CN1979949A - Digital television antenna - Google Patents

Abstract

The present invention is a digital television antenna, which includes an antenna area and a grounding area formed on a substrate in a printed circuit manner using a transmission line design principle. The antenna area forms an inductance area with an inductance value and a capacitance area with a capacitance value. In addition, the antenna area and the grounding area form a capacitance area with a capacitance value, so that the impedance value of the entire antenna is optimally matched with the received digital television signal, achieving the best effect of frequency resonance.

Description

digital tv antenna

【Technical field】

The invention relates to a digital TV antenna, especially a digital TV antenna arranged on a substrate in the form of a printed circuit.

【Background technique】

Nowadays, with the development of digital electronic technology, its application fields are also expanding, such as in-vehicle systems and traditional household appliances. In particular, digital TV is more and more accepted by consumers because of its advantages such as high definition.

The existing digital TV antenna is usually formed by a metal wire. Due to the needs of the antenna to receive the signal wavelength, its length must reach a certain length. On the other hand, because the existing digital TV antenna is made of a single metal wire, it is not easy to adjust its impedance value in antenna design to achieve the best matching value for receiving TV signals, although additional components such as capacitors and inductors are added to adjust The impedance value of the antenna, but because additional components are added, the position of these components such as capacitors and inductors must be considered, thus increasing manufacturing costs and production yield control issues.

In view of this, it is necessary to propose a new solution to overcome the aforementioned defects in the prior art.

【Content of invention】

The main purpose of the present invention is to provide a miniaturized digital TV antenna design, especially a digital TV antenna that is arranged on a substrate in the form of a printed circuit and has impedance matching and frequency resonance effects.

In order to achieve the above object, the present invention provides a digital TV antenna, which includes an antenna area formed on a substrate in a printed circuit manner using the transmission line design principle, the antenna area forms an inductance area with an inductance value and a capacitance area with a capacitance value, and is added to The antenna area and the ground area form a capacitive area with a capacitance value, so that the impedance value of the entire antenna can be best matched with the received digital TV signal, and the best effect of frequency point resonance can be achieved.

In the present invention, the digital television antenna is formed on the substrate by means of a printed circuit, and the appearance length of the antenna can be shortened while satisfying the antenna function. In addition, for the antenna formed on the substrate, its lines form an inductance area with a certain inductance value and a capacitance area with a capacitance value, and form a capacitance area with a capacitance value with the ground area, so that the antenna as a whole meets the impedance value matching the received signal , no need to add additional components, simple and practical.

【Description of drawings】

FIG. 1 is a schematic diagram of the appearance of the digital TV antenna of the present invention.

Fig. 2 is a schematic diagram of the rear structure of the digital TV antenna of the present invention.

FIG. 3 is a schematic diagram of the casing and fixing seat of the digital TV antenna of the present invention.

Figure 4 is a schematic diagram of two transmission lines and their equivalent circuits.

Fig. 5a is a schematic diagram of the principle that a high-impedance transmission line is equivalent to a series inductor.

Fig. 5b is a schematic diagram of the principle that a low-impedance transmission line is equivalent to a parallel capacitor.

FIG. 6 is a schematic diagram of an equivalent circuit in which high and low impedance transmission lines together form a transmission line.

Fig. 7 is a graph of the voltage standing wave ratio of the digital TV antenna of the present invention.

【Detailed ways】

Please refer to FIG. 1 , the digital TV antenna 10 of the present invention includes a substrate 1 , which can be a printed circuit board, on which a metal transmission line is plated with a printed circuit to form an antenna area 2 . In this embodiment, the antenna is designed for digital TV signals with a frequency of 533MHz to 599MHz. The aforementioned substrate 1 can be made of FR4 glass fiber double-sided material, which is not only cheap but also easy to obtain. It is very convenient to make the circuit.

As shown in FIG. 1 , the antenna area 2 plated on one side of the substrate 1 is formed on the substrate 1 by a printed circuit of metal material, and the metal material can be copper or other metals with good conductivity. The antenna area 2 includes a rectangular strip-shaped starting area 21 extending forward from the center of the end of the substrate 1 . Extending forward from the starting area 21 , a rectangular frame-shaped capacitor area 22 is formed. Extending forward from the rectangular frame-shaped capacitive area 22 , the inductive area 23 is formed into a curved waveform. Extending forward from the curved wave-shaped inductance area 23 , a rectangular connection area 24 is formed. A funnel-shaped receiving area 25 is formed extending forward from the end of the connection area 24 . At the end of the start area 21 of the antenna area 2 is provided a solder joint 4 , through which an external signal line (not shown) can be connected to the antenna area 2 .

Please refer to FIG. 2 , on the other side of the substrate 1 opposite to the surface where the antenna area 2 is located, from the same end of the substrate 1 as the starting area 21 of the antenna area 2, it extends forward near the two sides of the substrate 1 to form an approximate shape. U-shaped grounding area 3. The grounding area 3 is also formed on the substrate 1 by means of a printed circuit of conductive material. A welding point 5 is also provided at the end of the grounding area 3 , through which an external grounding wire (not shown) can be connected to the grounding area 3 .

As shown in FIG. 1 and FIG. 2 , in this embodiment, the grounding area 3 is located on the other side of the substrate 1 relative to both sides of the initial area 21 and the capacitance area 22 of the antenna area 2 , so between the antenna area 2 and the grounding area 3 forms a capacitive effect, while the inductive area 23 of the antenna area 2 has an inductive effect due to the curved wave structure.

