JPH0258902A - 180× hybrid circuit - Google Patents

Abstract

PURPOSE:To obtain a 180 deg. hybrid circuit to be miniaturized and made into a wide band by removing a lambda/4 length line as a distribution constant line. CONSTITUTION:Source electrodes S1 and S2 of field effect transistors(FET) 20 and 21 of grounded gate are commonly connected, a first microwave line 22 having a characteristic impedance ZOH is connected to both source electrodes S1 and S2, and two drain electrodes D1 and D2 of the FETs 20 and 21 are connected to a fourth microwave line 23 having a characteristic impedance ZOE. The drain electrodes are connected to second and third microwave lines 24 and 25 having a characteristic impedance ZO, respectively. Consequently, the lambda/4 length line is not needed. Thus, the 180 deg. hybrid circuit to be miniaturized and made into the wide band can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a micro e180 degree hybrid circuit formed by combining a series branch circuit and a parallel branch circuit. Hereinafter, a microwave line is a line for transmitting a signal with a frequency of approximately 1 Gllz or more, and includes a coplanar line,
Also refers to coplanar lines such as slot lines, microstrip lines, etc.

[Prior Art] In a frequency band lower than 1 GHz, a wire-wound hybrid coil is generally used as an 1802 hybrid, and its characteristics deteriorate rapidly in a microwave band of 1 GHz or higher. In contrast, conventional 180-degree hybrids that operate in the microwave band were realized by combining passive branch circuits.

Figure 9 shows a typical 180 in conventional microwave ICs.
In the examples of hybrid circuits, (A) is a rat race hybrid circuit, and (B) is a phase inversion hybrid circuit, in which an unbalanced microstrip line is used as the microwave line. Figure 9 (A), (
When a signal is manually input to terminal E in B), the two branched signals are respectively λ/4 long line 50.3 λ/4 long line 51
(or the phase inversion circuit 54) between the terminal Xl and the terminal x.
2 are output in opposite phases to each other. Here, electric fields of the same amplitude and opposite phase are simultaneously applied to the terminal H, resulting in an electrical short circuit. At this time, since the impedance of the terminal H seen from the terminals X1 and x2 through the λ/4 long line 52,53 is infinite, the human input signal from the terminal E is not transmitted to the terminal I], and the terminal I( The electrical short-circuit state of
Mizuko E, X 1. It has no effect on X2. on the other hand,
When a signal is input to terminal H, the two-branched signals are sent to terminal x1 and terminal x2 via λ/4 long lines 52 and 53, respectively.
It is output in phase with . Here, terminal E has the same amplitude and opposite 1
) An electrical short circuit occurs because the γ-phase electric field is applied at the same time.

At this time, λ/4 long line 50 from terminal x1 and terminal x2
．． Since the impedance of looking at the terminal E through the 3λ/4 long line 51 (or phase inversion circuit 54) is infinite,
The input signal from terminal H is not transmitted to terminal E, and the electrical short-circuit state of terminal E has no effect on the other three terminals.

In this way, conventional microwave 180 degree vibrissa! - The circuit was realized by combining r (number of λ/4 long lines). Therefore, it was large depending on the shape and size or wavelength (frequency), making it difficult to miniaturize the circuit, and furthermore, the circuit was The 2&1n characteristics were also narrow band.

Figure 10 shows a 180 using both sides of the microwave IC board.
This is another conventional example of a multi-hybrid circuit, in which the increase in shape and dimensions due to the λ/4 long line is kept to a minimum. In other words,
The combination of the λ/4 long line and 3λ/4 long line (or phase inversion type directional coupler) used in Fig. 9 to obtain a negative phase output is realized by a Y branch using a slot line. This reduces the number of λ/4 long lines used. First, when a signal is input to the slot line 55 from the terminal E, the signal is branched in opposite phase to the slot lines 58 and 59, and each signal excites the microstrip lines 56 and 57 via the through hole 61. They are output to terminal X1 and terminal X2 in opposite phases. Here, electric fields with opposite phases are simultaneously applied between the slot line 58, 59 and the intersection of the microstrip line 60 on the back side, resulting in an electrical short circuit. Therefore, the λ/4 long slot line 58, 59 is The end becomes a parallel stub with a short circuit, and no signal is transmitted to terminal H. Next, when a signal is input from terminal H, it is distributed in phase from microstrip line 60 to slot line 58.59 via through hole 62, and further passes through microstrip line 56.57 to terminal X1. and is output in the same phase to the terminal x2. Here, both conductors of the slot line 55 are at the same potential, and the signal is not transmitted to the j and i elements E. However, even if the circuit purchase is simplified as in the above example, the λ/4 long line cannot be completely removed, so there is still a limit to the miniaturization of its shape and dimensions.

