JP2001077619A - Active antenna - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active antenna, capable of impedance setting that the impedance of a helical antenna shows capacitance with a low frequency and inductance with a high frequency if viewed in terms of a wide band, the extension of impedance on a Smith chart is small if it is used in an inductive frequency and the characteristic of a high gain can be obtained in wide band and realizing impedance setting adapted to various purposes. SOLUTION: The active antenna is constituted of a helical antenna 5 and a semiconductor element 7, which are mounted on the same substrate 1. The lead 6 of the helical antenna 5 is connected directly to the input terminal or the output terminal of the semiconductor element 7 via a connection line or a matching circuit 8. The core diameter, the number of windings, and the inter- wiring pitch of the helical antenna are set, so that the impedance of the helical antenna in a use frequency becomes inductive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an active antenna in which a transistor or an amplifier is loaded on an antenna used for terrestrial microwave communication, mobile communication and the like.

[0002]

2. Description of the Related Art FIG.
FIG. 4 is a configuration diagram of a conventional active antenna indicated as a “receiving device” in Japanese Patent No. In the figure, 1 is a substrate, 2
Is a first layer wiring, 3 is a second layer wiring, 4 is a connection line, 100 is a coil antenna, and 101 is a multi-stage amplifier. The coil antenna 100 is configured by sequentially connecting the first layer wiring 2 and the second layer wiring 3. An active antenna is formed by configuring the coil antenna 100 and the multi-stage amplifier 101 on the same substrate and connecting them by the connection line 4.

Next, the operation will be described. The radio wave received by the coil antenna 100 propagates through the connection line 4 and is supplied to the multi-stage amplifier 101. By integrating the coil antenna 100 and the multi-stage amplifier 101 on the same substrate 1, both can be connected by a microstrip line, and a small active antenna can be configured.

[0004]

In the conventional active antenna, since the second layer wiring has an air bridge structure, if the core diameter of the coil antenna 100 is increased, the manufacturing becomes difficult and the vibration resistance is reduced.
When selecting the core diameter within the range that can be manufactured, the antenna impedance is limited and good output, efficiency, gain,
The problem that noise characteristics and the like cannot be obtained.
(1) There is a problem that the internal matching circuit and the coil antenna interfere with each other to deteriorate the radiation characteristic, a problem that unnecessary oscillation occurs, and the like.

According to the present invention, the impedance of a helical antenna is lower than that of a conventional active antenna having various problems as described above, and when viewed in a wide band, the impedance is low at a high frequency, and the high frequency is inductive. The impedance setting focuses on the fact that the impedance spreads on the Smith chart is small if used at a frequency that can be used, and high gain characteristics can be obtained in a wide band, and the impedance setting can be adapted to various applications It is intended to obtain an active antenna having a simple configuration.

Another object of the present invention is to provide an active antenna having excellent radiation characteristics and suppressed unnecessary oscillation, a strong active antenna having excellent vibration resistance, and an active antenna having a high degree of freedom in impedance setting.

[0007]

In order to achieve the above object, an active antenna according to the first aspect of the present invention comprises:
An active antenna comprising a helical antenna and a semiconductor element or an amplifier mounted on the same substrate, wherein the lead of the helical antenna is connected to an input terminal or an output terminal of the semiconductor element or the amplifier directly or via a connection line or a matching circuit. In the above, the core diameter, the number of turns, and the wiring pitch of the helical antenna are set so that the impedance of the helical antenna at the operating frequency becomes inductive.

An active antenna according to a second aspect of the present invention comprises a helical antenna and a semiconductor element or an amplifier mounted on the same substrate, and the semiconductor element or the amplifier is connected directly to a lead of the helical antenna or via a connection line or a matching circuit. In the active antenna applied to the receiving system connected to the input terminal of the above, the core diameter of the helical antenna, the number of turns, and the pitch between the wirings, the impedance of the helical antenna at the frequency used becomes inductive and the noise minimum impedance It is set as follows.

