JP2709509B2 - Bipolar transistor amplifier circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a bipolar transistor amplifier circuit suitable for amplifying a wideband signal.

[Prior art]

Conventionally, a transistor amplifier circuit described below with reference to FIG. 5 has been proposed. That is, from one end a, the DC blocking and coupling capacitive element 2
DC input terminal 1 and the DC bias power supply terminal 3 through the blocking inductance element 4, and the other end b is connected to the ground through the terminating resistor 5 and the DC blocking and coupling capacitive element 6. Not input signal line L ₁
Having. Further, a signal output terminal 7 is derived from one end c through a DC blocking / coupling capacitive element 8, a DC bias power supply terminal 9 is derived through a blocking inductance element 10, and the other end d.
Is connected to the ground through a terminating resistor 11 and a capacitive element 12 for DC blocking and coupling. Further, a plurality of gates are sequentially taken on the input signal line L1 from one end b side connected to the ground to the other end a side from which the signal input end 1 and the DC bias power supply end 3 are led out.
Connected at each of the connection points P ₁ , P ₂ ... _Pn ,
A plurality of n connection points are sequentially taken from the one end C side where the signal output end 7 and the DC bias power supply end 9 are led to the other end d side which is connected to the ground, on the output signal line L2. in _{M 1, M 2 ......... M n} , each connects, having a plurality of n field-effect transistors Q _1, Q ₂ ......... Q _n that are connected to both a source grounded. In FIG. 5, l ₁ in the input signal line L1,
l ₂ ... l _{(n + 1)} is one end b of the input signal line L1 and a connection point
Shown between P _1, between the connection point P ₁ and P _2, the impedance element without DC blocking is interposed in the equivalent impedance or between them no DC blocking between the one end a of ......... connection point P _n and the input signal line L1 . Further, m ₁ , m ₂ ... M in the output signal line L2
_{(n + 1)} is between one end c and the connection point M ₁ of the output signal line L2, equivalent without DC blocking between end d of the connecting points M ₁ and M ₂ between ......... connection point M _n and the output signal line L2 Fig. 3 shows an impedance or an impedance element interposed therebetween that does not block direct current. _{Further, q 1, q 2 ......... q} n , the field effect transistor
Q ₁ , Q ₂ ……… Connection point between the drain of Q _n and the output signal line L2
It shows the DC-blocking equivalent impedance of the connection line between M ₁ , M _2, ..., And _Mn , or the DC-blocking impedance element inserted in the connection line. The above is the configuration of the conventionally proposed transistor amplifier circuit. According to the transistor amplifier circuit having such a configuration, by connecting a DC bias power supply (not shown) to the DC bias power supply terminal 3, the field-effect transistor
Q _1, Q between ₂ gate and the source of ......... Q _n, the connecting point P _n to P ₁ of the input signal line L1, respectively, P _n to P _2, can provide the required bias voltage through ...... P _n it can. Further, by connecting another DC bias power source (not shown) to a DC bias power supply terminal 9, between the field effect transistor Q _1, Q ₂ the drain and source of ......... Q _n, connection of the output signal line L2 A required bias power can be supplied through points M ₁ , M _{1 to} M ₂ ,..., M _{1 to} M _n . Further, if an input signal is supplied to the signal input terminal 1, the input signal is connected to the input signal line L1 at the connection points P _n , P _(n−1).
... propagated as a traveling wave sequentially through P _1, The connection point P _n of the input signal line _{L1, P (n-1)} , the input signal components obtained in ......... P ₁ is a field effect transistor Q _n ,
Q _(n-1), respectively applied to the gates of ......... Q _1. Further, the field effect transistor _{Q n, Q (n-1} ) the drain of ......... Q ₁ is a connection point M _n ~M ₁ output signal lines _{L1, M (n-1)} ~
M ₁ ,... Are connected to the signal output terminal 7 through M ₁ . Therefore, if an input signal to be amplified is supplied to the signal input terminal 1 in a state where the required DC bias power is connected to the DC bias power supply terminals 3 and 9, the connection points P _n , P _{( n-1)} input signal components obtained respectively in ......... P ₁ are respectively amplified in a field effect transistor _{Q n, Q (n-1} ) ......... Q 1, and, the amplified signal component, the output Propagating as a traveling wave from the connection points M _n , M _(n−1) ,... M ₁ to the one end d of the output signal line L ₂ to the signal line L 2, reaches the signal output terminal 7, and thus the signal output terminal 7 Outputs an amplified output signal of the input signal supplied to the signal input terminal 3. In this case, the connection points P ₁ and P ₂ on the input signal line L1
……… _Pn position and connection points M ₁ and M ₂ on the output signal line L2
_If the position of _Mn is appropriately selected in advance, even if the input signal is a wideband input signal, the output signal can be output as a corresponding wideband output signal. As described above, the transistor amplifier circuit shown in FIG. 5 can amplify a wideband input signal.

