Microwave generator with power factor correction function and control method thereof

Patent metadata

Field	Value
Publication number	US-10476433-B2
Application number	US-201715632076-A
Country	US
Kind code	B2
Filing date	Jun 23, 2017
Priority date	Jul 5, 2016
Publication date	Nov 12, 2019
Grant date	Nov 12, 2019

Abstract

A microwave generator includes a power supply, an output circuit, a feedback oscillator, a pulse controller, a signal combination circuit and a semiconductor amplifier. The power supply converts input voltage and input current into output voltage and output current. The output circuit generates a microwave signal to an output terminal of the microwave generator and a feedback signal according to the microwave signal. The feedback oscillator generates an oscillation signal according to the feedback signal. According to a reference signal, the pulse controller generates a pulse signal. According to the oscillation signal and pulse signal, the signal combination circuit generates a control signal. The semiconductor amplifier generates and adjusts an amplified signal according to the control signal. The output circuit generates the microwave signal according to the amplified signal. The output current is adjusted according to the amplified signal. Consequently, the input current and the input voltage are in phase.

First claim

What is claimed is:

1. A control method for a microwave generator, the microwave generator outputting a microwave signal and comprising a power supply, a pulse controller, an output circuit, a feedback oscillator, a signal combination circuit and a semiconductor amplifier, the control method comprising steps of:
(a) the power supply converting an input voltage and an input current into an output voltage and an output current, and providing the output voltage and the output current to the semiconductor amplifier;
(b) the output circuit generating the microwave signal and generating a feedback signal according to the microwave signal;
(c) the feedback oscillator generating an oscillation signal according to the feedback signal;
(d) providing a reference signal to the pulse controller, so that the pulse controller generates a pulse signal according to the reference signal, wherein the reference signal is related to the input voltage and/or harmonics of the input voltage;
(e) the signal combination circuit generating a control signal according to the oscillation signal and the pulse signal; and
(f) the semiconductor amplifier generating and adjusting an amplified signal according to the control signal, and the output circuit generating the microwave signal according to the amplified signal, wherein the output current is adjusted according to the amplified signal, so that the input current and the input voltage are in phase;
wherein the pulse controller comprises a triangular wave generator and a comparator, and the step (d) comprises sub-steps:
(d1) the triangular wave generator generating a triangular wave signal;
(d2) the comparator judging whether a voltage level of the reference signal is higher than a voltage level of the triangular wave signal;
(d3) if a judging result of the sub-step (d2) is satisfied, outputting the pulse signal in a high level state from the comparator and subsequently performing the step (e); and
(d4) if the judging result of the sub-step (d2) is not satisfied, outputting the pulse signal in a low level state from the comparator and subsequently performing the step (e).

2. A microwave generator, comprising:
a power supply for converting an input voltage and an input current into an output voltage and an output current;
an output circuit connected with an output terminal of the microwave generator, wherein the output circuit generates a microwave signal to the output terminal and generates a feedback signal according to the microwave signal;
a feedback oscillator electrically connected with the output circuit, wherein the feedback oscillator generates an oscillation signal according to the feedback signal;
a pulse controller for receiving a reference signal related to the input voltage and/or harmonics of the input voltage and generating a pulse signal, wherein the pulse controller comprises:
a triangular wave generator for generating a triangular wave signal; and
a comparator, wherein a first input terminal of the comparator receives the reference signal, a second input terminal of the comparator is electrically connected with the triangular wave generator to receive the triangular wave signal, and an output terminal of the comparator is electrically connected with a semiconductor amplifier;

wherein the comparator generates the pulse signal to the semiconductor amplifier according to a result of comparing the reference signal and the triangular wave signal;
a signal combination circuit for combining the oscillation signal with the pulse signal to generate a control signal; and
wherein the semiconductor amplifier is electrically connected with the power supply, the signal combination circuit and the output circuit, wherein the semiconductor amplifier receives the output voltage and the output current, generates and adjusts an amplified signal according to the control signal, wherein the output circuit generates the microwave signal according to the amplified signal, and the output current is adjusted according to the amplified signal, so that the input current and the input voltage are in phase.

3. The microwave generator according to claim 1 , wherein if a voltage level of the reference signal is higher than a voltage level of the triangular wave signal, the pulse signal in a high level state is outputted from the comparator, wherein if the voltage level of the triangular wave signal is higher than the voltage level of the reference signal, the pulse signal in a low level state is outputted from the comparator.

4. The microwave generator according to claim 1 , wherein after a product of the square of the input voltage and a proportion coefficient is divided by a predetermined value, the reference signal is obtained, wherein after the input voltage is rectified by a bridge-type rectifier of the power supply, a rectified voltage is generated, wherein the predetermined value is equal to an average value of the rectified voltage.

5. The microwave generator according to claim 1 , wherein the semiconductor amplifier is a lateral diffusion metal oxide semiconductor or a gallium nitride high electron mobility transistor.

6. The microwave generator according to claim 1 , wherein the microwave generator is included in a microwave apparatus or a RF wireless apparatus.

7. The microwave generator according to claim 1 , wherein the signal combination circuit comprises an AND gate, wherein a first input terminal of the AND gate is electrically connected with the feedback oscillator to receive the oscillation signal, a second input terminal of the AND gate is electrically connected with the pulse controller to receive the pulse signal, and an output terminal of the AND gate is electrically connected with the semiconductor amplifier, wherein after the oscillation signal and the pulse signal are combined together by the AND gate, the control signal is generated to the semiconductor amplifier.

8. The microwave generator according to claim 1 , wherein the output circuit comprises a detecting circuit electrically connected with the feedback oscillator and an output terminal of the output circuit for generating the feedback signal according to the microwave signal.

9. A microwave generator, comprising:
a power supply for converting an input voltage and an input current into an output voltage and an output current;
an output circuit connected with an output terminal of the microwave generator, wherein the output circuit generates a microwave signal to the output terminal and generates a feedback signal according to the microwave signal;
a feedback oscillator electrically connected with the output circuit, wherein the feedback oscillator generates an oscillation signal according to the feedback signal;
a splitter electrically connected with the feedback oscillator for splitting the oscillation signal into plural segmented oscillation signals;
a pulse controller for receiving a reference signal related to the input voltage and/or harmonics of the input voltage and generating a pulse signal;
plural signal combination: circuits for combining the corresponding segmented oscillation signal with the pulse signal to generate corresponding control signals; and
plural semiconductor amplifiers electrically connected with the power supply, the corresponding signal combination circuits and the output circuit, wherein each semiconductor amplifier receives the output voltage and the output current, generates and adjusts a respective amplified signal according to the respective control signal, wherein the output circuit generates the microwave signal according to the respective amplified signals outputted from the plural semiconductor amplifiers, and the output current is adjusted according to the amplified signals outputted from t

Assignees

• Delta Electronics Inc

Inventors

• Jang Yungtaek
• Chen Yin-Yuan
• Li sheng-hua

Classifications

• H03K7/06

  Frequency or rate modulation, i.e. PFM or PRM · CPC title

• H03K7/02

  Amplitude modulation, i.e. PAM · CPC title

• H03K4/06 Primary

  having triangular shape · CPC title

• H03K4/08

  having sawtooth shape · CPC title

• H03K3/00

  Circuits for generating electric pulses; Monostable, bistable or multistable circuits (H03K4/00 takes precedence; for digital function generators in computers G06F1/02) · CPC title