JPH0477017A - Synchronous oscillating circuit - Google Patents

Abstract

PURPOSE:To reduce the cost and to generate a stable switching control signal by using a delay line as a part of an oscillation means and obtaining the switching control signal having a pulse timing in response to the delay timing of the delay line. CONSTITUTION:The synchronous oscillating circuit consists of a delay line 4, separation circuits 15, 16 and gate circuits 17, 18. Then a microwave component is separated by the separation circuits 15, 16 and fed to a switching circuit 6. On the other hand, the separation circuits 15, 16 separate the synchronous oscillating frequency component of the oscillation circuit being a component of a closed loop, that is, a TTL (transistor transistor logic) signal voltage is detected and fed to the switching circuit 6 as a switching control signal. Then the microwave (received wave) is switched at the switching circuit 6 by using the switching control signal to be an intermittent signal (transmission wave) and it is given to an amplifier 9 and a circulator 2 and the result is radiated from an antenna 1.

Description

[Detailed Description of the Invention] [Summary] A synchronous oscillation circuit used in a day-rate repeater type transmitting/receiving device that delays received microwaves, switches them using a switch control signal having a pulse width equal to the delay time, and transmits the signals as intermittent signals. Regarding this, the aim is to generate a stable switch control signal with a simple circuit configuration, regardless of variations in the delay time of the delay line due to temperature fluctuations and product variations. A separation circuit for separating the microwave component and the synchronous oscillation frequency component is provided on the input side and the output side of the delay line, and the terminal for extracting the synchronous oscillation frequency component of each separation circuit is connected to the terminal using two gate circuits. The configuration is such that the switch control signal is output from the connection point of the gate circuit.

[Industrial application field]

The present invention relates to a synchronous oscillation circuit used in a delayed repeater type transmitting/receiving device that delays received microwaves, switches them using a switch control signal having a pulse width equal to the delay time, and transmits the signals as intermittent signals.

In the delayed repeater type transmitter/receiver as described above, for example, five elements are used as elements that delay the received microwave.
When a 0 ns coaxial delay line or the like is used, the delay time of this delay line varies greatly due to temperature fluctuations and product variations. If there is such a variation in delay time, a timing difference will occur between the transmitted wave and the control signal, as will be described later, and a wraparound will occur between the transmitted wave and the received wave, resulting in problems such as oscillation. Therefore, even if there are variations in delay time, it is necessary to match the timing of the transmitted wave and the control signal to avoid problems such as oscillation.

[Conventional technology]

FIG. 4 is a circuit diagram of a conventional example, and FIG. 3 is an operation timing chart thereof. In FIG. 4, double lines indicate microwave transmission lines. In FIG. 4, the microwave (received wave) (FIG. 3(B)) received by antenna l is transmitted to circulator 2. The signal passes through an amplifier 3, is delayed by a delay line 4 with a delay time of 50 ns, and is supplied to a switch circuit 6 via an amplifier 5.

On the other hand, an oscillation signal from an oscillator (switch control signal source) 7 using a crystal resonator or the like is frequency-divided by a pulse forming circuit 8, and has a duty cycle of 5096 degrees and a pulse width of 50 nm.
s switch control signal (FIG. 3(A)). The received wave is switched by the switch control signal in the switch circuit 6 to become an intermittent signal (transmission wave) shown in FIG. 3(C), and then sent to the amplifier 9. It passes through the circulator 2 and is radiated from the antenna l. This delayed repeater type transmitter/receiver has 50 ns microwave reception and 5 ns microwave reception.
Microwave transmission of 0 ns is alternately repeated.

Here, the delay line 4 generally causes variations in delay time due to temperature fluctuations, causing a timing shift between the transmitted wave and the control signal as described below.

