JP2883884B2 - Switching circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching circuit for switching and outputting signals from a plurality of synthesizer circuits.

[0002]

2. Description of the Related Art There are two different
There is a switching circuit for switching a signal of a certain frequency, outputting a signal of one of the frequencies, and rapidly switching the frequency.

Conventionally, as a switching circuit for switching between these two kinds of signals having different frequencies, a switching method using a PIN diode and a circuit for switching ON / OFF the power supply of a three-stage circuit with a grounded base shown in FIG. is there.

[0004]

In the case where the amplifier section is constituted by the former transistor and the switch section is constituted by the PIN diode, the number of components and the circuit become complicated, and the switching time becomes long (for example, in an experiment). According to this, there is a problem that the length is as long as about 12 μs).

[0005] In the case of the latter circuit in which the power supply of the three-stage circuit with the grounded base shown in FIG.
There was a problem that it was extremely slow at 1.1 μs.

FIG. 5 shows an example of a conventional circuit (grounded base). This is because a signal from the synthesizer is received by a first-stage grounded base circuit, amplified by second-stage and third-stage grounded base circuits, and is amplified by a first-stage circuit, a second-stage circuit, and a third-stage circuit.
This is a circuit for switching by turning on / off the power supply of each transistor in the circuit of the stage.

[0007] The present invention solves these problems,
It is an object of the present invention to simplify the circuit and improve the electrical characteristics by forming the umbrella section and the switching circuit with the base ground and the emitter ground of the transistor.

[0008]

Means for solving the problem will be described with reference to FIG. In FIG. 1, a first circuit 1 is a circuit that receives a signal at the base of a transistor whose emitter is grounded and supplies or cuts off power to the collector of the transistor.

The second circuit 2 comprises a circuit that receives the signal at the emitter of the transistor whose base is grounded and supplies or cuts off the power to the collector of the transistor.

The third circuit 3 comprises a circuit that receives the signal at the emitter of the transistor whose base is grounded and supplies or cuts off the power to the collector of the transistor.

The synthesizer circuit 4 is a circuit for generating a predetermined high-frequency signal. Next, the circuit configuration will be described. The first circuit 1 comprises a circuit for receiving a signal from the synthesizer circuit 4 at the base of a transistor having a common emitter and supplying or cutting off power to the collector of the transistor. The second circuit 2 comprises an emitter of the first circuit. A third circuit 3 receives a signal output from the collector of the grounded transistor at the emitter of the transistor grounded at the base and supplies or cuts off power to the collector of the transistor. The third circuit 3 outputs the signal from the collector of the second circuit. A signal is received by the emitter of the transistor whose base is grounded, and a circuit for supplying or interrupting power to the collector of the transistor is provided. The third circuit 3 outputs a signal from the synthesizer circuit 4.

At this time, a resistor R for limiting current is inserted in series between the synthesizer circuit 4 and the base of the transistor whose emitter is grounded in the first circuit 1.
To reduce the impact of the load.

The first circuit 1, the second circuit 2, the third circuit
Are connected to the output terminals of the third circuit, and the signals from the two synthesizer circuits 4 are switched and output at high speed.

Further, the first circuit, the second circuit, and the third circuit are all constituted by transistors. Therefore, the umbrella section and the switching circuit are configured by the common base and the common emitter of the transistor, so that the circuit can be simplified and the electrical characteristics can be improved. And the switching ON / OFF ratio is -8.
An extremely good value of 2.33 dB was obtained.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments and operations of the present invention will be sequentially described in detail with reference to FIGS.

FIG. 1 is a circuit diagram showing one embodiment of the present invention.
In FIG. 1, a first circuit 1 is a circuit for receiving a signal from a synthesizer circuit 4, transmitting the signal to a next second circuit 2, or cutting off the signal, and as shown in FIG. It comprises a circuit that receives at the base of a transistor and supplies or cuts off power to the collector of the transistor. The ON / OFF of the switching signal is applied to the illustrated SW terminal to supply or cut off power to the collector of the transistor whose emitter is grounded. In order to receive the signal from the synthesizer circuit 4 with the emitter grounded, the input impedance increases,
In addition, even if the resistor R is inserted in series, the circuit operates sufficiently, and even if the load of the transistor having the common emitter fluctuates, the influence on the synthesizer circuit 4 on the input side can be extremely reduced.

The second circuit 2 receives, amplifies and outputs an output signal from the collector of the transistor of the first circuit 1, and outputs the amplified signal. The second circuit 2 receives the output signal from the collector of the common-emitter transistor of the first circuit. An output signal is received by an emitter of a transistor whose base is grounded, and a circuit for supplying or interrupting power to the collector of the transistor is provided.

The third circuit 3 receives, amplifies, and outputs an output signal from the collector of the transistor of the second circuit 2, and outputs the output signal from the collector of the second circuit 2 to the grounded base. And a circuit for supplying or cutting off power to the collector of the transistor while receiving at the emitter of the transistor.