An active antenna according to a third aspect of the present invention comprises a helical antenna and a semiconductor element or an amplifier mounted on the same substrate, wherein the leads of the helical antenna are connected directly or via a connection line or a matching circuit to the semiconductor element or the amplifier. In the active antenna applied to the transmission system configured by connecting to the output terminal of the helical antenna, the core diameter, the number of turns, and the wiring pitch of the helical antenna are adjusted so that the impedance of the helical antenna at the operating frequency is inductive, and the maximum output impedance or efficiency. It is set so as to have the maximum impedance.

According to a fourth aspect of the present invention, in the active antenna according to the first aspect, the semiconductor element is a field effect transistor, and the lead of the helical antenna is connected directly or via a connection line or a matching circuit. It is connected to the gate terminal or the drain terminal of the effect transistor, and the operating frequency is set in a frequency range in which the input impedance or the output impedance of the field effect transistor is capacitive.

According to a fifth aspect of the present invention, there is provided an active antenna according to any one of the first to fourth aspects, wherein the helical antenna and the semiconductor element or the amplifier or the field effect transistor are provided on the front and back of the substrate. It is mounted separately on two sides, and both are connected via through holes provided in the substrate.

According to a sixth aspect of the present invention, in the active antenna according to any one of the first to fourth aspects, the helical antennas are provided in two rows at a predetermined interval and a predetermined pitch on the substrate. The first and second rows of through holes are provided through the first and second rows of through holes and in close contact with the front and back surfaces of the substrate. It is formed in such a manner that it is continuously formed in a coil shape by metal wires that are sequentially connected on each surface.

An active antenna according to a seventh aspect of the present invention is the active antenna according to the sixth aspect, wherein the substrate is hollowed out between the first and second rows of through holes provided in the two rows. A hole having a relative permittivity different from that of the substrate is formed by providing a hole corresponding to the core of the helical antenna.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIG. 1 is an explanatory diagram of a configuration of an active antenna according to a first embodiment of the present invention. In the drawing, 5 is a helical antenna, 6 is a lead of the helical antenna, 7 is a semiconductor element, and 8 is matching with the outside of the active antenna. This is a matching circuit for obtaining An example in which the helical antenna 5 formed on a dielectric block or the like is mounted on the substrate 1 is shown. Further, the semiconductor element 7,
Although the matching circuit 8 is also mounted on the substrate 1 and the lead 6 is directly connected to the semiconductor element 7,
Any configuration may be adopted, such as mounting a connection line (not shown) or a matching circuit (not shown) to the semiconductor device 7 via the connection line or the matching circuit. Further, the present invention can be applied to a case where an amplifier including a semiconductor element or the like is used instead of the semiconductor element 7 and the matching circuit 8.

Here, the impedance of the helical antenna 5 is capacitive at low frequencies and inductive at high frequencies when viewed in a wide band. When used at frequencies that are inductive, the spread of the impedance on the Smith chart is small, and high-gain characteristics can be obtained over a wide band. Thus, the core diameter, the number of turns, and the pitch between the wirings are set so that the impedance becomes inductive at a desired frequency, and the leads 6 of the helical antenna 5 are connected directly or via a connection line or a matching circuit to the semiconductor element 7. When connected to the input or output terminal of the receiver, an active antenna of a receiving system or a transmitting system having a high gain over a wide band can be constituted.

Further, the core diameter, the number of turns, and the pitch between wires are set such that the impedance of the helical antenna 5 at a desired frequency is close to the noise minimum impedance of the semiconductor element 7, and the semiconductor element is connected directly or via a connection line or a matching circuit. When connected to the input terminal of No. 7, a receiving active antenna having low noise characteristics over a wide band can be constructed. When an amplifier is used in place of the semiconductor element 7 or the like, the impedance seen from the semiconductor element constituting the amplifier to the helical antenna 5 side via the input matching circuit should be close to the noise minimum impedance of the semiconductor element. To set.

Further, the core diameter, the number of turns, and the pitch between wires are set such that the impedance of the helical antenna 5 at a desired frequency is close to the maximum output impedance or the maximum efficiency impedance of the semiconductor element 7, and a direct or connection line or matching circuit is required. When the antenna is connected to the output terminal of the semiconductor element 7 via the semiconductor device 7, a transmitting active antenna having high output or high efficiency over a wide band can be configured. When an amplifier is used in place of the semiconductor element 7 and the like, the impedance seen from the semiconductor element forming the amplifier through the output matching circuit to the helical antenna 5 side is close to the noise minimum impedance of the semiconductor element. To set.

