阅读说明：本技术 一种功率可调固态射频源 (Power adjustable solid state radio frequency source ) 是由 陈杰 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种功率可调固态射频源,包括信号发生器、输出装置和至少一级功率放大器,所述功率放大器连接在信号发生器的输出端和输出装置的输入端之间,所述信号发生器包括有源晶体振荡器,有源晶体振荡器的电压输入端连通可连续调节的供电电压,信号发生器由可连续调节的供电电压,将晶振信号源的可连续调节功率输出至功率放大器,功率放大器将晶振信号源的可连续调节功率放大,并将经过放大的射频功率通过输出装置输出。本发明的功率可调固态射频源具有结构简单、节约成本、技术实现容易和电路性能稳定等优点。(The invention discloses a power-adjustable solid radio frequency source, which comprises a signal generator, an output device and at least one stage of power amplifier, wherein the power amplifier is connected between the output end of the signal generator and the input end of the output device, the signal generator comprises an active crystal oscillator, the voltage input end of the active crystal oscillator is communicated with a continuously adjustable power supply voltage, the signal generator outputs the continuously adjustable power of a crystal oscillator signal source to the power amplifier through the continuously adjustable power supply voltage, and the power amplifier amplifies the continuously adjustable power of the crystal oscillator signal source and outputs the amplified radio frequency power through the output device. The power-adjustable solid-state radio frequency source has the advantages of simple structure, cost saving, easy technical realization, stable circuit performance and the like.)

1. A power tunable solid state rf source, comprising: including signal generator (1), output device (2) and at least one-level power amplifier (3), power amplifier (3) are connected between the output of signal generator (1) and the input of output device (2), signal generator (1) is including active crystal oscillator, and the voltage input intercommunication of active crystal oscillator can continuously adjusted supply voltage, and signal generator (1) is by continuously adjustable supply voltage, but with the continuous adjustment power output of crystal oscillator signal source to power amplifier (3), but power amplifier (3) are with the continuous adjustment power amplification of crystal oscillator signal source to pass through output device (2) output with the radio frequency power of enlargiing.

2. The power tunable solid-state radio frequency source of claim 1, wherein: blocking capacitors are arranged between the output end of the signal generator (1) and the power amplifier (3) and between the power amplifier (3) and the input end of the output device (2).

3. The power tunable solid-state radio frequency source of claim 1, wherein: the power amplifier comprises two or more stages of power amplifiers (3), and a blocking capacitor is arranged between every two adjacent stages of power amplifiers (3).

4. The power tunable solid-state radio frequency source of claim 1, wherein: the power amplifier (3) comprises a power amplifier tube, an input matching circuit (31), a grid feeding circuit (32), a drain feeding circuit (33) and an output matching circuit (34); the grid of the power amplification tube is communicated with the output end of the signal generator (1)/the upper-stage power amplifier (3) through an input matching circuit (31), and is communicated with grid power supply voltage through a grid feed circuit (32); the drain electrode of the power amplification tube is communicated with the input end/next-stage power amplifier (3) of the output device (2) through an output matching circuit (34), and is communicated with the drain electrode power supply voltage through a drain electrode feed circuit (33); and the source electrode of the power amplifier tube is grounded.

5. The power tunable solid-state radio frequency source of claim 4, wherein: the input matching circuit (31) adopts a single-stage L-shaped network, and the output end of the signal generator (1)/the previous-stage power amplifier (3) is connected with a parallel matching capacitor to the ground and then connected with a series matching inductor to the grid input of the power amplifying tube.

6. The power tunable solid-state radio frequency source of claim 4, wherein: the grid feeding circuit (32) comprises a feeding resistor and a ground bypass capacitor, wherein one end of the feeding resistor is connected to the grid of the power amplification tube, and the other end of the feeding resistor is connected to the ground bypass capacitor to the ground and is also connected to a grid feeding voltage.

7. The power tunable solid-state radio frequency source of claim 4, wherein: the drain feed circuit (33) comprises a ground bypass capacitor and a choke inductor, one end of the choke inductor is connected with the drain of the power amplification tube, and the other end of the choke inductor is connected with the ground bypass capacitor to the ground and is also connected with the drain voltage.

