JP2009239404A - Multi-step directional coupler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multi-step directional coupler which eliminates an electric field and a magnetic field coupling between directional couplers, and obtains a small size and good basic characteristics. <P>SOLUTION: The invention is characterized by comprising: a main microstrip line L4 in which a corner is prepared between an input terminal P7 and an output terminal P8, and main coupling line units L41, L42 whose lengths are respectively odd times of a wavelength λ/4, are prepared in both sides of the corner; sub-coupling line units L51, L61 whose lengths are determined by odd times of the wavelength λ/4 are prepared respectively in parallel with the main coupling line units L41, L42; and sub-microstrip lines L5, L6 equipped with terminals for coupling P9, P11 and terminals for isolation P10, P12 are prepared in both sides of the sub-coupling line units L51, L61. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a directional coupler used for distributing and synthesizing high-frequency power in the UHF band and microwave band used in the communication field such as cellular phones.

  FIG. 4 is an explanatory diagram showing a configuration of a conventional multistage directional coupler. In FIG. 4, 1 is a dielectric substrate, L1 is a main microstrip line, L2 and L3 are sub-microstrip lines, L11 and L12 are main coupling line parts, L13 is a connection line part, L21 and L31 are sub-coupling line parts, P1 is an input terminal, P2 is an output terminal, P3 and P5 are coupling terminals, and P4 and P6 are isolation terminals.

  As shown in FIG. 4, the main microstrip line L1 is linearly provided on the dielectric substrate 1, and the input terminal P1 and the output terminal P2 are provided at both ends, respectively. The main microstrip line L1 includes main coupling line portions L11 and L12 having a length determined by an odd multiple of the wavelength λ / 4, and a connection line portion L13 that connects the main coupling line portions L11 and L12. A plurality of substantially U-shaped sub-microstrip lines L2 and L3 are provided on the dielectric substrate 1. The sub-microstrip lines L2 and L3 are provided with sub-coupling line portions L21 and L31 having a length determined by an odd multiple of the wavelength λ / 4 in parallel with the main coupling line portions L11 and L12, respectively. Coupling terminals P3 and P5 and isolation terminals P4 and P6 are provided at both ends of the sub-microstrip lines L2 and L3, respectively.

  That is, when high-frequency power is supplied from the input terminal P1 to the output terminal P2 of the main microstrip line L1, the main coupling line portions L11 and L12 and the sub-coupling line portions L21 and L31 correspond to the electric field and the magnetic field coupling, respectively. The coupling terminals P3 and P5 of the strip lines L2 and L3 respectively distribute and output power of −10 dB or less with respect to the input power.

  However, since the directional coupler performs power distribution using electric field and magnetic field coupling, in the case of the multistage directional coupler shown in FIG. If the directional coupler composed of the strip line L3 is coupled, the basic characteristics may not be obtained.

  In particular, when the length of the connecting line portion L13 is short, the coupling between the directional couplers becomes strong and it becomes difficult to obtain the characteristics.

Therefore, in order to avoid the coupling of the directional coupler composed of the sub-microstrip line L2 and the directional coupler composed of the sub-microstrip line L3, if the length of the connection line portion L13 is increased, the multistage directional coupler becomes large. There was a drawback to become.
Japanese Patent Laid-Open No. 7-12870

  Conventionally, when a multistage directional coupler is configured by arranging a plurality of directional couplers, there is a problem that performance cannot be obtained due to the influence of directional couplers, and in order to avoid this, a multistage directional coupler is There was a drawback of becoming large.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a multistage directional coupler that eliminates the electric field and magnetic field coupling between the directional couplers, and is small and can provide good basic characteristics.

  In order to achieve the above object, the multistage directional coupler according to the present invention has a corner provided between an input terminal and an output terminal, and a length determined by an odd multiple of a wavelength λ / 4 on both sides of the corner. A main microstrip line provided with a main coupling line part and a sub-coupling line part having a length determined by an odd multiple of a wavelength λ / 4 in parallel with each of the main coupling line parts. And a sub-microstrip line provided with a coupling terminal and an isolation terminal on both sides of the coupling line portion.

  The multistage directional coupler of the present invention can ensure good performance because the electric field and magnetic field coupling between the directional couplers are reduced.

  In addition, since the electric field and magnetic field coupling between the directional couplers can be ignored, there is an advantage that it is easy to design a small circuit.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a configuration explanatory view showing a multistage directional coupler according to a first embodiment of the present invention. In FIG. 1, 2 is a dielectric substrate, L4 is a main microstrip line, L5 and L6 are submicrostrip lines, L41 and L42 are main coupling line parts, L43 is a connection line part, L51 and L61 are subcoupling line parts, P7 is an input terminal, P8 is an output terminal, P9 and P11 are coupling terminals, and P10 and P12 are isolation terminals.

  As shown in FIG. 1, a main microstrip line L4 is provided on a dielectric substrate 2 in an L shape bent at a corner, and an input terminal P7 and an output terminal P8 are provided at both ends, respectively. The main microstrip line L4 connects the main coupling line portions L41 and L42 having a length determined by an odd multiple of the wavelength λ / 4, and the main coupling line portions L41 and L42 and a connection line portion L43 provided with a corner. Consists of including. A plurality of substantially U-shaped sub-microstrip lines L5 and L6 are provided on the dielectric substrate 2. The sub-microstrip lines L5 and L6 are provided with sub-coupling line portions L51 and L61 having a length determined by an odd multiple of the wavelength λ / 4 in parallel with the main coupling line portions L41 and L42, respectively. Coupling terminals P9 and P11 and isolation terminals P10 and P12 are provided at both ends of the sub-microstrip lines L5 and L6, respectively.

