JPS6143802A - Magic t made into ic using modified coupling slot line - Google Patents

Abstract

PURPOSE:To improve the impedance characteristic and isolation characteristic of a magic T by adopting the operation that an input wave from the 1st output terminal is outputted to the 3rd and 4th terminals in phase, no output is given to the 2nd terminal and the input wave from the 2nd terminal is outputted from the 3rd and 4th terminals in opposited phase and not outputted from the 1st terminal CONSTITUTION:When a magic T is energized from the 1st input/output terminal H, a signal propagated through a microstrip 26 from a terminal H is branched in parallel with a 1/4 wavelength modified slot line 21 in parallel and propagated to a line 22 with the state of an electric field with a direction shown in figure. This is the odd mode propagation, no output appears at a terminal E and branched in phase to terminals P1, P2. When the magic T is energized from the input/output terminal E, since the wave is propagated in the even mode on the modified coupling slot line 22, no output appears from the terminal H and branched in opposite phase to the P1, P2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magic T made into a microwave IC.

[Conventional technology]

Several Magic T's made into microwave ICs have been proposed. The fourth figure shows seven examples of Magic T using coupled slot lines. l/≠wavelength slot line on the surface of the board formed by connecting the ends, H is the seventh input/output terminal provided on the microstrip/l on the back surface of the board connected orthogonally to the connection point, PH coupling slot line The first output terminal, P1+FB, is connected to the microstrip saw on the back of the board, which is connected perpendicularly to the connecting part of the wavelength slot line. Microstrip lines formed on the back side of the board to be perpendicular to each other/3
The 3rd input/output terminal provided in the 3rd column, r and ri are front and back short-circuited conductors, and 10 is a cavity provided at the tip of the coupling slot line to increase the impedance of the coupling slot line. , 27Jλ). Note that in the above description, it is well known that the 1/4 wavelength portion may be an odd number multiple of the 1/4 wavelength portion (the same applies in the following description).

Figure 2a is a plan view showing the state of the electric field excited in slots 2 in/2 and 2 when power is supplied to this magic T from the input/output terminal H, and figure 2b is a plan view of the microstrip/2 portion at that time. The state of the excitation electric field in the thickness direction, FIG. 2c shows the state of the excitation electric field at the microstrip/3 portion. The electromagnetic waves input from the microstrip on the back surface are propagated to the right by the short-circuit conductor l over the slot lines l and λ on the front surface with an electric field as shown in FIG. 2a.

In the terminal E part! Slot line λ as shown in sdb diagram
Since the electric field is directed in opposite directions in the top and thickness directions, the slot line λ and the microstrip n on the back side are short-circuited at high frequency, and the microstrip /2 has a length λ/4t (or Since the microstrip 7.2 is open (an odd number multiple of that number), it is not short-circuited when viewed from the center of slot 2. No electromagnetic waves are excited in this microstrip 7.2, and no output is generated from the input/output terminal E. . Furthermore, as shown in FIG. 2c, in the microstrip /3 portion, since there is a short-circuit conductor, the electric fields are oriented in the same direction in the thickness direction, so that they are output from PllP in the same phase.

The excitation mode shown in Fig. 2a is called an odd mode.

The state of the electric field similar to the above when power is supplied from the input/output terminal B is shown in FIGS. 3a, 3b, and 3c.

Figure 3a is a plan view), and since power is supplied from terminal E, there is an electric field in the upward direction in the drawing above slots 2inl and C), and an electric field in the arc-shaped part of the slot line on the left side. changes direction little by little, and at the microstrip // portion from terminal H, the direction is reversed. Therefore, the short-circuited conductor t is short-circuited at high frequency, and no signal is output from the terminal H.

On the other hand, in the microstrip /3 part, as shown in Figure 3C, the electric field is in the opposite direction on both sides of the short-circuit conductor, so Pl,
P, are output in opposite phases to each other. This excitation mode is called even mode.

