RU2755262C1 - Microwave signal diode switch - Google Patents

Abstract

FIELD: radio engineering.

SUBSTANCE: invention relates to radio engineering, in particular to switches and limiters of microwave signal power. The diode switch of the microwave signal is made on the basis of a T-connection with two diodes in each arm. The diodes are connected through a quarter-wave line segment, with the first diodes installed at a distance of L/4 from the junction point. Each arm is additionally shunted with a detector diode installed in anti-parallel at a distance of L/4 from the second diode, while a pass capacitor is installed in the transmission line of each arm between the branch point and the first diode.

EFFECT: invention expands the functionality of the device by using the switch as a protective device.

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Description

The invention relates to radio engineering, in particular to switches and limiters of the microwave signal power and can be used to protect a microwave receiver with channel redundancy from overload and failure under the influence of a signal from its own transmitter and (or) powerful third-party signals.

Known two-position switch (switch) based on T-connection, with parallel connection of diodes at a distance λ / 4 from the branch. [A.V. Weisblat. Microwave switching devices based on semiconductor diodes. - M .: Radio and communication, 1987. Pp. 79] The switch is used at low and high power levels.

The disadvantages of such a device are:

- small loss of blocking;

- there is no limitation of the increased microwave power in the open channel.

The closest to the invention (prototype) is a switch (switch), with two cascaded diodes in the arm. [A.V. Weisblat. Microwave switching devices based on semiconductor diodes. - M .: Radio and communication, 1987. Pp. 84.] The switch allows you to significantly increase the locking losses.

The disadvantage of such a device is still the lack of limitation of the microwave power in the open channel.

The object of the invention is to implement the limiting of the input signal in the open channel while maintaining significant blocking losses.

The technical result consists in limiting the microwave power in the open channel, while it becomes possible to use the switch simultaneously and as a protective device.

The specified technical result is achieved in that the diode switch of the microwave signal is made on the basis of a T-connection with two diodes in each arm. The diodes are connected through a quarter-wave line segment, with the first diodes installed at a distance of λ / 4 from the branch point. Each arm is additionally shunted by a detector diode installed in anti-parallel at a distance of λ / 4 from the second diode, while a pass-through capacitor is installed in the transmission line of each arm between the branch point and the first diode.

The causal relationships of the features of the invention with the technical result are expressed in the following: when a certain threshold of the input power is exceeded, the detector diode in the open arm detects the input signal and opens the remaining diodes in this arm, which introduce additional losses and limit the microwave power.

The invention is illustrated by a drawing (Fig. 1), which shows a diagram of the claimed switch, where

arm 1 and arm 2 are connected at the branching point to which the microwave input is connected;

- diodes VD2, VD3, bypassing arm 1;

- diodes VD4, VD5, bypassing arm 2;

- detector diode VD1 shunting arm 1;

- detector diode VD6 shunting arm 2

- pass capacitors C1 and C2 included in the gap of arms 1 and 2, respectively.

The proposed switch works as follows. In the small signal mode, a positive direct current is supplied to the transmission line of shoulder 1, while the diode VD1 is closed, the diodes VD2 and VD3 are fully open, losses are introduced into the line of shoulder 1, while all diodes shunting the line of shoulder 2 are closed. The signal passes from the microwave input to the output 2 of the arm line 2 with minimal losses. With an increase in the input power, the VD6 diode opens, the detected current begins to flow through the VD4 and VD5 diodes, which introduce additional losses into the arm 2 line and limit the input signal. To switch the channel, it is necessary to remove the positive current from the arm line 1 and apply it to the arm line 2.

Capacitors C1 and C2 are used to isolate arms 1 and 2 of the DC switch.

Power limitation can also be carried out in active mode, for this it is necessary to supply a positive direct current to both lines of arms 1 and 2, while the diodes VD2, VD3, VD4, VD5 will be open, and significant losses will be introduced into both arms 1 and 2.

The implementation of the invention provides for the implementation of a microwave diode switch with protection against increased X-band power with an insertion loss of <0.8 dB, a blocking loss of at least 30 dB, an allowable input power of up to 2 W and a limitation of the output power in any arm of no more than 50 mW. The switch is made on diodes "Paragraph-D" produced by JSC NLP "Istok" them. Shokin "and detector diodes 3A138A-2.

Claims (1)

A diode switch of a microwave signal based on a T-connection with two diodes in each arm, connected through a quarter-wave line segment, while the first diodes are installed at a distance of λ / 4 from the branch point, characterized in that each arm is additionally shunted by a detector diode installed opposite parallel at a distance λ / 4 from the second diode, while a pass capacitor is installed in the transmission line of each arm between the branch point and the first diode.

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