JPS60106205A - Monolithic fet oscillator - Google Patents

Abstract

PURPOSE:To facilitate mass production, to omit a filter and to attain size reduction by forming a passive circuit and a field-effect transistor FET on the same substrate, and using a slot line. CONSTITUTION:The FET22 is formed on the semiconductor substrate 21 and conductors 26-28 connected to the gate electrode 23, drain electrode 24, and source electrode 25 of the FET22 are formed on the substrate 21. Further, the conductors 26 and 27 form a slot line 29 and the conductors 27 and 28 form a slot line 31 respectively. The line 29 is terminated in an open state at a position of finite length from the FET22 and terminated by a capacitor 32, and the line 31 is an output line. Therefore, the size and position are determined easily with high precision, the mass production is facilitated, and the size is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a monolithic FET oscillator which is formed into a monolithically integrated circuit using FET (field effect transistor) as an active element and is suitable for oscillation of microwaves, millimeter waves, and the like.

<Prior Art> FIGS. 1 and 2 show an example of a conventional FET oscillator formed into a hybrid integrated circuit. Dielectric substrates 2 and 3 are provided on the ground conductor 1, microstrip lines 4 and 5 are provided on the dielectric substrate 2.3, a microstrip high frequency blocking filter 6 and 7 having one end connected thereto, and the filter. Passive circuits such as DC application terminals 8 and 9 connected to the other end are formed. A FET tip 11 is mounted on the ground conductor 1 between the dielectric substrates 2 and 3, and is connected to the metal wires 12 and 13! l) The electrodes of the FET chip 11 and the microstrip lines 4 and 5 are connected.

In this conventional oscillator, the mounting position of the FET chip 11, the length of the metal wires 12 and 13, and the length of the metal wires 12 and 1
There are many parts where it is difficult to ensure the connection positions and manufacturing accuracy of No. 3, and therefore adjustments after circuit assembly are necessary. Furthermore, a high frequency blocking filter 6.7 is required to supply a DC bias, resulting in an increase in the size of the circuit.

<Summary of the Invention> An object of the present invention is to provide a monolift FET oscillator that can easily obtain relatively high dimensional two-position performance, is easy to manufacture, is easy to mass-produce, and can be made small. .

According to this invention, an FET is formed on a semiconductor substrate, and an FET is formed on the semiconductor substrate on which the FET is formed by a slot line.
Form an oscillation circuit including ET.

<Embodiment> FIGS. 3 and 4 show an embodiment of the present invention, in which an FET 22 is formed on a semiconductor substrate 21. In FIG. Gate electrode 23 of FET 22. Drain electrode 24 and north electrode, pole 2
Conductors 26, 27 and 28 connected to the semiconductor substrate 21 are formed on the semiconductor substrate 21, respectively. conductors 26 and 2
7 constitutes a slot line 29, and the conductors 27 and 2
8 constitutes a slot line 31. The end of the slot line 29 opposite to the FET 22 is terminated with a capacitor 32. That is, at this end of the slot line 31, the conductors 26 and 27 on both sides constituting the slot line are insulated fTg.
The capacitor 32 is ft'
4 It will be accomplished. Similarly, one conductor 27 constituting the slot line 31 by the capacitor 34 has its drain electrode 2.
The 4 side 27a and the output boat 35 side 27b are separated in terms of direct current. FETs on conductors 26, 27 and 28, respectively
DC bias application terminals 36, 37 and 3 for 22
8 is connected.

Here, if the capacitor 32 is placed at a position where the impedance seen from the FET 22 to the slot line 29 becomes inductive, the oscillation condition is satisfied, and an oscillation output can be obtained from the slot line 31 to the output port 35. The principle of this oscillation is the same as that of the conventional oscillator shown in FIGS. 1 and 2. Note that instead of terminating with the capacitor 32, the slot line 29 may have an open termination with an appropriate length. Since the high frequency electric field is concentrated in the vicinity of the slot lines 29 and 31, a high frequency blocking filter is not required by connecting the DC bias application terminals 36 to 38 to each conductor apart from the slot lines 28 and 31.

