KR20080041900A - Small size active antenna using dielectric resonator - Google Patents

Abstract

An active antenna using a dielectric resonator is provided to be miniaturized in a comparatively low frequency band and contribute to miniaturize various RF terminals and apparatuses in addition to terrestrial DMB(Digital Multimedia Broadcasting). An active antenna using a dielectric resonator(110) includes the dielectric resonator and a resonance circuit. The dielectric resonator resonates at a predetermined frequency band. The resonance circuit is coupled to the dielectric resonator and shifts a resonance frequency band of the dielectric resonator. The resonance circuit is composed of a core coil(120). A variation range of the resonance frequency band is determined according to user operation. The dielectric resonator and the resonance circuit are formed on a PCB(Printed Circuit Board).

Description

Active antenna using dielectric resonator {Small size Active Antenna Using Dielectric Resonator}

1 is an exemplary view showing a general antenna.

Figure 2 is a block diagram showing the configuration of an RF receiving antenna according to an embodiment of the present invention.

3 is a schematic diagram of a small RF antenna using a cored coil, a dielectric resonator, and an amplifier in a preferred embodiment of the present invention.

4 is a diagram illustrating a coil and a dielectric resonator coupled to a PCB according to FIG. 2;

5 is a view illustrating a form in which the amplifying circuit according to FIG. 2 is coupled to a PCB.

6 is a PCB diagram according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100: signal receiving terminal 110: dielectric resonator

120: resonant circuit 200: amplification circuit

300: PCB 400: signal receiving surface

500: Ground (GND)

The present invention relates to an antenna for receiving an RF signal, and more particularly, to an antenna used in a portable terminal and a small device using a coil having a dielectric resonator and a core.

The development of wireless communication technology is increasing the use of wireless communication devices. In recent years, the use rate of mobile electronic devices such as mobile communication phones and DMBs is much higher than that of wired communication phones, and the types thereof are becoming more diversified.

These wireless communication devices are all equipped with antennas for receiving RF signals. These antennas have various forms according to the frequency bands used by the corresponding wireless communication device, and the size of the antenna depends on the frequency band used by the wireless communication device.

Most wireless communication devices are required to be portable terminals or small devices, but the size of an antenna for receiving RF signals has been one of the important factors that hinders the miniaturization of portable terminals or wireless communication devices.

In particular, the terrestrial DMB, FM, which is a relatively low frequency band compared to other communication frequencies. In the case of a wireless LAN communication device, such a problem is further exacerbated.

1 is a diagram illustrating a perspective view of a general terrestrial DMB receiving antenna.

As shown in FIG. 1, an antenna used for terrestrial DMB broadcasting is a dipole type antenna that extends up and down, and it is quite inconvenient to use because the antenna must be pulled out long when watching a broadcast. The length of the antenna is proportional to the wavelength, and typically the length of the antenna is determined by the value of λ / 4 divided by the wavelength. When using a frequency of 170MHz, the terrestrial DMB frequency band, the normal antenna length is 20cm, and the length of the antenna is a significant obstacle to miniaturizing the device.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a small antenna that can be used in a relatively low frequency band, such as terrestrial DMB.

Another object of the present invention is to propose an RF receiving antenna having a small size in a low frequency band using a coil, a dielectric resonator, and an amplifier.

In addition, another object of the present invention is to propose an RF receiving antenna capable of improving the reception sensitivity as well as miniaturization in size in a wireless communication device.

In order to achieve the above object, according to a preferred embodiment of the present invention, a dielectric resonator for resonating a signal of a predetermined frequency band; And a resonant circuit coupled to the dielectric resonator to shift the resonant frequency band of the dielectric resonator, wherein the resonant circuit includes a core having a transition range of the resonant frequency band determined by a user's manipulation. There is provided an active antenna using a dielectric resonator, characterized in that it is composed of a coil.

More preferably, the dielectric resonator and the resonant circuit may be formed on a printed circuit board (PCB).

More preferably, the active antenna using the dielectric resonator may further include a ground (GND) surface formed on the same surface of the printed circuit board (PCB) on which the dielectric resonator and the resonant circuit are formed to facilitate electric field formation. It may include.

Further, more preferably, the active antenna using the dielectric resonator may further include an amplifier circuit formed on the printed circuit board (PCB) and amplifying and outputting a signal received through the dielectric resonator.

