JP3021857U - Shortened vertical and horizontal antenna matching device - Google Patents

Abstract

(57) [Abstract] [Problem] A long dipole antenna is required to radiate radio waves in a narrow space, such as amateur radio communication, which requires easy installation and good grounding. It was [Solution] A primary side coil l2 wound around a circular ring core and a resonance capacitor C3 constitute a series resonance circuit, and a secondary side coil l4 and a resonance capacitor C4 constitute a parallel resonance circuit. Since the maximum current obtained at the transmission side) can be efficiently transmitted to the secondary side (antenna side), the length of the antenna 8 can be made shorter than in the conventional case, and radio waves can be efficiently emitted and received.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical field to which the invention belongs] The present invention relates to a short-wavelength vertical and horizontal antenna matching device used in amateur radio communication.

[Prior Art] Short-wave frequencies used in amateur radio communication are 3.5MHz and 7MHz bands, and in order to transmit and receive, the λ / 2 dipole antenna in the 3.5MHz band has a total length of 40m and λ in the 7MHz band. A 1/2 dipole antenna requires a total length of 20 m for each.

Generally, the length of an antenna is obtained by obtaining the wavelength (λ) and making the length of one wavelength 1/2 or 1/4 is called λ / 2 antenna or λ / 4 antenna. For example, the wavelength of 3.5 MHz band Is the wavelength Normally, a horizontal dipole antenna resonates at a length of 1/2 wavelength, and a vertical antenna resonates at a quarter wavelength with the ground.

 In order to shorten the vertical / horizontal antenna, conventionally, an impedance conversion circuit has been used, and there are L type, π type, T type and the like. In the case of the L type, the value of L becomes large, so that the power consumption in L is large and the radiation efficiency for the input power is poor, so there was a limit to shortening the length of the antenna. In the case of π type, both input and output are suitable for high impedance, but not for low impedance.

In the case of T type, it is suitable for low impedance both input and output, around 70Ω.

 However, the impedance against high frequencies was high, the filter action was poor, and it was unsuitable.

[Problems to be solved by the invention] However, when transmitting and receiving in an amateur radio house living in an area with a small land area such as an amateur radio or in the field, a narrow space is used to transmit radio waves in a low frequency band (3 In the case of using a λ / 2 dipole antenna to radiate 0.5 M, 7 MHz), a long dipole antenna with a total length of 40 m in the 3.5 MHz band and a total length of 20 m in the 7 MHz band is required, which poses a problem that it cannot be easily installed. It was

 In the case of a vertical antenna, radio waves cannot be efficiently radiated unless a good ground is taken, so it is the most difficult and problematic to get a good ground.

 The purpose of the present invention is to solve such problems and to efficiently radiate electromagnetic waves with a short vertical and horizontal antenna.

[Means for Solving the Problems] In order to solve the above problems and to achieve the object, the present invention connects the end of the coil on the primary side wound around the circular ring core to the inner conductor of the coaxial cable on the transmitting side. , A primary side series resonance circuit configured by connecting the other end of the primary side coil to an outer conductor of the coaxial cable through a series connected resonance capacitor, and a secondary side wound around the circular ring core. And a secondary side parallel resonance circuit configured by connecting one end of a side coil to an antenna, grounding the other end of the secondary side coil, and connecting a resonance capacitor in parallel to the secondary side coil. Is characterized by.

[Embodiment of the Invention] FIG. 1 is a circuit diagram of a shortened vertical and horizontal antenna matching device according to a first embodiment of the present invention.

 In FIG. 1, (A) is a primary side (transmission side), (B) is a secondary side (antenna side), 1 on the primary side (A) is a coaxial cable, and the inner conductor 1A and the outside Conductor 1B. Reference numeral 2 surrounded by a dotted line is a primary side current detection circuit, which is a coil 11 for detecting current, a resistor r1, a die auto d1, and a capacitor c1, and a coil 12 for detecting a reflected current, a resistor r2, a die auto d2, a capacitor c2. The ratio of the primary side reflected wave to the traveling wave is read by the switching switch 3 and the state of the series resonance circuit and mutual induction is output and displayed on the resonance ammeter 4.

 Reference numeral 5 denotes a transformer, in which a primary coil 13 and a secondary coil 14 are wound around a circular ring core (toroidal core). One end of the primary coil 13 is connected to the inner conductor 1A of the coaxial cable 1 via a changeover switch 6, and the other end is connected to the grounded outer conductor 1B of the coaxial cable 1 via a resonance capacitor C3 connected in series. Connected to. The primary coil 13 of the transformer 5 and the resonance capacitor C3 constitute a series resonance circuit using the coaxial cable 1 as an oscillation source (transceiver in FIG. 2).

 The secondary coil 14 of the transformer 5 and the resonance capacitor C4 connected in parallel constitute a parallel resonance circuit. One end of the secondary coil 14 is connected to the antenna 8 via the changeover switch 7, and the other end is grounded 11. Reference numeral 9 surrounded by a dotted line is a secondary side current detecting circuit, which is composed of a current detecting circuit 15, a resistor r3, a diode d3 and a capacitor C5. This ammeter 10 directly reads a high frequency current to the antenna 8. Used for. The changeover switches 6 and 7 are switches for switching between radio waves of 3.5 MHz and 7 MHz, and are shared by one type of antenna.

The operation of this embodiment configured as above will be described. The resonance condition in the series resonance circuit on the transmission side (A) is that the reactances of L (l3) and C (C3) are equal. However, since the remaining current becomes maximum, the values of the primary coil 13 and the resonance capacitor C3 are selected so that the current becomes maximum.

 Then, in order to transfer the maximum current obtained in the primary side (A) series resonance circuit to the secondary side (B), a parallel resonance circuit including the secondary side coil 14 of the transformer 5 and the resonance capacitor C4. Tell. This is transmitted by the mutual induction action of the coils 13l4 on the primary side and the secondary side of the transformer 5, but since the transformer 5 uses a circular ring core (toroidal core), the degree of coupling is strong and is almost the same. All the electric power is transmitted to the secondary side.

 In the parallel resonant circuit on the secondary side (B), the currents i and ic cancel each other against the current i at the resonance frequency and the current i continues to flow in this, so the voltage at point a and point b becomes maximum, and the antenna Voltage is fed to 8 and a sufficient standing wave can be placed.

 In order to efficiently radiate the radio wave from the antenna 8 into the space, it is necessary to resonate at λ / 2 and λ / 4 of the radiating frequency, but if the device of the present embodiment is used, as a result of actual measurement, the If the length is 8 m, radio waves can be sufficiently radiated, and the distribution of the high frequency current is evenly distributed to the elements of the antenna 8, and the counterpoise (high frequency ground) can be shortened.

 2 is a diagram showing a use state in which a transceiver and an antenna are connected to the matching device of FIG. 1, 12 is the matching device of FIG. 1, 13 is a transceiver connected to the coaxial cable of FIG. 1, and FIG. The antenna 8 is composed of a vertical element 8a and a horizontal element 8b.

 The vertical element 8a operates as a vertical antenna, and the horizontal element 8b operates as a horizontal antenna. As a result of the actual measurement, the current distribution to the vertical element 8a in the vertical portion from the matching device 12 of the present invention becomes maximum at the point a, and gradually decreases toward the point b, and the current at the point b becomes uniform on the horizontal element 8b. Distributed in. Therefore, the surface wave transmission distance of radio wave propagation is longer than when using only the vertical antenna, and even in the case of short-distance communication, it has a sufficiently equivalent ability compared to λ / 2 and λ / 4.

 FIG. 3 shows a case where the vertical element 8a which operates as the vertical antenna of FIG. 2 is omitted and only the horizontal element 8b as the horizontal antenna is used. In this case, the earth 11 is not required, so that the installation is easy.

[Advantage of the Invention] As described above, the shortened vertical and horizontal antenna matching device of the present invention resonates with the secondary coil through the transformer having the primary and secondary coils wound around the circular ring core. By using a parallel resonant circuit that uses a capacitor to maximize the voltage supplied to the antenna, the length of the antenna can be shortened compared to conventional antennas, and the radiation and reception of waves can be performed efficiently. Has the effect. Moreover, while the current detection circuit 2.9 provided for the primary measurement and the secondary measurement monitors the current of the primary measurement and the secondary measurement with the ammeter 4.10, the changeover switch 6.7 performs the primary measurement and the secondary measurement. By switching the taps of the measuring coils l3 and l4, radio waves in the 3.5MHz band and 7MHz band can be shared by one type of antenna.

[Brief description of drawings]

FIG. 1 is a circuit configuration diagram of a shortened vertical and horizontal antenna matching device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a usage state in which a transceiver and an antenna are connected to the matching device of FIG.

FIG. 3 is a connection diagram when a transceiver is connected to the matching device of FIG. 1 and used only in a horizontal element.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Coaxial cable, 1A ... Outer conductor, 1B ... Inner conductor, 2 ... Primary current measuring circuit, 3.6.7 ... Changeover switch, 4 ... Resonance ammeter, 5 ... Transformer, 8 ... Antenna,
8a ... vertical element, 8b ... horizontal element, 9 ... 2
Next measured current detection circuit, 10 ... Ammeter, 11 ... Ground,
12 ... Matching device, 13 ... Transceiver, 13 ... Primary coil, 14 ... Secondary coil, C3, C4 ... Resonant capacitor.

Claims (1)

[Scope of utility model registration request] 1. A coaxial cable, wherein one end of a primary coil wound around a circular ring core is connected to an inner conductor of a coaxial cable on the transmitting side, and the other end of the primary coil is connected through a series-connected resonance capacitor. A primary side series resonant circuit configured to be connected to the outer conductor, and one end of a secondary coil wound around the circular ring core is connected to an antenna and the other end of the secondary coil is grounded. And a secondary side parallel resonance circuit configured by connecting a resonance capacitor in parallel to the secondary side coil, and a shortened vertical / horizontal antenna matching device.