FIG. 5 and FIG. 6 show a second embodiment of the present invention.
This is an oscillator that extracts harmonics. Two oscillation circuits 41, 4 having a structure similar to that shown in FIGS. 3 and 4
2 are arranged symmetrically on the same semiconductor substrate 21. Parts of the oscillation circuit 41 that correspond to those in FIGS. 3 and 4 are given the same reference numerals, and corresponding parts of the oscillation circuit 42 are given the same numbers and a dash "'". Slot lines 29, 29'
are parallel to each other, and the slot lines 31 and 31' are also made to be parallel to each other in the same way. [1, pole 24, 24
The conductors 27 and 27' connected to ' are a common conductor. Slot line 31, 31') FET 2
2 and 22' are connected to one end of a coplanar line 43. The coplanar line 43 is also formed on the semiconductor substrate 21, and the slot lines 31, 31' skin conductors 27 are extended to the inner conductor 43a of the coplanar line 43, and the outer conductors on both sides of the coplanar line 43 are the conductors 28, 2
8' is extended. Slot lines 31, 31
At the connection between the outer conductor 28 and the coplanar line 43, the outer conductors 28 and 28' on both sides of the coplanar line 43 are connected to the short-circuit conductor 4.
Connected at 4.

Here, if the lengths of the slot lines 31 and 31' are appropriately selected, the outputs of the two oscillation circuits 41 and 42 will be synchronized in opposite phases to each other, as shown by the arrows indicating the direction of the electric field in FIG. Among them, the fundamental frequency component is short-circuited by the short-circuit conductor 44 and does not appear on the coplanar line 43 of the output line. on the other hand,
Since the second harmonic components are in phase with each other, they can be extracted from the coplanar line 43 to the output port 35.

In these embodiments, by using slot lines! 2. There are no wires to connect the FET and passive circuit, and there is no need for a high-frequency heavy-duty filter.
It has good reproducibility and can be made extremely small.

<Effects> As explained above, in the oscillator of the present invention, the passive circuit and the FET are formed on the same semiconductor substrate, and the slot line is used, so it is easy to mass produce, and the filter can be omitted, reducing the circuit size. It has the advantage of being compact.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a conventional FET oscillator, FIG. 2 is a front view of FIG. 1, FIG. 3 is a plan view showing a first embodiment of the present invention, and FIG. 5 is a plan view showing a second embodiment of the present invention, and FIG. 6 is a sectional view taken along the line BB' in FIG. 21. Semiconductor substrate, 22-FET, 23.. Gate electrode, 24.. Train electrode, 25.. Source electrode, 26
, 27, 28...Conductor, 29, 31...Slot line, 32, 34...Capacitor, 35...Output port, 36, 37, 38--Bias application terminal,
41, 42-oscillation circuit, 43 coplanar line, 44
...Short conductor. Patent Applicant Nippon Telegraph and Telephone Public Corporation Agent Takufu Kusano 1 (branch) O 2 Omi 11 1 O 3 En 7 Kan 4 Yoshisa 5 Figure 10 〇 Figure

Claims (2)

[Claims] (1) KFETC field effect transistor on semiconductor substrate)
is formed, and the gate electrode of the FET is connected to the drain electrode and the source electrode, respectively. and a third conductor are formed on the semiconductor substrate, and these first conductors are formed on the semiconductor substrate.
A first slot line is formed by the conductor and the second conductor, and a second slot line is formed by the second conductor and the third conductor.
Kl path is configured, and the first slot line is connected to the F
A monolithic Ji'ET oscillator which is terminated with an open termination or a capacitor at a position of a finite length from the ET, and the second slot line is used as an output line. (2) Two thin films of the oscillator according to claim 1 are formed on a semiconductor substrate, the conductor connected to the drain electrode is common, and the direction of the two output lines consisting of slot lines is the same. The two output lines are connected to one coplanar line, which is used as a common output line, and the two outer conductors of the coplanar line are connected by a shorting conductor. A monolithic FET oscillator according to claim 1, characterized in that: