JP3143991B2 - Semiconductor device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device, and more particularly to a semiconductor device capable of amplifying two microwave signals with one device.

[0002]

2. Description of the Related Art A conventional satellite signal receiving apparatus for receiving two input signals has an expensive polarization conversion device capable of converting a plurality of polarization systems by one device before an amplifier, as shown in FIG. As described above, for example, in order to amplify two input signals from the polarization converter 8 for converting horizontal polarization and vertical polarization into low noise, two input matching circuits 9, two compound semiconductor devices 11, And a combination circuit 16 for combining output signals from the two compound semiconductor devices 11. 12 is an output matching circuit, 14 is a switch, and 15 is a comparator.

FIG. 6 is a view schematically showing a mounting peripheral portion of a conventional device.

[0004]

A device designed to cope with the plurality of polarization systems described above has a smaller loss due to mismatching and the like than the polarization converter 8 that converts one polarization. large. For this reason, the conventional receiving device provided with this conversion device has a disadvantage that the noise characteristics are poor because there is a loss before the signal from the satellite is amplified with low noise.

[0005] In addition, since a separate power supply for driving the converter is required, there is a disadvantage that the converter becomes very expensive.

The conventional device as shown in FIG. 5 has two sets of gate bias circuit 10 and drain bias circuit 13 for operating two compound semiconductor devices 11, input matching circuit 9 and output matching circuit 12. Since it has the synthesizing circuit 16 for synthesizing two outputs, there is a disadvantage that the device becomes large and miniaturization is difficult. Further, since the number of components is large, there is a disadvantage that mounting man-hours, adjusting man-hours and costs are extra.

An object of the present invention is to provide a semiconductor device in which two input signals are amplified by one device and can be directly connected to the next stage.

[0008]

Means for Solving the Problems] To achieve the above object, a semiconductor device according to the present invention is a semiconductor device for use in apparatus for receiving a signal from a satellite, the two input signals are respectively input two input terminals that said increase in two and two compound semiconductor chip for amplifying each a signal input to the input terminal, said two compound semiconductor chip
Possess a single combining circuit through each width has been two output signals, the gate bias conditions of the compound semiconductor chip
By changing, the signal is amplified from the two input signals.
This is to select the signal of the other .

[0009]

In the semiconductor device according to the present invention, the signals from two input terminals for inputting two input signals are amplified by the compound semiconductor chip, and those signals are combined and output as one signal.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIGS. 1 and 2 are schematic explanatory diagrams of the present invention. FIG. 3 is a schematic explanatory view of a mounting unit according to an embodiment of the present invention,
FIG. 4 is a block diagram showing one embodiment of the present invention.

In FIG. 1, two compound semiconductor chips 5 are mounted on a base 1 and connected to a gate lead 2, a source lead 3 and a synthesizing circuit 7 by bonding wires 17 respectively. Further, as shown in FIGS. 2A and 2B, sealing is performed with a ceramic cap 6.

As one embodiment of the present invention, a European communication satellite A
The case where a signal of stra-la is received will be described. The specifications of Astra-la are shown below.

The downlink frequency is f = 11.20.
There are 11.45 GHz and 16 channels. Odd channels of 1, 3, 5, 7, 9, 11, 13, 15 are horizontal polarization, 2, 4, 6, 8, 10, 12, 1
The even-numbered channels 4 and 16 emit radio waves with vertically polarized waves.

As shown in FIG. 4, two input signals that have passed through the polarization converters 8 corresponding to the horizontal and vertical directions respectively have f
= 1.95 to 11.70 to obtain characteristics within the band,
The signal is input through an input matching circuit 9 that matches the impedance of the two input terminals a and b of the semiconductor device 18 of the present invention.

For example, when channel 1 is selected by the receiving device, the control unit of the power supply circuit connected to the comparator 15 sets the power supply voltage to HIGH or LOW within a range that can be detected by the comparator 15.

For example, the power supply voltages +15 to +1
8V is set to HIGH, +12 to + 15V is set to LOW,
If the channel is HIGH, the channel is an odd-numbered channel of horizontal polarization, and if LOW, the channel is an even-numbered channel of vertical polarization. The comparator 15 detects this, and the switch 14 connects the gate bias circuit 10 to the respective input terminals a and b. Switch.