Embodiment 2 FIG. Embodiment 2 of the present invention
In FIG. 1, the semiconductor element 7 is a field effect transistor in FIG. 1 described in the first embodiment. In the case of the amplifier described in the first embodiment, the same applies to the case where the semiconductor element forming the amplifier is a field-effect transistor. The lead 6 is connected to the gate terminal or the drain terminal of the field effect transistor directly or through a connection line or a matching circuit. The input impedance and the output impedance of the field effect transistor depend on the gate width and the frequency, but are capacitive at a relatively low frequency. This is because at a relatively low frequency, the gate-source capacitance and the drain-source capacitance of the field effect transistor are dominant. When the helical antenna 5 is used under the condition that its impedance is inductive and the field-effect transistor is used under the condition that its impedance is capacitive, complex conjugate impedance matching is easily established, and an active antenna having a high gain over a wide band is obtained. Can be configured. Further, even when the lead 6 of the helical antenna 5 is connected to the drain or gate terminal of the field effect transistor via a matching circuit (not shown), a condition close to a complex conjugate matching between the helical antenna 5 and the field effect transistor is obtained. As a result, the necessary matching circuit can be realized with a simple configuration, and the active antenna can be reduced in size.

Embodiment 3 FIG. 2 is an explanatory diagram of a configuration of an active antenna according to a third embodiment of the present invention.
In the figure, 9 is a through hole provided in the substrate 1. Substrate 1
The lead 6 of the helical antenna 5 provided on the front surface of the helical antenna 5 is guided to the back surface of the substrate 1 through the through hole 9 and the lead 6 of the helical antenna 5 is connected to the input or output terminal of the semiconductor element 7 mounted on the back surface of the substrate 1 Configuration.
Other configurations are the same as those of the first embodiment,
A connection line or a matching circuit may be mounted on the back surface of the substrate 1 and the lead 6 may be connected to an input or output terminal of the semiconductor element via the connection line or the matching circuit.
Further, the lead 6 may be conducted through the through-hole 9 to the back surface, or may be conducted through the through-hole 9 without passing through.

Here, the setting of the impedance of the helical antenna 5 and the like are set in the same way as in the first embodiment. According to this embodiment, since the helical antenna 5 is provided on the front surface of the substrate 1 and the semiconductor element 7 and the matching circuit 8 are provided on the back surface of the substrate 1, electromagnetic coupling between them can be reduced, and the radiation characteristics of the active antenna can be reduced. It is possible to improve the performance and suppress unnecessary oscillation.

Embodiment 4 FIG. FIG. 3 is an explanatory diagram of a configuration of an active antenna according to a fourth embodiment of the present invention.
In the figure, reference numeral 10 denotes a metal wire provided in close contact with the substrate 1;
Reference numeral 1 denotes a through hole for continuously forming a metal wire 10 on the front and back surfaces of the substrate 1 into a coil shape, 12 denotes a first matching circuit provided on the substrate 1, and 13 denotes a second matching circuit provided on the substrate 1. A circuit 102 is an amplifier including the semiconductor element 7 and a first matching circuit 12 and a second matching circuit 13 serving as input / output matching circuits. A helical antenna 5 is formed by providing a metal wire 10 in a coil shape over both surfaces of the substrate 1 via a through hole 11, and a lead 6 of the helical antenna 5 is connected to the amplifier 102. The metal wire 10 may be formed into a coil shape by passing through the through hole 11 to form the helical antenna 5, or the metal wire 10 may be provided on the front and back surfaces of the substrate 1 and the front and back surfaces may be formed through the through hole 11. The helical antenna 5 may be formed by making the metal wire 10 conductive so as to form a coil. FIG.
Shows a case where the lead 6 is connected to the amplifier 102 via the connection line 4 mounted on the substrate 1, but the lead 6 is directly connected to the amplifier 102, or a connection line or a matching circuit is mounted on the substrate 1. However, any configuration, such as connection to the amplifier 102 via the connection line or the matching circuit, may be used.

