JPH0786851A - High frequency integrated circuit - Google Patents

Abstract

PURPOSE:To provide a high-performance high frequency integrated circuit for which the impedance matching of the high frequency integrated circuit is electrically adjusted and the 'dispersion' of characteristics is compensated. CONSTITUTION:By forming variable capacitance elements 30a and 30b on an integrated circuit substrate composed by forming an active element 1 (FET) and circuits 7a and 7b for the impedance matching of the active element 1, varying capacitance by adjusting a voltage applied to the variable capacitance elements 30a and 30b and adding the variable capacitance elements 30a and 30b to the impedance matching circuits 7c and 7d of the high frequency integrated circuit, the impedance matching is adjusted. Thus, the 'dispersion' of the high frequency characteristics of the high frequency integrated circuit is compensated and the high frequency characteristics are optimized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high frequency integrated circuit, and more particularly to a high frequency integrated circuit having an improved impedance matching circuit.

[0002]

2. Description of the Related Art As a high frequency integrated circuit, for example,
Monolithic microwave integrated circuit amplifier (hereinafter referred to as MMIC amplifier) that amplifies high frequency signals of GHz or higher
Will be described as an example. FIG. 7 is an equivalent circuit diagram showing a circuit configuration of a conventional MMIC amplifier formed on a GaAs substrate, for example, and FIG. 8 is a plan view showing an example of a chip pattern of the conventional MMIC amplifier.

In FIG. 7, reference numeral 1 indicates that the source is grounded,
A high-frequency transistor as an active element, 4 is an input signal terminal to which a high-frequency signal to be amplified by the high-frequency transistor 1 is input, and 7a is a high-frequency transistor 1 connected between the input signal terminal 4 and the gate of the high-frequency transistor 1. Impedance matching circuits 2a and 3a are an inductor and a capacitor connected in series between the input signal terminal 1 and the ground, and 6a is this inductor 2
DC bias application terminal of the high frequency transistor 1 connected to the connection point of the capacitor a and the capacitor 3a, 5 is an output signal terminal for outputting the high frequency signal amplified by the transistor 1, and 7b is a drain and an output signal terminal of the high frequency transistor 1. An impedance matching circuit of the high frequency transistor 1, 2b and 3b connected between the inductor 5 and the inductor 5 and a capacitor 3b connected in series between the output signal terminal 5 and the ground, and 6b the inductor 2b and the capacitor 3b. This is a DC bias application terminal of the high frequency transistor 1 connected to the connection point.

As shown in FIG. 8, the elements 1, 2a, 2b, 3a, 3b and the signal terminals 4, 5, 6 are provided.
a, 6b and matching circuits 7a, 7b are formed on one integrated circuit board 8, and a wiring pattern for connecting the respective circuit elements is formed of, for example, Au-based wiring metal.

Next, the operation will be described. The signal applied to the input signal terminal 4 is amplified by the high frequency transistor 1 and taken out from the output signal terminal 5. Here, the DC bias for operating the high frequency transistor 1 is supplied from the DC bias application terminals 6a and 6b.
Capacitors 3a and 3b and inductors 2a and 2b act as a DC bias applying circuit for high frequency transistor 1, pass only a DC component, and block a high frequency signal component. An impedance matching circuit 7 is used to match the input and output impedances of the high frequency transistor 1 with a predetermined characteristic impedance.

[0006]

Since the conventional MMIC amplifier is constructed as described above, it is impossible to adjust the characteristics of the impedance matching circuit. For this reason, if there is "variation" in the performance of the high-frequency transistor, the desired impedance matching characteristics cannot be obtained, and the desired gain characteristics cannot be obtained.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a high frequency integrated circuit capable of adjusting an impedance matching circuit.

[0008]

In a high frequency integrated circuit according to the present invention, an active element, a high frequency circuit for impedance matching of the active element, and an impedance matching of the high frequency circuit are adjusted on a semiconductor substrate. The variable capacitance element is formed.

