CN115588281A

CN115588281A - VSWR's warning circuit is listened to adjustable

Info

Publication number: CN115588281A
Application number: CN202211133869.4A
Authority: CN
Inventors: 尹柏林
Original assignee: Xiaotang Technology Shanghai Co ltd
Current assignee: Xiaotang Technology Shanghai Co ltd
Priority date: 2022-09-19
Filing date: 2022-09-19
Publication date: 2023-01-10

Abstract

The invention discloses an adjustable alarm circuit for detecting VSWR, which is externally connected with an antenna interface and comprises: the device comprises a CPU, a radio frequency transceiving unit, a first digital attenuator, a second digital attenuator, a coupler, an RMS logarithmic detector, a voltage comparator, an N-MOS switch and an indicator light; the CPU controls the radio frequency transceiving unit to transmit signals to the coupler, the coupler is connected with an antenna interface and generates forward coupling power and backward coupling power; forward coupling power and backward coupling power respectively pass through the second digital attenuator and the first digital attenuator and enter the RMS logarithmic detector to generate a voltage difference X between the forward coupling power and the backward coupling power; the voltage comparator compares the voltage difference X with a preset voltage value Y and outputs high voltage or low voltage; and the N-MOS switch is conducted when receiving the high voltage, so that the circuit of the indicator lamp is conducted. The invention can directly judge whether the antenna is in poor contact or not from the alarm indicator lamp.

Description

VSWR's warning circuit is listened to adjustable

Technical Field

The invention relates to the technical field of circuits, in particular to an adjustable alarm circuit for detecting VSWR (reflection coefficient).

Background

At present, when communication equipment is actually used, signals are transmitted and received through an antenna; the performance of the antenna and the perfection of the assembly therefore also directly affect the performance of a communication device; and the antenna equipment of the equipment is imperfect, the transmitted power can be reflected back to the radio frequency path, so that the power flows back and the radio frequency device is damaged. At present, an instrument for checking a station position is required to be added in a production line to detect whether an antenna is properly assembled; however, the time and labor are wasted, and if the antenna is in poor contact due to falling or aging of the equipment in the subsequent use, the subsequent operation cannot be intuitively judged, and professional actions such as disassembly and the like are required to be performed for inspection.

Disclosure of Invention

The invention aims to provide an adjustable VSWR (voltage distortion correction) detecting alarm circuit which can directly judge whether an antenna is in poor contact or not from an alarm indicator lamp.

The technical scheme for realizing the purpose is as follows:

the utility model provides an alarm circuit of VSWR is listened to adjustable, external antenna interface includes: the device comprises a Central Processing Unit (CPU), a radio frequency transceiving unit, a first digital attenuator, a second digital attenuator, a coupler, a logarithmic detector for Root Mean Square (RMS), a voltage comparator, an N-metal-oxide-semiconductor (N-MOS) switch and an indicator light;

the CPU controls the radio frequency transceiving unit to transmit signals to the coupler, the coupler is connected with an antenna interface and generates forward coupling power and backward coupling power;

forward coupling power and backward coupling power respectively enter the RMS (root mean square) logarithmic detector through the second digital attenuator and the first digital attenuator to generate a voltage difference X between the forward coupling power and the backward coupling power;

the voltage comparator compares the voltage difference X with a preset voltage value Y and outputs high voltage or low voltage;

and the N-MOS switch is conducted when receiving the high voltage, so that the circuit of the indicator lamp is conducted.

Preferably, the forward coupling power is power sampled by the coupler in a power transmission direction, and the backward coupling power is power reflected back and detected at the coupler in a power transmission reverse direction due to poor contact of the antenna interface.

Preferably, the second digital attenuator and the first digital attenuator are controllable devices, and their corresponding path attenuation values can be controlled by instructions of the CPU.

Preferably, the RMS pair detector converts the forward coupled power and the backward coupled power from the second digital attenuator and the first digital attenuator into corresponding voltage values and outputs a voltage difference X.

Preferably, the voltage difference X corresponds to a VSWR value, the different VSWR values corresponding to different degrees of adaptation of the antenna interface.

Preferably, the better the antenna interface contact, the closer the VSWR value, the worse the contact, the VSWR value being close to infinity.

Preferably, the attenuation values of the second digital attenuator and the first digital attenuator are calculated according to a preset VSWR value.

The invention has the beneficial effects that: the VSWR detection is adjustable through the digital attenuator; and the signal fault can be judged from the indicator light without disassembling the machine, and whether the antenna is in poor contact or not can be judged. And in addition, instruments and stations are not required to be added for detection during production, the result can be visually displayed through the indicating lamp, and the production cost is controlled. Therefore, poor antenna contact caused by vibration or falling aging and other reasons when the equipment is used subsequently is avoided.

Drawings

FIG. 1 is a circuit diagram of an adjustable VSWR detection alarm circuit according to the present invention.

In the figure: 1. a CPU; 2. a radio frequency transceiving unit; 3. a first digital attenuator; 4. a second digital attenuator; 5. a coupler; 6. an RMS log detector; 7. an antenna interface; 8. a voltage comparator; 9. an N-MOS switch; 10. and an indicator light.

Detailed Description

The invention will be further explained with reference to the drawings.

Referring to fig. 1, the adjustable VSWR detecting alarm circuit of the present invention, which is externally connected to the antenna interface 7, includes: CPU1, radio frequency transceiver unit 2, first digital attenuator 3, second digital attenuator 4, coupler 5, RMS logarithmic detector 6, voltage comparator 8, N-MOS switch 9 and indicator light 10.

