JP2005269584A - Resonant tunnel diode oscillation circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enlarge an oscillation voltage amplitude in an ultrahigh-frequency oscillation circuit, using a resonant tunnel diode to realize high outputs of the circuit with a view toward the difficulty in attaining a larger voltage amplitude than a negative differential resistivity region width, accordingly difficulty in heightening outputs, even though the ultrahigh-speed oscillation circuit with hundreds of GHz has been heretofore realized in the oscillation circuit which uses the resonant tunnel diode with a negative differential resistivity characteristic. <P>SOLUTION: When a three-terminal element, capable of performing ultrahigh-operation, is combined with the resonant tunnel diode and the diode switches from a peak to a valley, increment of the electrical potential difference generated between two electrodes of the diode is subjected to feedback to the three-terminal element. As a result, oscillation voltage amplitudes larger than the negative differential resistivity region width of the diode can be obtained. Further, by adding an inductance to the circuit, voltage variation is enlarged, to allow the oscillation state of the circuit to be maintained. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

    The present invention relates to a next-generation radio and optical fiber communication system and an ultrahigh frequency oscillation circuit necessary for realizing an advanced information processing system. In particular, the present invention relates to an oscillation circuit using a resonant tunneling diode known as an element capable of operating at the highest speed as a semiconductor element.

As a conventional super-high frequency oscillation circuit using a resonant tunneling diode, a circuit using a negative differential characteristic peculiar to the resonant tunneling diode is known (for example, see Non-Patent Document 1). Hereinafter, a conventional super-high frequency oscillation circuit using a resonant tunneling diode will be described with reference to FIGS. In FIG. 3, 301 and 302 are bias terminals, 303 is an output terminal, 304, 305 and 306 are inductors, resistors and resonant tunneling diodes, respectively, and 307 is a bias power source. In FIG. 4, 401 is a current-voltage characteristic of the resonant tunneling diode 306, and 402 is a resistance load line by a resistor 305. Although the load connected to the output terminal 303 is not described in FIG. 3, it is assumed that the load line 402 is drawn including the effect.
E. Brown, W. Goodhugh, T. Solner, “Fundamental Oscillation Up to 200 GHz Resonant Tunneling Diode and New Estimates of There Maximum Oscillation Frequency” From Stationery State Tunneling Theory, Journal of Applied Physics, 64 Volume 3, pages 1519 to 1529, issued August 1, 1988.

When the voltage value of the bias power supply 307 is adjusted so that 402 intersects in the negative differential resistance region 401, an output that oscillates with time as shown in FIG. 4 due to amplification based on the negative differential resistance characteristics. A voltage is obtained, and the circuit shown in FIG. 3 functions as an oscillation circuit. The real part of the impedance of the resonant tunneling diode 306 is determined by the value of the negative differential resistance in the low frequency region and is negative. The frequency at which the real part of the impedance changes from negative to positive determines the upper limit of the transmission frequency of this circuit. In a particularly devised resonant tunneling diode structure, this value is several hundred GHz, and an actual 712 GHz oscillation operation has been confirmed (for example, see Non-Patent Document 2).
E. Brown, J. Sederstrom, Sea Parker, El Mahone, Kay Mayer, T. Solner, “Oscillation Up to 712 GHz in InAs / AlSb Resonant Tunneling Diode”, Applied Physics Letters, Vol. 58 No. 2291 to 2293, issued May 20, 1991.

    As described above, an oscillation circuit using a resonant tunnel diode is excellent in super high frequency operation, but the oscillation voltage amplitude is limited by the negative differential resistance region width as shown in FIG. There is a problem that it is very difficult to obtain the voltage amplitude, and therefore it is difficult to increase the output. In order to achieve high output, a power combining method using a plurality of resonant tunneling diodes has been proposed, but there is a problem that the circuit becomes complicated and it is difficult to adjust element characteristics. An object of the present invention is to increase the oscillation voltage amplitude in a simple ultrahigh frequency oscillation circuit using a resonant tunneling diode, thereby realizing high output of the circuit.

    Combining a three-terminal element capable of ultra-high speed operation with a resonant tunneling diode, when the diode switches from peak to valley, the increase in potential difference generated between the two electrodes of the diode is fed back to the three-terminal element, and the diode Thus, it is possible to obtain an oscillation voltage amplitude larger than the negative differential resistance characteristic region width. Further, by adding an inductor to the circuit, this voltage change is expanded, and the circuit can maintain the oscillation state.

