outside of the ground electrode 22, that is, the back surface. Similarly, the conductor pattern 23 is formed on a sheet by printing or the like, and is formed by pressure bonding, drying and baking. The conductor pattern 23 can be formed in multiple layers, and passive elements such as capacitors, inductors and resistors can be formed. The conductor is drawn to the back surface from a predetermined portion of the conductor pattern 23 through a through hole and connected to the wiring pattern 24.

An active element such as the integrated circuit 25 may be mounted on the wiring pattern 24 on the back surface. As a result, the antenna is integrated with the passive element and the active element, and the antenna can be integrated with the filter and the amplifier.

[0019]

[Effect of the device]

 According to the present invention, since the electrode portion of the antenna is protected by the dielectric layer, a microstrip antenna having high reliability and little change over time can be obtained.

Further, since the radiation electrode is embedded in the dielectric, the gain is improved, and the resonance frequency can be adjusted by adjusting the thickness of the dielectric layer on the radiation electrode.

In addition, the circuit elements can be integrated, the receiving device can be downsized, and the reliability of these elements is also advantageous.

[Brief description of drawings]

FIG. 1 is a front sectional view of an embodiment of the present invention.

FIG. 2 is a front sectional view of another embodiment of the present invention.

FIG. 3 is a front sectional view of a conventional example.

[Explanation of symbols]

 10, 20: Dielectric laminate 11, 21: Radiation electrode 12, 22: Ground electrode

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Katsuyoshi Takano 828 Hinohara, Tamagawa, Hama-gun, Hiki-gun, Saitama Prefecture Toko Co., Ltd. Tamagawa factory

Claims (3)

[Scope of utility model registration request] 1. A microstrip antenna having a radiation electrode on the front side and a ground electrode on the back side across a ceramic dielectric, wherein the ceramic dielectric is a sintered body obtained by laminating ceramic dielectric sheets, and the radiation electrode and the ground are grounded. A microstrip antenna in which electrodes are formed inside a laminated body by being sandwiched by ceramic dielectrics. 2. A microstrip antenna having a radiation electrode on the front side and a ground electrode on the back side with a ceramic dielectric interposed therebetween, wherein the ceramic dielectric is a sintered body obtained by laminating ceramic dielectric sheets, and the radiation electrode and the ground are provided. The electrode is sandwiched between the ceramic dielectrics and formed inside the laminated body, and the ceramic laminated body having the circuit element formed inside is integrally formed on the ground electrode side, and the radiation electrode and the circuit element are inside the laminated body. A microstrip antenna characterized by being connected by. 3. A microstrip antenna having a radiation electrode on the front side and a ground electrode on the back side with a ceramic dielectric interposed therebetween, wherein the ceramic dielectric is a sintered body in which ceramic dielectric sheets are laminated, and the radiation electrode and the ground are grounded. The electrode is sandwiched between the ceramic dielectrics and formed inside the laminated body, and the ceramic laminated body having the circuit element formed inside is integrally formed on the ground electrode side, and the radiation electrode and the circuit element are inside the laminated body. And a circuit element inside the laminated body and another circuit element mounted on the surface of the laminated body on the ground electrode side are connected.