The CPU1 controls the radio frequency transceiving unit 2 to normally transmit signals, transmits the signals to the coupler 5, and the coupler 5 is connected with the antenna interface 7 and generates forward coupling power and backward coupling power; the forward coupling power is the power sampled by the coupler 5 in the power transmission direction, and the backward coupling power is the power reflected back and detected at the coupler 5 in the reverse direction of the power transmission due to poor contact of the antenna interface 7. Both powers can be detected simultaneously.

The forward coupling power and the backward coupling power respectively enter the RMS logarithmic detector 6 through the second digital attenuator 4 and the first digital attenuator 3, generating a voltage difference X between the two. Specifically, the RMS log detector 6 converts the forward coupled power and the backward coupled power from the second digital attenuator 4 and the first digital attenuator 3 into corresponding voltage values, and outputs a voltage difference X.

The voltage comparator 8 compares the voltage difference X with a preset voltage value Y, which is related to the type selection of the voltage comparator, and outputs a high voltage or a low voltage. If the voltage difference X is greater than or equal to the voltage value Y, the voltage comparator 8 outputs a high voltage, generally about 3V, and the N-MOS switch 9 is turned on when receiving the high voltage, so as to turn on the circuit of the indicator light 10. Whether the antenna is perfectly contacted or not can be judged through the lighting and the non-lighting of the indicator lamp.

The adjustability in the scheme is mainly embodied in that the digital attenuators of the two paths are controllable devices, and the attenuation values of the second digital attenuator 4 and the first digital attenuator 3 corresponding to the path attenuation values can be controlled by instructions of the CPU1 respectively. Thus, different VSWR values can be detected, the voltage difference X corresponds to the VSWR value, and the different VSWR values correspond to different degrees of adaptation of the antenna interface 7.

When the VSWR value is determined, it defines how much power is reflected back; for example, the transmission power is a, and the reflected power threshold is B; a becomes A 'after passing through the second digital attenuator, and B becomes B' after passing through the first digital attenuator;

the larger the power difference (a '-B') that needs to be detected by the RMS logarithmic detector, the larger the voltage difference is output, which has the advantage that the value of a-B can be adjustably amplified by different attenuation values set by the first digital attenuator and the second digital attenuator. Because sometimes the value of the VSWR definition is too small, the a-B difference is small, so that the RMS log detector does not necessarily detect such small differences. The introduction of a digital attenuator is an artificial amplification of this difference. The specific attenuation value is determined according to the actual application.

The better the antenna interface 7 is in contact with, the closer the VSWR value is to 1, and the worse the contact is, the VSWR value is close to infinity. When the VSWR value to be detected is determined, the attenuation values required by the second digital attenuator 4 and the first digital attenuator 3 can be calculated through calculation, so that the voltage difference X corresponding to the output of the RMS logarithmic detector 6 is compared with the voltage value Y, and whether the antenna is in perfect contact or not is judged through the on and off of the indicator light.

The above embodiments are provided only for illustrating the present invention and not for limiting the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and therefore all equivalent technical solutions should also fall within the scope of the present invention, and should be defined by the claims.

Claims

1. The utility model provides an adjustable alarm circuit who surveys VSWR, external antenna interface (7), characterized in that includes: the device comprises a CPU (1), a radio frequency transceiving unit (2), a first digital attenuator (3), a second digital attenuator (4), a coupler (5), an RMS logarithmic detector (6), a voltage comparator (8), an N-MOS switch (9) and an indicator light (10);

the CPU (1) controls the radio frequency transceiving unit (2) to transmit signals to the coupler (5), the coupler (5) is connected with an antenna interface (7), and forward coupling power and backward coupling power are generated;

forward coupling power and backward coupling power respectively pass through the second digital attenuator (4) and the first digital attenuator (3) and enter the RMS logarithmic detector (6) to generate a voltage difference X between the forward coupling power and the backward coupling power;

the voltage comparator (8) compares the voltage difference X with a preset voltage value Y and outputs high voltage or low voltage;

and the N-MOS switch (9) is conducted when receiving the high voltage, so that the circuit of the indicator light (10) is conducted.

2. The adjustable VSWR detection alarm circuit of claim 1, wherein the forward coupled power is power sampled by the coupler (5) in a power transmission direction, and the backward coupled power is power reflected back and detected at the coupler (5) in a power transmission reverse direction due to poor contact of the antenna interface (7).

3. The adjustable alarm circuit for detecting VSWR of claim 1, wherein the second digital attenuator (4) and the first digital attenuator (3) are controllable devices, and their corresponding path attenuation values can be controlled separately by instructions of the CPU (1).

4. The adjustable VSWR detection alarm circuit of claim 1, wherein the RMS log detector (6) converts forward and backward coupled power from the second digital attenuator (4) and the first digital attenuator (3) into corresponding voltage values and outputs a voltage difference X.

5. The adjustable VSWR detection alarm circuit of claim 1, wherein the voltage difference X corresponds to a VSWR value, and wherein different VSWR values correspond to different degrees of adaptation of the antenna interface (7).

6. The adjustable VSWR detection alarm circuit as claimed in claim 5, wherein the VSWR value is closer to 1 the better the antenna interface (7) is contacted, and the VSWR value is closer to infinity the worse the contact is.

7. The adjustable VSWR detection circuit as claimed in claim 5, wherein the attenuation values of the second digital attenuator (4) and the first digital attenuator (3) are calculated according to a predetermined VSWR value.