    Specifically, the first, second, and third bias terminals, an output terminal, an inductor, a field effect transistor, and a resonant tunneling diode are formed, and one terminal of the inductor is the first bias terminal, and the inductor The other terminal is connected to the drain of the field effect transistor, the gate of the field effect transistor is connected to the second bias terminal, and the source of the field effect transistor is connected to the resonant tunnel diode. A negative differential resistance characteristic region width of the diode is connected to one terminal and the output terminal, and the other one terminal of the resonant tunneling diode is connected to the third bias terminal. A larger oscillation voltage amplitude can be obtained.

    Furthermore, the first, second, and third bias terminals, an output terminal, an inductor, a field effect transistor, and a resonant tunnel diode, the drain of the field effect transistor is connected to the first bias terminal, One terminal of the inductor is connected to the second bias terminal, the other terminal of the inductor is connected to the gate of the field effect transistor, and the source of the field effect transistor is connected to one of the resonant tunnel diodes. An oscillation voltage amplitude larger than the negative differential resistance characteristic region width of the diode is obtained by a circuit connected to the terminal and the output terminal and the other terminal of the resonant tunneling diode is connected to the third bias terminal. It is possible to be done.

    Even if ultra-high frequency oscillation is possible in the conventional circuit, the practical oscillation voltage amplitude is limited to the negative differential resistance region width of the resonant tunneling diode. The performance is maintained as it is, and at the same time, a voltage amplitude much larger than the width of the negative differential resistance region can be obtained, so that it has an excellent feature that high power can be realized.

    FIG. 1 is a circuit diagram showing a first embodiment of the present invention. Reference numerals 101, 102, and 103 denote first, second, and third bias terminals, 104 denotes an output terminal, 105 denotes an inductor, 106 denotes a field effect transistor, 107 denotes a resonant tunnel diode, and 108 and 109 denote bias power supplies. FIG. 2 is an explanatory diagram of the oscillation operation in the circuit shown in FIG. Reference numeral 201 denotes a current-voltage characteristic of the resonant tunneling diode 107, and 202, 203, and 204 denote load lines caused by the field effect transistor 106. An oscillation amplitude exceeding the negative differential resistance region width of the resonant tunneling diode is obtained, which indicates that a much larger oscillation voltage amplitude can be obtained as compared with the conventional circuit shown in FIG.

    The oscillation operation of the circuit will be described with reference to FIG. First, an appropriate positive voltage is applied to the bias power source 108. Further, the voltage value of the bias power source 109 is sufficiently small, and the field effect transistor 106 is cut off. The circuit at this time is in a state indicated by a point O. Next, the voltage value of the bias power supply 109 is increased to a voltage value at which the load line by the field effect transistor 106 becomes 203. At this time, a point representing the state of the circuit is a point A. When the voltage value of the bias power supply 109 is further increased and the drain current becomes larger than the peak current value of the resonant tunneling diode, the load line changes to the state shown by 204 and the point indicating the circuit state moves toward the point B. At the same time, the resonant tunneling diode 107 goes over the negative differential resistance region and switches to a so-called valley state. As a result, a large potential difference occurs between both terminals of the diode 107, the potential difference between the gate and source of the field effect transistor 106 decreases, and the drain current decreases. Therefore, the load line changes from the state 204 to 202, and the point indicating the circuit state moves to the point C. However, in this state, the potential difference between both terminals of the diode 107 is small, the potential difference between the gate and source of the field effect transistor 106 is large, and the drain current increases. Accordingly, the load line changes again from the state 202 to 204. In this way, the bias power supplies 108 and 109 having a constant voltage value cause the point indicating the circuit state to reciprocate between the points B and C, thereby realizing the oscillation operation.

    The inductor 105 is necessary for realizing an oscillation state that reciprocates between points B and C. If this is not used, the circuit is in a monostable state and no oscillation operation is observed. Although it is possible to use an inductor that is parasitic on a circuit or an element without intentionally providing an inductor, an inductor 105 is shown in FIG. As described, the inductor in the present invention includes the use of this type of parasitic inductor.

    As apparent from FIG. 2, the oscillation amplitude of the output voltage greatly exceeds the width of the negative differential resistance region of the resonant tunneling diode, and a large oscillation voltage amplitude can be obtained as compared with the conventional circuit. You can see that it was realized.

    FIG. 5 is a circuit diagram showing a second embodiment of the present invention. Reference numerals 501, 502, and 503 are first, second, and third bias terminals, 504 is an output terminal, 505 is an inductor, 506 is a field effect transistor, 507 is a resonant tunnel diode, and 508 and 509 are bias power supplies. In this example, the position of the inductor 505 is different from that of the first embodiment shown in FIG. 1, but the basic operation of the circuit is the same as that shown in FIG. 2, and the field effect transistor 506 is switched by the switch of the resonant tunnel diode 507. The voltage between the gate and the source changes, and the change in the gate current generated at that time is emphasized by the inductor 505. This corresponds to the fact that the inductor 105 emphasizes the change in the drain current of the field effect transistor in the first embodiment, and a large voltage amplitude is obtained as in the first embodiment, contributing to higher output. There is a lot to do.