The high frequency integrated circuit according to the present invention is
A variable capacitor for forming an active element and a high frequency circuit for impedance matching of the active element on a semiconductor substrate, and for adjusting impedance matching of the high frequency circuit on a semiconductor substrate different from the semiconductor substrate. The element is formed.

Further, in the high frequency integrated circuit according to the present invention, an active element, a high frequency circuit for impedance matching of the active element, and a variable capacitance element for adjusting impedance matching of the high frequency circuit are provided on a semiconductor substrate. And a fixed capacitance element connected in parallel with this variable capacitance element.

[0011]

According to the present invention, the variable capacitance element is formed on the integrated circuit board on which the active element and the high frequency circuit for impedance matching of the active element are formed, and the variable capacitance element is electrically connected to the impedance matching circuit. However, since the characteristics of the impedance matching circuit are changed and adjusted by adjusting the capacitance value of the variable capacitance element, the characteristics of the impedance matching circuit can be changed by electrically adjusting the capacitance value of the variable capacitance element. Since the variation is corrected to correct the characteristic “variation” of the high frequency transistor, the characteristic of the high frequency integrated circuit becomes uniform and good.

Further, according to the present invention, an active element and a high-frequency circuit for impedance matching of the active element are formed on a semiconductor substrate different from an integrated circuit substrate,
A variable capacitance element is formed, and this is electrically connected to an impedance matching circuit, and the characteristics of the impedance matching circuit are
Since it is changed and adjusted by adjusting the capacitance value of the variable capacitance element, the characteristic of the high frequency circuit is changed by electrically adjusting the capacitance value of the variable capacitance element, and the characteristic “variation” of the high frequency transistor is changed. Is corrected, the characteristics of the high frequency integrated circuit are made uniform and good, and the size of the original integrated circuit board is reduced.

Further, in the present invention, the active element,
A variable capacitance element and a fixed capacitance element are formed in parallel with the variable capacitance element on an integrated circuit substrate on which a high-frequency circuit for impedance matching of the active element is formed, and the variable capacitance element and the fixed capacitance element are electrically connected to the impedance matching circuit. Since the characteristics of the matching circuit are changed and adjusted by adjusting the capacitance value of the variable capacitance element, the capacitance value of the variable capacitance element is electrically adjusted to finely adjust the capacitance value of the fixed capacitance element. It is possible to change the characteristics of the high frequency circuit,
Since the characteristic “variation” of the high-frequency transistor is corrected, the characteristic of the high-frequency integrated circuit becomes uniform and good.

[0014]

EXAMPLES Example 1. An embodiment of the present invention will be described below with reference to the drawings. 1 is an equivalent circuit diagram showing a circuit configuration of an MMIC amplifier according to a first embodiment of the present invention, and FIG. 2 is a plan view showing a pattern of a chip of the MMIC amplifier shown in FIG. In FIG. 1, the same reference numerals as those in FIG. 7 are the same, 1 is a high-frequency transistor as an active element whose source is grounded, 4 is an input signal terminal to which a high-frequency signal to be amplified by the high-frequency transistor 1 is input, 7
a is an impedance matching circuit of the high frequency transistor 1 connected between the input signal terminal 4 and the gate of the high frequency transistor 1, 2a and 3a are inductors connected in series between the input signal terminal 1 and the ground, The capacitor, 6a is the inductor 2a and the capacitor 3
A DC bias application terminal of the high frequency transistor 1 connected to the connection point with a, 5 is an output signal terminal for outputting the high frequency signal amplified by the transistor 1, and 7b is a drain of the high frequency transistor 1 and the output signal terminal 5. Impedance matching circuit of high frequency transistor 1 connected between 2b and 3b are inductors and capacitors connected in series with each other between output signal terminal 5 and ground, and 6b is a connection point between this inductor 2b and capacitor 3b. It is a DC bias application terminal of the high frequency transistor 1 connected to. Also, 7c, 7d and 30a, 3
0b and 31a, 31b are newly provided constituent elements in this first embodiment.

