JPH02268003A - Microwave integrated circuit and microwave amplifier - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a microwave integrated circuit and a microwave amplifier in which electromagnetic coupling between a plurality of microstrip lines is a problem.

Prior Art FIG. 7 is a block diagram of a conventional microwave integrated circuit. 1
0 is a ceramic substrate, 20.30 is a microstrip line, and 40.50 is an input terminal and an output terminal of the microwave active circuit 55, respectively, which are connected to one end 60170 of the microstrip lines 20 and 30, respectively. 80.90 are microstrip lines 40.90, respectively.
This is a terminal provided at the other end of 50. 100 is a bias terminal of the microwave active circuit 55, and 110 is a DC power supply.

In the conventional microwave integrated circuit configured as described above, the microstrip line 20 transmits the signal applied to the terminal 80 to the input terminal 40, and the microstrip line 30 transmits the signal generated at the output terminal 50 to the terminal 90. to communicate.

FIG. 8 is a block diagram of a conventional microwave amplifier. 20
0 is a ground conductor, 2o5 is a ceramic substrate, 210 is an amplifier input terminal, 215 is a bonding wire, 220 is a microstrip line forming an input matching circuit, 23
0 is a capacitor, and 240 is a bonding wire.

250 is an MMIC amplifier, 260 is an MMIC amplifier 25
0 is the input terminal, 270 is the output terminal of the MMIC amplifier 250, and 280 is the pi and as terminals of the MMIC amplifier 250. 290 is a bonding wire, 300.310.
3201330 is a capacitor, 340 is a bonding wire, 350.360 is an inductive line, 365.366 is a resistor, and 370 is a bonding wire. 380 surrounded by a broken line is a capacitor 300.310.320.33
0, bonding wire 340, inductive line 350.3
It is a bridge T-shaped circuit consisting of θ0 and resistors 365 and 366. 38S is a bonding wire, and 390 is an MMIC amplifier. 400 is the input terminal of the MMIC amplifier 390;
410 is the output terminal of the MMIC amplifier 390; 420 is the MMIC amplifier 390;
This is the bias terminal of the MIC amplifier 390. 430
is a bypass capacitor, 435 is a ceramic substrate 205
Through hole provided on top, 440.445.450
．． 460 is a bonding wire, 470 is a capacitor,
480 is a microstrip line constituting an output matching circuit, 490 is a bonding wire, and 495 is an output terminal. 500 is a bias supply line, 510 is a bonding wire, and 520 is a bias terminal. - A portion 530 surrounded by a dotted chain line is the conventional microwave integrated circuit shown in the conventional example of FIG.

In the conventional microwave amplifier configured as described above, input signals are input from the input terminal 2101 to the bonding wire 215. MMI via microstrip line 220
It is input to the input terminal 260 of the C amplifier 250. After the signal is amplified by MMIC amplifier 250, output terminal 270
is input to the bridging T-type circuit 380. The signal is bridge T
After the frequency fluctuation of the gain is corrected by the type circuit 380, the MM
The signal is supplied to an IC amplifier 390 via a bonding wire 385 and amplified again. After that, from the output terminal 410 to the bonding wire 450, the capacitor 4701, the microstrip line 480, and the bonding wire 49
0 to the output terminal 495. The bias voltage is applied from the bias terminal 520 to the bonding wire 51.
0, bias supply line 500, bonding wire 46
Two MMIC amplifiers 25 through 0.4401445
0.390 to each.

Problems to be Solved by the Invention However, in the configuration as shown in FIG. The leakage occurs to the terminal 90 due to the electromagnetic coupling between the microstrip lines 20 and 30. FIG. 2 is a characteristic diagram of the microwave circuit of FIG. 7. The characteristics shown by solid lines in FIG. 2 are that the impedances of the microwave active circuit 55 when viewed from the terminals 40 and 50 are both 50Ω, and the line spacing S =
0. 55 mm m1 Line length: 1:o, 7 mm1 This shows the isolation between the terminal 80 and the terminal 90 when each line width W=0.1 mm. As is clear from Figure 2, the isolation pin at IGHz is -47dB.
It is. The signal leakage between the terminals 80 and 90 increases as the line spacing S becomes narrower and as the line width W becomes narrower.

In the case of the amplifier shown in FIG. 8, which utilizes the microwave integrated circuit as described above as an input/output line of a high-gain amplifier, the microstrip line 220 and A microstrip line 480 is adjacent and electromagnetically coupled.

