JPH01235262A - Amplifier element device - Google Patents

Abstract

PURPOSE:To lower a noise factor of an active element, by packaging the active element on the top face of a board, attaching a cover within which a vacuum is established on the board so as to cover the active element and providing a thermoelectric cooling unit for cooling the active element on the bottom face of the board. CONSTITUTION:An active element 2 such as GaAs FET or the like is packaged on the top surface of a board 1 of a material having good heat conductivity such as ceramics or glass. The active element 2 has three leads. The active element 2 is covered with a cover 4 within which a vacuum is established. An thermoelectric cooling unit 5 utilizing the Peltier effect is secured closely to the bottom face of the board 1 directly under the active element 1. The thermoelectric cooling unit 5 has supply lines 6 for cooling elements. The cover 4 used herein is previously shaped into desired configurations and bonded to the board 1. A hole for drawing air is formed in a part of the cover 4. Air is drawn through the hole and the inside of the cover is sealed. If the cover 4 is of glass, it is fusion bonded to the board 1 and the air drawing hole is also thermally fusion bonded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to an amplification element device used in a low-noise amplifier, etc., particularly in the microwave band.

[Conventional technology 1] For example, in satellite broadcasting receiving antennas, which have recently been introduced in Japan, the reception performance is based on the Down-Funverter (hereinafter referred to as L N B [Low No.1se Block d
The evaluation is based on the antenna performance index G/T, which includes up to (referred to as amnconverterl). Here, G/T is the following formula % Formula % However, G: Antenna gain Ta: Antenna equivalent thermal noise α: Antenna feeding loss To: Ambient temperature F: Noise figure of LNH In the above formula, (F-1)T The term , occurs in LNB ・
is the equivalent temperature of the noise. As is clear from the above formula,
The noise figure NF of the LNB has a large influence.

For example, when the antenna temperature is 33dBi and the antenna gain is 33dBi, NF=2dBi
In LNB of B, G/T-9,4[dB/Kl, but if NF=1dB, G/T#11,7(dB/Kl).
This means that an improvement of 2 dB or more can be expected.

Here, as is well known, the NF of the LNB is determined by the NF of the amplification element (eg, GaAsFET or HEMT) used. In particular, (NF=101ogF) Fi: Noise figure of the i-th amplifier Gi: From the relationship of the gain of the i-th stage amplifier, it can be seen that this is largely caused by the noise figure of the first-stage amplifier. Therefore, it is sufficient to reduce the NF of the amplifying element used in the first stage amplifier in particular. Here, it is generally known that the lower the temperature, the better the NF.

[Problems to be Solved by the Invention] The present invention has been provided in view of the above-mentioned points, and provides an amplification element device for realizing a low-noise active element.

[Means for Solving the Problems] 1 Effect] The present invention mounts an active element on the upper surface of a substrate, attaches a cover that covers the active element and makes the inside a vacuum, and mounts the active element on the lower surface of the substrate. The present invention is characterized in that by providing an electronic cooling section for cooling the element, the electronic cooling section cools the active element and reduces the noise figure of the active element.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure shows a cutaway perspective view, and FIG. 2 shows an m-plane view.

For example, on the top surface of the substrate 1 made of ceramic, glass, etc. with good thermal conductivity, a GaAsFET or HEM
An active cord 2 such as T is mounted. Further, the active element 2 has three boards 3. A cover 4 covering the active element 1 is attached to the base @i. The inside of this cover 4 is kept in a vacuum. An electronic cooling section 5 utilizing the Peltier effect is brought into close contact with the lower surface of the substrate 1 directly below the active element 2. The electronic cooling unit 5 is led out by a cooling element electric current [16]. Here, the cover 4 is previously formed into a desired shape and adhered to the substrate 1, and a hole for evacuation is provided in a part of the cover 4, and a vacuum is applied through the hole to seal it. If the cover 4 is large enough, it is fused to the substrate 1 and the vacuum hole is also heat fused. Further, the cover 4 may be attached to the substrate 1 in a vacuumed Belshare for manufacturing. By using ceramic or the like with good thermal conductivity as the substrate 1 as described above and by creating a vacuum inside the cover 4, the active element 2 can be efficiently cooled.

FIG. 3 shows a case where an active element 2 in a chip shape is mounted on a substrate 1, and the chip-shaped active element 2 and a pattern 7 formed on the substrate 1 are connected by a lead wire 8. . With this configuration, the active element 2 can be cooled more efficiently.

In FIG. 4, a metal portion 9 is formed by depositing metal on the inner surface of the cover 4, thereby providing a shielding effect. Here, the metal parts are grounded and some of them are kept from touching the signal lines.

Furthermore, as shown in the figure, there is no metal vapor deposition on the part where the signal line passes ((a) in the figure). Metal foil may be used instead of metal vapor deposition.

With the above configuration, it is possible to lower the temperature of the active element 2 used in, for example, an amplifier of a planar antenna, and it is possible to reduce the NF of a circuit using this device.

[Effect of the invention 1] As described above, the present invention mounts active elements on the top surface of the substrate,
A cover that covers the active element and has a vacuum inside is attached to the upper surface of the substrate, and an electronic cooling section for cooling the active element is provided on the lower surface of the substrate, so that the active element can be cooled by the electronic cooling section. This has the effect of reducing the noise figure of the active element. Therefore, using this device, it is possible to realize an amplifier circuit that can reduce the noise figure.

[Brief explanation of the drawing]

Fig. 1 is a cutaway perspective view of an embodiment of the present invention, Fig. 2 is a cross-sectional view of the same as above, Fig. 3 is a cross-sectional view of the same active element in the form of a chip, and Fig. 14 is a metal vapor deposited inner surface of the same as above. FIG. 3 is a cross-sectional view of the cover when 1 is a substrate, 2 is an active element, 4 is a cover, and 5 is an electronic cooling unit. Agent Patent Attorney Ishi 1) Ai 7-N Sunshi (Volunteer to write amendments) 1. Indication of the case 1988 Patent A No. 61560 2, Title of the invention ・ Amplifying element device 3, person making the amendment Relationship to the case Patent applicant address Name of 1048 Kadoma, Kadoma, Mondoro City, Osaka Prefecture (58
3) Matsushita Electric Works Co., Ltd. Representative Toshio Miyoshi 4, agent postal code 530 5, date of amendment order [1] "3" on page 4, line 12 of the specification of the application is replaced with "
"Normally four," he corrected. Agent Patent Attorney Ishi 1) Ai Shichi

Claims (2)

[Claims] (1) An amplification element device comprising an active element mounted on the upper surface of a substrate, a cover covering the active element with a vacuum inside, attached to the upper surface of the substrate, and an electronic cooling unit provided on the lower surface of the substrate to cool the active element. . (2) The amplification element device according to claim 1, wherein the inner surface of the cover is metal-deposited or coated with foil.