JPS59204289A - Double terminal negative resistance element - Google Patents

Abstract

PURPOSE:To enable to realize a microwave oscillator of a high efficiency with a simple structure at a low cost by a method wherein a fixed impedance to microwaves and direct current is connected between the source of an FET and a terminal electrode. CONSTITUTION:The gate G of the FET is connected to the first terminal electrode of a diode package, and the drain D to the second terminal electrode. The impedance Zs satisfying the fomula ¦Zs¦>¦Ri+1/omegaCgs¦ to microwaves and the formula Zs=Rs=¦Vgs/IS¦ in DC manner is connected between the source and the first terminal electrode. Then, a negative bias voltage is impressed on the first terminal electrode, and a positive one on the second terminal electrode. Where, Ri; represents channel resistance, omega; the angular frequency of microwave, Cgs; gate input capacitance, Rs; bias resitance, Vgs; gate-source volage, Is; source current.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a two-terminal negative resistance element, and particularly to a two-terminal negative resistance element used in a microwave oscillator.

[Technical background of the invention and its problems]

Conventionally, a Gunn oscillator using a Gunn diode is widely known as an example of a microwave oscillator using a two-terminal negative resistance element. Since this diode has a two-terminal structure, a microwave oscillator using n and f has the advantage of a simple structure and low cost.

However, the Gunn oscillator has a low efficiency of 2 to 3 parts.
Also, to obtain microwave oscillation of 10 GHz, a bias voltage of about 8 mm is required. For this reason, for example, 10GHz
In order to obtain an output of 20 mW, a DC input of 1W is required, and as a result, there is a problem in that the co-container must be constructed with consideration for heat radiation.

In addition, as an example of a microwave excavator using a three-terminal element such as a transistor, a field effect transistor (FE
There is a fully used FgT oscillator. This FET
The oscillator has a high efficiency of about 20%, and operates with a low bias voltage of about 5 V to obtain 10 GHz oscillation.

Therefore, to obtain an output of 20 mW at 10 GHz, for example, 0. A direct current input to the IW is sufficient, and the resonator used does not necessarily have to be designed with heat dissipation in mind.

However, since the FET has a three-terminal structure, it cannot be directly connected to the waveguide resonator, and a microwave oscillator using the FET has a problem that the circuit becomes complicated and expensive.

For this reason, the two-terminal negative type has characteristics of low voltage, voltage operation and high efficiency like a FET, and can use an inexpensive resonator with a simple structure like the Gunn diode, which is a two-terminal negative resistance element. At present, a resistive element is desired.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned problems and the current situation, and provides a two-terminal negative resistance element using FEi'' that can realize a highly efficient microwave excavator with a simple structure and at low cost. I am 17 years old with this in mind.

[Summary of the invention]

That is, the present invention has a source, a drain, and a gate f.
11. The gate of the ET is connected to a first terminal voltage of a diode package comprising a first and a second terminal 4k.
The drain is connected to the second terminal electrode, and between the n1 source and the first terminal chamber frame, IZsl>IRi+
] Cgsl, in direct current terms Zs-Rs= l Vga/
A two-terminal negative resistance element, characterized in that an impedance Zs satisfying Is l is connected, and a bias voltage is applied such that the first terminal electrode has a negative polarity and the second terminal electrode has a positive polarity. It is.

[Embodiments of the invention]

First, Fig. 1 shows a simplified equivalent circuit of a two-terminal negative resistance element that has a source (S), a drain (D), and a gate ((2), and an impedance Zs is connected between the source (S) and the gate ((3). shows.

That is, in FIG. 1, the drain (DJ) and gate ((2)
The impedance between Zdg 'i is calculated as 11 from the figure.
=jω CgS°■g ・
...(1) V2=(I2-gmVg)Zd+ZS(I,
+I2) -(31), the fifth equation becomes 11;, -I.

