KR20020083044A - Mini-Antenna for International Mobile Telecommunication-2000 Terminal Equipment for Bulk Type Dielectric - Google Patents

Abstract

PURPOSE: A small antenna device for an IMT-2000 terminal is provided to reduce size and obtain superior gain and width band, while improving impedance characteristics by producing capacitance component between the probe and tuning patch. CONSTITUTION: A small antenna device comprises a feeder unit(300) for transmitting a high frequency signal from an RF signal processing unit to an antenna unit; a radiation element(200) for radiating the radio frequency signal transmitted to the feeder unit; a tuning patch(201) fixed to the radiation element and spaced apart from the feeder unit, and which changes characteristic impedance of the antenna; and a medium including a short-circuit plate(202) interposed between the radiation element and a ground(100). The short-circuit plate has a high dielectric constant.

Description

Mini-Antenna for International Mobile Telecommunication-2000 Terminal Equipment for Bulk Type Dielectric using IMM-2000 terminal using bulk dielectric

The present invention relates to a small antenna device for an IMT-2000 (IMT-2000) terminal using a bulk dielectric, and more particularly, to be mounted in a portable mobile communication terminal for an IMT-2000 service, which is a wireless communication device. In order to realize the antenna of the DRAs (Dielectric Resonator Antennas) method for the built-in, it is necessary to reduce the size of the antenna, to realize the gain and bandwidth that the antenna itself has, and to have a radiation pattern required by the mobile communication terminal. It relates to a small antenna device using a medium having a dielectric constant of).

Conventionally, the bulk dielectric antenna can be miniaturized by using a medium of high dielectric constant, has a simple structure, has a high radiation efficiency compared to a patch antenna, and controls a radiation pattern by using another resonance mode. There is an advantage that it can. In the hexahedral structure, the mode degeneracy or hybrid mode in the spherical or cylindrical DRAs, or the hybrid-mode hexahedral resonator antenna, is used to properly adjust the size and feed position of the three faces. By choosing, mode-degeneracy can be avoided which improves cross-pol size on the antenna side. The bandwidth of the hexahedral resonator antenna is relatively wider than that of the patch antenna and has an advantage in bandwidth control because it depends on the aspect ratio.

Prior arts related to such rectangular DRAs include radiation dielectrics for obtaining critical coupling to DRAs fed with microstrips in US Pat. No. 5,952,972 "Broadband Nonhomogeneous Multisegmented Dielectric Resonator Antenna System." Below, a multi-layer stack with a high dielectric material is presented, and a technique that uses notch-type DRAs that remove a portion of the dielectric of the microstrip feed to increase the bandwidth of the dielectric antenna is presented.

The present invention is to modify the structure of the dielectric medium constituting the radiating element, and to improve the characteristics due to the signal feeding structure, combined with the RF circuit in order to solve the narrow band problem of the conventional chip-type antenna In order to realize the miniaturization and slimming of the combined type RF module, the short circuit board is inserted into the dielectric of the radiating element, making it more compact and slimmer than the conventional L-band hexahedral dielectric antennas (DRAs). It is intended to be easily applied to various portable communication devices.

Accordingly, the present invention is an antenna device for a small terminal that can be used in the L-band IMT-2000 frequency band, the notch (Notch) to expand the bandwidth in a rectangular hexahedral bulk structure using a medium having a dielectric constant as a radiating element By incorporating a gold-inscribed structure and laying electrical shorts for small antenna devices, enabling miniaturization, having the benefits of antenna gain and bandwidth, and the radiation pattern required by mobile communications terminals. It is an object to provide a compact antenna device for the purpose.

In addition, another object of the present invention is to improve the impedance characteristics and tune the resonant frequency by making a capacitance component between the probe and the tuning patch to offset the inductance component of the probe itself, which is a disadvantage of the probe feeding unit.

