JPH04160804A - Monolithic antenna - Google Patents

Abstract

PURPOSE:To set an area occupied by a microstrip line and to improve the radiation circuit by allowing a radio wave amplified by an amplifier to radiate from a radiation conductor via a thin slit. CONSTITUTION:A radio wave propagated through a microstrip line 5 from a microwave integrated circuit at a feeder side passes through a phase shifter 7, in which the phase is set to a prescribed value, the radio wave is amplified through an amplifier 6 and radiates to a radiation conductor 3 at an opposite side being a component of a microstrip antenna 4 being a kind of a resonator via a thin slit 9 acting like a coupling hole with respect to the resonator and radiates in space. Thus, the area occupied by the microstrip line 5 is widened and an excellent antenna radiation characteristic is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a monolithic antenna in which a microwave integrated circuit and a microstrip antenna are integrated on a substrate made of semiconductor.

[Conventional technology] Conventional technology and shite are, for example, ACROWAVE JO [JR
°'MONOLITHICPHASED A published in NAL MARCH1988pp, 113-125
RRAYS FOREHF COMMtJNICATI
There is a monolithic antenna constructed on a semiconductor substrate as shown in "ONS TERMINALS". FIG. 3 shows an example of the construction of this conventional monolithic antenna.

Here, 1. Although the present invention integrates an antenna and a monolithic microwave integrated circuit, it does not relate to the individual constituent circuits of the microwave integrated circuit, but relates to a configuration method for integrating the antenna and the microwave integrated circuit. It is. Therefore, detailed explanations of the individual constituent circuits of the microwave integrated circuit will be omitted from the explanations regarding the figures. The conventional example shown in FIG. 3 is an example of a four-element monolithic antenna. In the figure, reference numeral 1 denotes a semiconductor substrate in which, for example, gallium arsenide or silicon is used as a semiconductor. Reference numeral 2 denotes a ground conductor provided on one surface of the semiconductor substrate 1. Radiation conductors 3 are formed at the four corners of the other surface of the semiconductor substrate 1, and together with the ground conductor 2, a microstrip antenna 4 is formed.

Further, circuits such as an amplifier 6 and a phase shifter 7 are configured using the microstrip line 5 as a circuit configuration line. These circuits are monolithic microwave integrated circuits constructed using field effect transistors as semiconductor elements, and circuit elements such as capacitors, inductors, and resistors (not shown here). That is, the radiation conductor 3 and the microwave integrated circuit constituting the microstrip antenna 4 are integrally formed on one semiconductor substrate 1, and is called a monolithic antenna.

The conventional monolithic antenna has a radiation conductor 3 on one side of the semiconductor substrate 1 as described above. Since the amplifier 6 and the like are configured, the radio waves propagating through the microstrip line ls5 from the input end 8 are distributed in the directions of the phase shifters 7 and 7, and the radio waves pass through each phase shifter 7 so that the phase reaches a predetermined level. The radio wave is set to a value, passes through each amplifier 6, is amplified, and is finally radiated into space from the radiation conductor 3 as the microstrip antenna 4.

Note that here, in order to simplify the explanation, the amplifier 6 and the phase shift W
A bias circuit for applying a necessary bias to the circuit r7 is not shown.

[Problems to be Solved by the Invention] In the conventional monolithic antenna as described above, a microstrip antenna 4 and a microwave integrated circuit are integrally formed on one surface of a semiconductor substrate 1. The microstrip antenna 4 requires a rectangular conductor with a length of about 172 wavelengths and a disc-shaped radiation conductor 3 with the same diameter, so it occupies a large area on the semiconductor substrate 1. Further, in an array antenna in which a large number of microstrip antennas 4 are arranged, the interval between each element antenna is determined to be from 1/2 wavelength to nearly 1 wavelength on the condition that grating lobes do not occur. The size occupied by the element antenna is on the same level as the spacing between the element antennas, and the space available for the board other than the antenna is small.

Therefore, the area that can be occupied by the phase shifter 7, the amplifier 6, and the microstrip line 5 is narrowed, and there are problems in that the arrangement and circuit configuration are restricted, or the circuit cannot be configured. Furthermore, since the microstrip antenna 4 and the microwave integrated circuit are arranged on the same plane, there is a problem in that radiation generated from discontinuous parts such as lines of the microwave integrated circuit affects the radiation characteristics of the antenna.

This invention was made to solve the above-mentioned problems, and it is possible to set a wide area that can be occupied by the microstrip line 5, and further improve the radiation characteristics of the antenna.