Please refer to FIG. 3 , a protective shell 6 made of plastic can be covered outside the antenna 10 to protect the structure of the digital TV antenna. A magnetic adsorption seat 7 can be arranged at the bottom of the antenna 10, so that the antenna can be adsorbed on the placed object, and the magnetic adsorption seat 7 can also enhance the effect of grounding.

The inductance value and capacitance value in this antenna 10 can be calculated and obtained by following principle: because the equivalent circuit of transmission line can be regarded as having the series effect of resistance component and inductance component; In the parallel connection of the components, the antenna area 2 and the ground area 3 in the antenna 10 are equivalent to two transmission lines. As shown in Figure 4, two parallel transmission lines and their equivalent circuits are shown. The equivalent circuit of the transmission line is regarded as a series component. If it is positive reactance, it is inductive. The two transmission lines are regarded as parallel components. If it is negative reactance, it is capacitive. , the equivalent circuit is shown in Figure 4, in which X/2=Z ₀ tan(βλ/2) (hereinafter referred to as (Formula 1)), B=1/Z ₀ sinβλ (hereinafter referred to as (Formula 2)).

If the transmission line is short enough (for example, βλ<π/4) and the characteristic impedance is very high, then (Formula 1) and (Formula 2) can be approximated as X≈Z ₀ βλ; B≈0, and its equivalent circuit is shown in Figure 5a A series inductor is shown. If the transmission line is short enough and its characteristic impedance is very low, then (Equation 1) and (Equation 2) can be approximated as X≈0; B≈Y ₀ βλ, and its equivalent circuit is shown as a capacitor connected in parallel in Figure 5b.

As shown in Figure 6, if a high-impedance transmission line and a low-impedance transmission line are combined to form a transmission line architecture. A high impedance (Z ₀ =Z _h ) transmission line can be approximated by a series inductor, while a series capacitance can be approximated by a low impedance (Z ₀ =Z _l ) transmission line.

In the present invention, the capacitive effect between the rectangular frame-shaped capacitance region 22 in the antenna region 2 and the ground region 3 can obtain an appropriate capacitance value by adjusting the structure of the capacitance region 22 of the antenna, and the inductance value of the inductance region 23 can be based on the inductance Formula L＝(0.394*(r＾2)*(N＾2))/((9*r)+(10*l))(L: capacitance, r: coil radius, N; number of coil turns, l: Coil length) calculation, adjust the inductance value by adjusting the length of the inductance area and the radius of the coil. Because of the capacitance effect between the antenna area 2 and the ground area 3 and the inductance effect of the inductance area 23 of the antenna area 2, the entire antenna 10 can have an impedance value matching the received signal by adjusting its own structure.

In this embodiment, the antenna 10 is designed for digital TV signals of 533MHz-599MHz, and its capacitive area 22 and inductive area 23 are rectangular squares and curved waveforms. In other implementation manners, the antenna can also be made into other shapes according to the aforementioned principles, so as to achieve predetermined capacitance and inductance values, so that the impedance value of the entire antenna can match the received signal.

In this embodiment, the antenna area 2 is located on one side of the substrate 1. In other embodiments, the antenna area 2 can also have the capacitive area 22 or the inductive area 23 located on different sides of the substrate, as long as the capacitive area and the inductive area of the antenna are satisfied. The capacitance and inductance values of the antenna can be adjusted so that the overall impedance of the antenna reaches a predetermined value.

Please refer to FIG. 7 , through experiments, the voltage standing wave ratio (Voltage Standing Wave Ratio, VSWR) of the antenna 10 is less than 2 in the 533MHz-599MHz frequency band, so it is confirmed that the digital TV antenna of the present invention has a good matching design.

The digital TV antenna of the present invention can save the length occupied by the antenna when the length of the antenna is satisfied, because the metal transmission line constituting the antenna area is formed on the substrate in the form of a printed circuit. Moreover, the antenna area itself is formed into a shape with capacitance and inductance, so that the overall impedance of the antenna can be matched with the impedance of the signal to be received, so as to enhance the transmission quality of the digital TV antenna.

Claims (10)

1. a digital TV antenna, it is characterized in that: it comprises substrate, antenna field and access area, antenna field is formed in the printed circuit mode on the surface of this substrate, is formed with a capacity effect district and an inductive effect district on this antenna field; The access area is formed on this substrate another surface relative with this antenna field in the printed circuit mode, and it forms capacity effect with respect to the both sides that this capacity effect district is formed at this substrate.

2. digital TV antenna as claimed in claim 1 is characterized in that: this capacity effect district is a rectangular block.

3. digital TV antenna as claimed in claim 1 is characterized in that: this inductive effect district is a crooked waveform district.

4. digital TV antenna as claimed in claim 1 is characterized in that: this access area is the district that takes the shape of the letter U.

5. digital TV antenna as claimed in claim 1 is characterized in that: this antenna field also comprises a funnel-form reception area that extends from this inductive effect district one end.

6. digital TV antenna as claimed in claim 1 is characterized in that: this antenna field also comprises a sintering of extending from this capacity effect district one end.

7. digital TV antenna as claimed in claim 1 is characterized in that: be provided with a solder joint with this antenna field connecting place on this substrate, this antenna field is by this solder joint transmit antenna signal.

8. digital TV antenna as claimed in claim 1 is characterized in that: be provided with a solder joint with this access area connecting place on this substrate, ground connection is reached by this solder joint in this access area.

9. digital TV antenna as claimed in claim 1 is characterized in that: this antenna comprises that in addition a plastic protection shell cover covers this substrate.

10. digital TV antenna as claimed in claim 1 is characterized in that: this antenna comprises that in addition one can be arranged at the magnetic holder of this digital TV antenna fixed placement on this substrate the end near this access area.

Images