Feedback then occurs between the input and output of the amplifier. FIG. 5 is a characteristic diagram of the microwave amplifier of FIG. 8. The solid line in FIG. 5 shows the microstrip line 220.
and the distance between the microstrip line 480 S = 0.
55 m ffb Length of adjacent section l = 0
．． 7. Actual measurement values of the gain of the microwave amplifier shown in FIG. 8 when each line width W=0.1.

The electromagnetic coupling between the microstrip line 220 and the microstrip line 480 causes feedback from the output of the microwave amplifier to the input. 8GH2 to 1.9GH
The gain varies by about 5 dB between z. in this way,
Conventional microwave amplifiers have had the problem that feedback occurs between input and output due to miniaturization of the circuit, resulting in deterioration of characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide a microwave integrated circuit that is unlikely to cause coupling between lines even when two lines are close to each other.

Another object of the present invention is to provide a microwave amplifier in which feedback does not occur and the characteristics do not deteriorate even if the input and output lines are close to each other.

Means for Solving the Problems The present invention provides first and second microstrip lines that are provided on a circuit board and have portions that are close to each other, and that the first microstrip line and the second microstrip line are connected to each other. A third microstrip line provided in a gap between adjacent parts and having a length longer than the adjacent parts, and at least one capacitor having one end grounded and the other end connected to the third microstrip line. The present invention provides a microwave integrated circuit characterized by the following.

Further, the present invention includes the microwave integrated circuit and an amplification active element or an amplification circuit,
The input terminal of the active amplification element or the amplification circuit is connected to the microstrip line of the second microstrip line, the output terminal of the active element for amplification or the amplification circuit is connected to the second microstrip line of the microwave integrated circuit, The present invention provides a microwave amplifier characterized in that the amplifying active element or the bias terminal of the amplifying circuit is connected to the third microstrip line of the wave integrated circuit.

Function The microwave integrated circuit of the present invention has the above-described configuration, so that the third microstrip line is grounded at high frequency,
Electromagnetic coupling between the first microstrip line and the second microstrip line on both sides is interrupted, and isolation between the first microstrip line and the second microstrip line is improved. Moreover, since the third line is not grounded in terms of direct current, it can be used as a bias circuit with a bypass capacitor.

The microwave amplifier of the present invention has the above-mentioned configuration, and the third
The microstrip line of the microstrip line is grounded at high frequency, and the electromagnetic coupling between the first microstrip line and the second microstrip line connected to the input terminal is cut off, and the feedback from the output of the microwave amplifier to the input is interrupted. In addition to preventing deterioration of the performance of the microwave amplifier, the third microstrip line is used to supply bias to the amplification active element or the amplification circuit, thereby making it possible to downsize the microwave amplifier.

Embodiment FIG. 1 is a block diagram showing a microwave integrated circuit according to an embodiment of the present invention. In FIG. 1, parts that are the same as those in the conventional example shown in FIG. 7 are given the same numbers and their explanations will be omitted. The difference between FIG. 1 and FIG. 7 is that the microstrip line 2
A microstrip line 600 is provided between 0 and 130, and both ends of the microstrip line 600 are grounded by capacitors 610 and 620 with one end grounded, and one end of the microstrip line 600 is connected to the bias terminal 100a of the microwave active circuit 55. , the other end is a DC power supply 110
This means that it is connected to a.

In the microwave integrated circuit of this embodiment configured as described above, the microstrip line 20 transmits the signal applied to the terminal 80 to the input terminal 40, and the microstrip line 30 transmits the signal generated at the output terminal 50. terminal 90
to communicate.

The microstrip line 600 is grounded at high frequencies, cuts off electromagnetic coupling between the microstrip line 20 and the microstrip line 30 on both sides, and improves the isolation between the microstrip line 20 and the microstrip line 30. For example, as shown by the broken line in Fig. 2, the impedance when looking from the terminals 60 and 70 toward the microwave active circuit side is both 50Ω.
ml This figure shows the isolation between the terminal 80 and the terminal 90 when each line width W=0.1 mm. The characteristic shown by the solid line is the isolation characteristic under the same conditions as in FIG. 7, which is a conventional example.

As shown in FIG. 2, the isolation of the embodiment of the present invention shown in FIG. 1 is improved by about 15 dB compared to the conventional example shown in FIG. Moreover, the microwave active circuit 55 is connected to the microstrip line 600 between the microstrip lines 20 and 30.
There is no need to provide another bias supply circuit to supply bias to the capacitors 810 and 620, and the capacitors 810 and 620 function as bypass capacitors, thereby reducing the size of the entire circuit.