Here, the setting of the impedance of the helical antenna 5 and the like are set in the same way as in the first embodiment. According to this embodiment, the metal wire 10 forming the helical antenna 5 can be provided in close contact with the substrate 1, and the lead 6 of the helical antenna 5 can be connected to the amplifier 102 in close contact with the substrate 1. A strong active antenna with excellent vibration resistance can be realized. Further, when the metal wire 10 is not passed through the through hole 11, the metal wire 10 and the lead 6 can be formed by a pattern such as etching or vapor deposition, and a low-cost active antenna can be realized.

Embodiment 5 FIG. 4 is an explanatory diagram of a configuration of an active antenna according to a fifth embodiment of the present invention.
In the figure, 10 is a metal wire, 11 is a through hole for a metal wire for forming the metal wire 10 on the front and back surfaces of the substrate 1 into a coil shape, and 12 is a first matching circuit provided on the substrate 1 , 13 are a second matching circuit provided on the substrate 1, and 102 is a first matching circuit 12 serving as an input / output matching circuit with the semiconductor element 7.
An amplifier 14 including a second matching circuit 13 and the like is a hole corresponding to the core of the helical antenna 5 formed by hollowing out the substrate 1 at the helical antenna 5 formation site. Further, the helical antenna 5 is formed by providing a metal wire 10 in a coil shape over both surfaces of the substrate 1 via the through hole 11, and the lead 6 of the helical antenna 5 is connected to the amplifier 1.
02. The method of forming the helical antenna 5 is the same as that described in the fourth embodiment. FIG. 4 shows a case where the lead 6 is connected to the amplifier 102 via the connection line 4 mounted on the substrate 1, but the lead 6 may be directly connected to the amplifier 102, or may be connected to the substrate 1 by a connection line or a matching circuit. , And may be connected to the amplifier 102 via the connection line or the matching circuit.

Here, the setting of the impedance of the helical antenna 5 and the like are set in the same way as in the first embodiment. In setting the impedance,
According to this embodiment, since the core-equivalent holes 14 are provided, the dielectric constant can be set to a relative dielectric constant of air or an insertion substance different from the relative dielectric constant of the substrate 1, and the degree of freedom in impedance setting can be increased. it can. When air is used, it contributes to the weight reduction of the active antenna.

[0025]

As described above, according to the first aspect of the present invention, the helical antenna core diameter, the number of turns, and the wiring pitch are set so that the impedance of the helical antenna at the operating frequency becomes inductive. There is an effect that a high-gain active antenna of a receiving system or a transmitting system can be configured over a wide band.

According to the second aspect of the present invention, the core diameter, the number of turns, and the pitch between wires of the helical antenna are set so that the impedance of the helical antenna at the operating frequency is inductive and has the minimum noise impedance. This has the effect that a receiving active antenna having low noise characteristics over a wide band can be configured.

According to the third aspect of the present invention, the core diameter, the number of turns, and the wiring pitch of the helical antenna are adjusted so that the impedance of the helical antenna at the operating frequency is inductive and the output maximum impedance or the efficiency maximum impedance. Is set, the transmission system active antenna having high output or high efficiency characteristics over a wide band can be constituted.

According to the fourth aspect of the present invention, the semiconductor element is a field-effect transistor, and the core diameter, the number of turns, and the pitch between wires of the helical antenna are determined by setting the impedance of the helical antenna at the operating frequency to be inductive and operating frequency. Is set in the frequency range in which the input impedance or output impedance of the field effect transistor is capacitive, complex conjugate impedance matching is easily achieved, and there is an effect that a high-gain active antenna can be configured over a wide band.

Further, according to the fifth aspect of the present invention, the helical antenna and the semiconductor element or the amplifier or the field effect transistor are mounted separately on the front and back surfaces of the substrate, and both are mounted via the through holes provided in the substrate. Connected
Electromagnetic coupling between the two can be reduced, the radiation characteristics of the active antenna can be improved, and unnecessary oscillation can be suppressed.

According to the sixth aspect of the present invention, the helical antenna is provided through the first and second rows of through holes provided in the substrate in two rows at a predetermined interval and pitch. And the corresponding through-holes of the first and second rows are successively formed in a coil shape by metal wires that are sequentially connected to the front and back surfaces of the substrate. ,
The metal wire forming the helical antenna can be provided in close contact with the substrate, which has the effect of realizing a strong active antenna with excellent vibration resistance.