1 is a structural diagram of typical isolated rectangular dielectric antenna antennas (DRAs),

2 is an overall structural diagram of a DRAs scheme according to the present invention;

3 is a plan view of the DRAs antenna of the present invention,

4 is a graph showing the return loss characteristics of the DRAs antenna of the present invention,

5 is a graph showing the impedance characteristics of the DRAs antenna of the present invention,

6 is a graph showing the return loss characteristics according to the probe length of the present invention,

7a and 7b are graphs showing the radiation pattern shown on the simulation of the present invention,

8 is a graph showing the return loss measured by the network analyzer of the present invention,

9 is a graph showing a Smith chart measured by the network analyzer of the present invention.

♣ Explanation of symbols for main part of drawing ♣

100: ground 200: radiating element (dielectric)

201: Tuning patch (metal strip) 202: Shorting plate

300: feeder

The present invention for achieving the above object, in the small antenna device for the IMT-2000 terminal of the hexahedral dielectric antenna (DRAs) method using a bulk dielectric material, the high-frequency signal from the RF signal processing unit of the antenna device A feeding element for transmitting to the antenna unit, a radiating element for radiating a radio frequency signal (RF) transmitted to the feeding unit, and a capacitor component fixed to the radiating element and maintained by maintaining a constant distance from the feeding unit IMT-2000 using a bulk dielectric, comprising a tuning patch for changing the characteristic impedance of the antenna and a medium including a shorting plate disposed between the radiating element and the ground plane. 2000) Provided is a small antenna device for a terminal.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of hexagonal dielectric antennas (DRAs) for describing a relationship between a resonance frequency and a bandwidth according to an aspect ratio of isolated hexahedral dielectric antennas (DRAs) excluding a feeding network in a free space. The overall structure is shown. Equation for determining the resonant frequency of the hexahedral isolated dielectric antenna (Isolated DRAs) excluding the feed network is as follows.

If we use the condition a, b> d It can be seen that the mode is the lowest frequency, which has a magnetic potential in the z direction The mode can be excited.

Using the magnetic potential pi_mz, the field inside the radiating element can be obtained as follows.

remind Since the field components in the other directions except for the field components form fields in directions that cancel each other out of the field, Only the main contribution is to radiation. Interface of radiating element Wow Applying Magnetic Wall Boundary Conditions at Wow Can be written as

In addition, propagation constants using a dielectric waveguide model (DWM) We can use Transcendental Equation to get

In addition, the propagation constants k _x , k _y , and k _z in the x, y, and z directions must satisfy the following equation.

Where k ₀ is the propagation constant in free space.

By fixing the dielectric constant of the dielectric medium at any design frequency through Equations 1 to 10, a resonant frequency according to the size of an isolated hexahedral dielectric antenna (Isolated DRAs) can be obtained, and vice versa. The size of the dielectric medium can be determined to obtain.

Assuming that ε _r is very large, the resonant frequencies of the dielectric antennas DRAs are It is proportional to, but it does not satisfy the broadband conditions that are characteristic of the IMT-2000 service, it is necessary to select the dielectric constant of the appropriate dielectric medium.

2 is an overall structural diagram of the present invention.

The antenna radiating element 200 is a main component that transmits and receives a high frequency signal. The antenna radiating element 200 is for radiating a radio frequency signal (RF) transmitted to the feeding unit 300, and the feeding unit 300 supplies an RF signal. The shorting plate 202 is connected between the radiating element 200 and the ground plane 100 to miniaturize the antenna.

The tuning patch (metal strip) 201 is to change the characteristic impedance of the antenna with a capacitor component fixed to the radiating element 200 and induced by maintaining a constant distance from the power supply unit 300.

The radiating dielectric, which is the radiating element 200, has been applied a technique for increasing the efficiency of the antenna by improving the impedance characteristics by creating a capacitance component while maintaining a proper distance from the probe feeding unit 300. In addition, the radiating element 200 has a notched antenna structure to implement a broadband.

In addition, the shorting plate 202 disposed between the radiating element 200 and the ground plane 100 is a medium having a high dielectric constant, and the shorting plate 202 reduces the total area of the radiating element 200. At the same time, it is optimized for easy embedding in mobile communication terminals.