Furthermore, since all of the above three examples require a λ/4 long line, there is also the problem that the operating frequency band is limited to a specific band due to the frequency dependence of wavelength.

[Problems to be solved by the invention] Conventional 180-degree hybrids are realized only with passive circuit elements, and a terminal that is electrically short-circuited or a λ/4 long line to avoid electrically affecting other terminals. was essential, making it difficult to miniaturize the circuit. Furthermore, due to the frequency dependence of the λ/4 length, there is a drawback that the usable frequency band is limited (approximately 50% or less of the fractional band).

An object of the present invention is to solve the above problems and provide a 180-degree hybrid that is significantly smaller in size and has a wider band by eliminating the above-mentioned distributed constant line.

[Means for Solving the Problem] In order to achieve the above object, the present invention provides two transistors in which the same electrode is grounded, and a second transistor in which the same electrode and the ground electrode of the two transistors are not grounded.・It is possible to connect one microwave circuit, and to connect another microwave circuit between the other ungrounded electrodes of the two transistors or between the other electrode and the ground electrode. It is characterized by

Furthermore, the present invention provides a method for connecting two transistors whose first electrodes are common or whose first electrodes are connected to each other and whose second electrode is grounded and the first electrode of the transistor or these transistors. a first microwave line connected to the conductor and the 29th electrode; second and third microwave lines connected to the third electrode of each transistor and the second conductor; A fourth microphone 0-wave line connected to the third electrode.

Further, the present invention provides that the resistance connected in parallel to each of the first microwave line and the second microwave line is set to 0;
It is characterized by having η.

[Function] With the above configuration, a signal input from the first microwave line is transmitted to the second and third microwave lines by a transistor whose third electrode is different and whose second electrode is grounded. distributed in phase across the paths. At this time, the two third electrodes have the same potential, the fourth microwave line becomes open, and no signal is output. On the other hand, the signal manually inputted from the fourth micrometer line gives a signal potential of opposite phase to the two third electrodes, and this is applied to the second and third micrometer 2F! i. It is transmitted to the railroad tracks. At this time, these signals are not transmitted to the first microwave line due to the irreversibility of the transistor. Although there is some leakage in actual transistors, the first microwave line is excited by electric fields with opposite phases and the same amplitude, resulting in a short-circuit state.
In the end, no signal is transmitted to the first microwave line. At the same time, if the second electrode is a gate electrode (or base electrode) or a source electrode (or emitter electrode), the impedance of the trans/meta seen from the third electrode is sufficiently large, and the resulting signal Since the attenuation of can be ignored, the signal can be transmitted to the second and third microwave lines with little loss.

Furthermore, since the conventionally used λ/4 long line is not required at all, there are almost no elements that limit the operating frequency band.
Has ultra-wideband characteristics. In addition, by miniaturizing the circuit composed of the two transistors mentioned above, the 180
The hybrid circuit can be significantly downsized compared to the conventional example.

[Example] The basic circuit diagrams (Δ) to (C) in FIG.
FIG. 2 is a configuration diagram of a first basic circuit of an 80-degree hybrid circuit.

In Figure 1 (A), FET20 and FE with gate grounded
The source electrodes S1 and 82 of T21 are connected in common, and both source electrodes S, and 82 have a characteristic impedance Z. 5. is connected to the first microwave line 22 having FET2
0 and the two drain electrodes of FET21, ,D, is the characteristic impedance Z. The fourth microwave line 2 with 0
Connected to 3.

Further, each of the above drain electrodes has a characteristic impedance Z. second and third microwave lines 24.25 having
It is connected to the.

In FIG. 1(B), source-grounded FET20 and FE
The gate electrodes G and G2 of T21 are commonly connected, and both gate electrodes G and G2 have a characteristic impedance Z. , l is connected to the first microwave line 22 having FET2
0 and the two drain electrodes of FET21, ,D, is the characteristic impedance Z. The fourth microwave line 2 with E
Connected to 3.

In addition, each of the above drain electrodes has a characteristic impedance Z. second and third microwave lines 24.2 having
5.

In FIG. 1(C), drain grounded FET20 and FE
Case 1 of T21 [poles G, , G, are connected together, whereas the characteristic impedance Z. , 4 is connected to the first microwave line 22 having FET 20 and FET 21.
two source electrodes s I+ s .

is the characteristic impedance Z. It is connected to a fourth microwave line 23 having E. Further, each of the above source electrodes has a characteristic impedance Z. It is connected to second and third microwave lines 24 and 25 having the following characteristics.