[Problems to be solved by the invention]

However, the conventional transistor amplifier circuit shown in FIG. 5, but are operated field effect transistor Q ₁ to Q _n as active elements, field effect transistors Q ₁ to Q _n thereof as an active element, for the gate Since the change of the current of the output signal output from the drain with respect to the change of the input signal voltage (g _m ) is relatively low, the output signal can be output with relatively low power. Was. Accordingly, the present invention proposes a novel bipolar transistor amplifier circuit that does not have the above-mentioned disadvantages.

[Means for Solving the Problems]

The bipolar transistor amplifier circuit according to the present invention comprises:
A signal input terminal and a first DC bias power supply terminal are derived from one end, an input signal line having the other end connected to ground, and a signal output terminal and a second DC bias power supply terminal are derived from one end, An output signal line having the other end connected to ground, a base connected to the input signal line, and the signal input terminal and the first DC bias power supply terminal derived from one end connected to the ground. a plurality of n connection points P _1, P ₂ ......... P _n taken sequentially toward the other end side are respectively connected, the collector, to the output signal line, the signal output terminal and said second At a plurality of n connection points M ₁ , M _2, ..., M _n sequentially taken from one end side from which the DC bias power supply end is led out to the other end side connected to the ground, respectively, an emitter, a plurality of n capacitor elements _{C 1, C 2, ......... C} n
Are connected to the ground through each of the plurality of n bipolar transistors T ₁ , T _2, ..., T _n , and one end is connected to a connection point.
F _n as a resistor line connected to the emitter of the bipolar transistor T _n and the other end connected to ground,
The bipolar transistors T ₁ , T ₂ ... T
_(n-1) the emitter of, to the resistor track, a plurality (n-1 taken successively toward the other end connected to the emitter of the bipolar transistor T _n from one end connected to the ground ) Connection points F ₁ , F ₂ ... F _(n-1) .

[Action / Effect]