Reference numerals 7c and 30a denote connection points between the impedance matching circuit 7a and the gate of the high frequency transistor 1, and
An impedance matching circuit and a variable capacitance element connected in series with each other with the ground, 31a is a voltage supply terminal connected to a connection point between the impedance matching circuit 7c and the variable capacitance element 30a, and the variable capacitance element 30a is By varying the applied voltage with the voltage supply terminal 31a, the capacitance value can be adjusted.

Further, 7d and 30b are impedance matching circuits and variable capacitance elements connected in series with each other between a connection point between the drain of the high frequency transistor 1 and the impedance matching circuit 7b and the ground, and 31b is an impedance matching circuit. 7d is a voltage supply terminal connected to the connection point between the variable capacitance element 30b and the variable capacitance element 30b.
The capacitance value of b can be adjusted by varying the applied voltage by the voltage supply terminal 31b.

Then, as shown in FIG.
2a, 2b, 3a, 3b, 30a, 30b, signal terminals 4,5, 6a, 6b, 31a, 31b, and matching circuits 7a, 7b, 7c, 7d are formed on one integrated circuit board 8. The wiring pattern for connecting the respective circuit elements is formed of, for example, Au-based wiring metal.

Next, the operation will be described. The signal applied to the input signal terminal 4 is amplified by the high frequency transistor 1 and taken out from the output signal terminal 5. Here, the DC bias for operating the high frequency transistor 1 is supplied from the DC bias application terminals 6a and 6b.
Capacitors 3a and 3b and inductors 2a and 2b act as a DC bias applying circuit for high frequency transistor 1, pass only a DC component, and block a high frequency signal component. In order to match the input and output impedances of the high frequency transistor 1 to the specified characteristic impedance,
The impedance matching circuits 7a and 7b are used.

The above operation is similar to that of the conventional device,
In the first embodiment, as a countermeasure against the case where the performance of the high frequency transistor 1 has "variation" and the desired impedance matching characteristic cannot be obtained, the inductor 2 which is the input and output impedance of the high frequency transistor 1 is used.
Impedance matching circuits 7c and 7d and variable capacitance elements 30a and 30b are provided to match a and 2b with a predetermined characteristic impedance, and the variable capacitance elements 30a and 30b are provided.
Impedance matching can be varied by adjusting the voltage applied to b. Therefore, even when the characteristics of the high frequency transistor 1 have “variation”, the voltage supply terminals 3 of the variable capacitance elements 30 a and 30 b are not included.
By adjusting the voltage applied to 1a and 31b and changing the capacitance of the variable capacitance elements 30a and 30b by, for example, several tens of pF, impedance matching can be adjusted and desired high frequency characteristics can be obtained.

Example 2. FIG. 3 is an equivalent circuit diagram showing a high frequency integrated circuit according to a second embodiment of the present invention, and FIG. 4 is a plan view showing the pattern of the chip. In FIG. 3, 3
0 is a variable capacitance element, and in this second embodiment,
7c and 7d of FIG. 1 formed by a pattern similar to
The variable capacitance element is not provided at the other ends of the impedance matching circuits 7e and 7f corresponding to, but is provided on the integrated circuit substrate 8 independently of other circuit elements.
Further, 70 is an external impedance matching circuit formed on a substrate different from the integrated circuit substrate 8, 31 is a voltage supply terminal provided on the substrate on which the external impedance matching circuit 70 is formed, and 5a is shown in FIG. Output signal terminals 5b corresponding to 5 are input signal terminals to which a signal from the output signal terminal 5a of the integrated circuit board 8 is input, and one end of the external impedance matching circuit 70 is connected. 5c is an output signal terminal from which the signal impedance-matched by the external impedance matching circuit 70 is output to the outside,
Reference numeral 9a is a terminal connected to the non-ground side of the variable capacitance element 30, and 9b is a terminal connected to the other end of the external impedance matching circuit 70.

