JP2801805B2 - Microwave pulse high power transistor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pulse-operated microwave pulse high-output transistor used in a high-output amplifier such as a radar device.

[0002]

2. Description of the Related Art Generally, a silicon bipolar transistor of class C operation is used as this kind of microwave pulse high output transistor. This microwave pulse high-output transistor is self-biased in synchronization with the input signal when the pulse is input, and is automatically biased when the pulse is on and is automatically biased off when the pulse is off, so that power consumption is reduced. And is suitable for a pulse operation amplifier.

On the other hand, if the fall of the input pulse becomes faster, the time until the charge stored in the base-emitter junction is swept becomes longer than the fall time of the input pulse. There is a problem that a self-bias is applied and a transistor operation state (free-run) occurs. In particular, in the case of a high-output transistor, its base-emitter junction area is large, and the amount of accumulated charge increases, so that the time until the charge is swept (several hundred ns or less) increases, and the free-run time increases. , Noise rise in the band (spurious)
Occurs. The power of this noise increases as the free-run time increases.

FIG. 4 shows such a conventional microwave pulse high-output transistor 20, which employs a so-called grounded base configuration. That is, the base electrode 1a of the transistor chip 1 is connected to the envelope 3 by the bonding wire 2.
Is connected to the ground, and its emitter electrode 1b is connected to an input lead 7 through an internal matching circuit composed of capacitive elements 4 and 5 and bonding wires 2 and an input lead pattern 6.
More connected to the outside. The lower surface of the transistor chip 1 serves as a collector electrode,
The bonding wire 2 is taken out of the output lead 11 via the output lead pattern 10 to the outside.

[0005] The microwave pulse high output transistor 20 configured as described above is connected to an external matching circuit as shown in FIG. That is, the output lead 11 of the microwave pulse high power transistor 20 is connected to the output matching circuit 30.
The output matching circuit 30 is connected to a power supply 32 via a coil 31 and is biased by the power supply 32. The input lead 7 is connected to the input matching circuit 33. The input matching circuit 33 is connected to a through hole 35 connected to a ground circuit via a coil 34. At this time, the coil 34 is arranged as close as possible to the input lead 7 connected to the input matching circuit 33, and its length dimension does not affect the characteristics of the amplification frequency body, and furthermore, it is DC-directed. By setting the inductance to be as short as possible so that the inductance is as small as possible, it is possible to suppress the noise rise (spurious) of the input microwave signal.

However, in the above-mentioned microwave pulse high-output transistor, when connected to an external matching circuit, the spurious is optimized by grounding as close as possible to the base-emitter junction. 2, input lead pattern 6, input lead 7
However, there is a problem that a spur is generated because a delay due to each inductance remains. For example, the pulse width is 1.0 ms, the duty ratio is 25%, and the RBW is 1 MHz.
, The output spectrum is about 300 to 400 MHz at the carrier frequency (S band) as shown in FIG.
z A spurious of about 40 dBc is generated at a high position.

According to this, when the area of the base-emitter junction is increased in order to achieve a higher output, the accumulated charge increases, resulting in a further spurious increase. Further, there is a problem that it is difficult to improve a spurious value due to the delay of the inductance of the transistor itself.

[0008]

As described above, the conventional microwave pulse high output transistor has a problem that it is difficult to reduce spurious.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a microwave pulse high-output transistor which can easily and effectively reduce spurious generation. .

[0010]

According to the present invention, there is provided an envelope having an input / output terminal, a dielectric substrate having one side mounted on a ground portion in the envelope and the other side coated with a conductive film, A transistor chip mounted on the dielectric substrate via the conductive film, an internal matching circuit including a capacitive element, mounted on a ground portion in the envelope on the input side of the transistor chip, and An output electrode pad of the transistor chip is connected to an output terminal of the envelope via a conductor film of the dielectric substrate, and an input electrode pad of the transistor chip and an electrode pad of a capacitive element of the internal matching circuit are connected. And a first bonding wire for connecting the electrode pad of the capacitive element of the internal matching circuit to the input terminal of the envelope. The transistor chip input electrode pads of, be one that connects the ground portion electrode either within the envelope of the electrode pad of the electrode pads and the bonding wire relay terminal of the capacitive element of the internal matching circuit,
Large impedance content than the input impedance of the transistor chip amplifier frequency band, and a second bonding wire which defines the inductance so that a very low resistance at low frequency band and DC,
Charge stored in the input capacitance of the transistor chip
In the envelope via the second bonding wire.
Is configured to discharge to the ground electrode .

[0011]

According to the above structure, the electric charge accumulated at the base-emitter junction of the transistor chip is transferred to the second bond.
By discharging from the ground electrode through the gwire, the time for sweeping the charge of the input-side capacitance is shortened.
The self-bias time when the input pulse is off is shortened. As a result, spurious components are suppressed, the occurrence of spurious components is reduced, and a high output can be achieved.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows a microwave pulse high output transistor according to an embodiment of the present invention. The same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof will be omitted. That is, a feature of the present invention is that an electrode pad constituting an internal matching circuit, for example, an electrode pad of a capacitive element 4 is DC-grounded to an envelope 3 forming a ground circuit via a bonding wire 40 for grounding. Have connected. The bonding wire 40 has an impedance equivalent to the transistor chip 1 in the amplification frequency band.
For example, its length is set to be sufficiently long so that it does not affect the amplification frequency band, and the resistance is extremely low in the low frequency band and DC so that the spurious does not become large. The inductance is set so that As a result, when the input pulse is turned off, the electric charge accumulated at one base-emitter junction of the transistor chip is discharged to the envelope through the bonding wire 40. As a result, the influence of inductance on the bonding wire 2, the input lead 7, and the input lead pattern 6 due to the electric charge is eliminated. In addition, since the impedance of the bonding wire 40 is set to be larger than the input impedance of the transistor chip 1 in the amplification frequency band, there is no adverse effect on the internal matching circuit.