[Problem that the invention seeks to solve]

As is clear from the figure, such a magic T requires drilling holes in the board to provide the front and back short-circuit conductors ♂t, which increases manufacturing errors and deteriorates balance. Another disadvantage is that the conversion characteristics of the line in a high frequency band are deteriorated due to impedance discontinuity.

[Means for solving problems]

In order to solve these drawbacks, the present invention proposes a microwave IC Magic T using a modified coupling slot line with conductors arranged on both sides of the substrate as shown in Fig. 5.
, the drawings will be described in detail below.

〔Example〕

FIG. 7 shows an embodiment of the present invention, where 2/ is a deformed slot line with a length that is an odd multiple of the l/μ wavelength, with conductors arranged on both sides of a dielectric substrate, here is a deformed coupling λλ slot line, 23 and 25 are microstrip lines arranged perpendicular to the slot line J, and 2 Hiro is connected to all the modified joint slot lines //41. This is a slot line whose length is an odd number multiple of the wavelength.

FIG. 6 shows the state of the excitation electric field when power is supplied to the Magic T of the present invention from the first input/output terminal H.

The signal propagated from the H terminal to microstrip 2B is 1
It is branched in parallel to the /4 wavelength deforming slot line 2/, and is transmitted to the diine λλ in an electric field state in the direction shown in the figure. This is odd mode propagation, and no output appears at terminal E based on the same principle as in Figure 2b, and no output appears at terminal E based on the same principle as in Figure 2C.
1 and P are in-phase distributed.

Figure 7 shows the case where power is supplied from the input/output terminal E, and even mode propagation occurs on the modified coupling slot line 22, so no output appears from the H terminal, and the output from the input/output terminal E is reversed. [Effects of the Invention] As explained above, according to the present invention, it is possible to eliminate the need for substrate drilling, which causes deterioration in manufacturing accuracy, and thus has the following advantages.

(1) Magic T's impedance characteristics and isolation characteristics can be improved.

(2) Since there is no drilling required, manufacturing can be simplified.

(3) Since there is little variation in manufacturing, it can be realized even in high frequency bands above the X band.

[Brief explanation of the drawing]

FIG. 1 shows an embodiment of the present invention, FIGS. 2a and 2b. Figures 20 and 20 are excitation electric field diagrams when the conventional Magic T is supplied with power from the H terminal, Figures 3a and 3b, and Figure 3C are excitation electric field diagrams when the conventional Magic T is supplied with power from the 1kB terminal. Figure 3 is a cross-sectional view of a modified coupling slot line, Figure 3 is an excitation electric field diagram when power is supplied to the Magic T of the present invention from the H terminal, and Figure 7 is a diagram of the present invention. It is an excitation electric field diagram when power is supplied to the magic T from the E terminal. /...//Hiro wavelength slot line, -...coupling slot line, Ir#ta...front and back short-circuit conductor, 10.
...Slotline cavity, i to i2.13-=mic four stripline, 21...//μ deformed slotline, here...deformed combined slotline 1.23.2!
, 2g...microstrip line, 2≠.../
/Hiroba Slot Line.

Claims (1)

[Claims] A first deformed slot line having a length of an odd multiple of 1/4 wavelength is connected to one end of the first deformed coupling slot line using both sides of a dielectric substrate, and the second deformed slot line and the other are connected to each other. The ends are connected to each other, a first microstrip input/output terminal is coupled to the connection point, and a second microstrip input/output terminal is connected to the connection point between the first modified coupling slot line and the second modified slot line. The other end of the first deformed coupled slot line is branched into two microstrip lines to serve as third and fourth input/output terminals, and a 1/4 wavelength By coupling a slot line with an odd number of lengths orthogonally to the microstrip line, the input wave from the first input/output terminal is outputted in phase to the third and fourth terminals, and the second wave is outputted to the third and fourth terminals. A modification characterized in that the input wave from the second terminal is outputted in reverse phase from the third and fourth terminals, and is not outputted from the first terminal. IC magic T using a connecting slot line.