JPS6361802B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microwave hybrid integrated circuit using a ceramic substrate, and more particularly to a microwave hybrid integrated circuit in which a three-terminal microwave semiconductor element is operated by a single power supply using a thick film capacitor.

1a, 1b and 1c are plan views showing a conventional microwave hybrid integrated circuit;
They are an A' cross-sectional view and a B-B' cross-sectional view thereof. In the figure, 1 is a dielectric substrate made of ceramic or the like having low dielectric loss in the microwave band;
2 is a microwave transmission line, 3 is a low-pass filter type drain electrode bias line, 4 is a low-pass filter type gate electrode bias line, 5 is a source ground electrode grounded by a metallized through hole, and 6 is a gold wire. A three-terminal microwave semiconductor element connected to each transmission line by wires such as 7, a microwave chip capacitor with low dielectric loss and high dielectric constant in the microwave band, 8 a resistance value Rb
A bias resistor such as a thick film resistor or a chip resistor, 9 is a resistor end grounding electrode grounded by a metallized through hole, etc., 10 is a three-terminal microwave semiconductor device 6 connected to a microwave transmission line 2 and a microwave chip capacitor 7. A wire such as a gold wire to be connected, 11, connects the source electrode to a bias resistor 8
12 is a ground electrode, and 13 is a metallized through hole.

Note that FIG. 2 is an electrical equivalent circuit of FIGS. 1a to 1c.

Next, the operation of the microwave hybrid integrated circuit having the above configuration will be explained. First, when a DC bias is applied to the three-terminal microwave semiconductor device 6 through the drain electrode bias line 3 and gate electrode bias line 4 that constitute a low-pass filter,
Operates as an amplifier. At this time, in terms of direct current, the source potential V _S is higher than the ground potential by the product of the drain-source current I _DS and the resistance value Rb of the bias resistor 8, V _S = I _DS × Rb, and the gate bias is grounded. Therefore, the source-gate V _GS is V _GS = −
A bias of V _S =−I _DS ×Rb is applied. Also,
In terms of microwaves, it is grounded through a microwave chip capacitor 7. Therefore, it operates as a single-power source common-source microwave amplifier.

However, conventional microwave hybrid integrated circuits require processes such as soldering to attach microwave chip capacitors, and also have drawbacks such as the need for additional wire bonding processes for electrical connections.

Accordingly, an object of the present invention is to provide a microwave hybrid integrated circuit which can simplify the manufacturing process by providing a capacitor structure on a substrate without mounting a chip capacitor.

In order to achieve such an object, the present invention consists of a dielectric substrate such as a ceramic substrate, and three layers: an upper metal, an insulator, and a lower metal, and the lower metal is grounded through a metallized through hole to connect the dielectric A thick film capacitor formed on a substrate, a three-terminal microwave semiconductor element mounted on the upper metal of the thick film capacitor, and a bias resistor terminal of the thick film metallization connected to the upper metal of the thick film capacitor. This will be described in detail below using examples.

3a, 3b, and 3c are a plan view, a cross-sectional view along the line C-C', and a cross-sectional view along the line D-D', showing an embodiment of the microwave hybrid integrated circuit according to the present invention. be. In the figure, 14 is an insulator such as ceramic having low dielectric loss, 15 is an upper metal serving as a capacitor electrode, and 16 is a line connecting this upper metal 15 and one end of the bias resistor 8.

Incidentally, FIG. 4 shows an electrical equivalent circuit of FIGS. 3a to 3c.

Next, the configuration of the microwave hybrid integrated circuit having the above configuration will be explained. First, the lower metal of the source ground electrode 5, which serves as the lower metal of the capacitor,
Since a thick film capacitor can be formed from three layers of an insulator 14 with low dielectric loss and an upper metal serving as the upper electrode of the capacitor, it can of course operate as a single power source common microwave amplifier, as mentioned above. It is. Therefore, the chip capacitors shown in FIGS. 1a to 1c become unnecessary, and the manufacturing process can be simplified.

In the above-described embodiments, it is of course possible to use various transistors such as field effect transistors and junction transistors as the three-terminal microwave semiconductor device.

As described in detail above, according to the microwave hybrid integrated circuit according to the present invention, the number of parts and work steps are reduced, so that the manufacturing process can be simplified and reliability can be improved. Further, since the thick film capacitor structure can be easily produced using ceramic multilayer substrate technology, it has the advantage of being highly practical.

[Brief explanation of drawings]

1a, 1b and 1c are plan views showing a conventional microwave hybrid integrated circuit;
A' sectional view and its B-B' sectional view, Figure 2 is the electrical equivalent circuit of Figures 1a to 1c, Figure 3a,
3b and 3c are a plan view showing an embodiment of the microwave hybrid integrated circuit according to the present invention, a cross-sectional view taken along the line C-C' and a cross-sectional view taken along the line D-D', and FIG. 3A to 3C are electrically equivalent circuits. DESCRIPTION OF SYMBOLS 1... Dielectric substrate, 2... Microwave transmission line, 3... Drain electrode bias line, 4... Gate electrode bias line, 5... Source grounded electrode,
6...Three-terminal microwave semiconductor element, 7...Microwave chip capacitor, 8...Bias resistor, 9...Resistance end ground electrode, 10...Wire, 1
1... Source potential electrode, 12... Ground electrode, 13
...Metallized through hole, 14...Insulator,
15...upper metal, 16...railway. Note that the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] 1. A thick film capacitor composed of a dielectric substrate such as a ceramic substrate, and three layers: an upper metal, an insulator, and a lower metal, and the lower metal is grounded through a metallized through hole and formed on the dielectric substrate; A three-terminal microwave semiconductor element mounted on the upper metal of the thick film capacitor, and a thick film metallized line connecting the upper metal of the thick film capacitor and the thick film metallized bias resistance terminal. A microwave hybrid integrated circuit featuring: