JP2007228456A - Combined antenna - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combined antenna for a travelling object which is small in its installation area and can transmit/receive radio waves in a plurality of bands. <P>SOLUTION: In the combined antenna which is installed in a travelling object such as an automobile, a monopole antenna is composed of an inverse L-shaped antenna, a rod antenna 2 is attached to an inverse L-shaped projecting end of the monopole antenna so that its root can rise and fall, and broadcasting waves received by the rod antenna 2 are transmitted to a circuit pattern 5 of a circuit board 4 via the monopole antenna 3. Furthermore, the rod antenna 2 includes a helical metal wire 11 and a rod-like resin material 10 is provided inside the helical metal wire 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite antenna that combines, for example, a rod antenna for AM / FM radio and a monopole antenna for radio telephone.

  Conventionally, a composite antenna combining an AM / FM radio rod antenna and a monopole antenna is known. 4 and 5 are diagrams in which the rod antenna and the monopole antenna are combined and installed. In this antenna, for example, a monopole antenna (including the periphery) 21 and a rod antenna 22 are arranged side by side on a die-cast base 20 attached on the ceiling of a vehicle body. The die-cast base 20 is made of a material such as aluminum and is entirely covered with an antenna cover (not shown).

  The rod antenna 22 has a rod-shaped resin material (not shown), and a long and thin wire 23 is spirally wound around the rod-shaped resin material. The surface of the wire 23 is further protected by a resin. Yes. The rod antenna 22 is downsized by shortening the wavelength by the relative permittivity of the rod-shaped resin material and extending the electrical length by extending the wire 23 in a spiral shape. The rod antenna 22 is connected to the circuit pattern 26 of the circuit board 25 via the power supply pin 24 and is supplied with power. The rod antenna 22 is not housed in the antenna cover but protrudes outside the cover.

  The monopole antenna 21 is a metal plate-like quarter-wave monopole antenna. One of the metal plates penetrates the circuit board 27 and is connected to a circuit pattern 28 formed on the surface of the circuit board 27. A ground metal surface 29 is formed on the circuit board 27, and an extraction pattern is formed on the ground metal surface 29 so that the monopole antenna 21 does not conduct.

Patent Document 1 listed below discloses a small in-vehicle composite antenna capable of receiving UHF and VHF, and Patent Document 2 discloses a rod-shaped multi-region radiator that can be used for four different frequency bands in a wide band. Is disclosed.
Japanese Patent Laid-Open No. 8-8637 JP-A-5-75330

  However, in the composite antenna shown in FIG. 4 and FIG. 5, the monopole antenna 21 and the rod antenna 22 are arranged at the front and back at a desired interval, and the entire two antennas occupy a large area on the projection plane. Therefore, there is a problem that the installation area becomes large when it is attached to the ceiling of the vehicle body.

  An object of the present invention is to provide a composite antenna that can receive radio waves having a wide frequency range and can be easily miniaturized.

  In order to solve the above-described problems, a composite antenna of the present application is a composite antenna installed in a moving body, wherein the first antenna having a spiral metal wire for receiving a broadcast wave and a frequency band separated from the broadcast wave are provided. A second antenna for receiving radio waves, the second antenna also serving as a feeding pin for the first antenna, and the first antenna is connected to a receiving circuit for receiving radio waves via the second antenna. It is characterized by.

  The composite antenna according to claim 2 of the present application is characterized in that in the composite antenna according to claim 1, the radio wave transmitted and received by the second antenna is a radio wave applied to a frequency of a portable radio telephone.

  Furthermore, the composite antenna according to claim 3 of the present application is the composite antenna according to any one of claims 1 and 2, wherein the first antenna is a rod antenna in which a helical metal wire for receiving a broadcast wave is wound around a rod-shaped resin. The second antenna includes an inverted L-type monopole antenna that extends vertically upward from a circuit board disposed below the second antenna and then extends in either the front or rear direction to transmit and receive radio waves for mobile phones. In addition, the rod antenna is mounted on a horizontally extending projecting end of the inverted L-shaped monopole antenna so that the angle can be adjusted up and down.

  According to the composite antenna of claim 1 of the present application, even if the first antenna is connected to the receiving circuit via the second antenna, the spiral metal wire of the first antenna generates an inductive component, while the first antenna Are separated from the frequency of the radio wave received by the second antenna. For this reason, even if the second antenna also serves as the power supply pin of the first antenna, the second antenna is not affected by the operation of the first antenna and can transmit and receive. Further, since the first antenna is attached to the second antenna, the installation area can be reduced on the installation projection plane, and even when installing on the vehicle body or the like, the installation work can be facilitated by reducing the number of attachment parts as much as possible.

  According to the composite antenna of claim 2 of the present application, broadcast waves can be received and mobile phones can be transmitted and received by this composite antenna.

  According to the composite antenna of claim 3 of the present application, the installation area on the horizontal plane does not increase and the height increases even when installed on a vehicle body ceiling or the like.

  Hereinafter, a composite antenna according to the best mode for carrying out the present invention will be described with reference to the drawings. FIG. 1 is a side view of the composite antenna according to the embodiment, and FIG. 2 is a plan view of the composite antenna of FIG. 1 and 2, reference numeral 1 is a composite antenna, 2 is a rod antenna as a first antenna having a spiral metal wire for receiving broadcast waves, and 3 is a radio wave in a frequency band separated from broadcast waves. Inverted L-type monopole antenna as a second antenna for receiving radio waves, 4 is a circuit board including a broadcast wave receiving unit, a mobile phone radio wave transmitting / receiving unit, a power source and other elements, and 5 is a broadcast wave receiver A circuit pattern connected to the unit part and the radio wave transmission / reception unit part for the mobile phone and the power source and other elements, 6 is a die-cast base, and 7 is a shield case.