As described above, according to this embodiment, by providing a microstrip line with both ends grounded by a capacitor between two microstrip lines, electromagnetic coupling between the two microstrip lines can be cut off. , improving isolation between two microstrip lines. Furthermore, since the microstrip line 600 is not grounded in terms of direct current, it can be used as a bias circuit with a bypass capacitor, allowing the circuit to be miniaturized.

FIG. 3 is a configuration diagram of a microwave integrated circuit in another embodiment of the present invention. In FIG. 3, parts that are the same as those in FIG. 7 are given the same numbers and explanations will be omitted. The difference between FIG. 3 and FIG. 7 is that there is a lower metal film 640 between the microstrip lines 20 and 30, a dielectric film 645 provided thereon,
Further, an upper layer metal film 850 provided thereon
IM (Metal In5ulator Meta
l) type capacitor 655, upper layer metal film 65
One end of 0 is grounded through a through hole 660 and the other end is grounded with a bonding wire 665, the DC power supply 110a is connected to a microstrip line 670 connected to one end of the lower metal film 640, and the microstrip is connected to the other end. This is the point where the line 675 is connected to the bias terminal 100a.

In the microwave integrated circuit of this embodiment configured as described above, the microstrip lines 20 and 30 function as transmission paths for high frequency signals. The upper metal film 850 is completely grounded, and the microstrip line 20 on both sides
The electromagnetic coupling between the microstrip line 20 and the microstrip line 30 is further reduced than in the case of FIG.
and the microstrip line 30. Moreover, MI is in a grounded state at high frequencies.
Since bias is supplied to the microwave active circuit 55 using the lower electrode 640 of the M-type capacitor, there is no need to provide a new bias circuit, and the entire circuit can be miniaturized.

As described above, according to this embodiment, an MIM capacitor is provided between two microstrip lines, the upper electrode of the MIM capacitor is grounded, and the lower electrode is used to supply bias to the microwave active circuit. By doing so, it breaks the electromagnetic coupling between the two microstrip lines, improves the isolation between the two microstrip lines, and at the same time configures the bias circuit for the microwave active circuit, making it possible to miniaturize the circuit. do.

FIG. 4 is a configuration diagram showing a microwave amplifier in one embodiment of the present invention. In FIG. 4, parts that are the same as those in FIG. 8 are given the same numbers and their explanations will be omitted. FIG. 4 shows that the positions of the output terminal 495a and the bias terminal 520a are swapped with the positional relationship of the output terminal 220 and the bias terminal 520 in FIG. 8, and that the bias supply line 500 in FIG. 8 is replaced by a microstrip line. This differs from the conventional example shown in FIG. 8 in that bias is supplied to the MMIC amplifiers 250 and 390 using a bias supply microstrip line 700 provided between the microstrip line 480a and the microstrip line 480a. In addition, microstrip line 700
Bypass capacitors 430 and 710 are connected to both ends of the circuit using bonding wires 460a and 720, respectively.
The microstrip line 700 is grounded at high frequency. - The part 730 surrounded by the dotted chain line is micros) IJ
Part of Tsubu line 220 and microstrip line 480a
The microwave integrated circuit shown in FIG.

The operation of the microwave amplifier of this embodiment configured as described above will be explained below. Micros) IJ
The tube line 700 is grounded at high frequencies, cutting off electromagnetic coupling between the microstrip line 220 and the microstrip line 480a on both sides, and improving the isolation between the microstrip line 220 and the microstrip line 480a.

FIG. 5 shows the distance S between the microstrip line constituting the microstrip line 220 and the microstrip line constituting the microstrip line 480 or 480a, the length of the adjacent section 11, and the line width W of each under the same conditions. 8 shows the gain of the microwave amplifier of FIG. 8 and FIG. 4 when In FIG. 5, the gain of the microwave amplifier of FIG. 8 is shown by a solid line, and the gain of the microwave amplifier of FIG. 4 is shown by a dotted line. As is clear from FIG. 5, in the case of FIG. 8, the microstrip line 22
0 and the microstrip line 480, feedback occurs between the input and output of the microwave amplifier, and the 0.8G
The gain fluctuates by about 5 dB between Hz and 1.9 GHz. In the case of the microwave amplifier of the present invention shown in FIG. 4, the gain variation is within 1.5 dB in the same frequency range, and the microstrip line forming the microstrip line 220 and the strip forming the microstrip line 480a This is due to the improvement in isolation between lines. Moreover, in the embodiment shown in FIG. 4, the microstrip line 700 is also used as a bias circuit with a bypass capacitor, so that the circuit can be miniaturized.