If the delay time of the delay line 4 changes from 50 ns to, for example, 55 ns due to temperature fluctuations, the timing of the signal passing through the delay line 4 will be as shown in Fig. 3 (D), and the switch control signal (Fig. 3 (A) ) and timing deviation (55-
50 = 5 ns), and as a result, the signal to be transmitted (transmitted wave) or received wave wraps around in the closed loop,
As a result, problems such as oscillation will occur. Therefore, conventionally, in order to prevent such problems from occurring,
Temperature compensation is performed by temperature compensation means as described below. The environmental temperature information detected by the temperature detector IO is supplied to the temperature compensation circuit 11, where a temperature compensation signal synchronized with the timing of the switch control signal detected by the synchronization trigger detection circuit 12 is obtained. The generation timing of the output signal of the oscillator 7 is controlled by the temperature compensation signal from the temperature compensation circuit II, and the timing deviation (5
As a result, even if the delay time of the delay line 4 varies due to temperature fluctuations, the switch control signal (FIG. 3 (E)) has a timing corresponding to the transmitted wave.
Transmission and reception can be performed without causing problems such as oscillation as described above.

[Problem to be solved by the invention]

However, the conventional example shown in FIG. 4 includes a temperature detector 10, a temperature compensation circuit 11. The synchronization trigger requires a temperature compensation means consisting of a detection circuit 12, etc., and an oscillator 7 for generating a switch control signal. The pulse forming circuit 8 is required, which makes the circuit complicated and increases the cost. Furthermore, the delay time of the delay line 4 varies not only due to temperature fluctuations but also due to products, and the conventional example has the problem of not being able to deal with variations in delay time depending on products.

SUMMARY OF THE INVENTION An object of the present invention is to provide a synchronous oscillation circuit that has a simple circuit configuration and can generate a stable switch control signal regardless of variations in delay time of a delay line due to temperature fluctuations and product variations.

[Failure to solve the problem]

FIG. 1 shows a diagram of the principle of the present invention. In the figure, 20 is a delay line, 2 is a switch circuit, and a signal obtained by delaying the microwave by the delay line 20 is switched and extracted by a switch control signal by a switch circuit 21.

The present invention uses delay line 20 as part of an oscillating means for generating switch control signals. 22.23 is a separation circuit,
It is provided on the input side and the output side of the delay line 20, and separates the microwave component and the synchronous oscillation frequency component. Gate circuits 24 and 25 connect terminals for extracting the synchronous oscillation frequency components of the respective separation circuits 22 and 23. Gate circuit 24
．． The configuration is such that a switch control signal is output from 25 connection points.

[Effect]

In the present invention, the delay line 20 is used as part of the oscillation means,
A switch control signal having pulse timing corresponding to the delay timing of the delay line 20 is obtained.

Therefore, even if the delay time of the delay line varies due to temperature fluctuations, product variations, etc., a switch control signal with pulse timing corresponding to the variation can be obtained, and even if there are temperature fluctuations or product variations, the received wave of the transmitted wave It is possible to prevent detours to occur.

In this case, in the present invention, there is no need to provide a temperature compensation means or an oscillator (switch control signal source) using a crystal oscillator, etc. as in the conventional example, and the circuit can be constructed more easily and at a lower cost than in the conventional example. Can be configured to cost.

〔Example〕

FIG. 2 shows a circuit diagram of an embodiment of the present invention, in which the same components as in FIG. 4 are given the same numbers.

In Fig. 2, reference numerals 15 and 16 denote separation circuits, each consisting of a capacitor for passing microwaves and an inductance for blocking microwaves, and connected to the input side and output side of the delay line 4, respectively. , to separate the microwave component and the synchronous oscillation frequency component.

Reference numerals 17 and 18 denote gate circuits such as inverters, which are connected to the separation circuits 15 and 16 and output switch control signals from the connection point of the gate circuits 17 and 18.

Reference numeral 19 denotes a buffer (gate circuit) that adjusts the timing of the switch control signal, and does not need to be provided in principle.

In the present invention, a synchronous oscillation circuit is configured by the delay line 41 separation circuit 15, 16° gate circuit 17, 18, that is, the delay line 41
is used as a part of an oscillation circuit to obtain a switch control signal having a pulse timing that corresponds to variation (dispersion) in the delay time of the delay line 4.

Next, the operation will be explained in conjunction with the operation timing chart shown in FIG. In FIG. 2, the microwave (received wave) received by antenna 2 (FIG. 3 (B)) is transmitted to circulator 2. The signal passes through an amplifier 3, is delayed by a delay line 4 with a delay time of 50 ns, and is supplied to a switch circuit 6 via an amplifier 5.