Figures 2 (A) to (C) show the train electrodes of FETs 20 and 21 (
or source electrode) and the ground electrode, each with a resistor of 2
6.27 (resistance value RL) is a configuration diagram of a second basic circuit connected.

FIG. 3 is a diagram in which the relationship between the fourth microwave line and ground in FIGS. 1 and 2 is rewritten using the ideal transformer 23 and the microwave line 23''. Terminal T3 of No. 3 is connected to a microwave line 23''' having a characteristic impedance Z.E. Here, the signal applied to the terminal T3 is divided into two terminals T, , T, with mutually opposite phases.

A resistor 30 (RT) connected between the terminal T of the transformer and the midpoint of the terminal T2 and ground is connected to the second and third microwave lines from the fourth microwave line 23, which should be considered in the embodiments described below. This is the resistance of the path through which the signal is transmitted to the microwave lines 24 and 25. For example, when using a grounded gate FET, this is the resistance along the length of the gate.

First, let us calculate the tenth mutual contactance of FET20,2
ll, the terminals connected to the first, fourth, second, and third microwave lines are terminals H, E, Xi, and X2, respectively;
The operation will be explained by taking the circuits shown in FIG. 1(A) and FIG. 2(A) as examples.

The circuits in FIGS. 1(A) and 2(A) utilize the irreversibility of FETs to handle the left and right circuits independently regarding terminals Xi and Return loss and isolation are determined only by the relationship with terminal E.

(1) Terminal 1 (3-terminal circuit terminal H consisting of , Xi, and X2
The impedance matching condition for two common gate FETs is
Reflection coefficient S of equation (1) at source electrodes 20 and 21
It is given by HH.

Here, matching at terminal I4 can be obtained by setting the gate width and bias of the FET so that 2g1°ZOH becomes a value close to 1 or l.

The microwave signal input from terminal I4 is sent to terminals X1 and
2 in phase. The degree of distribution from terminal H to terminals X1 and x2 is given by equation (2).

(2) Here, the terminal E is open to the signal input from the terminal 1-1, and no signal is transmitted from the terminal H to the terminal E.

(2) Three-terminal circuit consisting of terminals E, XI, and The return loss and isolation of each terminal can be found from the circuit. Figure 4 (A) shows an isochoral circuit during ODD excitation, and Figure 4 (B) shows an isochoral circuit during EVEN excitation. Here, OI] 1] During excitation, the resistor R'F becomes the ground potential and does not appear in the equinodal circuit. Also, during EVEN excitation, the terminal E is released, so it does not contribute to the anti-Q;t relationship. From the equinodal circuit in Figure 4 , terminals Xi, X during ODD excitation
Reflection coefficient F, - at 2 and terminal xl during EVEN excitation.

Reflection coefficient at x2 F8. are given by equations (3) and (4), and using these, the reflection losses S, , l of terminals Xi and
, l S, 21 and isolation l512, Is
,,l is given by equations (5) and (6).

Reflection loss: ``、＋　　r、.

S,,1=lS221-...(5
) Isolation: ",--r',.

51-l = l S21 l =
...(6) If the signal is input from terminal E, resistor RT
becomes the ground potential, the reflection loss of the terminal E is given by ls,,l, and the degree of distribution l5IE,I from the terminal E to the terminals xl and x2 are given by equations (7) and (8).

Oppressed by inversion. The characteristics of the 180-degree hybrid obtained from the above basic circuit examination results are summarized in Tables 1 and 2. Here, Zoll=Zo8=Z.

-50Ω. Further, the effect due to the parasitic capacitance of the FET will be ignored for simplicity.

Table 1 shows the characteristics of the basic circuit shown in FIG. 1(A).

Here, since the basic circuit does not include resistors 26 and 27, R
Let it be L-00. Also, 2g-ZOI! -1,0,
Assume that perfect matching is achieved at terminal 1-[.

Table 1 Characteristics of 180 degree hybrid l5ij...(7
)...(8) No signal is transmitted from terminal E to terminal H due to the irreversibility of the FET and the shorting of the H terminal. In addition, the signal transmission from terminals X1 and X2 to terminal H is shown in Figure 1 (A
), the in-phase distribution is -3.5 dB and the negative phase distribution is -6.0 dB, and the isolation is excellent except between terminals X1 and X2. Return loss at 3 terminals other than H terminal and terminal X1-X
Although the isolation between terminals 2 and 2 is less than 10 dB, which is somewhat insufficient, from Table 1 and the above explanation, terminals H and E are completely electrically isolated, and terminals 1-1 to 1-1 are connected to terminals Xi and X2. It can also be seen that it has the basic performance as a 180-degree hybrid, in which signals are distributed from terminal E to terminals X1 and X2 in the same phase and in opposite phase, respectively.

