Radio-frequency signal source device of short-wave therapeutic apparatus

Abstract

The invention discloses a radio-frequency signal source device of a short-wave therapeutic apparatus, which belongs to the technical field of radio-frequency signal processing and comprises a crystal oscillator, an electric control switch buffer, a level shifter, a radio-frequency narrow-band filter, an electric control attenuator and a signal change-over switch. By arranging a crystal oscillator, an electric control switch buffer, a level translator, a radio frequency narrow-band filter, an electric control attenuator and a signal change-over switch, after a radio frequency signal is adjusted by the radio frequency signal source processing device, a signal source which is large in pulse modulation proportion, low in time delay and low in frequency spectrum clean harmonic level is obtained; and radio frequency signals and control signals processed by each functional module belong to small-signal low-level signals, so that the system has the advantages of high response speed, small voltage and current stress, safety and reliability.

Description

Technical Field

[0001] The present invention belongs to the technical field of radio frequency signal processing, and particularly relates to a radio frequency signal source device for a short-wave therapeutic apparatus. Background Art

[0002] Generally, a short-wave therapeutic apparatus generates a stable radio frequency signal by a crystal oscillator, then amplifies the signal through a radio frequency amplifier, outputs it to an impedance converter, and then connects to electrodes to radiate electromagnetic waves to the human body to achieve the treatment purpose; in the currently implemented technology, a crystal oscillator is often used to generate a signal, which passes through a pre-amplifier of the signal source, and then through a driving module or a medium-power amplifying tube as a driving stage. After the radio frequency signal source is amplified, it drives a push-pull power amplifier at the rear stage to amplify, and then outputs to the load after amplification. During the treatment process, for different treatment parts and symptoms, it is necessary to perform pulse modulation and power control on the output high-frequency electromagnetic wave to control the treatment part from overheating and achieve a good treatment effect. Therefore, the processing of the signal source is very important;

[0003] For the existing short-wave therapeutic apparatus, to adjust the output power, the power supply voltage of the final-stage amplifier is adjusted in segments to control the output power. The disadvantage of this power control method is that the adjustment of the output power by the segmented power supply voltage is too rough, and the difference in the output power between two-stage adjustments is large. It is impossible to finely adjust the output power. In use, when increasing one level, the output power is too large, and when decreasing one level, the output power is too small, and it is always impossible to reach the appropriate power; moreover, this method will make the final-stage amplifying tube work in a severely compressed state, generating a large amount of harmonic power and causing electromagnetic interference to the outside; for the pulse modulation of the output power, the power supply voltage of the final-stage amplifier is turned on and off for pulse modulation. The disadvantages of this method are: the energy storage capacitor on the power supply loop of the final-stage power amplifier and the working current of the power amplifier tube are very large, and the switching circuit needs to bear a large pulse current stress, which is easy to damage the parts of the switching circuit, resulting in functional failure. Therefore, a radio frequency signal source device for a short-wave therapeutic apparatus is needed to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a radio frequency signal source device for a short-wave therapeutic apparatus to solve the problems raised in the above background art.

[0005] To achieve the above object, the present invention provides the following technical solution: A radio frequency signal source device for a short-wave therapeutic apparatus, comprising a crystal oscillator, an electronic control switch buffer, a level converter, a radio frequency narrow-band filter, an electronic control attenuator, and a signal switching switch. The output end of the crystal oscillator is connected to the input end of the electronic control switch buffer. The output end of the electronic control switch buffer is connected to the input end of the radio frequency narrow-band filter. The output end of the radio frequency narrow-band filter is connected to the input end of the electronic control attenuator. The output end of the electronic control attenuator is connected to the input end of the signal switching switch. The output end of the level converter is connected to the input end of the electronic control switch buffer. The output end of the level converter is connected to the input end of the signal switching switch;

[0006] Wherein, the control end of the level converter is connected to the modulation pulse input;

[0007] The control end of the electronic control attenuator is connected to the adjustment voltage input.

[0008] The radio frequency signal source device of the short-wave therapeutic apparatus processes signals for modulation, filtering, attenuation, and switching.

[0009] As a preferred embodiment, the crystal oscillator generates a stable radio frequency signal source waveform through a crystal resonator.

[0010] As a preferred embodiment, the electronic control switch buffer adopts a buffer with a tri-state output and a Schmitt trigger input. By changing the high and low levels of the chip enable terminal, the signal from the crystal oscillator is output through the buffer or the output is turned off.

[0011] As a preferred embodiment, the level converter is composed of an inverter digital chip, receives pulse or level signals from a microprocessor, generates a reverse-phase and a forward-phase control signal, and controls the electronic control switch buffer and the signal switching switch to perform pulse modulation and switching of radio frequency signals.

[0012] As a preferred embodiment, the radio frequency narrow-band filter consists of an inductor and a capacitor to form a "T" type band-pass filter, selectively passes radio frequency signals with set frequencies, and blocks other useless radio frequency signals.