As described above, according to this embodiment, by arranging a microstrip line with both ends grounded by a bypass capacitor between the input and output lines of the amplifier, the distance between the input and output lines of the amplifier can be improved without increasing the interval between the input and output lines. Returns can be prevented. Moreover, by using the microstrip line whose both ends are grounded as a bias circuit, it is possible to downsize the entire amplifier circuit.

FIG. 6 is a pattern diagram of an MMIC amplifier chip using a microwave amplifier in another embodiment of the present invention. In Fig. 6 °, 800 is an MMI made of a GaAs substrate.
C chips, 810 and 820 are FETs, respectively. 8
30 is the source terminal of FET810, 840 is FET82
0, and 850 and 860 are bonding pads for grounding each. 870 is FE
Gate terminal of T810, 880 is drain terminal, 890
is the gate terminal of FET820, and 900 is the drain terminal of FET820. 910 is an input terminal of the MMIC chip 800, and 915 is a microstrip line for transmitting an input signal to the FET 810. The MIM type capacitor 920 has a lower metal film 930 connected to a grounding pad 935, and functions as a bypass capacitor for the gate bias terminal 955 of the FET 810.

960 is a micros that performs input matching of FET810)
This is the IJ Tsubu line. 970 and 980 are respectively M (M
type capacitor, and share an upper layer metal film (electrode) 990. The upper metal film 990 is grounded using a through hole 1000 and a grounding pad 1010. and lower type pii.

20 is a drain bias terminal 1030 and a microstrip line 103 that constitutes an output matching circuit of FET 81o.
5, the MIM type capacitor 970 functions as a bypass capacitor. Similarly, lower electrode 1
040 is a gate bias terminal 1050 and a microstrip line 105 that constitutes an input matching circuit of FET 820.
5, the MIM type capacitor 980 functions as a bypass capacitor. 1060, 1070
1080 is a microstrip line for interstage connection, and 1080 is an MIM type capacitor for interstage DC interruption. 1090.
1100 is a microstrip line, and 1110 is an output terminal. 1120 is a microstrip line for output matching, 1130 is a drain bias terminal of FET820, and 1140 is an M that functions as a bypass capacitor.
It is an I M type capacitor. The lower electrode 1150 of the MIM type capacitor is a grounding pad 1160.
connected to. - 1170 surrounded by a dotted chain line is the microwave integrated circuit composed of microstrip lines 915.1100 and MIM type capacitors 970.980.

In the MMIC amplifier chip using the microwave integrated circuit of this embodiment configured as described above, when a negative voltage is applied to the gate bias terminals 955 and 1050 and a positive voltage is applied to the drain bias terminals 1030 and 1160, the input The signal applied to terminal 910 is amplified and output to output terminal 111.
Appears at 0. In the case of MMIC, the chip size is small, and the distance between microstrip line 915 and microstrip line 1100 is extremely narrow. However, the microstrip line 915 and the microstrip line 110
MIM type capacitors 970 and 980 provided between
Since the upper layer metal film 990 is directly grounded at both ends,
The microstrip line 915 and the microstrip line 1100 are difficult to couple electromagnetically (this makes it possible to narrow the spacing between the lines. Also, since the MIM capacitors 970 and 980 function as bypass capacitors, the bias There is no need to newly provide a bypass capacitor in the circuit.Therefore, the MMIC chip 800 can be made smaller than before.

As described above, according to this embodiment, an MIM type capacitor with one electrode grounded is configured between the input and output lines of an MMIC amplifier chip, and the other electrode of the MIM type capacitor is used as a bias supply line for an active element. This makes it possible to miniaturize the circuit, reduce electromagnetic coupling between input and output, reduce feedback from the output to the input, and prevent deterioration of the characteristics of the amplifier.

In the embodiment shown in FIG. 1, the microstrip line whose both ends are grounded by a capacitor is a microstrip line.Although there is only one IJ tube line 610, a plurality of IJ tube lines 610 may be used. Second
The specific line width W in the characteristic diagram shown in the figure.