Table 2 shows the characteristics of the basic circuit shown in FIG. 2(A). here,
In order to suppress the drop in distribution as much as possible and achieve a return loss of 10 dB or more, RL-300Ω, 2g□Zo+(-1,
It is set at 5.

(Leaving space below) Table 2 Characteristics of 180Ii Hybrid 1sij In this way, resistor 26.27 is added between the drain D of FET 20 and the ground conductor or between the drain D of FET 21 and the ground conductor, and the resistor 26.27 is added between the drain D of FET 20 and the ground conductor. By adjusting the bias of 21, it is also possible to make the in-phase distribution (-5, 8 dB) and the negative-phase distribution (-42 dB) relatively equal. Also, the reflection loss in each b;it1 child is 10d13
Isolation” (excluding between terminals X1 and X2)
is obtained. This characteristic poses no problem in practice, and the present invention has a wide range of applications due to its essential ultra-wide band characteristics and compact size.

Furthermore, it also has a feature that could not be achieved with conventional passive 180 degree hybrid circuits, in that the human input signals from terminals X1 and X2 are not transmitted to terminal E regardless of whether they are in phase or out of phase. Note that the characteristic impedance of each microwave line is not limited to 50Ω, but can be set to any value as long as 2g-Zo is set in the same way. This also applies to the following basic circuits and embodiments.

By utilizing the irreversibility of FETs, the basic circuits in Figures 1 (B) and (C) and Figures 2 (B) and (C) can be
Terminal X 1. They are exactly the same in that they can handle circuits that are left and right symmetrical with respect to X2 independently. therefore,
The above basic circuit basically operates in the same manner as the detailed basic circuits shown in FIG. 1 ()\) and FIG. 2 (A). However, the basic circuit differs from the basic circuits in FIG. 1(A) and FIG. 2(A) in the following points.

(1) In the case of the basic circuits shown in Figures 1 (B) and 2 (B), the three-terminal circuit consisting of terminals E, Xi, and X2 is the same, but because the FET is source-grounded, the terminal Signal transfer characteristics from [to terminals xl, x2 1s, 1.1
and Is2.1 may indicate the gain.

Also, is terminal 1-1 connected? It has high impedance because it is connected to two poles.

(2) In the case of the basic circuits shown in Figures 1(C) and 2(C), the impedance seen from the source electrode of the drain-grounded FET is as low as 1/g. Figure 1 (A) shows the signal transmission losses 1s, , 1 and 526.
It can be made larger than the case shown in FIG. 2(A). This is effective for matching the signal distribution degree from terminal E and the signal distribution degree from terminal H, and for optimizing the t-objective relationship of these distribution degrees in Table 1.2. Furthermore, since the terminal H is connected to the gate electrode, it has the characteristic of being a constant impedance.

Embodiment 5 FIG. 5(A) is a plan view of a 180-degree hybrid monolithic microwave integrated circuit which is the first embodiment of the present invention, and FIG. FIG. 5(C) is a longitudinal sectional view taken along line BB' in FIG. 5(A).

In FIGS. 5(A) to 5(C), the same parts as in the above-mentioned drawings are designated by the same reference numerals.

In FIGS. 5A to 5C, an active layer 19 formed by implanting impurity ions is formed approximately in the center of the rectangular semi-insulating GaAs semiconductor substrate 1, and a shot film is formed on this active layer 19. There are 20 and 21 key gate field effect transistors (hereinafter referred to as MESFETs) installed.

On the operating layer 19, there are source electrodes 32 in the horizontal direction in the figure.
is provided in common to both MESFETs 20, 2].

Further, in the figure on the operating layer 19, M
The drain electrodes 33, 34 of the ESFETs 20, 21 are formed at a predetermined distance from the source electrode 32, and the drain electrodes 33, 34. Rectangular gate electrodes 30 and 31 are provided between the source electrode 32 and the gate electrodes 30 and 31, which extend parallel to each other in the horizontal direction in the figure.

The left end of the gate electrode 30 of the MESFET 20 in the diagram is the substrate 1.
The drain electrode 33 is integrally connected to the conductor 11 provided at the upper left half of the base, and the drain electrode 33 is integrally connected to the conductor 13 provided at the right J2'l= portion.

On the other hand, the upper left end of the gate electrode 31 of the M1Σ5FET 21 is integrally connected to the conductor 12 provided in the lower left half of the substrate N1, and the drain electrode 34 is connected to the conductor 12 provided in the lower right half of the substrate 1''2. It is integrally connected to 14. The right ends of both gate electrodes 30, 31 are connected to each other by a conductor 35 provided on the base l'f12i.