In other words, the microwave current flowing through the impedance Zs is almost zero, and the third equation is V2-(I2- gmVg) Zd = (]]+-
7 nails-1 Zd・I2-(61JωCgS).

Therefore, the impedance Zgd between the drain (DJ) and the gate (G1) is...
FBT is in the drain)
and the gate (G1) exhibits negative resistance.

For example, in a mortar-shaped microwave FET, Gcl:l:
2, 5 ms, Cgs'Z0, 6 pF, gm
:; Since it is 50 ms, Cds is 0.03 pF
If it is above, it is made as a negative resistance element by die+.

Normally, Cds is about 0.2 pF, which is a sufficient value for producing a negative resistance element. Ota 7th formula Cds, Cgs
Isometric Cds and Cgs may be used when including the stray capacitance existing outside the tdFET, and when it is placed in a package, they become large values when including the stray capacitance of the package.

That is, 1Zsl between source (S) and gate (01:
＞l 几” jr,＞Cg3 l impedance Z
By connecting s, the FET can operate as a two-terminal negative resistance element between the drain (D) and gate ((2)).

The 21st screen 1 is a basic circuit diagram of a two-terminal negative resistance element using a FET indicated by a symbol.

First, Fig. 2(a) shows the case where a bias resistor R,s is connected between the source (S) and the gate (2).This bias resistor aS is connected between the source (S) and the gate (2) of the FET. G) is set to a negative width to determine the DC bias current, and its value is, when the DC current Is flowing through the source (8) is, for example, 20 mA, the source (S)
Assuming that the voltage Vgs of the gate (G) is -1°5V, Rs = l Vgs / Is l = 75
is the value of Ω. At this time, the impedance Zs in the microwave is Zs=Rs=75Ω.几i in open type microwave FBT.

Cgs is Ri: 2, 6Ω, Cgs: ;0, 6p
F and 10 GHz, that is, the bias resistance Rs is larger than that of the old 10-A65-, and it can be seen that it operates as a 2-terminal negative resistance element.
Bias resistance Rs is 1 loss +j (I). It has been confirmed that practical Ki production can be achieved with gSl or higher.

The following figure 2 (b) is an example in which a series circuit of Fi bias resistor Rs and inductor Ls is connected between the source (8) and gate (G), and the impedance Zs is Zs =) Ls
+ jo) Ls, which is larger by ``ωLs than when only the bias resistor is used, and l Zs l ) I R
+ + , , c, , -l conditions can be satisfied. Also, the inductor Ls is approximately λ/4 (λ is the wavelength)
Even if If is replaced with the transmission line of , the same result can be obtained.

In the next diagram (C), a transmission line (Lt) which is approximately λ/4 at the operating frequency is connected to the source (S), and a bias resistor 1' (,
s and a capacitor Cs are connected in parallel.

In this case, the impedance Zs”f at the operating frequency
■It becomes.

Here, the bias resistor Rs determines the direct current Is applied to the source (S) of the FET and the bias voltage Vg, s between the gate < 01 and the source (81), so a diode is used instead of the bias resistor 1 (s). The anode of this diode is connected to the source (S) and cathode of the eFET to the gate (Gl).
It may be arranged to flow as four forward currents of diodes. For example, Vgs; -1.5V can be obtained by connecting two GaAs diodes in series.

Figures 2 (a), (b), and (C) described above show that in the oscillation state, a detection current due to the oscillation amplitude may flow through the gate (0), which may deteriorate long-term reliability. (Next 2 Figure 1 (d) (e) (f)
The specific example is valid. These examples use Zs as a source (S
) and the terminal (0'), and the gate (G) and the terminal (G'
), a capacitor Cg and a parallel impedance 212g1r of high resistance R and g are connected. Others are shown in Figure 2 (at (b) (
Since it is the same as cl, there is no special explanation.

With such a circuit configuration, the microwave current can be limited by flowing through the capacitor Cg n1, the detection current can be limited by the high resistance Rg, and two terminals can be connected between the drain (D) and the new gate terminal (G'). Operates as a negative resistance element.

