JPH03247101A - Variable coupling type directional coupler - Google Patents

Abstract

PURPOSE:To control an output power obtained from a coupling output opening at a microwave region widely and continuously by constituting the coupler with two directional couplers, a power distributer, a power synthesizer and a broad band variable phase shifter deciding the degree of coupling and varying the phase shifter so as to control the degree of coupling. CONSTITUTION:Input openings 31, 41 of two directional couplers 3, 4 are connected to two output terminals of a power distributer 1, output openings 32, 42 of the directional couplers 3, 4 are connected to two input terminals of a power synthesizer 2. The same performance of directional couplers is adopted for the directional couplers 3, 4. An isolation opening 44 of the directional coupler 4 is terminated by a resistive terminator 6 and an input terminal of a broad band variable phase shifter 5 is connected to a coupling output terminal opening 43 of other terminal and an output terminal of the phase shifter 5 is connected to the isolation opening 34 of the directional coupler 3. When the phase shift angle of the phase shifter 5 is selected to be 0 deg., an output power obtained from the coupling output opening 33 is doubled. When the phase shift angle of the phase shifter 5 is set to 180 deg., the output power obtained from the coupling output opening 33 is theoretically zero.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a broadband directional coupler that can be used in high frequency bands, particularly in the microphone A-wave region.

(Prior Art) In conventional directional couplers, it is not possible to obtain various degrees of coupling with one directional coupler, and a new one is manufactured depending on the required degree of coupling.

Additionally, a method has been adopted in which the degree of coupling is changed equivalently using an attenuator.

(Problem to be Solved by the Invention) However, the former method requires a lot of cost to newly design and manufacture a directional coupler, and the latter method requires an attenuator due to heat loss when handling high power. There was a problem that the shape etc. became large.

(Means for Solving the Problems) In order to solve these problems, the present invention includes two directional couplers, a power divider, a power combiner, a wideband variable phase shifter for determining the degree of coupling, and a wideband variable phase shifter for determining the degree of coupling. The phase shifter provided between the sub-lines of the bidirectional coupler is varied to control the degree of coupling over a wide band and over a wide range.Examples will be explained below in detail with reference to the drawings. .

(Embodiment) Fig. 1 shows an embodiment of the present invention, which includes a two-way power divider 1, first and second directional couplers 3.4 with a coupling degree of 6 dB, and a wideband variable phase shifter (hereinafter referred to as phase shifter). The configuration of a variable-coupling directional coupler using a directional coupler (referred to as a directional coupler) 5 is shown.

Two directional couplers 3 to the two output terminals of the power divider 1
and 4, and the output apertures 32.42 of the directional couplers 3 and 4 are connected to the two input terminals of the power combiner 2. Here, each directional coupler 3.
4 are of the same performance, and the input apertures 31 and 41, the output apertures 32 and 42, the combined output apertures 33 and 43, and the isolation apertures 34 and 44 have the same amplitude and the same phase.

The phase difference between the output apertures 32 and 42 of the directional couplers 3 and 4 and the combined output apertures 33 and 43 is 90° over the operating frequency range. In addition, two directional couplers 3
, 4, the phase angle of the output apertures 32 and 42 is 0° as described above.
is maintained. Therefore, the output aperture 3 of the directional coupler 3
The two coupled output apertures 33.
The phase angles of 43 are both 90'.

The isolation aperture 44 of the directional coupler 4 is terminated with the non-reflection terminator 6, the input terminal of the phase shifter 5 is connected to the coupling output aperture 43 at the other end, and the output terminal of the phase shifter 5 is connected to the directional coupler 4. Connect to the isolation opening 34 of the sexual coupler 3.

When the phase shift angle of the phase shifter 5 is set to 0°, the sub line of the directional coupler 3 becomes in phase with the amplitude of the phase angle 90', and the output power obtained from the coupled output aperture 33 is doubled. This is equivalent to the coupling degree of the directional coupler 3 being 3 dB.

Further, when the phase shift angle of the phase shifter 5 is set to 180°, the phase angle of the amount that can be supplied to the isolation aperture 34 is 270°, so the amplitude is changed to the sub line of the directional coupler 3 at a phase angle of 90°. The output power obtained from the combined output aperture 33 is theoretically O.

2, 3, and 4 are characteristic diagrams showing the measurement results of the embodiment shown in FIG. The relationship between the phase shift angle and the degree of coupling when varied up to 180° is shown. Figure 3 is 4G
The frequency characteristics of the degree of coupling with the phase shift angle as a parameter from Hz to 8 GHz are shown. Moreover, FIG. 4 shows the insertion loss and directionality when the degree of coupling is maximum and minimum.

(Effects of the Invention) As explained above, by changing the phase shift amount of the phase shifter, the output power obtained from the coupled output aperture can be controlled over a wide range and continuously in the broadband microwave region. can be easily done.

Furthermore, since a phase shifter is used, there is almost no heat loss and miniaturization is possible even when handling large amounts of power.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 shows the measurement results of the embodiment of Fig. 1, and shows a phase shift angle-coupling characteristic diagram, and Fig. 3 also shows a frequency-coupling characteristic diagram. Figure 4 also shows the frequency -
FIG. 3 is an insertion loss and directionality characteristic diagram. 1. Power divider, 2. Power combiner, 3. First directional coupler, 4. Second directional coupler, 5.
・Wideband variable phase shifter, ・Reflection-free terminator.

Claims (1)

[Claims] A power divider that divides high frequency power into two, first and second directional couplers that connect the main line to each output terminal of the power divider, and each output of the two directional couplers is combined. a power combiner, and between the isolation aperture of the first directional coupler and the coupling output aperture of the second directional coupler, the isolation aperture being terminated by a non-reflection terminator. A variable coupling amount directional coupler, characterized in that the coupling power is obtained from the coupling output aperture of the first directional coupler with a phaser interposed therebetween.