The source 7u pole 32 is connected to a conductor 10 provided between the conductors 11 and 12 and spaced apart from the inner conductors II and +2.

Also, the conductor 10. It, 12 refers to conductor 10 as the center conductor, conductor 11 . A coplanar line 2 with +2 as a ground conductor is constructed, and conductors 13 and 14, conductors 11 and 13, conductors 12 and 14, conductors 13 and 35, and conductors 14 and 35 are slot lines 3, 4, and 5.67, respectively. It consists of

With the above configuration, the gate electrodes of MESFETs 20 and 21 are connected to the ground conductor 11.12, respectively, and the gate electrodes of MESFETs 20 and 21 are
A coplanar line 2, which is a first microwave line, is connected to the common source electrode 32 of 21, and a slot line 4.5, which is a second and third microwave line, is connected to the drain electrodes 33 and 34, respectively. Furthermore, the drain electrode 3
3.34 is connected to the slot line 3, which is the fourth microwave line, and is made of a conductor 13.14.

Here, the conductor 35 connects the human input signal from the slot line 3 to the drains of M E S F E T 20 and 21.
It has a function of applying signals only between the gates and a function of applying signals having opposite phases to each other between the respective drains and gates of the MESFETs 20 and 21 via the slot lines 6 and 7. Also, MESFE T 20 or M
In E S F E T 21, the drain electrode 33
and the gap between the train electrode 34 and the gate electrode 31, and the gap between the source electrode 32 and the gate electrode 30.
The gap or gap between source electrode 32 and gate electrode 31 is electrically isolated from each other by the electrical irreversibility of each MESFE'F. Therefore, the coplanar line 2 and the other three slot lines are electrically separated from each other 141E. The equivalent circuit of this 180 degree hybrid is the same as the circuit shown in FIG. 1(A), and the signal input from the coplanar line 2 is distributed in phase to the slot line 4.5 via MESFET 20 and MESFET 21, and It is not transmitted to the slot line 3. Furthermore, the signal input from the slot line 3 is transmitted to the conductor 35.
The signal is distributed in reverse phase to the slot lines 6 and 7 through the gap between the drain electrode 33 and the gate electrode 30 and the gap between the train electrode 34 and the gate electrode 31, respectively, and output to the slot line 4.5. is not transmitted. Therefore, a zsob hybrid circuit that does not require any λ/4 long line can be obtained.

FIGS. 6(A) and 6(B) show measured frequency characteristics of a 180-degree hybrid circuit manufactured using the configuration shown in FIG. Characteristics close to those in Tables 1 and 2 above are obtained in the frequency band IGHz to 13GHz. Fifth
In the 180 degree hybrid circuit shown in the figure, the resistor RL (
26, 27) are not used, but in reality, the impedance when looking at the FET from the drain side is finite, and the FET
It seems that better characteristics than those in Table 1 are obtained in terms of return loss and isolation due to losses caused when signals propagate through the gap between the gate and train of the ET. Note that this 180 degree hybrid circuit uses FETs with a unit gate width of 75 μm, and the dimensions of the 180 degree hybrid circuit are extremely small, within several hundred μm square.

Possible λ 7(C) is a vertical sectional view taken along line BB' in FIG. 7(A), FIG. 7(D) is a longitudinal sectional view taken along line BB' in FIG. FIG. 3 is a vertical cross-sectional view taken along line DD'' of A).

In FIGS. 7(A) to 7(D), the same parts as in the above-mentioned drawings are designated by the same reference numerals.

This embodiment has almost the same configuration as the first embodiment shown in FIG. to be different. Resistors 26, 27 are formed in this example as follows. In (A) to D) of FIG. 7, similar to the active layer 19 of the FET, the MESFETs 20 and 21 of the rectangular semi-insulating GaAs substrate 1 are located near the position where they are formed and between the conductors 11 and 13. and conductor 1
2 and 1.1, impurity ions are implanted from the upper surface of the semiconductor substrate 1 to form a resistance layer 18.
Both ends of the conductors 11 and 13 and 12 and 14 are brought into contact with each other. The picture electrodes (conductor 26a and conductor 26b, or conductor 27a and 27b) of resistor 26 or resistor 27 are formed integrally with conductor 13 and conductor 11, or conductor 14 and conductor 12, respectively. Here, the planar shape of the resistors 26 and 27 is a rectangular shape having two sides: a long resistor length 1r and a resistor width Wr parallel to the left-right direction in the drawing of the semiconductor substrates 1&1.