FIG. 3 shows different embodiments applied to a specific F'ET in FIG. 2(a)'fc, and FIG. A resistor (4) is connected between the child (3),
It operates as a two-terminal negative resistance resistor between the gate terminal (3) and the drain terminal (5).

Figure 3(b) shows a circuit board in which an FET chip (7) and a resistor (8) are fixed by soldering on a metal or dielectric substrate (6).
, the resistor (8), the source (9) and the gate +101 are connected by metal wires (lla) (llb) using microwave integrated circuit (hereinafter referred to as MIC) technology,
It operates as a two-terminal negative resistance element between the blind gate 00) and the drain (12+).

Fig. 3 (C) shows the source (14I) and gate (one above) of the F E'l' chip (j3), which is connected to a resistor (161) using monolithic microwave integrated circuit (hereinafter referred to as MMIC) technology.
'(r-glued, but in this case also gate 0(
It operates as a two-terminal negative resistance element between the drain u7) and the drain u7).

Also, Figure 4 (al is Figure 2 (dl) from MMIC Technology VC
The circuit configuration has been realized.

That is, a parallel circuit of two capacitors and a high resistance C is formed between the gate (20) and the gate terminal (2I), and a resistor (25a) is formed between the source (24a) (24b) and the gate terminal C!υ. ) (25b) is formed and operates as a two-terminal negative resistance element between the drain (26) and the gate terminal (29).

The following figure 4 (b) is the same (Figure 2 (
The circuit configuration of f) is fully realized.

That is, transmission lines (28a x 28b) with an oscillation frequency of approximately λ/4 are connected to the sources (27a) and (27b).
: Connect the gate terminal (warm capacitor (30a) (
30b) and resistors (31a) (31b) are formed, and a parallel circuit is formed between the gate (3 terminals and the gate terminal (2'0) and the capacitor (33) and high resistance -). , operates as a two-layer negative resistance element between the drain C35+ and the gate terminal end.

Similarly, the other circuit examples shown in FIG. 2 are all f'1. Also M
It can be realized using IC and MMIC technology.

In addition, since these devices are two-terminal negative resistance elements, the same packaging technology as Gunn diodes can be applied, and when sealed in a package, they act as two-terminal negative resistance resistors similar to Gunn diodes. Become.

FIG. 5(a) is a cross-sectional view of a microwave diode package, such as a pill prong, which is generally used in Gunn diodes.

That is, the microwave diode package consists of a first electrode (40) and a cylindrical alumina ceramic (4'3), a first electrode (1 (negative) and a 2-terminal (9) resistor). Fix the FET (43f-half 1) configured in the element with a metal wire + 44) (44') to the first,
The gate and drain are all connected to the second electrode (4 (TL cap) side) for airtight control.

At this time, the drain is fully connected to the first space and the pole (40) side.
Then, v
Although it is convenient for C to work, the gate may be connected to the first electrode')#, ((f) side.

FIG. 5(b) is a cross-sectional view of a microwave molded flat package.

That is, the FETI 261 configured as a two-terminal negative abrasive element is fixed on the first electrode (4) with solder, etc., and the first and second electric currents wj,
(45) (c) and hermetically sealed with a dielectric (49).

When placed in a package, it has the structure of a two-terminal negative resistance element similar to a Gunn diode, and can be handled in the same way.

FIG. 6 is an example of a waveguide type microwave resonator using the two-terminal negative resistance element of the present invention. In this case, the two-terminal negative resistance element corresponds to a conventional Gunn diode.

That is, a two-terminal resistance element (53) in a package is connected between the waveguide (screw post 61 configured in 5 (1)) and the choke post (52), and the bias Microwaves are generated by applying a DC bias to the terminal (54).

Here, the two-terminal negative resistance element 53) is a FET shown in FIG. 5(a), which is connected so that a positive bias voltage is applied to the drain. Microwave Φ′ as well as Gunn oscillator
, you can gain power.