Next, the operation will be described. The signal applied to the input signal terminal 4 is amplified by the high frequency transistor 1 and taken out to the outside from the output signal terminal 5a, and the terminal 5 of the substrate on which the external impedance matching circuit 70 is formed.
It is output to the outside via b and 5c. Here, the DC bias for operating the high frequency transistor 1 is supplied from the DC bias application terminals 6a and 6b. Capacitors 3a and 3b, and inductors 2a and 2b
Acts as a DC bias applying circuit of the high frequency transistor 1, passes only the DC component, and blocks the high frequency signal component. Impedance matching circuits 7a and 7b are used to match the input and output impedances of the high frequency transistor 1 to a predetermined characteristic impedance.

The above operation is almost the same as that of the conventional device, but in the second embodiment, as a countermeasure when the desired impedance matching characteristic cannot be obtained due to "variation" in the performance of the high frequency transistor 1. , The variable capacitance element 30 is independently formed on the integrated circuit board 8, and
It is electrically connected to the external impedance matching circuit 70,
Similar to the first embodiment, the impedance matching can be varied by adjusting the voltage applied to the variable capacitance element 30 via the voltage supply terminal 31. Therefore, there are “variations” in the characteristics of the high frequency transistor 1.
Even if there is, by adjusting the voltage applied to the voltage supply terminal 31 of the variable capacitance element 30 to change the capacitance of the variable capacitance element 30 by, for example, several tens of pF, the impedance matching is adjusted to a desired value. High frequency characteristics can be obtained.

In the high frequency integrated circuit according to the second embodiment, since the external impedance matching circuit is used, the area of the impedance matching circuit formed on the semiconductor substrate can be reduced as compared with the first embodiment. , The increase in the area of the MMIC chip can be suppressed to a minimum, and the cost can be reduced accordingly.

Example 3. FIG. 5 is an equivalent circuit diagram showing a high frequency integrated circuit according to a third embodiment of the present invention, and FIG. 6 is a plan view showing the pattern of the chip. In FIG. 5, 3
c, 3d are variable capacitance elements 30a,
It is a capacitor formed so as to be connected in parallel with 30b.

In the third embodiment, the capacitors 3c,
3d in parallel with the variable capacitance element 3 on the semiconductor substrate.
0a, 30b are connected to each other, and voltage supply terminals 31c,
By adjusting the voltage applied to the variable capacitance elements 30a and 30b via 31d, the capacitance value of the capacitor 3 can be added to the adjustable capacitance value.

In the high frequency integrated circuit according to the third embodiment, the capacitance values required for correcting the characteristic "variation" of the high frequency transistor 1 are variable capacitance elements 30a and 30b.
When it cannot be achieved within the variation range of the high frequency transistor 1, the capacitance values of the capacitors 3c and 3d formed on the semiconductor substrate so as to be connected in parallel with the variable capacitance elements 30a and 30b are added as an offset. The characteristic “variation” can be corrected as necessary.

Example 4. In addition, the third shown in FIG.
Also in this embodiment, a fixed capacitor may be connected in parallel to the variable capacitance element 30. In this case, when the capacitance value required for correcting the characteristic “variation” of the high frequency transistor 1 cannot be achieved within the change width of the variable capacitance element 30, the variable capacitance element 30 is provided on the integrated circuit substrate 8.
By adding the capacitance value of a fixed capacitor formed so as to be connected in parallel to the capacitor as an offset, it is possible to correct the characteristic “variation” of the high-frequency transistor 1, and on the semiconductor substrate as compared with the first embodiment. It is possible to reduce the area of the impedance matching circuit formed in the above, and it is possible to minimize the increase in the area of the MMIC chip, thereby reducing the cost.

In the first to third embodiments, the monolithic microwave integrated circuit amplifier has been described as an example. However, the present invention can be applied to a microwave band high frequency oscillator, a mixer, etc. It is possible to obtain the same effect as that of each of the third embodiment.