By configuring as shown below, MESFET2O
and 21 gate electrodes are ground conductors 11 and 12, respectively.
MESFET20 and MESFET
T21 has a common source electrode, and a first
A coplanar line 2, which is a microwave line, is connected to drain electrodes 33 and 34, respectively, and a slot line 4.5, which is a second and third microwave line, and a resistor 26.
27 are connected, and furthermore, the two conductors of the slot line 3, which is the fourth microwave line consisting of the drain electrodes 33, 34 and the conductors 13, 14 formed integrally with each other, are connected to the drain electrodes 3334 of both MESFETs. Ru. Here, the conductor 35 receives the input signal from the slot line 3 by M
It has the function of applying signals only between the train gates of ESFET 20 and MESFET 21, and also has the function of applying signals of opposite phases to each other between the drains and gates of IviESFETs 20 and 21 via the slot line 6.7. Also, MESFET20 or MES
In the FET 21, the drain electrode 33 and the gate electrode 3
The gap or the gap between the drain electrode 34 and the gate electrode 31, the gap between the source electrode 32 and the gate electrode 30, or the gap between the source electrode 32 and the gate electrode 31 are the respective M
They are electrically isolated from each other by the electrical irreversibility of the E S FET. Therefore, the coplanar line 2 and the other three slot lines are electrically isolated from each other.

The equivalent circuit of this 180 degree hybrid 7D circuit is shown in Figure 2 (
As shown in A), the signal input from the coplanar line 2 is distributed in phase to the slot line 4.5 via MESFET 20 and MESFET 21. Here, resistance 26
．． 27 is connected in parallel to the input microwave signal, and its resistance value is Z. 6. Signal attenuation can be suppressed by making it sufficiently larger than Zo. In addition, by setting the gate widths of MESFETs 20 and 21 so that the mutual fundance g, , of MESFET20 and MESFET2 becomes g, 1Z on> l, or by adjusting the bias conditions of each MESFET. By adding coplanar line 2 and ME
The above attenuation can be corrected while generally maintaining impedance matching with the S The inverse f-th signal of
The signals are outputted to the slot line 4.degree. 5 through the gap between the drain electrode 33 and the gate electrode 30 and the gap between the drain electrode 34 and the gate electrode 31, respectively. Here, by setting the resistance value of the resistors 26 and 27 small while satisfying the above conditions, the reflection coefficient in the slot lines 4 and 5 becomes the first
This is improved compared to the case of the embodiment.

Third Embodiment FIG. 8(A) is a plan view of a 180-degree hybrid monolithic microwave integrated circuit according to the third embodiment of the present invention, and FIG. 8(B) is a plan view of a 180-degree hybrid monolithic microwave integrated circuit according to the third embodiment of the present invention. 8(C) is a vertical sectional view taken along line BB" of FIG. 8(A), and FIG. 8(D) is a longitudinal sectional view taken along line cc' of FIG. 8(A). 8(A) to 8(D). FIG.
), the same reference numerals are given to the same parts as in the above-mentioned drawings.

In FIGS. 8(A) to 8D), MESFE is formed on active layers 19a and 19b which are formed separated from each other approximately at the center of the rectangular semi-insulating GaAs semiconductor substrate 1.
T20 and T21 are formed.

Upper b of the diagram of the operating layer 19a: jA side drain region (
It may be a source area. ), a part of the rectangular conductor 41 provided on the upper left half of the substrate 1 in the figure is provided as a drain (source) electrode 45, and a conductor 43 formed on the upper right half of the substrate 1 is provided for the above operation. A source (drain) electrode 47 is formed to protrude in a rectangular shape to the upper and lower ends of the layer 19a in the figure. Further, a gate electrode 30 is formed between the drain electrode 45 and the source electrode 47.

MESFET 20 is formed as described above.

A part of the rectangular conductor 42 provided in the lower left half of the substrate 1 is connected to the drain region (which may also be a source region) on the upper and lower sides of the active layer 19b in the figure. A conductor 44 provided as a source (train) electrode 46 and formed on the lower right half of the substrate 1 protrudes in a thin rectangular shape to the upper end of the operating layer 19b in the drawing.
8). Further, a gate electrode 31 is formed between the drain electrode 46 and the source electrode 48.

MESFET 21 is formed as described above.

Each gate electrode 30 and 31 of both MESFETs 20.21 is connected between conductors 41 and 42 on the substrate l.
Further, it is provided continuously and integrally with the conductor 40 which is formed insulated from the conductors 41 and 42.

