JPH04250701A - Ridge waveguide-microwave integrated circuit connection structure - Google Patents

Abstract

PURPOSE:To obtain an excellent propagation characteristic by facilitating the positioning in a connection structure connecting a ridge waveguide and a microwave integrated circuit and relaxing discontinuity of the characteristic impedance. CONSTITUTION:A step difference is provided to a connection section 6 between a dielectric board and a ridge waveguide 1 of a metallic plate 5 supporting the dielectric board 3, and an inductive stub is provided on a microstrip line 4 in the vicinity of the said connection section.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a ridge waveguide-microwave integrated circuit connection structure for propagating an electromagnetic field from a waveguide to a microstrip line.

0002

[Prior Art] When connecting a waveguide to a microwave integrated circuit (hereinafter referred to as MIC), a ridge waveguide is used in the K-band and higher frequency bands.
is often used. FIG. 4 is a perspective view illustrating a conventional connection structure of this type, and FIG. 5 is a sectional view thereof. In each figure,
1 is a ridge waveguide, 2 is a ridge portion thereof, 3 is a dielectric substrate constituting the MIC, 4 is a microstrip line, and 5 is a ground plane (metal plate).

Further, symbols a and b shown in the figure are the width and height of the waveguide 1, s is the width of the ridge portion 2, h is the thickness of the dielectric substrate 3, and w is the width of the microstrip line. represent.

As shown in FIGS. 4 and 5, in the conventional connection structure, the end of the waveguide 1 and the end of the dielectric substrate 3 are brought into contact with each other on a ground plane 5, which is a flat metal plate. Since the waveguide 1 has a structure in which the electric field distribution is concentrated on the ridge portion 2, the characteristics of the waveguide 1 can be made close to those in the TEM mode. An electromagnetic field is propagated to the strip line 4.

[0005]

The problem to be solved is that in the conventional connection structure, the ridge width and the microstrip line width do not match, and good propagation characteristics cannot be obtained. That is, the ridge width s is the dielectric substrate 3
is determined by the thickness h of the microstrip line 4 and the characteristic impedance of the microstrip line 4. Therefore, in the conventional connection structure shown in FIG.
It is difficult to match the width of this portion, and a sudden change in the width of this portion causes parasitic capacitance, making it difficult to obtain good characteristics.

[0006] Furthermore, since the connection between the ridge portion 2 and the microstrip line 4 is made using a gold ribbon, tab, etc.,
The connections become complicated and reproducibility is also lacking.

[0007]

[Means for Solving the Problems] The present invention provides a step at the connection portion between the ridge waveguide and the dielectric substrate on the ground plane supporting the dielectric substrate, and also provides guidance on the microstrip line near the connection portion. The most important feature is the provision of a sex stub.

Therefore, the ridge width and the width of the microstrip line can be matched, and the inductive circuit formed on the microstrip line cancels out the parasitic capacitance, achieving the purpose of obtaining a structure with good high frequency characteristics. , achieved with a simple configuration.

[0009]

[Embodiment] Fig. 1 is a perspective view showing one embodiment of the present invention, and Fig. 2
are cross-sectional views thereof, and in each figure, 1 is the ridge waveguide, 2 is the ridge portion, 3 is the dielectric substrate constituting the MIC, 4 is the microstrip line, 5 is the ground plane (metal plate), and 6 is the ridge waveguide. indicates a step provided on the ground plane 5.

Further, symbols a and b shown in the figure are respectively the width and height of the waveguide 1, s1 is the width of the ridge portion 2, h is the thickness of the dielectric substrate 3, and h1 is the protrusion from above the ground plane 5. The height of the protrusion of the dielectric substrate 3 is shown.

As shown in FIGS. 1 and 2, a ridge waveguide 1
The ground plane 5 supporting the dielectric substrate 3 is provided with a step 6 of a predetermined height, and this step 6 reduces the height of the dielectric substrate 3 protruding from the plane of the ground plane 5 to h1. It can be held down.

Therefore, the actual thickness of the dielectric substrate 3 can be reduced to h1, and the ridge width can therefore be reduced to s1.By setting the step 6 to a predetermined height, the ridge width can be reduced to s1. The width w of the microstrip line 4 can be made to match the width w of the microstrip line 4, and sudden changes (discontinuities) in the width at the connection portion can be alleviated.

Furthermore, by providing the step 6, the height of the ridge surface of the ridge portion 2 and the height of the conductor surface of the microstrip line 4 can be matched, and as shown in FIGS. The microstrip line 4 is held down by the ridge surface of the ridge part 2, and the ridge part 2 and the microstrip line 4 can be reliably connected.

FIG. 3 is a plan view of the dielectric substrate 3 in this embodiment, and in the figure, 7 indicates an inductive stub. In a structure that connects a ridge waveguide and a microwave integrated circuit, in the propagation of the electromagnetic field from the ridge waveguide 1 to the microstrip line 4, due to the step and discontinuity of permittivity at the boundary (connection) part. , resulting in an equivalent parallel capacitance.

Therefore, in the present invention, an inductive stub 7 is provided on the microstrip line 4 near the boundary to cancel out the generated parallel capacitance and prevent deterioration of the characteristics.

[0016]

As explained above, the connection structure of the present invention provides a step at the connection part to facilitate alignment, and also matches the ridge surface and the conductor surface of the microstrip line, as well as their respective widths. Discontinuities can be alleviated and good characteristics can be obtained, and discontinuities caused by steps and differences in dielectric constant can be made extremely small by using an inductive stub circuit installed near the connection, resulting in connections with good high frequency characteristics. It has the advantage of providing structure.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing an embodiment of the present invention.

FIG. 3 is a plan view showing a dielectric substrate of the present invention.

FIG. 4 is a perspective view showing a conventional structure.

FIG. 5 is a sectional view showing a conventional structure.

[Explanation of symbols]

1 Ridge waveguide 2 Ridge part 3 Dielectric substrate 4 Microstrip line 5 Ground plane (metal plate) 6 Steps 7 Inductive stub s1 Width of ridge part h Thickness of dielectric substrate h1 Height of protrusion

Claims (1)

[Claims] Claim 1: In a ridge waveguide-microwave integrated circuit connection structure in which an output part of a ridge waveguide is connected to a microstrip line formed on a dielectric substrate to propagate an electromagnetic field, the dielectric substrate is A ridge waveguide-microwave characterized in that a step is provided at the connection portion between the supporting ridge waveguide of the metal plate and the dielectric substrate, and an inductive stub is provided on the microstrip line near the connection portion. Integrated circuit connection structure.