JPS6252483B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a microwave integrated circuit in which two microwave transmission lines intersect with each other with good electrical characteristics.

(Background Art) A conventional circuit of this type in a microstrip line is shown in FIG. 1 and 2 are microstrip circuits, 3 is a three-dimensional intersection that intersects via an insulating layer, and 4 to 7 are signal terminals. The signal coming in from 4 is transmitted through the microstrip line 1 and output to 5, but at the grade crossing at 3, some of the signals are transferred to 2.
6 and 7 by coupling to the microstrip lines of
Output to the terminal. As described above, since the conventional circuits of this type intersect at one point, coupling occurs between the two lines, making it impossible to obtain high isolation.

(Problem of the Invention) The present invention is intended to improve the above-mentioned drawbacks of the conventional technology, and its purpose is to create a structure in which a first microstrip line is branched into two in an intersecting structure of two microstrip lines. Then, extend each branch line so that the electrical length from the branch point is equal to each other, and make the branch line 1/2 of the second microstrip line.
A first microstrip line is constructed by crossing the second microstrip line at wavelength intervals through an insulating layer, and by extending the crossed branch lines so that the electrical lengths from the crossing point are equal to each other. Microwave integrated circuits such as those having a structure synthesized with

(Structure and operation of the invention) FIG. 2 shows an embodiment of the invention, in which 8 is a branch part;
9 is a combining section, and the remaining symbols are the same as in FIG. The microstrip line 1 is branched into two and intersects the microstrip line 2 at an equal distance from the branch point via an insulating layer. The branch circuit has a structure that equally divides the power into two parts, and can be configured as a Y branch or a Wilkinson type branch circuit. The interval between the two intersections 3 is equal to the electrical length of the microstrip line 2, which is 1/2 of the tube wavelength λ.

At the intersection 3, the line 4-5 and the line 6-7 are not coupled in terms of direct current, and the respective conductors are insulated by an air layer or an insulator.

Next, the operation will be explained. The signal input from 4 is divided into two equal parts by a branching section 8, and after being transmitted over an equal distance, the signals are combined again by a combining section 9 and output from 5. Part of the input signal is 2 for microstrip line 2.
However, since the distance between the two intersections to be coupled is an electrical length of 1/2 wavelength with respect to the microstrip line 2, the signals cancel each other out and the signals are transmitted to the terminals 6 and 7. No output.

Further, the input signal from 6 is outputted to terminal 7, and the signal coupled to microstrip line 1 is canceled by branching section 8 and combining section 9, and is not outputted to terminals 4 and 5. The same operation is performed for the input signal from 5 or 7. In FIG. 2, the interval between the intersections may be 1/2 of the wavelength within the microstrip line 2, and the shape thereof does not need to be a straight line.

(Effects of the Invention) As explained above, the signals combined at the two intersections of the two microstrip lines cancel each other out, which has the advantage of increasing the isolation between the two intersecting lines.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a conventional crossing line, and FIG. 2 is a block diagram of an embodiment of the present invention. 1, 2...Microstrip line, 3...2
Intersection of main lines, 4 to 7... Signal input/output terminals, 8... Line branching part, 9... Line combining part.

Claims (1)

[Claims] 1. In a cross-over structure of two microstrip lines, the first microstrip line is branched into two, and each branch line is extended so that the electrical length from the branch point is equal to each other, and the branch line is The two microstrip lines intersect with the second microstrip line via an insulating layer at intervals of 1/2 wavelength of the second microstrip line, and the electrical lengths of the crossed branch lines from the intersection are mutually 1. A microwave integrated circuit characterized by having a structure in which the microstrip lines are equally stretched and combined into a first microstrip line.