[0029]

As described above, according to the high frequency integrated circuit of the present invention, the active element, the high frequency circuit for impedance matching the active element, and the impedance matching adjustment of the high frequency circuit are provided on the semiconductor substrate. Since the variable capacitance element for performing the above is formed, the impedance matching can be adjusted by the variable capacitance element, so that the "variation" of the high frequency characteristic is small, and the stable characteristic can be obtained. There is an effect that can be realized.

Further, according to the high frequency integrated circuit of the present invention, the active element and the high frequency circuit for impedance matching of the active element are formed on the semiconductor substrate, and the high frequency circuit is provided on a semiconductor substrate different from the semiconductor substrate. In addition, since the variable capacitance element for adjusting the impedance matching of the high frequency circuit is formed, the impedance matching of the variable capacitance element is suppressed by minimizing the increase in the area of the semiconductor substrate on which the active element is formed. The adjustment can be performed, and thus, there is an effect that a high-frequency integrated circuit in which “variation” of high-frequency characteristics is small and stable characteristics are obtained can be realized at low cost.

Further, in the high frequency integrated circuit according to the present invention, the active element, the high frequency circuit for impedance matching the active element, and the variable capacitance element for adjusting the impedance matching of the high frequency circuit are provided on the semiconductor substrate. Since the variable capacitance element and the fixed capacitance element connected in parallel with each other are formed, the impedance matching can be adjusted by the capacitance value that cannot be covered by the capacitance of the variable capacitance element alone. There is an effect that it is possible to realize a high-frequency integrated circuit in which there is little "variation" in high-frequency characteristics and stable characteristics are obtained.

[Brief description of drawings]

FIG. 1 is an equivalent circuit diagram showing a high frequency integrated circuit according to a first embodiment of the invention.

FIG. 2 is a plan view showing a pattern of a chip of the high frequency integrated circuit of FIG.

FIG. 3 is an equivalent circuit diagram showing a high frequency integrated circuit according to a second embodiment of the invention.

4 is a plan view showing a pattern of a chip of the high frequency integrated circuit of FIG.

FIG. 5 is an equivalent circuit diagram showing a high frequency integrated circuit according to a third embodiment of the invention.

6 is a plan view showing a chip pattern of the high-frequency integrated circuit of FIG.

FIG. 7 is an equivalent circuit diagram showing a pattern of a chip of a conventional high frequency integrated circuit.

FIG. 8 is a plan view showing a pattern of a chip of a conventional high frequency integrated circuit.

[Explanation of symbols]

 1 High Frequency Transistor 2a, 2b Inductor 3a, 3b Capacitor 4 Input Signal Terminal 5 Output Signal Terminal 6 DC Bias Applying Terminal 7a, 7b Impedance Matching Circuit 8 Integrated Circuit Board 30, 30a, 30b Variable Capacitance Element 31a, 31b Voltage of Variable Capacitance Element Supply terminal 70 External impedance matching circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H01L 21/06 H03F 3/195 7436-5J

Claims (3)

[Claims] 1. In a high frequency integrated circuit, an active element formed on a semiconductor substrate, a high frequency circuit formed on the semiconductor substrate for impedance matching of the active element, and formed on the semiconductor substrate, A high frequency integrated circuit, comprising: a variable capacitance element for adjusting impedance matching of the high frequency circuit. 2. In a high frequency integrated circuit, an active element formed on a semiconductor substrate, a high frequency circuit formed on the semiconductor substrate for impedance matching of the active element, and a semiconductor substrate different from the semiconductor substrate. A high-frequency integrated circuit, comprising a variable capacitance element which is formed on the variable capacitance element for adjusting impedance matching of the high-frequency circuit. 3. In a high-frequency integrated circuit, an active element formed on a semiconductor substrate, a high-frequency circuit formed on the semiconductor substrate and performing impedance matching of the active element, formed on the semiconductor substrate, A high frequency integrated circuit, comprising: a variable capacitance element for adjusting impedance matching of a high frequency circuit; and a fixed capacitance element formed on the semiconductor substrate and connected in parallel with the variable capacitance element. circuit.