The gate bias circuit 10 has two types, A and B.
Is set to a gate voltage in a region where a drain current equal to or lower than the cutoff voltage does not flow, and when the gate bias circuit A is connected to the input terminal a, the gate bias circuit B is connected to the input terminal b. In this manner, even if two input signals are input to the input terminals a and b, only the signal to which the gate bias circuit A is connected can be amplified by the switch 14 with low noise.

The amplified signal is output from the drain lead 4 through the synthesizing circuit 7 shown in FIG. Since the drain bias circuit 13 can apply a constant voltage irrespective of the selection of the channel, it can be operated by one. Similarly, one output matching circuit 12 can be connected to the next stage.

FIG. 5 shows an example of a conventional device. Compared with FIG. 4, an output matching circuit 12, a drain bias circuit 13,
Further, it can be seen that the synthesis circuit 16 is additionally required.

FIGS. 3 and 4 are schematic diagrams showing the vicinity of the mounting portion of one embodiment of the present invention and the vicinity of the mounting portion of the conventional device.
According to the present invention, the number of matching circuits and bias circuits can be reduced, the number of components such as chip capacitors, resistors, and Trs can be reduced, and the size of the device can be reduced.

Further, in one embodiment of the present invention, the switching of the signal to be amplified is performed by changing the gate bias condition of the device. The isolation characteristics of the chip that is not used are improved. The data of an experiment in our typical heterozygous form FET, V _GS ≒ -0.6 to the gate bias V _GS to a normal operating state
V, V _GS = −2 V at which I _D hardly flows below the cutoff voltage, and the drain bias V _DS
If There was the combination of V _DS = 2V and V _DS = 0V of normal operation, V _GS = -0.6V, V than when the V _DS = 0V _GS =
It is known that the isolation is improved by 3 dB or more at f = 12 GHz when −2 V and V _DS = 2 V.

That is, the normal operation state V _DS = 2 V, V _GS
The isolation is better when controlled by the gate bias as in the present invention than when V _DS = 0 as in the conventional device from −0.6 V.

[0024]

As described above, the present invention relates to a device for receiving a signal from a satellite, two input terminals for inputting two input signals, and two compound semiconductors for amplifying each signal. It has a chip and a synthesizing circuit for synthesizing the output from each chip to make one signal, and has an effect that two input signals can be amplified by one device and connected to the next stage as it is.

Further, as shown in FIGS. 3 and 4, the mounting area and the number of components can be reduced by almost half, so that there is an effect that the size and cost of the device can be reduced.

Further, as shown in FIG. 4, the switching by the gate bias has an effect that the isolation can be improved by 3 dB or more at f = 12 GHz as compared with the conventional system.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of the present invention.

FIG. 2A is a plan view showing one embodiment of the present invention,
(B) is the same side view.

FIG. 3 is a schematic view of a mounting peripheral portion according to an embodiment of the present invention.

FIG. 4 is a block diagram of one embodiment of the present invention.

FIG. 5 is a block diagram showing a conventional device.

FIG. 6 is a schematic diagram of a mounting peripheral portion of a conventional device.

[Explanation of symbols]

 Reference Signs List 1 base 2 gate lead 3 source lead 4 drain lead 5 compound semiconductor chip 6 ceramic cap 7 synthesis circuit 8 polarization converter 9 input matching circuit 10 gate bias circuit 11 compound semiconductor device 12 output matching circuit 13 drain bias circuit 14 switch 15 comparator 16 Synthesis circuit 17 Bonding wire 18 Semiconductor device

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-19403 (JP, A) JP-A-61-265910 (JP, A) JP-A-61-194376 (JP, A) JP-A-2-194 54637 (JP, A) JP-A-2-81503 (JP, A) JP-A-58-206212 (JP, A) JP-A-55-115114 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H03F 3/60 H03F 3/193 H03F 3/68

Claims (1)

(57) [Claims] 1. An apparatus for receiving a signal from an artificial satellite .
A semiconductor device comprising: two input terminals to which two input signals are respectively input; and two amplifiers each of which amplifies a signal input to the two input terminals.
Compound semiconductor chips and two outputs amplified by the two compound semiconductor chips
Possess a single combining circuit signal passes each changing the gate bias conditions of the compound semiconductor chip
By this, one of the two input signals to be amplified is
A semiconductor device for selecting a signal .