In this case, for example, to obtain an output of 20 mW with lOGl-Iz, in the case of a Gunn diode, the air pressure is approximately 8v1.
The current required is approximately 125 mA, whereas the current of the present invention is approximately 125 mA.
When a terminal negative resistance element is used, the power supply voltage may be approximately 5 mA and the current may be approximately 20 mA, similar to the conventional PET.

That is, by using a simple and inexpensive resonator such as a Gunn oscillator, it is possible to obtain a low voltage, low current, and high efficiency excavator similar to the conventional FET oscillator.

FIG. 7 shows an example of the characteristics of a waveguide microwave oscillator using the resonator shown in FIG. 6. -As you can see from the figure, when the oscillation frequency is 10 GHz and the bias voltage is 5 V, the characteristics of Ichihara 22 mA, output 22 mW, and efficiency 20% are obtained, which is about 10 times more efficient than N5 and Gan Kasaku 4. Microwave oscillator could be fully realized.

The excavator described above is an example of a microwave oscillator at 10 () Hz using a waveguide resonator, but the Gunn diode can be used not only for waveguide resonators but also for other resonators. This is similar to the case of an oscillator using

〔Effect of the invention〕

As described above, according to the present invention, a microwave oscillator with low voltage, low current, and high efficiency similar to a conventional FET oscillator can be realized using a resonator with a simple two-terminal structure such as a Gunn oscillator. Also, compared to Gunn oscillators, the DC input power is approximately 1
/10, so the heat dissipation structure can be simplified, so the fifth
A molded package as shown in Figure (b) can also be used, making it possible to manufacture inexpensive microwave oscillators, so its industrial value is extremely large.

[Brief explanation of drawings]

Figure 1 is a simplified equivalent circuit diagram when FET is a two-terminal negative resistance element, Figure 2 (al (b) (C) (d)
(e) (f) shows different basic circuit diagrams of two-terminal negative resistance elements using FETs indicated by the symbols in Figure 3 (a).
) (b) (c) is a concrete example of Figure 2 (a).
Plan views showing different embodiments to which TK is applied,
Figure 41 (a) and (b) are respectively shown in Figure 2 (d) (
Figure 5(a) (b)
) is a cross section showing the state in which the two-terminal negative resistance element of the present invention is housed in a package named 94, No. 61.
ltdCross-section showing an example of a high-frequency tube microwave oscillator using the two-terminal negative resistance element of the present invention (Figs. 1, 4!, 7)
Reference numeral 1 indicates a cell 7 showing an example of the characteristics of the microwave oscillator shown in FIG. 1, 7. 13...FW'l' 4,8.6・
...Resistance 9, 14.24.27...Source 10.
15.20.32...Gate 12, 17.26.35
... Drain 50 ... Waveguide resonator 53 -
・2-terminal negative resistance element 54...Bias terminal agent Patent attorney Inoue -M Figure 5 (tL) (b) Figure 6 Figure 7 Figure DI 13 4L,! 5 Nbia Marriage Tano i Vo (TJ

Claims (2)

[Claims] (1) The gate of a field effect transistor having a source, a drain, and a gate is connected to the first terminal electrode of a diode package having first and second terminal electrodes, and the drain is connected to the second terminal' For microwaves, l Zs I > l Ri +
1/ωCgsl + In terms of direct current, Zs=几s= l V
Impedance Zs that satisfies gs/Is I-
2. A two-terminal negative resistance element, characterized in that when the first terminal electrode is connected, a bias voltage is applied such that the first terminal electrode has a negative polarity and the second terminal electrode has a positive polarity. However, R, i: channel resistance, ω: microwave angular frequency, Cgs: gate input capacitance, S: bias resistance, Vgs: gate-source voltage, ■s: source current. (2) The two-terminal negative resistance element according to claim 1, characterized in that an impedance zg consisting of a parallel circuit of a capacitor and a resistor is connected between the gate, the first terminal chamber, and the electrode.