Here, the basic configuration of the delay line 4 and gate circuit 1 is as follows.
A closed loop consisting of 7.18 constitutes a well-known oscillation circuit, and is widely used as a means for generating a pulse signal with a certain period.

Microwave components are separated by separation circuits 15 and 16,
This microwave component is supplied to the switch circuit 6. On the other hand, the separation circuits 15 and 16 separate the synchronous oscillation frequency components of the oscillation circuits constituting the closed loop, that is, TTL
(Transistor-Transistor-Logic) signal voltage is detected and supplied to the switch circuit 6 as a switch control signal (FIG. 3(A)). The microwave (received wave) (Fig. 3 (B)) is switched by the switch control signal (Fig. 3 (A)) in the switch circuit 6 and becomes an intermittent signal (transmission wave) shown in Fig. 3 (C). , amplifier 9. It is radiated from the antenna via circulator 2.

If the delay time of the delay line 4 becomes, for example, 55 ns due to temperature fluctuations, or if the delay time of the delay line 4 becomes 55 ns due to product variations,
A case will be explained in which a delay line 4 having a delay time of 5 ns is used. As mentioned above, the delay line 41 isolation circuit 15.
16. The oscillation circuit constituted by the gate circuit 17゜I8 is configured to output the synchronous oscillation frequency component (TTL signal voltage) separated by the separation circuit 15゜16 as a switch control signal, so this switch control signal is delayed. It has a pulse timing corresponding to the delay timing of line 4. Therefore, even if the delay time of the delay line 4 fluctuates due to temperature fluctuations, product variations, etc., a switch control signal (Fig. 3 (E)) with a pulse timing corresponding to the fluctuation can be obtained. Even if there is a signal, it is possible to prevent the transmitted wave from going around to the received wave. In this case, in the present invention, there is no need to provide a temperature compensation means or an oscillator (switch control signal source) using a crystal oscillator, etc. as in the conventional example, and the circuit can be simplified compared to the conventional example. It can be configured at low cost and can adequately handle even a very wide range of temperature fluctuations.

Note that the pulse timing of the switch control signal is controlled by the delay line 4.
To perfectly match the delay timing of the buffer 19
The number of inverter stages can be increased or decreased, or separation circuits 15.16
You can easily make fine adjustments by adjusting the inductance value.

〔Effect of the invention〕

As explained above, since the present invention has a configuration in which the delay line is used as a part of the oscillation means that generates the switch control signal, when applied to a delayed repeater type transmitting/receiving device, the delay line can be delayed with a simple circuit. It is possible to generate a stable switch control warning signal that adapts to time variations, it can be constructed at low cost, and it can sufficiently cope with a wide variation range of delay time.

[Brief Description of the Drawings] Figure 1 is a principle diagram of the present invention, Figure 2 is a circuit diagram of an embodiment of the present invention, Figure 3 is an operation timing chart of the present invention and the conventional example, and Figure 4 is the conventional example. It is a circuit diagram of an example. In the figure, l is an antenna, 2 is a circulator, 4.20 is a delay line, 6.2I is a switch circuit, 15.16.22.23 is an isolation path, 17.18, 1
9.24 and 25.26 indicate gate circuits. Patent applicant: Fujitsu Ltd. Operation timing of the present invention and conventional example - f↑ - Fig. 3 Circuit diagram of a conventional example Fig. 4

Claims (2)

[Claims] (1) In a circuit that outputs a signal obtained by delaying a microwave with a delay line (20) by switching it with a switch control signal in a switch circuit (21), the delay line (20) is oscillated to generate the switch control signal. A separation circuit (22,
23), and the terminals for extracting the synchronous oscillation frequency components of the respective separation circuits (22, 23) are connected to two gate circuits (23).
4, 25) and outputs the switch control signal from the connection point of the gate circuit (24, 25). (2) A gate circuit for adjusting the pulse timing of the switch control signal (
26). The synchronous oscillation circuit according to claim 1, wherein the synchronous oscillation circuit has a configuration in which the synchronous oscillation circuit 26) is connected.