As described above, the antenna can be miniaturized by using the radiating element 200 and the electrical shorting plate 202, which are dielectric materials having a high dielectric constant, and employ a structural deformation in the form of a notch engraved with gold to obtain broadband characteristics. The size of the device can be further miniaturized, and it can be implemented as a built-in type in a portable mobile communication terminal device.

Therefore, it is possible to apply high-sensitivity small terminal antenna for IMT-2000, and it has the characteristics that can greatly reduce the loss due to the space limitation and mechanical impact of the conventional monopole antenna of the protrusion type.

3 is a plan view of a dielectric antenna (DRAs) type antenna of the present invention, the position of the probe feeder 300 is located at the center of the radiating element 200, and the tuning patch 201 is also formed of the radiating element 200. Located in the middle of the top.

4 shows a return loss (S1.1) value of the dielectric antenna (DRAs) antenna of the present invention. A bandwidth of -10dB is 19%, indicating wideband characteristics.

5 is a graph illustrating impedance characteristics of a dielectric antenna (DRAs) antenna of the present invention.

6 illustrates the return loss according to the feeding probe length of the dielectric antenna (DRAs) antenna of the present invention. It can be seen that the probe length for impedance matching is an important design parameter, and the variation of the resonance frequency according to the probe length is weak.

7A and 7B show a radiation pattern of the dielectric antenna (DRAs) antenna of the present invention. It can be seen that the radiation pattern of H-Plane satisfies the isotropic pattern required by the mobile communication terminal, and the E-Plane radiation pattern at phi = 90 maintained symmetry.

8 shows the return loss measurement of the dielectric antenna (DRAs) antenna, and FIG. 9 shows the Smith chart measurement of the dielectric antenna (DRAs) antenna.

As described above, the small antenna device for the IMT-2000 (IMT-2000) terminal using the bulk-type dielectric of the present invention expands the market demands of the digital communication area and reduces the size of the wireless mobile communication device. In the application of the most suitable antenna, a bulk-type medium having a high dielectric constant was used as a radiating element, and it was further miniaturized compared to the existing method by appropriate structural improvement of the appearance of the dielectric medium. It is slim and can achieve excellent results in terms of electrical characteristics required by mobile communication terminal antennas. In particular, it can be built-in inside the terminal, thereby eliminating the space limitations and breakages of conventional monopole antennas. It can overcome the problems such as risk and realize free appearance and design in the final product. It can have an effect that improves the functionality and reliability of the mobile communication terminal.

Such a small antenna device for an IMT-2000 (IMT-2000) terminal using a bulk dielectric of the present invention is not limited to the above-described embodiment, and can be easily changed or replaced by those skilled in the art.

Claims (4)

In the small antenna device for the IMT-2000 terminal of the hexahedral dielectric antenna (DRAs) method using a bulk dielectric material, A feeder for transmitting a high frequency signal from the RF signal processor of the antenna device to the antenna; A radiating element for radiating a radio frequency signal (RF) transmitted to the feeding part; A tuning patch for changing the characteristic impedance of the antenna with a capacitor component fixed to the radiating element and induced by maintaining a constant distance from the feeder; A small antenna device for an IMT-2000 (IMT-2000) terminal using a bulk dielectric, characterized in that consisting of a medium comprising a short-circuit plate disposed between the radiating element and the ground plane. The IMT-2000 (IMT-2000) terminal using a bulk dielectric according to claim 1, wherein the shorting plate disposed between the radiating element and the ground plane is a medium having a high dielectric constant. Miniature antenna device. According to claim 1, The radiating element is a small for the IMT-2000 (IMT-2000) terminal using a bulk-type dielectric, characterized in that having a Notched antenna structure to implement a broadband Antenna device. According to claim 1, wherein the short-circuit plate while reducing the total area of the radiating element and at the same time optimized to facilitate the built-in (Built-in) in the mobile communication terminal using the bulk (bulk) -type dielectrics Small antenna device for 2000 (IMT-2000) terminal.