[0013] As a preferred embodiment, the electronic control attenuator is composed of resistors, capacitors, and PIN diodes. By applying different voltages to the control end, the attenuation amount of the radio frequency signal is different. When the voltage is low, the attenuation amount is large and the output radio frequency signal level is low. When the voltage is high, the attenuation amount is small and the output radio frequency signal level is high. It adjusts the level of the radio frequency signal output to the amplifier, so that the power of the finally output radio frequency signal changes with the control voltage.

[0014] As a preferred embodiment, the signal switching switch adopts a radio frequency signal switch chip. By applying different high or low levels to the control terminal, the input of the power amplifier is controlled to be connected to the output terminal of the electronic control attenuator or to the ground wire, thereby controlling whether the radio frequency signal enters the amplifier. The control terminal is synchronously linked with the control terminal of the electronic control switch buffer, and finally the pulse modulation and switching functions of the radio frequency signal are obtained.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] In the present invention, by setting a crystal oscillator, an electronic control switch buffer, a level converter, a radio frequency narrowband filter, an electronic control attenuator, and a signal switching switch, after the radio frequency signal is processed by the radio frequency signal source processing device, a signal source with a large pulse modulation ratio, a low time delay, a clean spectrum, and a low harmonic level is obtained. Moreover, the radio frequency signals and control signals processed by each functional module are all small signals with low levels, having the advantages of fast response speed, small voltage and current stress, and safety and reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the present invention.

[0018] In the figure: 1. Crystal oscillator; 2. Electronic control switch buffer; 3. Level converter; 4. Radio frequency narrowband filter; 5. Electronic control attenuator; 6. Signal switching switch. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The present invention will be further described below in conjunction with embodiments.

[0020] The following embodiments are used to illustrate the present invention, but cannot be used to limit the protection scope of the present invention. The conditions in the embodiments can be further adjusted according to specific conditions. Any simple improvement of the method of the present invention under the premise of the concept of the present invention belongs to the protection scope required by the present invention.

[0021] Please refer to Figure 1 , the present invention provides a radio frequency signal source device for a short-wave therapeutic apparatus, including a crystal oscillator 1, an electronic control switch buffer 2, a level converter 3, a radio frequency narrowband filter 4, an electronic control attenuator 5, and a signal switching switch 6. The output terminal of the crystal oscillator 1 is connected to the input terminal of the electronic control switch buffer 2. The output terminal of the electronic control switch buffer 2 is connected to the input terminal of the radio frequency narrowband filter 4. The output terminal of the radio frequency narrowband filter 4 is connected to the input terminal of the electronic control attenuator 5. The output terminal of the electronic control attenuator 5 is connected to the input terminal of the signal switching switch 6. The output terminal of the level converter 3 is connected to the input terminal of the electronic control switch buffer 2. The output terminal of the level converter 3 is connected to the input terminal of the signal switching switch 6;

[0022] Among them, the control terminal of the level converter 3 is connected to the modulation pulse input;

[0023] The control terminal of the electronically controlled attenuator 5 is connected to the adjustment voltage input.

[0024] The crystal oscillator 1 generates a stable radio frequency signal source waveform through the crystal resonator;

[0025] The electronic control switch buffer 2 uses a buffer with a three-state output and a Schmitt trigger input. By changing the high and low levels of the chip enable terminal, the signal from the crystal oscillator 1 passes through the buffer to output a signal or closes the output;

[0026] The level converter 3 is composed of an inverter digital chip, receives pulse or level signals from the microprocessor, generates a reverse-phase and a forward-phase control signal, and controls the electronic control switch buffer 2 and the signal switching switch 6 to perform pulse modulation and switching of the radio frequency signal;

[0027] The radio frequency narrowband filter 4 is composed of inductors and capacitors to form a "T" type band-pass filter, selectively passes the radio frequency signal with a set frequency, and blocks other useless radio frequency signals;

[0028] The electronically controlled attenuator 5 is composed of resistors, capacitors and PIN diodes. By applying different voltages to the control terminal, the attenuation amount of the radio frequency signal is different. When the voltage is low, the attenuation amount is large and the output radio frequency signal level is low. When the voltage is high, the attenuation amount is small and the output radio frequency signal level is high. It adjusts the level of the radio frequency signal output to the amplifier, so that the power of the finally output radio frequency signal changes with the control voltage;

[0029] The signal switching switch 6 uses a radio frequency signal switch chip. By applying different high or low levels to the control terminal, it controls the input of the power amplifier to be connected to the output terminal of the electronically controlled attenuator 5 or to the ground wire, thereby controlling whether the radio frequency signal is input to the amplifier. This control terminal is synchronously linked with the control terminal of the electronic control switch buffer 2, and finally obtains the pulse modulation and switching functions of the radio frequency signal;

[0030] After the device processes the radio frequency signal through the combination of the above modules, the response time of the pulse modulation signal reaches the microsecond level, the modulation depth can reach more than 50 dB, and the power control range reaches 30 dB.

