JPH066601Y2 - Microwave amplifier - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a microwave amplifier for amplifying a microwave signal by interposing a field effect transistor (FET) in a microwave pattern covered by a microwave shield wall. .

[Prior Art] FIG. 2 shows a conventional microwave amplifier. In FIG. 2, reference numeral 11 denotes a dielectric substrate.
A conductor-shaped conductor ground pattern 12 having a ladder shape is formed on the component surface 11a. A microwave input pattern 13 and a microwave output pattern 14 are formed at the center of the component surface 11a of the dielectric substrate 11 which is divided by the ground pattern 12. The ground pattern 12 is connected to the copper foil ground surface 11b of the dielectric substrate 11 via through holes 15 at various places.

A field effect transistor (FET) 16 having a gate terminal G and a drain terminal D connected thereto is interposed between the input pattern 13 and the output pattern, and a source terminal S of the field effect transistor 16 has a ground pattern 12 therebetween.
Connected to. Then, the microwave input pattern 1
3, output pattern 14, and field effect transistor 16
Is covered with a microwave shield wall 17 made of metal which is in contact with the ground patterns 12 on both sides thereof and is grounded.

[Problems to be Solved by the Invention] However, in the microwave amplifier having the above configuration,
When the input return loss is measured as the amplification characteristic, as shown by the solid line B in FIG. 3, an attenuation range due to abnormal oscillation (a range in which the input return loss is negative) is observed near a frequency of 12 GHz. Here, it is considered that the abnormal oscillation is caused by the overlapping of various resonance conditions in the space inside the microwave shield wall 17. In this microwave amplifier, the existence of an attenuation region due to abnormal oscillation is extremely harmful, and a countermeasure against it is desired.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a microwave amplifier capable of performing stable amplification operation without causing an attenuation region due to abnormal oscillation.

[Means and Actions for Solving the Problem] That is, in the microwave amplifier according to the present invention, the ground pattern to which the source terminal of the field effect transistor is connected and the wall surface of the microwave shield wall are connected by a conductor wire, It is configured so that the resonance condition that causes abnormal oscillation is broken.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of the microwave amplifier. In FIG. 1, 11 is a dielectric substrate, and a ladder-shaped conductor ground pattern 1 is provided on a component surface 11a of the dielectric substrate 11.
2 is formed. A microwave input pattern 13 and a microwave output pattern 14 are formed at the center of the component surface 11a of the dielectric substrate 11 which is divided by the ground pattern 12. The ground pattern 12 is connected to the copper foil ground surface 11b of the dielectric substrate 11 via through holes 15 at various places.

A field effect transistor (FET) 16 having a gate terminal G and a drain terminal D connected thereto is interposed between the input pattern 13 and the output pattern, and a source terminal S of the field effect transistor 16 has a ground pattern 12 therebetween.
Connected to. Then, the microwave input pattern 1
3, output pattern 14, and field effect transistor 16
Is covered with a microwave shield wall 17 made of metal which is in contact with the ground patterns 12 on both sides thereof and is grounded.

The above is the same structure as the microwave amplifier in FIG. 2, wherein the microwave amplifier according to the present invention has the ground pattern 12 to which the source terminal S of the field effect transistor 16 is connected and the microwave shield wall. The wall surface of 17 is connected by a conductor wire 21 such as a jumper wire. The conductor wire 21 is the microwave shield wall 1
The microwave shield space covered by 7 is connected to each other by soldering 22a and 22b so that the microwave shield space is partially crossed.

That is, when the input return loss is measured as the amplification characteristic in the microwave amplifier having the above-mentioned configuration, as shown by a broken line A in FIG. It can be seen that the negative range) is eliminated, and stable amplification operation can be obtained at any frequency.

That is, in the space covered by the microwave shield wall 17, in a state of partially crossing the shield space,
By connecting the ground pattern 12 to which the source terminal S of the field effect transistor 16 is connected and the wall surface of the microwave shield wall 17 by the conductor line 21, the resonance condition causing abnormal oscillation is destroyed and stable amplification is achieved. The motion will be obtained.

In this case, the arrangement position of the conductor wire 21 that connects the ground pattern 12 and the microwave shield wall 17 is found by repeated experiments.

[Advantage of the Invention] As described above, according to the present invention, the resonance that causes an abnormal oscillation by connecting the ground pattern to which the source terminal of the field effect transistor is connected and the wall surface of the microwave shield wall with a conductor wire Since the conditions are collapsed, it is possible to provide a microwave amplifier capable of stable amplification operation without causing an attenuation region due to abnormal oscillation.

[Brief description of drawings]

FIG. 1 is a block diagram showing a microwave amplifier according to an embodiment of the present invention, FIG. 2 is a block diagram showing a conventional microwave amplifier, and FIG. 3 is a conventional microwave amplifier and a microwave of the embodiment of the present invention. It is a figure which compares and shows the microwave amplification characteristic with a wave amplifier. 11 ... Dielectric substrate, 11a ... Component surface, 11b ... Ground surface, 12 ... Ground pattern, 13 ... Input pattern, 14 ...
Output pattern, 15 ... Through hole, 16 ... Field effect transistor, 17 ... Microwave shield wall, 21 ... Conductor wire, 22a, 22b ... Soldering.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Nobuyasu Era 1406 Hasunuma, Omiya-shi, Saitama Yagi Antenna Co., Ltd. Omiya factory (56) References JP-A-62-183607 (JP, A)

Claims (1)

[Scope of utility model registration request] 1. A microwave pattern formed on one surface of a dielectric substrate, a ground pattern formed in the center of the microwave pattern on the same substrate surface, and a gate terminal on the input side of the microwave pattern. A field effect transistor having a drain terminal on the output side and a source terminal connected to the ground pattern, and a microwave shield wall that contacts the ground pattern and covers the microwave pattern and the field effect transistor. In the microwave amplifier, a conductor pattern is connected between the ground pattern to which the source terminal of the field effect transistor is connected and the wall surface of the microwave shield wall.