Further, the conductors 40, 41.42 constitute the coplanar line 2 with the conductor 41.42 as the ground conductor, and the conductors 43 and 44, the conductors 41 and 43, and the conductors 42 and 44 constitute the slot lines 3, 4.5, respectively. are doing.

Furthermore, the drain electrode 45 of the MESFET 20 and the MES
Drain electrode 46 of FET 21 (respectively conductor 41.4
2 may also be included. ) is MESFET20,21
The bridge-like conductor 49I) that spans the
It is connected to a conductor 49a provided on the substrate 1 between T20 and T21.

With the above configuration, the source electrodes (or drain electrodes) of MESFET 20 and MESFET 2 are connected to the ground conductor 41 and 42, and the gate electrodes of MESFET 20 and MESFET 2+ are connected to the gate electrode. A coplanar line 2, which is a microwave line of 1, is connected to the drain electrode (or source electrode) 45 and 46, respectively.
A slot line 4.5, which is a microwave line, is connected, and a drain electrode (or source electrode) 47.48 is connected.
A slot line 3, which is a fourth microwave line, is connected to the slot line 3, which is a fourth microwave line formed by conductors 43 and 44 integrally formed with each other.

Here, the conductor 49a distributes the input signal from the straight line 3 to the gap between the conductor 17 and the conductor 49a and the gap between the conductors 48 and 49a with equal amplitude and opposite phase. Has a function. These distributed signals are applied between the conductors 47.45 and 48.46 via the bridge-like conductor 49b, and are applied to the slot lines 4.5 and 48.46, respectively.
to communicate. At this time, conductor 47 (drain electrode or source electrode) and conductor 40.30 (gate electrode) are also connected to conductor 48 (drain electrode or source electrode) and conductor 40.
31 (gate electrode) are MESFETs 20 and 2, respectively.
They are electrically isolated from each other due to the irreversibility of 1.

Therefore, the two distributed signals are MESFE'
is applied only between the drain electrode (or source electrode) and ground. On the other hand, the human power signal from the coplanar line 2 is branched into two, and then applied between the gate electrode 30 and the train electrode (or source electrode) 45 and between the gate electrode 31 and the drain electrode (or source electrode) 46, respectively. The signal is amplified by the MESFETs 20 and 21 and transmitted to the slot lines 4 and 5 in phase. At this time, the amplified signal potential described above is also applied between the conductors 47 and 49a and between the conductors 48 and 4'9a, but since these potentials have the same amplitude and the same phase, they are not transmitted to the slot line 3. do not.

In this way, the left and right circuits of this embodiment regarding the slot lines 4 and 5 are electrically independent from each other. The equivalent circuit of this 180 degree hybrid is shown in Figure 1 (B) or Figure 1 (C).
)become that way.

Furthermore, as in the second embodiment shown in FIG. 7, if a resistor is connected in parallel to each of the slot lines 4 and 5, the equivalent circuit can be formed as shown in FIG. 2(B) or FIG. C), and a 180-degree hybrid circuit that does not require all λ/4 lines can be obtained.

In other embodiments to L embodiments, a MESFET is used as an active element for electrically isolating the ◇:14 elements, but the present invention is not limited to this, and other types of FETs or bipolar transistors may also be used. good. Also, Srono! can be used as an input/output line! - Although a line and a coplanar line are used, the present invention is not limited to this, and another balanced line may be used for the slot line portion, and another unbalanced line may be used for the coplanar line portion.

Further, although 50Ω is used as the characteristic impedance of the microwave line connected to the 180-degree hybrid 71 of the present invention, the impedance is not limited to this, and other values may be used. In this case, the mutual tuftance of the FET and the resistance R
The value of L is changed in accordance with the above characteristic impedance.

[Effects of the Invention] As detailed above, according to the present invention, two second electrode grounded transistors that share (or are connected to) a first electrode, and a conductor connected to the first electrode, an unbalanced line (first microwave line) used as a conductor, a balanced line (fourth microwave line) made of mutually different conductors connected to the two third electrodes of the transistor, and the above-mentioned balanced line. Since it is constructed with two sets of balanced lines (second and third micro-l skin lines) consisting of a conductor that constitutes the above-mentioned unbalanced line and a ground conductor that constitutes the unbalanced line, the λ/4 line that was previously indispensable can be completely eliminated. It is possible to construct an ultra-wideband 180-degree hybrid circuit that does not require this.

Here, due to the input/output irreversibility of the transistor, the terminal (H terminal) that is electrically shorted in the conventional example is electrically isolated from the other three terminals, so there is no need to use a λ/4 line. Therefore, the present invention is essentially wide-band and compact, and enables frequency converters, modulators, etc. that conventionally use hybrid circuits that require a λ/4 line to be made significantly wider and smaller.