    FIG. 6 is a circuit diagram showing a third embodiment of the present invention. Reference numerals 601, 602, and 603 are first, second, and third bias terminals, 604 is an output terminal, 605 is an inductor, 606 is a field effect transistor, 607 is a resonant tunnel diode, and 608 and 609 are bias power supplies. In this example, although the position of the inductor 605 is different from that of the first embodiment shown in FIG. 1, the basic operation of the circuit is the same as that shown in FIG. 2, and the field effect transistor 606 is switched by the switch of the resonant tunneling diode 607. The voltage between the gate and the source changes, and the change in the drain current generated at that time is emphasized, and a large voltage amplitude is obtained as in the first embodiment, which greatly contributes to higher output.

    FIG. 7 is a circuit diagram showing a fourth embodiment of the present invention. Reference numerals 701, 702, and 703 are first, second, and third bias terminals, 704 is an output terminal, 705 is an inductor, 706 is a field effect transistor, 707 is a resonant tunnel diode, and 708 and 709 are bias power supplies. In this example, the position of the inductor 705 is different from that of the first embodiment shown in FIG. 1, but the basic operation of the circuit is the same as that shown in FIG. 2, and a field effect transistor 706 is switched by a switch of the resonant tunneling diode 707. The voltage between the gate and the source changes, and the change in the drain current generated at that time is emphasized. As in the first embodiment, a large voltage amplitude is obtained, which greatly contributes to high output.

    In the above embodiment, the field effect transistor is used as the three-terminal element used by the circuit of the present invention, but this includes a field effect transistor using a heterojunction. It is obvious that the same effect can be obtained by using other three-terminal elements such as a bipolar transistor and a heterojunction bipolar transistor.

    A circuit in which a resonant tunneling diode and a three-terminal element are integrated has already been manufactured using existing technology, and industrial applicability is obvious.

1 is a circuit diagram showing a first embodiment of the present invention. It is explanatory drawing of the oscillation operation | movement in 1st Example of this invention. It is a circuit diagram based on a prior art. It is explanatory drawing of the oscillation operation | movement in the circuit based on a prior art. It is the circuit diagram which showed the 2nd Example of this invention. It is the circuit diagram which showed the 3rd Example of this invention. It is the circuit diagram which showed the 4th Example of this invention.

Explanation of symbols

101, 102, 103, 501, 502, 503, 601, 602, 603, 701, 702, 703 Bias terminal 104, 504, 604, 704 Output terminal 105, 505, 605, 705 Inductor 106, 506, 606, 706 Electric field Effect type transistors 107, 507, 607, 707 Resonant tunnel diodes 108, 109, 508, 509, 608, 609, 708, 709 Bias power supply 201 Current-voltage characteristics of resonant tunnel diodes 202, 203, 204 Load lines by field effect transistors 301, 302 Bias terminal 303 in conventional circuit Output terminal 304 in conventional circuit Inductor 305 in conventional circuit Resistor 306 in conventional circuit Resonant tunnel diode 307 in conventional circuit 307 Resistive load line in the current-voltage characteristic 402 conventional circuit resonant tunneling diode in bias power supply 401 conventional circuit

Claims (2)

  The first, second, and third bias terminals, an output terminal, an inductor, a field effect transistor, and a resonant tunnel diode, and one terminal of the inductor is the first bias terminal and the other one of the inductor The terminal is connected to the drain of the field effect transistor, the gate of the field effect transistor is connected to the second bias terminal, the source of the field effect transistor is one terminal of the resonant tunnel diode, and the A resonant tunneling diode oscillation circuit, wherein the resonant tunneling diode oscillation circuit is connected to an output terminal, and the other terminal of the resonant tunneling diode is connected to a third bias terminal.   The first, second, and third bias terminals, an output terminal, an inductor, a field effect transistor, and a resonant tunnel diode, and the drain of the field effect transistor is connected to the first bias terminal, and one of the inductors Is connected to the second bias terminal, the other terminal of the inductor is connected to the gate of the field effect transistor, and the source of the field effect transistor is connected to one terminal of the resonant tunneling diode and the A resonant tunneling diode oscillation circuit, wherein the resonant tunneling diode oscillation circuit is connected to an output terminal, and the other terminal of the resonant tunneling diode is connected to a third bias terminal.

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