JPH0330504A - Field effect transistor - Google Patents

Abstract

PURPOSE:To effectively decrease the output capacity or input capacity of a transistor and to improve high frequency performance by providing an inductance, which is formed by fine metallized patterns, and a capacitor, which is equipped with a certain fixed area and formed by metallized patterns connected to the fine metallize patterns, between a source electrode and a drain electrode. CONSTITUTION:Between a drain electrode 1 and a source electrode 2, an inductance 4 formed by the fine metallized patterns and a capacitor 5 formed by the metallized patterns having a certain fixed area and connecting to the above mentioned fine metallized patterns are equipped. When the capacity between the drain and source (output capacity) is defined as Cds, the value of the inductance 4 is defined as L and the capacity of the capacitor 5 is defined as Co, parallel resonance is made occur at the time of an operational frequency omegaby incorporating the inductance 4 so that the condition of (LCds)<-1/2> can be almost established for the angular frequency omega. Then, the capacity Cds between the drain and source (output capacity) is widely reduced practically and the high frequency performance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is utilized in the structure of a field effect transistor chip, and particularly relates to a high frequency, high power field effect transistor used with a common source.

〔overview〕

The present invention provides a field effect transistor in which an inductance made of a thin metallized pattern is provided between a source electrode and a drain electrode or a gate electrode, and a capacitor made of a metallized pattern having a certain area connected to this inductance. , which effectively reduces the output capacitance and/or input capacitance of the transistor and improves high frequency performance.

[Conventional technology]

Conventionally, this type of field effect transistor chip has a structure in which a drain electrode, a gate electrode, and a source electrode are each provided in a planarly separated arrangement.

[Problem that the invention seeks to solve]

In the conventional field effect transistor chip described above, the gate-source distance is 1c9. and drain-source distance of 1 cds are connected to the input and output sides, respectively, so when operating at high frequencies, the input and output side impedances become small, and the phase difference increases with frequency fluctuations. However, there is a drawback that the matching with the external matching circuit becomes insufficient, causing a decline in high frequency performance.

An object of the present invention is to provide a field effect transistor having a chip structure that improves high frequency performance by eliminating the above-mentioned drawbacks.

[Means for solving problems]

The present invention relates to a field effect transistor having a source electrode, a drain electrode, and a gate electrode, and includes an inductance formed by a thin metallized pattern and a metallized pattern having a certain area and connected to the thin metallized pattern. A capacitor is provided between the source electrode and the drain electrode.

The present invention also provides a field effect transistor including a source electrode, a drain electrode, and a gate electrode, including an inductance formed by a thin metallized pattern,
A capacitor having a certain area and formed by a metallized pattern connected to the thin metallized pattern is provided between the source electrode and the gate electrode.

[Effect]

The drain electrode and the source electrode are connected to each other by an inductance and a DC blocking capacitor, and the drain
When the source capacitance Cd% and the inductance resonate in parallel at that frequency during high frequency operation, the drain-source capacitance Cd, (output capacitance) is effectively reduced. Similarly, the gate electrode and the source electrode are connected to each other by an inductance and a DC blocking capacitor, and the gate-source capacitance Cgs and the inductance resonate in parallel at that frequency during high frequency operation, so that the effective Gate-source capacitance C9- (input capacitance) is reduced.

Therefore, it is possible to improve high frequency performance.

〔Example〕

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

FIG. 1(a) is a plan view showing essential parts of a first embodiment of the present invention, and FIG. 1(a) and FIG. 1(b) are equivalent circuit diagrams thereof.

The present embodiment describes a field effect transistor having a drain electrode 1, a source electrode 2, and a gate electrode 3, and an inductance 4 formed by a thin metallized pattern, which is a feature of the present invention, and an inductance having a certain area. A capacitor 5 is provided between the drain electrode l and the source electrode 2. The capacitor 5 is formed by a metallized pattern connected to the thin metallized pattern.

Next, the operation of the present embodiment will be explained.

As shown in Figure 1, the drain-source capacitance (output capacitance) is Cds, the inductance is 4, the capacitance l of the capacitor 5 is 00, and the angular frequency is ω.
If C8 is selected such that ωL>> ωC0, and if the inductance 4 is created so that
The inter-source capacitance (output capacitance) C4 is significantly reduced and high frequency performance is improved.

FIG. 2(a) is a plan view showing essential parts of a second embodiment of the present invention, and FIG. 2(a) is an equivalent circuit diagram thereof.

The second embodiment has an inductance 4a and a capacitor 5a.
is provided between the source electrode 2 and the gate electrode 3. As in the case of the first embodiment, the gate-source capacitance C9% (manpower capacitance) and the inductance 4a resonate in parallel at the operating frequency, thereby effectively reducing the manpower capacitance of the field effect transistor, and It is possible to improve the characteristics.

〔Effect of the invention〕

As explained above, the present invention effectively increases the field effect transistor output capacitance or human power capacitance by adding an inductance and a DC blocking capacitor between the source electrode and the drain electrode or source electrode in the field effect transistor chip. This has the effect of reducing the energy consumption and improving high frequency performance.

1...Drain electrode, 2...Source electrode, 3...
Gate electrode, 4.4a...Inductance, 5.5a
...Capacitor.

Claims (1)

[Claims] 1. In a field effect transistor comprising a source electrode, a drain electrode, and a gate electrode, an inductance formed by a thin metallized pattern, and a metallized pattern having a certain area and connected to the thin metallized pattern. A field effect transistor characterized in that a capacitor formed by the above is provided between the source electrode and the drain electrode. 2. In a field effect transistor equipped with a source electrode, a drain electrode, and a gate electrode, an inductance formed by a thin metallized pattern, and a capacitor formed by a metallized pattern having a certain area and connected to the thin metallized pattern. is provided between the source electrode and the gate electrode. A field effect transistor.