Furthermore, since the input signals from the second and third microwave lines are not transmitted to the first microwave line,
It can be used like a known isolator. That is, the input signal from the first microwave line is transmitted only to the second or third microwave line;
The input signal from the fourth microwave line can be transmitted only to the fourth microwave line.

The above effect is remarkable in the microwave band, or is effective not only in the microwave band but also in lower frequency bands.

[Brief explanation of the drawing]

1(A) to 1(C) are circuit diagrams showing basic circuits of a 180-degree hybrid circuit using transistors, which are embodiments of the present invention, and FIG. 2(A) to 2(C) ) is a circuit diagram showing the basic circuit of a 180 degree hybrid circuit using still another transistor of the present invention, and FIG.
Rewriting the basic circuit in Figure (C) to make it more general and equally economical 1
Circuit diagram of 80 degree hybrid circuit, Figure 4 (A) and Figure 4
Figure (B) is a circuit diagram showing the equivalent circuit for two different modes of the circuit in Figure 3, and Figure 5 (A) is a circuit diagram showing the equivalent circuit of the circuit in Figure 3 (B).
), FIG. 5(B) is a vertical sectional view taken along line BB' in FIG. 5(A), and FIG. 5(C) is a plan view of the specific device of the embodiment shown in FIG. 6(A) and 6(B) are a vertical cross-sectional view taken along line c-c' in FIG. 6(A). 7 (Δ) is a plan view of the specific device of the embodiment shown in FIG. 2 (B), and FIG. 7 (B) is a graph showing the measured frequency characteristics of FIG. 7(C) is a longitudinal sectional view taken along line BB' of FIG. 7(A), FIG. 7(D) is a longitudinal sectional view taken along line cc' of FIG. 7(A), 8 [] (A) is a plan view of still another specific device of the embodiment shown in FIG. 2 (B), and FIG. 8 (B) is FIG. 8(A) is a longitudinal sectional view taken along line BB', FIG. 8(C) is a longitudinal sectional view taken along line cc' in FIG. 8(A), and FIG. 8(D) is a longitudinal sectional view taken along line BB' in FIG. A vertical cross-sectional view taken along line I)-D' in FIG. 8(A), FIG. 9(A) is a circuit diagram showing the first conventional rat race type hybrid circuit, and FIG. 9(B) is a FIG. 10 is a circuit diagram showing a second conventional example of a phase inversion type hybrid circuit. FIG. 10 is a sectional view taken along line AA' in FIG. 10. I... Semiconductor substrate, 2... Coplanar line (first microwave line), 3.
4.5... Slot line (fourth, second, third microwave line), 22... First microwave line, 23.24.25... Fourth, second, third microwave line Microwave line, 20.21...Transistor, Schottky gate field effect transistor (MES FET), S l+ 32+ 32... Source electrode, D,, D2
,33.34...Drain electrode, G, ,G2,30
31... Gate' electrode, 45.46... Drain electrode or source electrode, 47.48... Source electrode or drain electrode, ZOHIZOE Characteristic impedance of the first and fourth microwave fH3, respectively, Zo Second, Characteristic impedance of the third microwave line, 26.27 Resistance (RL), 30 Resistance (R□), 49b Bridge-shaped conductor. Figure 1 (Bl) Figure 2 (B) Figure 1 (C) Figure 2121 (C) Figure (A) ×1 Figure (B) ×1 Figure (A) ;6 (B) Circumference 2 (GHz) Figure (C1 Figure (Dl Figure (A) Figure (B) Figure Figure

Claims (4)

[Claims] (1) A first microwave circuit can be connected to two transistors with the same electrode grounded, and the same electrode of the two transistors that is not grounded and the ground electrode, and the first microwave circuit is connectable to the ground electrode of the two transistors that are not grounded. 1 characterized in that it is possible to connect another microwave circuit between the other electrodes or between the other electrode and the ground electrode.
80 degree hybrid circuit. (2) two transistors whose first electrodes are common or whose first electrodes are connected to each other and whose second electrodes are grounded, and the first electrodes of the transistors or a conductor that connects them; a first microwave line connected to the second electrode; second and third microwave lines connected to the third electrode and second conductor of each of the transistors; A 180 degree hybrid circuit comprising: a fourth microwave line connected to the electrode. (3) The 180-degree hybrid circuit according to claim (1), further comprising a resistor connected in parallel to each of the second microwave line and the third microwave line. (4) The 180-degree hybrid circuit according to claim (2), further comprising a resistor connected in parallel to each of the second microwave line and the third microwave line.