[0031] Working principle and usage process of the present invention: 1) RF signal process: The RF signal is generated by the crystal oscillator 1 and connected to the input end of the electronic control switch buffer 2. After passing through the electronic control switch buffer 2, it is connected to the input end of the RF narrowband filter 4. The signal is output from the output end of the filter and connected to the input end of the electronic control attenuator 5. The regulated signal is output from the output end of the electronic control attenuator 5 and connected to one port of the signal switching switch 6. After passing through the signal switching switch 6, it is connected to the input end of the amplifier for signal amplification and then output;

[0032] 2) RF signal modulation or switching process: The control signal pulse or high and low levels are connected to the input end of the level converter 3 by the microprocessor. After transformation, one inverted level control signal is connected to the control end of the electronic control switch buffer 2 to control whether the signal generated by the crystal oscillator 1 passes through the buffer for output;

[0033] When the control signal input to the level converter 3 is at a high level, the RF signal is output to the RF narrowband filter 4 through the buffer;

[0034] When the control signal input to the level converter 3 is at a low level, the RF signal is blocked from passing through the buffer, and no RF signal is output to the RF narrowband filter 4;

[0035] Another inverted and in-phase level control signal is connected to the control end of the signal switching switch 6. When the control signal input to the level converter 3 is at a high level, the signal switching switch 6 connects the output end of the electronic control attenuator 5 to the input end of the amplifier, and amplifies the RF signal and then outputs a high-power RF signal;

[0036] When the control signal input to the level converter 3 is at a low level, the signal switching switch 6 disconnects the output end of the electronic control attenuator 5, connects the input end of the amplifier to the ground, blocks the signal from entering the amplifier, and shuts off the output of the high-power signal;

[0037] 3) RF power adjustment: The adjustment voltage terminal output by the microprocessor is connected to the control end of the electronic control attenuator 5. The level of the adjustment voltage controls the attenuation amount. A low voltage results in a large attenuation of the signal and a low level of the output RF signal, while a high voltage results in a small attenuation of the signal and a high level of the output RF signal.

[0038] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A shortwave therapeutic apparatus radio frequency signal source device, comprising a crystal oscillator (1), an electrically controlled switch buffer (2), a level converter (3), a radio frequency narrowband filter (4), an electrically controlled attenuator (5) and a signal switching switch (6), characterized in that: The output end of the crystal oscillator (1) is connected to the input end of the electrically controlled switch buffer (2), the output end of the electrically controlled switch buffer (2) is connected to the input end of the radio frequency narrowband filter (4), the output end of the radio frequency narrowband filter (4) is connected to the input end of the electrically controlled attenuator (5), the output end of the electrically controlled attenuator (5) is connected to the input end of the signal switching switch (6), the output end of the level converter (3) is connected to the input end of the electrically controlled switch buffer (2), and the output end of the level converter (3) is connected to the input end of the signal switching switch (6); Wherein, the control end of the level converter (3) is connected to the modulation pulse input; The control end of the electrically controlled attenuator (5) is connected to the regulating voltage input.

2. A shortwave therapeutic apparatus radio frequency signal source device according to claim 1, characterized in that: The crystal oscillator (1) generates a stable radio frequency signal source waveform through a crystal resonator.

3. A shortwave therapeutic apparatus radio frequency signal source device according to claim 1, characterized in that: The electronically controlled switch buffer (2) uses a buffer with a three-state output and a Schmitt trigger input. By changing the high and low levels of the chip enable terminal, the signal from the crystal oscillator (1) passes through the buffer to output the signal or turn off the output.

4. A shortwave therapeutic apparatus radio frequency signal source device according to claim 1, characterized in that: The level converter (3) is composed of an inverter digital chip, which receives a pulse or level signal from a microprocessor and generates a negative-phase control signal and a positive-phase control signal to control an electronically controlled switch buffer (2) and a signal switching switch (6) to perform pulse modulation and switching of a radio frequency signal.

5. A shortwave therapeutic apparatus radio frequency signal source device according to claim 1, characterized in that: The radio frequency narrowband filter (4) is a "T"-shaped bandpass filter composed of an inductor and a capacitor, which selectively passes radio frequency signals of a set frequency and blocks useless radio frequency signals of other frequencies.

6. A shortwave therapeutic apparatus radio frequency signal source device according to claim 1, characterized in that: The electrically controlled attenuator (5) is composed of a resistor, a capacitor and a PIN diode. By applying different voltages to the control end, the attenuation of the radio frequency signal is different, and the level of the radio frequency signal output to the amplifier is adjusted. When the voltage is low, the attenuation is large, and the output radio frequency signal level is low. When the voltage is high, the attenuation is small, and the output radio frequency signal level is high. Therefore, the power of the radio frequency signal outputted finally changes with the change of the control voltage.

7. A shortwave therapeutic apparatus radio frequency signal source device according to claim 1, characterized in that: The signal switching switch (6) uses a radio frequency signal switch chip, and controls the input of the power amplifier to be connected to the output end of the electrically controlled attenuator (5) or to the ground line by applying different high or low levels to the control end, thereby controlling whether the radio frequency signal enters the amplifier. The control end is synchronously linked with the control end of the electrically controlled switch buffer (2), and finally the pulse modulation and switching functions of the radio frequency signal are obtained.

Images