Length of adjacent sections of microstrip line 11
The characteristics of the microwave integrated circuit of the present invention in the case of the line spacing S have been shown, but the line width W has different values, and the length of the adjacent section of the microstrip line is 1. Track spacing S
It goes without saying that microwave integrated circuits of 1 to 3 have similar effects. In the embodiment shown in FIG.
Instead of grounding 50, the lower metal film 840 may be grounded and the upper metal film 650 may be used as a bias circuit.
A plurality of MIM type capacitors may be provided. In the embodiment shown in FIG. 4, the microwave integrated circuit of the present invention is used as an amplifier operating in the IGH2 band, but an amplifier in other bands may be used. Further, although the MMIC amplifier chip 800 is used in the embodiment of FIG. 4, a microwave amplifier circuit using discrete elements such as FETs and transistors may be used. Fifth
In the characteristic diagram shown in the figure, the characteristics of the microwave amplifier of the present invention in the case where the specific line width W and the length of the adjacent section of the microstrip line are 11 and the line spacing S are shown.
Line width W of different values, length of adjacent section of microstrip line 1. It goes without saying that a microwave amplifier with a line spacing S also has a similar effect. In the embodiment shown in FIG. 6, the upper metal film 990 is grounded and the lower substrate 102011040 is used as a bias line, but the upper metal film 990 is separated into two parts, and the lower metal film 102
0.1040 may be grounded and a separate upper layer metal film 990 may be used to supply a bias.

As described in detail of the invention, in the microwave integrated circuit of the present invention, the isolation 3 between the input and output of the microwave integrated circuit is
This not only improves the performance of microwave integrated circuits, but also reduces the size of microwave integrated circuits, which has great practical effects.

Further, in the microwave amplifier of the present invention, the circuit can be miniaturized without deteriorating the characteristics of the microwave amplifier, which has a great practical effect.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram of a microwave integrated circuit according to an embodiment of the present invention, Fig. 2 is a characteristic diagram of a microwave circuit comparing the above embodiment and a conventional example, and Fig. 3 is a diagram showing the characteristics of a microwave circuit according to an embodiment of the present invention. A configuration diagram of a microwave integrated circuit in another embodiment, FIG. 4 is a configuration diagram of a microwave amplifier in an embodiment of the present invention, and FIG. 5 is a microwave amplifier showing a comparison between the above embodiment and a conventional example. 6 is a pattern diagram of an IC chip using a microwave amplifier according to another embodiment of the present invention, FIG. 7 is a configuration diagram of a conventional microwave integrated circuit, and FIG. 8 is a diagram of a conventional microwave integrated circuit. FIG. 2 is a configuration diagram of an amplifier. 20.30.220. 480 a, 600. 7
00, 940, 960, 1040, 1100...Microstrip line, 610.620.7101...
Capacitor, 655.920.970.980...M
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Claims (5)

[Claims] (1) A first microstrip line and a second microstrip line that are provided on a circuit board and have portions that are close to each other, and the first microstrip line and the second microstrip line are close to each other. A third microstrip line, comprising one or more third microstrip lines provided in a gap between the parts, and at least one capacitor having one end grounded and the other end connected to the third microstrip line. A microwave integrated circuit characterized in that one end of the third microstrip line is connected to a DC power source, and the other end of the third microstrip line is connected to a bias terminal of an active element or an active circuit. (2) Capacitors each having one end grounded are provided near both ends of the portion of the third microstrip line located in the gap between the first microstrip line and the second microstrip line adjacent to each other. The microwave integrated circuit according to claim 1, characterized in that: (3) A first microstrip line and a second microstrip line that are provided on a monolithic IC board and have portions that are close to each other, and the first microstrip line and the second microstrip line are close to each other. One or more MIM type capacitors each including a first metal film provided in a gap between the parts, a dielectric film formed on the first metal film, and a second metal film formed on the dielectric film. The first metal film or the second metal film of the MIM capacitor is grounded, one end of the other metal film of the MIM capacitor is connected to a DC power supply, and the other end of the metal film is grounded. A microwave integrated circuit characterized in that a microwave integrated circuit is connected to a bias terminal of an active element or an active circuit. (4) the microwave integrated circuit according to claim 1 or 2;
a second microstrip line of the microwave integrated circuit; a third microstrip line of the microwave integrated circuit, and a bias terminal of the active amplification element or the amplifier circuit is connected to a third microstrip line of the microwave integrated circuit. amplifier. (5) The microwave integrated circuit according to claim 3 and an amplifying active element or an amplifying circuit are provided, and the input terminal of the amplifying active element or the amplifying circuit is connected to a first microstrip line of the microwave integrated circuit. and connecting the output terminal of the amplifying active element or the amplifying circuit to the second microstrip line of the microwave integrated circuit, and connecting the DC power source of the first or second metal film of the microwave integrated circuit. A microwave amplifier characterized in that one end of the metal film is connected to the bias terminal of the amplification active element or the amplification circuit.