Further, according to the invention of claim 7, 2
Between the first row and the second row of through holes provided in the row,
A hole corresponding to the core of the helical antenna formed by hollowing out the substrate was provided, and a part having a relative dielectric constant different from that of the above substrate was formed, so the dielectric constant was set to the relative dielectric constant of air or an inserted substance different from that of the substrate. This has the effect of increasing the degree of freedom in impedance setting. In the case of using air, there is an effect of reducing the weight of the active antenna.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an active antenna according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating a configuration of an active antenna according to a third embodiment of the present invention.

FIG. 3 is an explanatory diagram of a configuration of an active antenna according to a fourth embodiment of the present invention.

FIG. 4 is an explanatory diagram of a configuration of an active antenna according to a fifth embodiment of the present invention.

FIG. 5 is a configuration diagram of a conventional active antenna.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Substrate, 2nd layer wiring, 3rd layer wiring, 4 connection lines, 5 helical antennas, 6 leads, 7 semiconductor elements, 8 matching circuits, 9 through holes, 10 metal wires, 1
1 through hole, 12 first matching circuit, 13 second
Matching circuit, 14 core equivalent holes, 100 coil antenna, 101 multi-stage amplifier, 102 amplifier.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masatoshi Nakayama 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Kenichi Horiguchi 2-3-2 Marunouchi 3-chome, Chiyoda-ku, Tokyo Rishi Electric Co., Ltd. (72) Inventor Toru Fukasawa 2-3-2 Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 5J021 AA01 AB04 CA03 FA01 FA26 HA05 HA10 JA09

Claims (7)

[Claims] 1. A helical antenna and a semiconductor element or an amplifier mounted on the same substrate, wherein a lead of the helical antenna is connected to an input terminal or an output terminal of the semiconductor element or an amplifier directly or via a connection line or a matching circuit. In an active antenna configured with
An active antenna, wherein the core diameter, the number of turns, and the pitch between wires of the helical antenna are set so that the impedance of the helical antenna at the used frequency becomes inductive. 2. A helical antenna and a semiconductor element or an amplifier mounted on the same substrate, wherein a lead of the helical antenna is connected to an input terminal of the semiconductor element or the amplifier directly or via a connection line or a matching circuit. In the active antenna applied to the receiving system,
An active antenna, wherein the core diameter, the number of turns, and the wiring pitch of the helical antenna are set so that the impedance of the helical antenna at the operating frequency is inductive and has a minimum noise impedance. 3. A helical antenna and a semiconductor element or an amplifier mounted on the same substrate, wherein a lead of the helical antenna is connected to an output terminal of the semiconductor element or the amplifier directly or via a connection line or a matching circuit. In an active antenna applied to the transmission system,
An active antenna, wherein the core diameter, the number of turns, and the wiring pitch of the helical antenna are set so that the impedance of the helical antenna at the operating frequency is inductive and the maximum output impedance or the maximum efficiency efficiency. 4. The active antenna according to claim 1, wherein the semiconductor element is a field effect transistor, and a lead of the helical antenna is connected to a gate terminal or a drain terminal of the field effect transistor directly or via a connection line or a matching circuit. An active antenna, wherein the active frequency is set within a frequency range in which the input frequency or the output impedance of the field effect transistor is capacitive while being connected. 5. The active antenna according to claim 1, wherein the helical antenna and the semiconductor element or the amplifier or the field effect transistor are mounted separately on two sides of the substrate. An active antenna, wherein both are connected via a through hole provided in a substrate. 6. The active antenna according to claim 1, wherein the helical antenna is
The first substrate provided in two rows at a predetermined interval and pitch on the substrate
The first and second through-holes are provided through the through-holes of the row and the second row, and are provided in close contact with the front and back surfaces of the substrate.
An active antenna, wherein the through-holes corresponding to the through-holes of the row and the second row are continuously formed in a coil shape by metal wires that are sequentially connected on the front and back surfaces of the substrate. 7. The active antenna according to claim 6, wherein a hole corresponding to a core of the helical antenna formed by hollowing out the substrate is provided between the through holes of the first and second rows provided in the two rows. An active antenna, wherein a portion having a relative dielectric constant different from that of the substrate is formed.