According to the bipolar transistor amplifier circuit of the present invention, the connection point P _i (i = _i ) from the first DC bias power supply terminal to one end of the input signal line on the first DC bias power supply terminal side.
1, 2... N), the base and the emitter of the bipolar transistor T _i , and the resistance of the resistance line from the connection point F _i of the resistance line to the ground, and the bipolar transistor T _i reaching the ground. The base-emitter DC bias current path is formed. Also, the second DC bias power supply terminal, and the line portion of the second from one end of the DC bias power supply end to the connection point M _i output signal line, and the collector and emitter of the bipolar transistor T _i, the connection resistance line the collector-emitter bias current path of the bipolar transistor T _i from the point F _i reaches the ground through a resistance line component to ground is formed. Further, the line portion of one end of the signal input terminal side to the connection point P _i input signal path from the signal input terminal and a base and emitter of the bipolar transistor T _i, a bipolar transistor T _i capacitor viewed ground side from the emitter of the C ₁ -C _n and the input signal line of the bipolar transistor T _i reaching through the impedance circuit Z _gi comprising resistors line R to the ground is formed. Also, from the signal output terminal, viewed and the line portion of the one end of the signal output end side of the output signal line to a connection point M _i, and the collector and emitter of the bipolar transistor T _i, the ground side from the emitter of the bipolar transistor T _i capacity element C ₁ -C _n and the resistor line output signal line of the bipolar transistor T _i reaching through the impedance circuit Z _gi consisting of R to the ground is formed. For this reason, if an input signal is supplied to the signal input terminal in a state where the required DC bias power is supplied to the first and second DC bias power supply terminals, the input signal passes through the connection point P on the input signal line. _n , P _(n-1) ……… propagates as a traveling wave toward ground through P ₁ , and in the process of propagation, to connection points P _n , P _(n-1) , ……… P ₁ The input signal components obtained are respectively amplified in the bipolar transistors T _n , T _(n−1) ,..., T ₁ , and the amplified signal components are connected on the output signal line to the connection points M _n , M _{(n -1),} with mechanisms that propagate as a traveling wave toward the signal output from ......... M _1, the signal output terminal, the amplified output signal of the input signal is output. Then, in this case, the connection points P ₁ , P ₂ ,.
…… _Pn position and connection points M ₁ and M ₂ on the output signal line
_If the position of... _Mn is appropriately selected in advance, even if the input signal is a wideband input signal, the output signal can be output as a corresponding wideband output signal. If the positions on the connection points F ₁ , F _2, ..., F _n on the resistance lines are appropriately selected in advance, the bipolar transistors T ₁ , F ₂
T ₂ ......... T _n input signal components each other have approximately equal levels based can be injected, further, at the same time, the base and emitter of the bipolar transistor T _1, T ₂ ......... T _n DC bias voltages substantially equal to each other can be applied therebetween. Therefore, all the bipolar transistors T _{1 to} T _n are
Since it can be operated as an active element utilizing both the large g _m inherently provided, an output signal can be obtained with higher power than in the case of the conventional bipolar transistor amplifier circuit described above with reference to FIG. .