Further, more preferably, the dielectric resonator, the resonant circuit, the amplifying circuit, and the ground plane may be integrally formed on the printed circuit board (PCB).

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the RF antenna using a surface-mount coil.

Figure 2 is a block diagram showing the configuration of an RF receiving antenna according to an embodiment of the present invention, Figure 3 is a micro RF antenna using a coil, a dielectric resonator and an amplifier with a core in a preferred embodiment of the present invention It is a block diagram.

2 and 3, an RF antenna using a dielectric resonator according to an exemplary embodiment may include a signal receiving terminal 100, an amplifying circuit 200, and a PCB 300.

Further, more preferably, the signal receiving terminal 100 according to the present invention may be composed of a dielectric resonator 110 and a resonant circuit 120.

The dielectric resonator 110 functions to resonate the received RF signal at a specific frequency. The resonance frequency of the dielectric resonator 110 is determined by the shape and size of the dielectric resonator 110. According to a preferred embodiment of the present invention, the dielectric resonator 110 used in the antenna according to the present invention is a dielectric resonator which resonates higher than a frequency to be received by the antenna. The size of the dielectric resonator 110, like the antenna, is also inversely proportional to frequency.

For example, the dielectric resonator 110 having a resonance frequency of 900 MHz band is smaller than the dielectric resonator 110 having a resonance frequency of 200 MHz band. In order to minimize the size while using the dielectric resonator 110, the dielectric resonator itself is to use the dielectric resonator 110 having a resonance frequency larger than the frequency to be received through the antenna.

The present invention can be usefully applied to receiving DMB signals and FM signals having a relatively lower frequency band than other communication methods. According to an embodiment of the present invention, a dielectric resonator of 900 MHz band may be used to receive DMB frequency signals of 200 MHz band. 110) is used.

In this case, the shape of the dielectric resonator 110 is generally a rectangular parallelepiped, and has a size of about 3 mm in width, 3 mm in length, and 7 mm in height. The 900 MHz band dielectric resonator 110 is not only smaller in size than the 200 MHz band dielectric resonator 110 but also significantly reduced in size compared with a conventional dipole antenna receiving 200 MHz band.

The dielectric resonator 110 is provided with a resonance circuit 120. The resonant circuit 120 performs a function of shifting the resonant frequency of the dielectric resonators 110 coupled in series or in parallel. For example, the dielectric resonator 110 itself may be a resonator having a shape and size that resonates at 900 MHz, or may shift the resonance frequency of the dielectric resonator 110 to the 200 MHz band by using the resonant circuit 120.

The resonant circuit 120 may be composed of a combination of at least one core (inductor component) and / or at least one capacitor.

The capacitor and / or inductor (coil) constituting the resonant circuit 120 shifts the resonant frequency in the dielectric resonator corresponding to the value. Capacitors and / or inductors typically serve to determine the value of the characteristic frequency of a circuit in a circuit such as a filter, where the capacitor and the inductor determine the frequency at which the resonance resonates through the dielectric resonator through the available frequency determination characteristics of the inductor and capacitor. Change it.

The resonant circuit 120 is the most essential component of the present invention, and enables the dielectric resonator 110 of a small high frequency band to receive a low frequency signal. According to an embodiment of the present invention, the resonant circuit 120 is formed on the PCB board 300, and the antenna according to the present invention may be implemented in a form in which the PCB board 300 on which the resonant circuit is formed is coupled to the dielectric resonator. There will be. Of course, the resonant circuit of the present invention is not limited to being formed on the PCB board 300, and it will be apparent to those skilled in the art that it may have various other forms.

The resonant circuit 120 according to the present invention may be more preferably configured using a coil having a core. A coil is a concrete part that realizes inductance, which is one of its basic constants in an electric circuit. A coil with a core used in the present invention means that a coil is wound around a core, and the core is operated by a user. Means to enter or exit the coil. Therefore, the inductance value of the coil changes as the core moves up and down, and the user can adjust the coil core to set the resonance point of the desired dielectric resonator 110 as desired.

In addition, the present invention configures the signal receiving terminal 100 using the dielectric resonator 110 and the coil 120 having a core, and an amplifying circuit 200 for amplifying the signal received through the signal receiving terminal 100 described above. It may be configured to further include).

