JPH0616564B2 - Balanced diode attenuator - Google Patents

Description

TECHNICAL FIELD The present invention relates to a balanced diode attenuator, and more particularly to a bias supply circuit for a balanced diode attenuator used at high frequencies.

(Prior Art) A balanced diode attenuator is composed of one 90 ° power equalizing circuit, two diode attenuating circuits and one 90 ° power combining circuit. Is widely used because of its excellent wide band. In order to make full use of the above characteristics, as a method of supplying a bias to two diode attenuator circuits from the outside, it is necessary to provide a bias circuit having the same configuration to each of the diode attenuator circuits.

(Problems to be solved by the invention) However, in the configuration in which the supply lines of both bias circuits are independently drawn out of the high frequency circuit of the diode attenuator, the bias supply terminals are required on both sides of the diode attenuator. However, there is a drawback in that the structure for housing in a higher-level device becomes complicated.

FIG. 2 is a configuration diagram of an example of a conventional diode attenuator, where 1 is an input terminal, 2 is an input side 90 ° hybrid in which one of the input terminals is terminated at 50Ω (equal power division circuit),
3 and 4 are two-stage diode attenuator circuits with the same characteristics, 5 is an output side 9 ° hybrid (power combining circuit) in which one of the output terminals is terminated at 50Ω, 6 is an output terminal, 11 and 12 are inductors L Bias circuits composed of a bypass capacitor C, reference numerals 7 and 8 are bias circuits, and bias supply terminals 11 and 12. When the supply line from the bias circuit to the bias supply terminal crosses the signal transmission line of another diode attenuator circuit, the characteristics of the attenuator are affected. Therefore, in the conventional balanced diode attenuator, as shown in FIG. 2, bias supply terminals are provided on both sides of the diode attenuator circuit to avoid the influence of the bias supply line. However, with this configuration,
When a bias is externally supplied to the balanced diode attenuator, the bias is supplied to both sides of the diode attenuator circuit, which complicates the mounting configuration.

The present invention has been made to eliminate the above-mentioned drawbacks of the prior art, and an object of the present invention is to realize a mounting configuration without deteriorating high frequency characteristics such as input / output impedance and transmission characteristics. To provide a simple balanced diode attenuator.

(Means for Solving the Problems) A balanced diode attenuator according to the present invention has first, second, third and fourth terminals, and a high frequency signal input to the first terminal is a third signal. And a fourth terminal, a terminating resistor is connected to the second terminal, the second terminal is DC-connected to the third terminal and is DC-insulated from the fourth terminal. The first 90 ° hybrid and this first 90
A second 90 ° hybrid having the same structure as the first 90 ° hybrid, and a first 90 ° hybrid connected between the third terminal of the first 90 ° hybrid and the fourth end of the second 90 ° hybrid. And the first 9
A second diode attenuator circuit connected between the fourth terminal of the 0 ° hybrid and the third terminal of the second 90 ° hybrid, and a bias voltage for the first and second diode attenuator circuits. Supply first and second respectively
A bias circuit and a bias supply terminal for receiving a bias voltage supplied from a bias power source to the first and second bias circuits, the first bias circuit comprising: A first 90 ° hybrid connected to the second terminal or the first diode attenuator circuit, the second bias circuit comprising: the first bias circuit connected to the second terminal of the first 90 ° hybrid. When connected to the terminal, it is connected to the second diode attenuator circuit, and when the first bias circuit is connected to the first diode attenuator circuit, the second 90 ° hybrid second device. The first and second bias supply terminals are connected to the first terminal and the main signal from the first 90 ° hybrid to the second 90 ° hybrid. Feeding wherein the is arranged on one side of the direction.

Embodiments Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a configuration diagram of an embodiment of the present invention, and the same portions as those in FIG. 2 are designated by the same reference numerals. In this embodiment, as shown in the figure, the difference from the configuration of FIG. The point where the circuit 13 is added and connected to the bias supply terminal 9 and the bias is not supplied to the bias circuit 12, but since it is equivalent to the bias circuit 11 in impedance, the diode attenuation circuits 3 and 4 have the same characteristics. Therefore, the good impedance and transmission characteristics that are characteristic of the balanced diode attenuator are the same as those of the conventional example. Further, even if the bias circuit 13 is added to the input end of the 90 ° hybrid 2 on the input side which is terminated to 50Ω, the impedance of the diode attenuator is not affected because it is terminated to 50Ω.

(Effect of the Invention) As described above, according to the present invention, it is possible to provide a balanced diode attenuator capable of supplying a bias from one side, whereas the bias is conventionally supplied from both sides of the diode attenuating circuit. Therefore, by adopting the balanced diode attenuator of the present invention, it is possible to simplify the mounting of the high frequency device, which is very effective.

In the embodiment of FIG. 1, the bias circuit 13 is connected to the terminating terminal of the input side 90 ° hybrid 2, and the bias supply terminal 7 is provided in the bias circuit 11, so that the two bias supply terminals 7 and 9 are mainly connected. It was placed on one side of the track.
However, the present invention is not limited to the embodiment shown in FIG.
The bias supply terminal 7 is provided in the bias circuit 12, and the two bias supply terminals 7,
There is no problem even if 9 is arranged on one side of the main line.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional balanced diode attenuator. 1 ... Input terminal, 2 ... Equal power division circuit, 3,4 ... Diode attenuation circuit, 5 ... Power combining circuit, 6 ... Output terminal, 7,8,9 ... Bias supply terminal, 11,12 ,13……
Bias circuit.

Claims (1)

[Claims] 1. A first terminal, a second terminal, a third terminal and a fourth terminal,
The high-frequency signal input to the first terminal is guided to the third and fourth terminals, and the terminating resistor is connected to the second terminal,
Is connected to the third terminal in a direct current manner and is insulated from the fourth terminal in a direct current manner, and a second 90 ° hybrid having the same structure as the first 90 ° hybrid.
90 ° hybrid, a first diode attenuator circuit connected between the third terminal of the first 90 ° hybrid and the fourth end of the second 90 ° hybrid; A second diode attenuator circuit connected between the fourth terminal of the first 90 ° hybrid and the third terminal of the second 90 ° hybrid, and the first and second diode attenuator circuits. A balanced diode attenuator comprising first and second bias circuits for respectively supplying a bias voltage and a bias supply terminal for receiving a bias voltage supplied from a bias power source to the first and second bias circuits, The first bias circuit is connected to the second terminal of the first 90 ° hybrid or the first diode attenuating circuit, and the second bias circuit is connected to the second bias circuit. A path connects to the second diode attenuator circuit when the first bias circuit is connected to the second terminal of the first 90 ° hybrid, and the first bias circuit connects to the second bias circuit. When connected to one diode attenuator circuit, it is connected to the second terminal of the second 90 ° hybrid, and the first and second bias supply terminals are connected to the first 90 ° hybrid.
Balanced diode attenuator, characterized in that it is arranged on one side of the main signal transmission direction from the ° hybrid to the second 90 ° hybrid.