  That is, when high frequency power is passed from the input terminal P7 of the main microstrip line L4 to the output terminal P8, the main coupling line portions L41 and L42 and the sub coupling line portions L51 and L61 respectively correspond to each other in an electric field and a magnetic field coupling. The coupling terminals P9 and P11 of the strip lines L5 and L6 respectively distribute and output power of −10 dB or less with respect to the input power.

  In the case of this multistage directional coupler, the direction of the electric field and the magnetic field is changed by the corner provided in the main microstrip line L4. Therefore, the directionality composed of the directional coupler composed of the sub microstrip line L5 and the sub microstrip line L6. The coupling between the couplers is weakened, and good basic characteristics can be obtained.

  In this way, since the coupling between the directional coupler composed of the sub-microstrip line L5 and the directional coupler composed of the sub-microstrip line L6 is avoided by the corner, the length of the connection line portion L43 can be shortened. There is an advantage that the multistage directional coupler can be miniaturized.

  FIG. 2 is a configuration explanatory view showing a multistage directional coupler according to a second embodiment of the present invention. In FIG. 2, 3 is a dielectric substrate, L7 is a main microstrip line, L8, L9 and L10 are sub-microstrip lines, L71, L72 and L73 are main coupling line parts, L74 and L75 are connection line parts, L81 and L91. , L101 are sub-coupling line sections, P13 is an input terminal, P14 is an output terminal, P15, P17, and L19 are coupling terminals, and P16, P18, and L20 are isolation terminals.

  As shown in FIG. 2, on the dielectric substrate 3, a main microstrip line L7 is provided in a substantially U shape bent at a corner, and an input terminal P13 and an output terminal P14 are provided at both ends, respectively. The main microstrip line L7 connects the main coupling line portions L71, L72, and L73 having a length determined by an odd multiple of the wavelength λ / 4 and the main coupling line portions L71 and L72, and L72 and L73, respectively. Connection line portions L74 and L75 provided with corners. A plurality of substantially U-shaped sub-microstrip lines L8, L9, and L10 are provided on the dielectric substrate 3. The sub-microstrip lines L8, L9, and L10 correspond to the main coupling line portions L71, L72, and L73, and are parallel to the sub-coupling line portions L81, L91, and L101 having a length determined by an odd multiple of the wavelength λ / 4. And the coupling terminals P15, P17, and L19 and the isolation terminals P16, P18, and L20 are provided at both ends of the sub-microstrip lines L8, L9, and L10, respectively.

  That is, when high frequency power is supplied from the input terminal P13 to the output terminal P14 of the main microstrip line L7, the main coupling line portions L71, L72, and L73 and the sub-coupling line portions L81, L91, and L101 correspond to electric field and magnetic field coupling, respectively. The sub-microstrip lines L8, L9, and L10 are connected to the coupling terminals P15, P17, and L19, and power of −10 dB or less is distributed and output with respect to the input power.

  In the case of this multistage directional coupler, the direction of the electric field and magnetic field is changed by the two corners provided on the main microstrip line L7, so that the directional coupler composed of the sub microstrip line L8 and the sub microstrip line L9. The coupling between the directional couplers and between the directional coupler composed of the sub-microstrip line L9 and the directional coupler composed of the sub-microstrip line L10 is weakened, and good basic characteristics can be obtained.

  Thus, the coupling between the directional coupler composed of the sub-microstrip line L8 and the directional coupler composed of the sub-microstrip line L9, and the directional coupler composed of the sub-microstrip line L9 and the sub-microstrip line L10. Since the coupling between the directional couplers is avoided by the corners, the lengths of the connection line portions L74 and L75 can be reduced, and the multistage directional coupler can be reduced in size.

  FIG. 3 is an explanatory diagram of a configuration of a multistage directional coupler according to a third embodiment of the present invention. In FIG. 3, the same parts as those in FIG. In FIG. 3, 4 is a dielectric substrate, 5 is a wiring substrate, and 51 and 52 are wiring spaces.

  As shown in FIG. 3, two corners of the dielectric substrate 4 of the multistage directional coupler are cut out and attached to the wiring substrate 5.

  That is, when the multistage directional coupler is attached to the wiring board 5, wiring spaces 51 and 52 are generated in the cut-out portion of the dielectric substrate 4 of the multistage directional coupler. Therefore, connectors and electronic components are provided in the wiring spaces 51 and 52. Etc., and the wiring board 5 can be used effectively.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

1 is a configuration explanatory view showing a multistage directional coupler according to a first embodiment of the present invention. It is composition explanatory drawing which shows the multistage directional coupler which concerns on the 2nd Embodiment of this invention. It is a configuration explanatory view showing a multistage directional coupler according to a third embodiment of the present invention. It is structure explanatory drawing which shows the conventional multistage directional coupler.

Explanation of symbols

  2 ... Dielectric substrate, L4 ... Main microstrip line, L5, L6 ... Sub microstrip line, L41, L42 ... Main coupling line part, L43 ... Connection line part, L51, L61 ... Sub coupling line part, P7 ... Input terminal P8, output terminals, P9, P11, coupling terminals, P10, P12, isolation terminals.

Claims (1)

A main microstrip line in which a corner is provided between the input terminal and the output terminal, and a main coupling line part having a length determined by an odd multiple of the wavelength λ / 4 is provided on both sides of the corner;
A sub-coupling line portion having a length determined by an odd multiple of the wavelength λ / 4 is provided in parallel to each of the main coupling line portions, and a coupling terminal and an isolation terminal are provided on both sides of the sub-coupling line portion. A multistage directional coupler comprising a sub-microstrip line provided.

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