【Example】

Next, an embodiment of a bipolar transistor amplifier circuit according to the present invention will be described with reference to FIG. In FIG. 1, parts corresponding to those in FIG. 5 are denoted by the same reference numerals, and detailed description is omitted. The bipolar transistor amplifier circuit according to the present invention shown in FIG. 1 derives a signal input terminal 1 from one end a through a DC blocking / coupling capacitive element 2 as in the case of the conventional transistor amplifier circuit described above with reference to FIG. In addition, an input signal line L1 is provided which derives the DC bias power supply end 3 through the blocking inductance element 4 and connects the other end b to the ground through the terminating resistor 5 and the DC blocking / coupling capacitive element 6. 5, a signal output terminal 7 is derived from one end c through a DC blocking / coupling capacitive element 8 and a DC bias power supply terminal is connected through a blocking current inductance element 10 as in the case of the conventional transistor amplifier circuit described above with reference to FIG. 9 is derived,
The other end d is connected to a terminating resistor 11 and a DC blocking / coupling capacitive element 12.
And has an output signal line L2 connected to ground through. Further, a plurality of bases are sequentially taken on the input signal line L1 from the one end b side connected to the ground to the other end a side leading out the signal input end 1 and the DC bias power supply end 3.
Connected at each of the connection points P ₁ , P ₂ ... _Pn ,
A plurality of collectors are connected to the output signal line L2 in order from the one end c from which the signal output terminal 7 and the DC bias power supply terminal 9 are led to the other end d which is connected to the ground. M _1, M ₂ ......... in M _n, respectively connected, the capacity of the plurality of n emitter elements C _1, C ₂ ......... C plurality are connected to ground through _n n number of field-effect transistors T ₁ , T ₂ ……
... with a T _n. Further, one end e, as a connection point F _n, connected to the emitter of the bipolar transistor T _n, has a resistance line R connecting the other end f to ground. Then, the above-described bipolar transistors T ₁ , T ₂ ......
... T _(n-1) the emitter of, the resistance line R, a plurality taken sequentially toward the other end e side connecting from one f side connected to ground to the emitter of the bipolar transistor T _n (n
-1) Connection points F ₁ , F ₂ ... F _(n−1) . In FIG. 5, l ₁ in the input signal line L1,
_{l 2 ......... l (n + 1} ) is the same as the case of the conventional transistor amplifier circuit described above in FIG. 5, between the one end b and the connection point P ₁ of the input signal line L1, the connection points P ₁ and P _{2 denotes an} equivalent impedance that does not block direct current between the connection point _Pn and one end a of the input signal line L1 or an impedance element that does not block direct current inserted therebetween. Further, m ₁ , m ₂ ... M in the output signal line L2
_{(n + 1) is} also one end c of the output signal line L2 and the connection point as in the case of the conventional transistor amplifier circuit described above with reference to FIG.
Between M _1, showing an impedance element without DC blocking is interposed between the non-impedance or their DC blocking between end d of the connecting points M ₁ and M ₂ between ......... connection point M _n and the output signal line L2. _{Further, q 1, q 2 ......... q} n is a bipolar transistor
T ₁ , T ₂ ……… Connection point between the collector of T _n and the output signal line L2
It shows the DC non-blocking equivalent impedance of the connection line between M ₁ , M _2, ..., M _n, and the DC non-blocking impedance element inserted in the connection line. Further, in the resistance line _{R, r 1, r 2 .........} r n is between connection points f ₁ and one end f, between the connection point F ₂ and F _1, ......... F _n and F
The resistance element between _(n-1) is shown. The above is the configuration of the embodiment of the bipolar transistor amplifier circuit according to the present invention. According to the bipolar transistor amplifier circuit of the present invention having such a configuration, one end a of the input signal line L1 on the side of the DC bias power supply terminal 3 is connected from the DC bias power supply terminal 3.
From the line to the connection point P _i (i = 1, 2,..., N)
The base and emitter of the bipolar transistor T _i, the base-emitter bias current path through the resistor line component to ground from the junction F _i of the resistance line R leading to the ground bipolar transistor T _i is formed . Further, the direct current from the bias power supply terminal 9, and the line component to the connection point M _i from the DC bias power supply terminal 9 side of the one end c of the output signal line L2, and the collector and emitter of the bipolar transistor T _i, a connection point of the resistor lines R A collector / emitter DC bias current path is formed for the bipolar transistor T _i to ground through the resistance line from F _i to ground. Furthermore, from the signal input terminal 1, and the line portion of the one end a of the signal input terminal 1 side of the input signal line L1 to the connection point P _i, the base and emitter of the bipolar transistor T _i, the ground from the emitter of the bipolar transistor T _i Capacitive element seen from the side
An impedance circuit Z _gi composed of C _{1 to} C _n and a resistance line R
And an input signal line of the bipolar transistor T _i reaching the ground through the gate. Also, from the signal output terminal 7, the connection point M _i of the output signal line L2
