JPS6010806A - Microstrip array antenna - Google Patents

Abstract

PURPOSE:To reduce the thermal deformation in an outer space dividing a base plate and a dielectric core constituting the 1st sandwich panel of double sandwich structure into plural pieces. CONSTITUTION:A ground conductor 7 is formed at one side of a nylon fiber reinforced dielectric honey-comb core 6 by a carbon fiber reinforced plastic, a base plate 5 is formed on the other side and the 1st sandwich panel A is constituted by coating a metallic foil to the base plate 5 so as to form a radiation element 4. In order to improve the entire rigidity of the antenna panel 1, the double sandwich structure is constituted by combining a light weight aluminum honey-comb core 8 and the 2nd sandwich panel B consisting of a skin member 9 made of a carbon fiber reinforced plastic. The base plate 5 and the core 6 are cut off to divide the panel A into eight pieces, allowing to release a force causing out-of-plane deformation due to temperature difference, reduce thermal deformation and make the entire panel flat.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microstrip array antenna made of a sandwich structure.

2. Description of the Related Art Conventionally, there have been antennas of this type shown in FIGS. 1 to 4 as deployable microstrip array antennas for mounting on artificial satellites.

Figure 1 is a schematic diagram of a deployable microstrip array antenna for use on a satellite, Figure 2 is a cross-sectional view of the antenna panel, Figure 6 is a diagram showing an actual example of the constituent materials shown in Figure 2, and Figure 4 is a diagram showing an actual example of the constituent materials shown in Figure 2.
The figure shows the state of the antenna after it has been thermally deformed after being deployed in orbit.

In Figures 1 to 4, 1 antenna panel, 2 a deployment hinge, 3 a satellite, 4 a radiation element, 5 a substrate, 6 a dielectric core, 7 a ground conductor, 8 a core, and 9 a The radiating element 4, the substrate 5, the dielectric core 6, and the ground conductor 7 constitute a first sandwich panel, and the ground conductor 7, the core 8, and the skin material 9 constitute a second sandwich panel. It forms a sandwich panel.

Next, the operation will be explained.

FIG. 1 shows a plurality of antenna panels I attached to a satellite 3 and connected to each other by deployment hinges 2 in a deployed state.

FIG. 2 is a sectional view of the antenna panel 1, showing an actual example of a microstrip array antenna.

In the figure, the antenna panel I has a ground conductor 7 on one side of a substrate 5 made of a dielectric material, which has high electrical conductivity like gold, silver, copper, etc., and is lightweight and highly rigid. The first sandwich panel A is composed of a dielectric core 6 made of a material having a low dielectric constant, a lightweight core 8 and a lightweight and highly rigid skin material 9 to increase the rigidity of the entire antenna panel. and the second sandwich panel B in combination constitutes a double sandwich structure.

FIG. 3 shows an actual example of the constituent materials of a conventional microstrip array antenna.

In FIG. 6, the radiating element 4 in FIG. 2 is made of copper foil, the substrate 5 is made of glass fiber reinforced plastic material, the dielectric core 6 is made of nylon fiber reinforced honeycomb core, the ground conductor 7 is made of carbon fiber reinforced plastic material, and the core 8 is made of aluminum. Carbon fiber reinforced plastic material is used for the honeycomb core and the skin material 9, respectively.

By the way, in a composite material, if the average coefficient of thermal expansion on both sides from the neutral plane of the cross section of the bonded material is the same, the out-of-plane deformation will be small even if a temperature difference occurs, but the difference in the average coefficient of thermal expansion on the plane side will be large. The larger the difference, the greater the out-of-plane deformation, similar to bimetals.

Since the coefficient of thermal expansion of glass fiber is larger than that of carbon fiber, conventional antenna panels suffer from large out-of-plane deformations due to temperature differences, similar to the case with semi-metal.

The entire antenna panel does not need to be flat due to electrical performance requirements.

However, the conventional microstrip array antenna
With the above structure, each layer has a different coefficient of thermal expansion, so there is a temperature difference between the ground before the satellite is launched and the outer space after the satellite is launched. This caused thermal deformation of the antenna panel.

However, due to the requirements for antenna electrical performance, it is necessary to minimize thermal deformation and make it flat, and it is necessary to consider and change the constituent materials to make each layer have the same coefficient of thermal expansion. In order to reduce thermal deformation, it is necessary to consider and change the structure, such as strengthening the rigidity.
There were drawbacks such as a slight increase in weight.

The present invention has been made to eliminate these drawbacks, and provides a highly accurate and lightweight deployable microstrip array antenna for use on an artificial satellite.

An embodiment of the present invention will be described below.

In FIG. 5, the basic configuration and structure are the same as those in FIG. The cross section of the dielectric core 6 formed of a fiber-reinforced honeycomb core was cut, and the first sandwich panel A of the dielectric core 6 and the substrate 5 provided with the radiating element 4 was divided into eight parts as shown in FIG. ing.

As described above, according to the present invention, the cross section of the substrate 5 made of glass fiber reinforced plastic material constituting the first sandwich panel A and the dielectric core 6 formed of nylon fiber reinforced Nicum core is cut, The force that causes out-of-plane deformation at the cut portion of the first sandwich panel A was released, and the amount of out-of-plane deformation was reduced by J. The double sandwich structure has the advantage of reducing thermal deformation in space and making the entire panel flat.

[Brief explanation of the drawing]

1 to 4 are diagrams for explaining a conventional deployable strip array antenna for use onboard an artificial satellite, and FIGS. 5 and 6 are diagrams for explaining the features of the microstrip array antenna of the present invention. It is a diagram. In the figure, 1 is an antenna panel, 2 is a deployment hinge, 3 is a satellite, 4 is a radiating element, 5 is a substrate, 6 is a dielectric core, 7 is a ground conductor, 8 is a core, and 9 is a skin material. J

Claims (1)

[Claims] A first substrate having a carbon fiber reinforced plastic forming a ground conductor on one side of a dielectric core, and a substrate covered with a metal foil forming a radiating element on the other side of the dielectric core. A microstrip array antenna having a double sandwich structure, comprising a sandwich panel and a second sandwich panel made of a carbon fiber reinforced plastic skin and core, which is bonded to a ground conductor such as the carbon fiber reinforced plastic. A microstrip array antenna, wherein the substrate and the dielectric core constituting the first sandwich panel are divided into a plurality of pieces.