That is, the amplification circuit 200 according to the present invention receives the RF signal from the signal receiving terminal 100 of the present invention consisting of the dielectric resonator 110 and the resonant circuit 120, and the signal conversion, frequency modulation / demodulation and It is configured to perform general signal processing such as signal amplification.

Radio waves are different in distance or strength depending on the surrounding environment. At this time, if the radio wave is received in an area with a poor radio wave environment, the received radio wave is weak in strength and signal processing cannot be performed by the electronic device. The amplification circuit 200 amplifies the received signal to amplify the signal to a sufficient size and then transfers to the signal processing unit of the electronic device.

The amplification circuit 200 is composed of a surface-mounted coil, a resistor, a capacitor, an amplification field effect transistor (FET), and the coil value and the FET may be changed according to the frequency of the received signal. That is, the coil changes in value as the frequency is high and low. The coil value is high when the received frequency is low, and the coil value is low when the received frequency is high.

As a general example, for amplifying frequencies in the 200 MHz band, coil values should be approximately 100-120 nH, and for 900 MHz, use 10-15 nH. The FET should be selected to match the frequency band to be amplified.

4 is a diagram illustrating a form in which a circuit is formed on a PCB according to FIG. 3, and FIG. 5 is a diagram illustrating an entire antenna configuration according to an exemplary embodiment of the present invention.

4 and 5, the active antenna using the dielectric resonator according to the present invention has a signal receiving surface 400 on the same surface of the PCB board 300 on which the dielectric resonator 110 and the resonant circuit 120 are formed. ) And the ground plane 500 to facilitate the formation of an electric field. In this case, it will be apparent to those skilled in the art that the size or shape of the ground plane 500 formed on the PCB 300 varies depending on the frequency band. .

The signal receiving surface 400 transmits a signal received from the dielectric resonator to an input part of the amplifying stage through the resonant circuit. In addition, since the ground plane 500 is a ground plane in the general monopole antenna, the field formation is not constant according to the situation, so the electric field strength of the received signal may be weak. ) So that the electric field strength is formed uniformly.

As such, the idea of the invention, which can significantly reduce the size of the antenna, may be used in various devices. The present invention can greatly contribute to the miniaturization of a relatively low frequency communication terminal device such as a terrestrial DMB terminal, a terrestrial DMB USB driver, and a terrestrial DMB cell phone, as well as cellular or PCS.

In addition, if the general dipole antenna has a low Q value and the length of the antenna is not accurately determined, the resonance point may be distorted, thereby significantly reducing the gain of the antenna. However, according to the present invention, a coil having a higher Q value and a dielectric resonator may be included. Therefore, it can have a wider reception bandwidth.

Preferred embodiments of the present invention described above are disclosed for purposes of illustration, and those skilled in the art will be able to make various modifications, changes and additions within the spirit and scope of the present invention. Additions should be considered to be within the scope of the following claims.

As described above, according to the active antenna using the dielectric resonator according to the present invention, it is possible to implement a small antenna in a relatively low frequency band such as terrestrial DMB, which will greatly contribute to miniaturization of various RF terminals and devices as well as terrestrial DMB. There are advantages to it.

In addition, according to the present invention, the reception sensitivity is improved compared to the conventional dipole type antenna even when the micro antenna is used.

Claims (5)

A dielectric resonator for resonating a signal of a preset frequency band; And And a resonant circuit coupled to the dielectric resonator to shift a resonant frequency band of the dielectric resonator. The resonant circuit is an active antenna using a dielectric resonator, characterized in that consisting of a coil having a core (core) that determines the transition range of the resonant frequency band according to the user's operation. The method of claim 1, The dielectric resonator and the resonant circuit is an active antenna using a dielectric resonator, characterized in that formed on the PCB (Printed Circuit Board). The method of claim 2, The active antenna using the dielectric resonator, And a ground (GND) surface formed on the same surface of the printed circuit board (PCB) on which the dielectric resonator and the resonant circuit are formed to facilitate electric field formation. The method of claim 3, The active antenna using the dielectric resonator, An active antenna using a dielectric resonator formed on the PCB (Printed Circuit Board), further comprising an amplifier circuit for amplifying and outputting the signal received through the dielectric resonator. The method of claim 4, wherein The dielectric resonator, the resonant circuit, the amplifier circuit and the ground plane is an active antenna using a dielectric resonator, characterized in that formed integrally on the printed circuit board (PCB).

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