And the line component to the collector and emitter of the bipolar transistor T _i, to ground through an impedance circuit Z _gi consisting bipolar transistor T capacitive element C ₁ is viewed ground side from the emitter of the _i -C _n and the resistor line R throughout the bipolar transistor T _i of the output signal lines are formed. For this reason, if an input signal is supplied to the signal input terminal 1 in a state where a required DC bias power supply (not shown) is applied to the DC bias power supply terminals 3 and 9, respectively, the input signal is supplied to the input signal line L1. the connection point _{P n, P (n-1} ) through ......... P ₁ propagates as a traveling wave toward the ground and, in its propagation process, the connection point _{P n, P (n-1} ), ...... ... input signal components respectively obtained P ₁ is, bipolar transistors T _n,
T _(n-1) ,..., T ₁ , respectively, and the amplified signal components are connected on the output signal line L2 to the connection points M _n ,
M _(n−1) ,... A mechanism in which the signal propagates from M ₁ to the signal output terminal 7 as a traveling wave, and an amplified output signal of the input signal is output to the signal output terminal 7. In this case, the connection points P ₁ and P ₂ on the input signal line L1
……… _Pn position and connection points M ₁ and M ₂ on the output signal line L2
_If the position of _Mn is appropriately selected in advance, even if the input signal is a wideband input signal, the output signal can be output as a corresponding wideband output signal. Also, the positions on the connection points F ₁ , F _2, ..., F _n on the resistance line R (in this example, the resistance elements r ₁ , r ₂ ,.
The ... value of r _n), if choose advance properly, bipolar transistors T _1, T ₂ ......... T _n is by having an input resistance viewed from a relatively small base, from the signal input terminal 3, bipolar in line portion of the transistors T _1, T ₂ ......... T _n input signal lines L1 to based, mutually different propagation to the input signal component to be injected to the base of the bipolar transistor T _1, T ₂ ......... T _n Compensate for any loss,
The base of all the bipolar transistor T ₁ through T _n, it is possible to inject the mutually substantially equal the input signal component level, and further, at the same time, bipolar transistor
T mutually can give approximately equal DC bias voltage between the base and emitter of the ₁ through T _n. Now, this will be described as follows. That is, the bipolar transistors T _i (i = 1, 2,...)
... N) are represented by the equivalent circuit shown in FIG. Note that in FIG. 2, B is the base terminal, E is an emitter terminal, C is the collector terminal R _b is the base resistance, R _c is the collector resistance, R _e is the emitter resistance, R _ee emitter differential resistance, C _BE is input The capacitance, C _cb indicates an output capacitance, and I _c indicates a current source. Now, as shown in FIG.
The impedance when the ground side is viewed from the emitter of T _i is Z _gn, and furthermore, the bases of the bipolar transistors T _{1 to} T _n
Assuming that the input impedance between the emitters is equal to each other,
Its impedance is Z _i and the bipolar transistor
The input impedance of T _i is given by the following equation, where it is Z _in . Z _in = Z _i + Z _gn Z _gn = {jωC _g · (R _gn + Z _gn-1 )} / (jωC _g + R _gn + Z
_gn-1 ) Z _i = R _b + R _e + {(jωC _be · R _ee ) / (jωC _be + R _ee )} where the signal propagation coefficients between adjacent connection points of the input signal line L1 are equal to each other. as it was with the alpha, also when the voltage of the input signal and V _0, the input voltage V _in of the bipolar transistor T _{i is, V in = (Z i /} Z in) · α n-n + 1 · V Given as ₀ . In this case, ω has a value of 10 ⁹ to 10 ¹¹ , and C _g , C _be , C
_bc has a value of 10 ⁻¹² (F) or less, and usually, R _e
Since << is R _b, if omitted R _e, V _in it can be approximated to the following equation. Where _{V in = R ee / (R} ee + R b + n · R g) · α n-n + 1 · V 0, and corrects the propagation loss on the signal input line L1, the input voltage of the bipolar transistor T _n, the input voltage of the bipolar transistor T ₁ is the same as the following condition _{is, {R ee / (R ee} + R b + n · R g)} · α n-n + 1 = {R ee / (R
Because it is _{ee + R b + R g)} } · α n-1 + 1, when the value of the resistance element r ₁ ~r _n in the resistor line R and mutually equal R _g, the R _g is satisfies the following equation I just need. R _g = {(1−α _n−1 ) (R _ee + R _b )} / (nα ⁿ⁻¹ −1) When the input signal line L1 is a lossless line, α =
Since it is 1, R _g = 0. However, nα ^n-1 -1 <
When 0, for example, if α = 0.9 and n = 4, R _g = 0.1
4 · (R _ee + R _b ). From the above, the line loss as described above, together with it can be seen that can be corrected, it can be understood that equally a DC bias voltage of the bipolar transistor T ₁ through T _n. From the above, according to the bipolar transistor amplifier circuit according to the present invention shown in FIG. 1, the bipolar transistor T _1, T ₂ ......... T _n is by having an input resistance viewed from a relatively small base, the signal input from the edge 3, in line of the bipolar transistor T _1, T ₂ ......... T _n input signal lines L1 to the base of a bipolar transistor
T _1, T ₂ even with a mutually different propagation loss to the input signal components are injected into the base of ......... T _n, and compensate for, each other of the base to the level of all the bipolar transistor T ₁ through T _n can be injected substantially equal input signal components, and further, at the same time, it can provide mutually substantially equal DC bias voltage between the base and emitter of the bipolar transistor T ₁ through T _n. Therefore, according to the bipolar transistor amplifier circuit according to the present invention shown in FIG. 1, all the bipolar transistor T ₁ through T _n, it is possible to operate as an active element which utilizes both a large gm which has originally An output signal having a gain range within ± 1.5 db over a wide frequency as shown in FIG. 4 can be obtained with higher power than the conventional bipolar transistor amplifier circuit described above with reference to FIG. . In the above, only a few embodiments of the present invention have been shown, and various modifications and changes could be made without departing from the spirit of the present invention.