As described above, the microwave pulse high output transistor is provided with the bonding wire 40 for discharging the electric charge accumulated at the base-emitter junction of the transistor chip 1 from the ground electrode.
Since the charge accumulated at the base-emitter junction of the transistor chip 1 is discharged from the ground electrode through the zero, the time for sweeping the charge of the input-side capacitance is effectively shortened. The self-bias time at the time of turning off is shortened. As a result, the output spectrum has a pulse width of 1.0 m as in the case of FIG.
When the s, duty ratio is 25%, and RBW is 1 MHz, the measurement is performed as shown in FIG. To be reduced. As a result, high-precision characteristics with reduced spurious can be easily realized, and high output as a transistor can be easily achieved.

[0015] Further, according to this, the spurious optimization is realized at the same time as the production, so that the assembling workability is improved as compared with the case where the spurious is connected to the external matching circuit as in the prior art. Has the effect that it can be achieved.

The present invention is not limited to the above embodiment, but may be configured as shown in FIG. That is, provided with an electrode pad of the capacitor 41 to resonate in the amplification frequency band and the ground bonding wire 40, configured to connect the electrode pads of the electrode pad and the capacitor 4 of the capacitor element 41 by a bonding wire 42 . According to this, the effect of the bonding wire 40 can be further reduced by the action of the electrode pad of the capacitive element 41 and the bonding wire 42 , and an effective effect is expected.

In the above embodiment, the case where the electrode pad of the capacitive element 4 is connected to the envelope 3 by using the ground bonding wire 40 has been described. However, the present invention is not limited to this. An input electrode pad of the chip 1, an electrode pad of a capacitive element 5 of another internal matching circuit,
Similarly, by connecting any of the electrode pads of the bonding wire relay terminal such as the input lead pattern 6 and the bonding wire wiring electrode pattern (not shown in the above embodiments) to a ground circuit such as the envelope 3. The effect is expected.

Further, in the above embodiment, the case where the bonding wire 40 is used as an inductance element has been described. However, the present invention is not limited to this. For example, a gold foil or the like may be used.

Further, in the above-described embodiment, the description has been given of the case where the grounded base structure is used. However, the present invention is not limited to this, and the grounded emitter structure may be used. In this case, the input electrode of the transistor chip 1 becomes a base electrode pad. Therefore, it is needless to say that the present invention is not limited to the above-described embodiment, and that various modifications can be made without departing from the scope of the present invention.

[0020]

As described above in detail, according to the present invention, it is possible to provide a microwave pulse high-output transistor capable of easily and effectively reducing spurious generation.

[Brief description of the drawings]

FIG. 1 is a diagram showing a microwave pulse high output transistor according to one embodiment of the present invention.

FIG. 2 is a diagram showing an output spectrum of FIG. 1;

FIG. 3 is a diagram showing another embodiment of the present invention.

FIG. 4 is a diagram showing a conventional microwave pulse high output transistor.

FIG. 5 is a diagram showing a connection configuration with an external matching circuit of FIG. 4;

FIG. 6 is a diagram showing an output spectrum of FIG. 4;

[Description of Signs] 1 ... transistor chip, 1a ... base electrode, 1b ... emitter electrode, 2 ... bonding wire, 3 ... envelope,
4, 5: Capacitance element, 6: Input lead pattern, 7: Input lead, 8: Dielectric substrate, 9: Conductive film, 10: Output lead pattern, 11: Output lead, 20: Microwave pulse output transistor, 30 ... Output matching circuit, 31 coil, 32 power supply, 33 input matching circuit, 34 coil,
35 ... through hole, 40 ... bonding wire, 41
... capacitance element, 42 ... bonding wire.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-57-91542 (JP, A) JP-A-55-82515 (JP, A) IEEE TRANS. , VOL. M TT-19, NO. 7, 1971, p. 589-p. 590 (58) Fields investigated (Int. Cl. ⁶ , DB name) H03K 17/04 H03K 17/16 H03F 3/60

Claims (1)

(57) [Claims] 1. An envelope having input / output terminals, a dielectric substrate mounted on one side on a ground portion in the envelope, and a dielectric film coated on the other side with a conductive film, and the conductor provided on the dielectric substrate. A transistor chip mounted via a film, an internal matching circuit mounted on a ground portion in the envelope on the input side of the transistor chip and including a capacitive element, and an output electrode pad of the transistor chip. Connecting the input electrode pad of the transistor chip to the electrode pad of the capacitive element of the internal matching circuit while connecting to the output terminal of the envelope via the conductive film of the dielectric substrate; A high-power microwave pulse transistor comprising: a first bonding wire for connecting an electrode pad of the capacitive element to an input terminal of the envelope; Input electrode pads, it is one that connects the ground portion electrode either within the envelope of the electrode pad of the electrode pads and the bonding wire relay terminal of the capacitive element of the internal matching circuit, the impedance component amplification band in the transistor larger than the input impedance of the chip, and a second bonding wire which defines the inductance so that a very low resistance at low frequency band and DC, the transistor chip
The electric charge stored in the input side capacitance of the
Discharge to the ground electrode in the envelope via the grounding wire.
Microwave pulse height output transistor, characterized in that the so that.