[Means for Solving the Problems] A monolithic antenna according to the present invention has a ground conductor 2 on a first surface of a substrate 1 made of a semiconductor, a line 5 made of a strip conductor and a semiconductor element on a second surface, A ground conductor 2 which constitutes a microwave integrated circuit by forming circuit elements such as capacitors and inductors, and which is provided on the first surface of the substrate l.
A part of the ground conductor 2 is removed to form a slit 9 in the ground conductor 2, and a dielectric layer 10 is applied so as to cover the ground conductor 2 including the slit 9.
The radiation conductor 3 of the microstrip antenna 4 is formed on the surface of the dielectric layer 10 that is integrally formed with the semiconductor substrate 1 and does not come into contact with the semiconductor substrate 1.

[Function] In the monolithic antenna of the present invention, the radio waves amplified by the amplifier 6 are radiated from the radiation conductor 3 via the slit 9.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. In this invention, gallium arsenide (GaAs) used in monolithic microwave integrated circuits (MMIC) is used as a substrate constituting the line.
, and semiconductor substrates such as silicon (Si). FIG. 1 shows an embodiment of the present invention, and FIG. 1(a)
is a view from the microstrip antenna side, Figure 1 (
b) is a view seen from the opposite side of FIG. 1(a), that is, from the microwave integrated circuit side. In the figure, 1 is a semiconductor substrate, 2 is a ground conductor formed on the first surface of the semiconductor substrate 1, and a part of this ground conductor 2 has a thin hole large enough to serve as a coupling hole for the resonator. A gap 9 is provided, and a dielectric layer 10 is provided so as to cover the gap 9 and the ground conductor 2 by vapor deposition, chemical semiconductor process technology such as plasma CVD, or screen printing and baking, thereby configuring the microstrip antenna 4. Together with the microwave integrated circuit, the whole constitutes a monolithic antenna. Note that lines 5 made of strip conductors and circuit elements such as semiconductor elements, capacitors, and inductors are formed on the second surface of the semiconductor substrate 1, and at the four corners of the surface of the dielectric layer 10 opposite to the semiconductor substrate 1. A radiation conductor 3 is provided. In this case, each slit 9 is formed at a portion corresponding to each radiation conductor 3, and the radiation conductor 3 is coupled to the amplifier 6 side located on the reflection side.

In the monolithic antenna with this configuration, considering the transmission state, the radio waves propagating through the microstrip line 5 from the input end 8 of the microwave integrated circuit on the feeding side pass through the phase shifter 7, and the phase is set to a predetermined value. The radio wave is amplified through the amplifier 6, and propagated to the radiation conductor 3 on the opposite side, which constitutes the microstrip antenna 4, which is a type of resonator, through the slit 9, which serves as a coupling hole for the resonator. and is radiated into space.

The above description is based on the case where the microstrip antenna 4 made of the radiation conductor 3 has four elements, but it may also be a multi-element array antenna as shown in FIG. The effects of the present invention can be further exhibited without restrictions on the arrangement.

[Effects of the Invention] As described above, in the monolithic antenna according to the present invention, a slit is provided in a part of the ground conductor provided on the first surface of the semiconductor substrate, and a slit is provided so as to cover the ground conductor including the slit. A layered dielectric layer is applied to the semiconductor substrate, and a radiation conductor is formed on the side of the dielectric layer that does not come into contact with the semiconductor substrate, so the area that can be occupied by the phase shifter, amplifier, and microstrip line becomes larger. There are no restrictions on the layout and circuit configuration, and the circuit configuration becomes easy. Furthermore, since the microstrip antenna and the microwave integrated circuit are configured on different surfaces, good antenna radiation characteristics can be obtained that do not affect the antenna radiation characteristics generated from discontinuities such as lines of the microwave integrated circuit. be able to.

[Brief explanation of the drawing]

FIG. 1 is a front and back view showing the configuration of a monolithic antenna according to an embodiment of the present invention, FIG. 2 is a diagram showing another embodiment of the invention, and FIG. 3 is a diagram showing the configuration of a conventional monolithic antenna. It is a diagram. In the figure, 1 is a semiconductor substrate, 2 is a ground conductor, 3 is a radiation conductor, and 4
5 is a microstrip antenna, 5 is a microstrip line, 6 is an amplifier, 7 is a phase shifter, 8 is an input end, 9 is a gap, and 10 is a dielectric layer. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. Agent Patent Attorney Jun Miyazono

Claims (1)

[Claims] A ground conductor is formed on a first surface of a substrate made of a semiconductor, and a line made of a strip conductor and circuit elements such as semiconductor elements, capacitors, and inductors are formed on a second surface to constitute a microwave integrated circuit, A part of the ground conductor provided on the first surface is removed to provide a slit in the ground conductor, and a layered dielectric layer is provided so as to cover the ground conductor including the slit. A radiation conductor of a microstrip antenna corresponding to the gap is formed on the surface not in contact with the semiconductor substrate, and this radiation conductor is coupled to the microwave integrated circuit side through the gap. Features a monolithic antenna.