[Brief description of the drawings]

FIG. 1 is a connection diagram showing an embodiment of a bipolar transistor amplifier circuit according to the present invention. FIG. 2 is a diagram showing an equivalent circuit of a bipolar transistor used in the circuit. FIG. 3 is a connection diagram showing the input side of the bipolar transistor as an equivalent circuit for explanation of the bipolar transistor amplifier circuit shown in FIG. FIG. 4 is a diagram showing frequency gain characteristics of the bipolar transistor amplifier circuit according to the present invention shown in FIG. FIG. 5 is a connection diagram showing a conventional transistor amplifier circuit. DESCRIPTION OF SYMBOLS 1 ... Signal input terminal 2 ... Capacitance element for DC blocking / coupling 3 ... DC bias power supply terminal 4 ... Inductance element for blocking current 5 ... Terminal resistance 6 ... Capacitance element for DC blocking / coupling 7 ... Signal output Terminal 8 DC blocking / coupling capacitive element 9 DC bias power supply end 10 Blockage inductance element 11 Terminating resistor 12 DC blocking / coupling capacitive element Q _{1 to} Q _{3 (= n)} … Bipolar transistors T _{1 to} T _{3 (= n)} … Field effect transistors C _{1 to} C _{3 (= n)} … Capacitance element R… Resistance lines F _{1 to} F _{3 (= n)} … Connection point P ₁ ~ P _{3 (= n)} …… Connection point M _{1 to} M _{3 (= n)} …… Connection point

Claims (1)

(57) [Claims] 1. An input signal line which derives a signal input terminal and a first DC bias power supply terminal from one end and connects the other end to ground, a signal output terminal and a second DC bias power supply terminal from one end. And an output signal line having the other end connected to the ground, a base connected to the input signal line, the signal input end and the first DC bias power supply connected from the one end connected to the ground. At the plurality of n connection points P ₁ , P _2, ..., P _n sequentially taken toward the other end side from which the ends are derived, the collectors are connected to the output signal line and the signal output terminals, respectively. and a plurality of n connection points M _1, M ₂ ......... M _n from one end side taken sequentially towards the other end connected to the ground which is derived the second DC bias power source terminal , Respectively, and connect the emitters to a plurality of n capacitive elements C ₁ , C ₂ ,.
... and a plurality of n bipolar transistors T _1, T ₂ ......... T _n that through the C _n respectively connected to ground, one end, as the connection point F _n, the bipolar transistor
A resistance line connected to the emitter of T _n and the other end connected to ground, and the emitters of the bipolar transistors T ₁ , T ₂ ... T _(n-1) are connected to the resistance line, said plurality from one end connected to the ground taken sequentially towards the other end connected to the emitter of the bipolar transistor T _{n (n-1)} pieces of connecting points F _1, F ₂ ......... F _{(n-1) The} bipolar transistor amplifier circuit, which is connected to each other.