The synthesizer circuit 4 is a circuit for oscillating a predetermined high-frequency signal, and is, for example, 1.669500 GHz
A circuit that oscillates a high-frequency signal of z and that oscillates sequentially at predetermined frequency intervals (synthesizer circuit). Here, two synthesizer circuits 4 are used, and the two are alternately switched to output a high-frequency signal at a predetermined frequency interval at high speed.

As described above, the input stage from the synthesizer circuit 4 is connected to the grounded emitter of the first circuit 1, the input impedance is increased, the influence of load fluctuation on the synthesizer circuit 4 is minimized, and the stable high frequency is used when switching. A signal can be obtained, and the second circuit 2 and the third circuit 3 are grounded at the base, so that the switching ON / OFF ratio is large and the isolation characteristics between the synthesizer circuits 4 can be improved (FIG. 2 to 4 will be described later).

FIG. 2 shows the switching ON / OF of the present invention.
The example of F ratio measurement is shown. This switching ON / OFF ratio measurement example is based on one of the synthesizer circuits 4 (PL
L1) when the ON or OFF signal is supplied to the SW, that is, when the power supply to the collector of the transistor with the common emitter of the first circuit 1 is turned ON or OFF, the output ratio of the signal output from OUT is determined. Measured. As shown in the figure, the value of the switching ON / OFF ratio measurement obtained here is a value of -82.33 dB. The conditions at that time are as shown below.

· CENTER frequency: 1.669500 GHz · SPAN: 2.000 MHz · RBW: 10 kHz · VBW: 100 Hz · SWP: 5.0 sec As described above, the power supply of the first circuit in the circuit configuration of FIG.
Switching ON / OFF ratio when N / OFF is
An extremely good value of -82.33 dB was obtained.

FIG. 3 shows an actual measurement example (grounded emitter,
The 1) is shown. This is a copy of the measurement screen when the channel switching time (f Span 80 KHz) is measured at 2.44 μs at the illustrated frequency of f = 1.66950 GHz in the circuit of FIG. Thus, it has been found that the channel switching time of the circuit of FIG. 1 is 2.44 μs, and a stable signal can be obtained at a very high speed when the channel is switched, compared to the channel switching time of the conventional pin diode of 12 μs. .

FIG. 4 shows a measurement example of the present invention (common emitter,
The 2) is shown. This is a copy of the measurement screen when the channel switching time (f Span 20 KHz) is measured to be 2.22 μs at the illustrated frequency of f = 1.66950 GHz in the circuit of FIG. 1. As described above, it has been found that the channel switching time of the circuit of FIG. 1 is 2.22 μs, and a stable signal can be obtained at a very high speed when the channel is switched, as compared with the channel switching time of the conventional pin diode of 12 μs. .

[0025]

As described above, according to the present invention,
Since the circuit of the amp section and the switching circuit is configured by the common ground of the transistor and the common ground of the transistor, the high-frequency signal can be switched at a very high speed,
Moreover, a switching circuit having a large switching ON / OFF ratio can be realized. According to the experimental example, the channel of the frequency signal of 1.66950 GHz can be stably switched in 2.22 μs (f Span 20 KHz) with the circuit configuration of FIG.
An excellent value of -82.33 dB was obtained.

[Brief description of the drawings]

FIG. 1 is a circuit diagram of one embodiment of the present invention.

FIG. 2 is a measurement example of a switching ON / OFF ratio according to the present invention.

FIG. 3 is a measurement example (common emitter, part 1) of the present invention.

FIG. 4 is an actual measurement example (common emitter, part 2) of the present invention.

FIG. 5 is an example of a conventional circuit (grounded base).

FIG. 6 is an actual measurement example (grounded base, part 1) of a conventional circuit.

[Explanation of symbols]

 1: first circuit 2: second circuit 3: third circuit 4: synthesizer circuit R: resistor

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-256078 (JP, A) JP-A-6-164385 (JP, A) JP-A-6-237169 (JP, A) (58) Survey Field (Int.Cl. ⁶ , DB name) H03L 7/16-7/23 H03K 17/00 H03K 17/62 H01P 1/15

Claims (4)

(57) [Claims] 1. A switching circuit for switching and outputting signals from a plurality of synthesizer circuits, a first circuit receiving a signal from the synthesizer circuit at a base of a transistor having a common emitter, and a common emitter of the first circuit. A second circuit for receiving the output signal from the collector of the transistor at the emitter of the common-base transistor; and a third circuit for receiving the output signal from the collector of the second circuit at the emitter of the common-base transistor. Is provided for each synthesizer, and power is supplied to or cut off from the collectors of the transistors of the first circuit, the second circuit, and the third circuit to switch to and output a signal from an arbitrary synthesizer circuit. Switching circuit characterized. 2. A current limiting resistor is connected in series between the synthesizer circuit and the base of a transistor whose emitter is grounded in the first circuit to reduce the influence of a load on the synthesizer circuit. The switching circuit according to claim 1, wherein 3. The first circuit, the second circuit, and the third circuit are provided in two sets, the output terminals of the third circuit are connected, and the signals from the two synthesizer circuits are switched at high speed. 3. The switching circuit according to claim 1, wherein the switching circuit outputs the output. 4. The switching circuit according to claim 1, wherein said first circuit, said second circuit, and said third circuit are all constituted by transistors.