  The rod antenna 2 is a broadcast wave rod antenna for receiving AM / FM radio waves, and the monopole antenna 3 is a quarter-wave monopole antenna for transmitting and receiving mobile phone radio waves.

  3A to 3D show the configuration of the rod antenna 2. The rod antenna 2 includes a rod-shaped resin material 10 therein, and a spiral metal wire 11 is wound around the outer periphery of the rod-shaped resin material 10. A connecting portion 12 at the lower end of the spiral metal wire 11 is attached to and electrically connected to the inverted L-shaped protruding end of the monopole antenna 3. The rod antenna 2 is attached so as to be rotatable up and down. After the spiral metal wire 11 is wound around the rod-shaped resin material 10, the whole of the spiral metal wire 11 wound around is further protected with resin, so that the rod antenna 2 is configured.

  The monopole antenna 3 is a metal inverted L-type small monopole antenna for transmitting and receiving radio waves for mobile phones, and the height in the vertical direction can be set low. The lower end portion of the monopole antenna 3 penetrates the circuit board 4 and is connected to a mobile phone wireless transmission / reception unit section (not shown) including the circuit board 4 and the circuit pattern 5. A rod antenna 2 is attached to a protruding end portion of the monopole antenna 3 that extends horizontally in an inverted L shape. The monopole antenna 3 has a structure that functions as a feed pin for the rod antenna 2. The monopole antenna 3 is for transmitting / receiving radio waves for mobile phones, and the frequency handled by the rod antenna 2 is different from that for AM / FM, and the frequency band (0.8 Ghz) is very high compared to the AM / FM frequency band. The above is used bandwidth.

  The rod antenna 2 is electrically connected to the monopole antenna 3, but the spiral metal wire 11 of the rod antenna 2 generates a very large inductive component (inductance component). The rod antenna 2 is regarded as an open state, and the reception operation of the monopole antenna 3 is not affected. The AM / FM wave received by the rod antenna 2 passes through the monopole antenna 3 and is transmitted to the AM / FM wave receiver formed on the circuit board 4 and the circuit pattern 5.

  The signal separation due to the presence of a large inductance component such as the rod-shaped resin material 10 and the spiral metal wire 11 of the rod antenna 2 is generally better over a wider band than the method using other resonance phenomena or the method using phase rotation. Signal processing becomes possible.

  The AM / FM signal from the rod antenna 2 is input to the circuit pattern 5 together with the telephone signal of the monopole antenna 3, and the circuit board 4 and the circuit pattern 5 are provided with a high-pass filter element and a low-pass filter element. Each signal is separated, and the signal is transmitted to each circuit.

  Although the shield case 7 is provided in FIGS. 1 and 2, the shield case may not be required depending on the structure and specifications of the die cast base 6.

  As described above, the composite antenna 1 according to the embodiment of the present application is a composite antenna that is installed on a moving body such as an automobile, and the monopole antenna 3 is configured by an inverted L-type antenna. Since the base of the rod antenna 2 is attached to the projecting end of the horizontal part of the mold so that the angle can be adjusted, the rod antenna 2 is provided with a spiral metal wire 11, and the rod-shaped resin material 10 is provided inside the spiral metal wire 11. The broadcast wave received by the rod antenna 2 via the monopole antenna 3 is transmitted to the circuit pattern 5 on the circuit board 4. Since the rod antenna 2 has a large inductance component, the frequencies of radio waves received by the rod antenna 2 and the monopole antenna 3 are separated. For this reason, even if the monopole antenna 3 serves as a feed line for the rod antenna 2, the monopole antenna 3 is not affected by the radio wave received by the rod antenna 2. Since the transmission / reception unit comprising the circuit board 4 and the circuit pattern 5 to which the monopole antenna 3 is connected has a low-pass filter unit for broadcast waves and a high-pass filter unit for transmission / reception of radio waves for mobile phones, Broadcast wave reception and mobile phone radio wave transmission and reception are possible. Further, since the rod antenna 2 is attached to the projecting end portion of the inverted L-type monopole antenna 3 so that the angle can be adjusted up and down, the installation area can be reduced on the installation projection plane, and the attachment portion etc. As much as possible, mounting work is easy.

FIG. 1 is a diagram showing a configuration of a composite antenna according to an embodiment of the present invention. FIG. 2 is a plan view of the composite antenna of FIG. 3A to 3D are views showing the structure of the rod antenna of FIG. FIG. 4 is a diagram showing a composite antenna configuration in which a conventional rod antenna and a monopole antenna are arranged side by side. FIG. 5 is a diagram showing a configuration of a composite antenna having a conventional rod antenna and monopole antenna.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite antenna 2 Rod antenna 3 Monopole antenna 4 Circuit board 5 Circuit pattern 6 Aluminum die-cast 7 Shield case 10 Bar-shaped resin material 11 Spiral metal wire

Claims (3)

In complex antennas installed on mobile objects,
A first antenna having a spiral metal wire for receiving a broadcast wave; and a second antenna for receiving a radio wave in a frequency band separated from the broadcast wave, the second antenna being a feed pin of the first antenna And the first antenna is connected to a receiving circuit for receiving radio waves via the second antenna. The composite antenna according to claim 1, wherein
The radio wave transmitted and received by the second antenna is a radio wave for a mobile phone. The composite antenna according to claim 1 or 2,
The first antenna is a rod antenna in which a spiral metal wire for receiving a broadcast wave is wound around a rod-shaped resin, and the second antenna extends vertically upward from a circuit board disposed below the second antenna. After that, it is an inverted L-type monopole antenna that extends in the horizontal direction either forward or backward and transmits / receives radio waves for mobile phones. Composite antenna characterized by being adjustable.

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