CN-115051659-B - Frequency adjusting device of power amplifier and shortwave therapeutic apparatus

Abstract

The invention discloses a frequency adjusting device of a power amplifier and a shortwave therapeutic apparatus, which are applied to the field of power amplification. The power amplifier is used for conducting the first end of the power amplifier and the second end of the power amplifier according to the control end; the frequency selecting module is used for adjusting the input impedance of the power amplifier to an ideal input impedance at the target frequency, and the ratio of the ideal input impedance to the actual output impedance at the target frequency is-1. The input impedance of the power amplifier is adjusted to have the ratio of-1 with the actual output impedance through the frequency selection module, the amplitude and the phase of the input impedance and the output impedance are balanced, the input impedance and the output impedance are matched at the moment, and the power amplifier can achieve higher frequency.

Inventors

• HE YONGZHENG
• LIU JIAJIA
• ZHENG SHIMING
• Li Chuangkai
• GUO XIAOYAN

Assignees

• 河南翔宇医疗设备股份有限公司

Dates

Publication Date

20260505

Application Date

20220607

Claims (7)

1. 1. The frequency adjusting device of the power amplifier is characterized by comprising the power amplifier, a frequency selecting module and a first inductor; The power supply is connected with the first end of the first inductor, the second end of the first inductor is respectively connected with the first end of the load, the first end of the frequency selection module and the first end of the power amplifier, the second end of the frequency selection module is connected with the control end of the power amplifier, and the second end of the power amplifier is grounded after being connected with the second end of the load; the impedance of the first inductor and the load under the target frequency is the actual output impedance of the power amplifier under the target frequency; the frequency selection module is used for adjusting the input impedance of the power amplifier to an ideal input impedance at a target frequency, and the ratio of the ideal input impedance to the actual output impedance at the target frequency is-1; the frequency selecting module comprises a third inductor and a first capacitor; The first end of the first capacitor is used as the first end of the frequency selection module, the second end of the first capacitor is connected with the first end of the third inductor, and the second end of the third inductor is used as the second end of the frequency selection module; The equivalent impedance of the first inductor and the load is actual output impedance zo=rl+jx2, wherein RL is the impedance of the load, and jx2 is the impedance of the first inductor; The ideal input impedance zin= -r-jX1 of the frequency selection module and the power amplifier, wherein-r is the impedance of the power amplifier, -jX1 is the impedance of the frequency selection module; The relation between the ideal input impedance and the actual output impedance is Zin/zo= -1; The power amplifier further comprises a direct current bias module, wherein the direct current bias module is connected with the control end of the power amplifier; The direct current bias module is used for providing the working frequency of the power amplifier and assisting in starting the oscillation of the power amplifier.
2. 2. The frequency adjustment device of a power amplifier of claim 1, further comprising a filter module, a first end of the filter module being connected to the power supply, a second end of the filter module being connected to a first end of the first inductor; The filtering module is used for filtering out harmonic waves of the power supply output.
3. 3. The frequency adjustment device of the power amplifier of claim 2, wherein the filtering module comprises a first capacitance module, a second inductance and a second capacitance module; The first end of the first capacitor module is used as the first end of the filter module, the second end of the first capacitor module is connected with the first end of the second inductor, the second end of the second inductor is connected with the first end of the second capacitor module, and the second end of the second capacitor is used as the second end of the filter module.
4. 4. The frequency adjustment device of claim 1, further comprising an input impedance matching module, a first end of the input impedance matching module being connected to a control end of the power amplifier, the input impedance matching module being configured to impedance match a signal output by the frequency selection module with the power amplifier.
5. 5. The frequency adjustment device of claim 1, further comprising an output impedance matching module, a first end of the output impedance matching module being connected to the first end of the power amplifier, a second end of the output impedance matching module being connected to the first end of the load, the output impedance matching module being configured to impedance match a signal output by the power amplifier to the load.
6. 6. The frequency adjustment device of a power amplifier according to claim 1, wherein when the power amplifier is an NPN-type transistor, a base of the NPN-type transistor is used as a control terminal of the power amplifier, a collector of the NPN-type transistor is used as a first terminal of the power amplifier, and an emitter of the NPN-type transistor is used as a second terminal of the power amplifier.
7. 7. A shortwave therapeutic apparatus comprising a frequency adjustment device of a power amplifier according to any one of claims 1 to 6.

Description

Frequency adjusting device of power amplifier and shortwave therapeutic apparatus Technical Field The invention relates to the field of power amplification, in particular to a frequency adjusting device of a power amplifier and a shortwave therapeutic apparatus. Background The short wave therapeutic apparatus adopts the power amplifier to amplify the signal, but in the prior art, the power amplifier cannot work in a high-frequency band due to the existence of the Miller effect, and the normal work of the power amplifier is affected. Disclosure of Invention The invention aims to provide a frequency adjusting device of a power amplifier and a shortwave therapeutic apparatus, wherein the input impedance of the power amplifier is adjusted to have the ratio of-1 with the actual output impedance through a frequency selecting module, the amplitude of the input impedance and the output impedance are balanced, the phase is balanced, the input impedance is matched with the output impedance at the moment, and the power amplifier can realize higher frequency. In order to solve the technical problems, the invention provides a frequency adjusting device of a power amplifier, which comprises the power amplifier, a frequency selecting module and a first inductor; The power supply is connected with the first end of the first inductor, the second end of the first inductor is respectively connected with the first end of the load, the first end of the frequency selection module and the first end of the power amplifier, the second end of the frequency selection module is connected with the control end of the power amplifier, and the second end of the power amplifier is grounded after being connected with the second end of the load; the impedance of the first inductor and the load under the target frequency is the actual output impedance of the power amplifier under the target frequency; The frequency selection module is used for adjusting the input impedance of the power amplifier to an ideal input impedance at a target frequency, and the ratio of the ideal input impedance to the actual output impedance at the target frequency is-1. Preferably, the power supply further comprises a filtering module, wherein a first end of the filtering module is connected with the power supply, and a second end of the filtering module is connected with a first end of the first inductor; The filtering module is used for filtering out harmonic waves of the power supply output. Preferably, the filtering module comprises a first capacitor module, a second inductor and a second capacitor module; The first end of the first capacitor module is used as the first end of the filter module, the second end of the first capacitor module is connected with the first end of the second inductor, the second end of the second inductor is connected with the first end of the second capacitor module, and the second end of the second capacitor is used as the second end of the filter module. Preferably, the power amplifier further comprises a direct current bias module, wherein the direct current bias module is connected with the control end of the power amplifier; the DC bias module is used for assisting in starting oscillation of the power amplifier. Preferably, the power amplifier further comprises an input impedance matching module, wherein a first end of the input impedance matching module is connected with a control end of the power amplifier, and the input impedance matching module is used for performing impedance matching on signals output by the frequency selection module and the power amplifier. Preferably, the power amplifier further comprises an output impedance matching module, wherein a first end of the output impedance matching module is connected with a first end of the power amplifier, a second end of the output impedance matching module is connected with a first end of the load, and the output impedance matching module is used for performing impedance matching on signals output by the power amplifier and the load. Preferably, when the power amplifier is an NPN transistor, a base of the NPN transistor is used as a control terminal of the power amplifier, a collector of the NPN transistor is used as a first terminal of the power amplifier, and an emitter of the NPN transistor is used as a second terminal of the power amplifier. Preferably, the frequency selecting module comprises a third inductor and a first capacitor; The first end of the first capacitor is used as the first end of the frequency selection module, the second end of the first capacitor is connected with the first end of the third inductor, and the second end of the third inductor is used as the second end of the frequency selection module. Preferably, the equivalent impedance of the first inductor and the load is actual output impedance zo=rl+jx2, where RL is the impedance of the load and jx2 is the impedance of the first inductor; The ideal input impedance zin= -r-jX1 of the frequency s