8. The power tunable solid-state radio frequency source of claim 4, wherein: the output matching circuit (34) adopts an L-shaped network, and the drain electrode of the power amplifying tube is connected with a series matching inductor and then connected with a parallel matching capacitor to the ground.

9. The power tunable solid-state radio frequency source of claim 1, wherein: the output device (2) is a radio frequency coaxial connector.

Technical Field

The invention relates to the technical field of solid-state radio frequency sources, in particular to a power-adjustable solid-state radio frequency source.

Background

The solid-state radio frequency source has wider application in the fields of medical treatment, science, industry, consumption and the like, and with the aggravation of market competition and the wide application of industry, the cost performance is one of the key considerations of the solid-state radio frequency source. In order to meet the technical application of various industries, the solid-state radio frequency source is often required to realize continuous adjustment of the power.

The existing common adjusting modes are generally as follows: 1. as shown in fig. 1, an adjustable gain amplifier is disposed between a primary power amplifier and a secondary power amplifier or between a signal source and a primary amplifying circuit, and the gain is controlled by a digital signal or an analog signal. 2. As shown in fig. 2, an electrically tunable attenuator is disposed between the first-stage power amplifier and the second-stage power amplifier or between the signal source and the first-stage amplifying circuit, and the attenuation is controlled by a digital signal or an analog signal. 3. As shown in fig. 3, the gate voltages of the first-stage amplifier and the second-stage amplifier are adjusted separately or jointly to adjust the gain of the whole amplification link, however, the adjustment of the gate voltages brings about the adjustment of the quiescent operating point, the harmonic characteristics and stability of the power amplifier may change, and oscillation may even occur in some cases. 4. As shown in fig. 4, the drain voltages of the first-stage amplifier and the second-stage amplifier are adjusted individually or jointly to adjust the gain of the whole amplification link, but the drain voltage is provided by a high-power dc power supply, and to achieve the adjustment of the drain voltage, an output-adjustable dc power supply needs to be selected, which increases more system cost.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a power-adjustable solid-state radio frequency source which has the advantages of simple structure, cost saving, easy technical realization and stable circuit performance.

In order to solve the technical problems, the technical scheme provided by the invention is as follows:

the utility model provides a power adjustable solid-state radio frequency source, includes signal generator, output device and at least one-level power amplifier, power amplifier connects between signal generator's output and output device's input, signal generator includes active crystal oscillator, and the voltage input end intercommunication of active crystal oscillator can continuously be adjusted supply voltage, and signal generator is by continuously adjustable supply voltage, but with the continuous regulation power output of crystal oscillator signal source to power amplifier, but power amplifier is with the continuous regulation power amplification of crystal oscillator signal source to the radio frequency power that will pass through the output device output of will amplifying.

As a further improvement of the above technical solution:

and DC blocking capacitors are arranged between the output end of the signal generator and the power amplifier and between the power amplifier and the input end of the output device.

The power adjustable solid radio frequency source comprises two or more stages of power amplifiers, and a DC blocking capacitor is arranged between every two adjacent stages of power amplifiers.

The power amplifier comprises a power amplifier tube, an input matching circuit, a grid electrode feed circuit, a drain electrode feed circuit and an output matching circuit; the grid of the power amplification tube is communicated with the output end of the signal generator/the upper-stage power amplifier through the input matching circuit and is communicated with grid power supply voltage through the grid feed circuit; the drain electrode of the power amplification tube is communicated with the input end/the next stage power amplifier of the output device through the output matching circuit and is communicated with the drain electrode power supply voltage through the drain electrode feed circuit; and the source electrode of the power amplifier tube is grounded.

The input matching circuit adopts a single-stage L-shaped network, and the output end of the signal generator/the previous-stage power amplifier is connected with a parallel matching capacitor to the ground and then connected with a series matching inductor to the grid input of the power amplifying tube.

The grid feed circuit comprises a feed resistor and a ground bypass capacitor, one end of the feed resistor is connected to the grid of the power amplifier tube, and the other end of the feed resistor is connected to the ground bypass capacitor and the ground and is also connected to grid feed voltage.

The drain electrode feed circuit comprises a ground bypass capacitor and a choke inductor, one end of the choke inductor is connected with the drain electrode of the power amplification tube, and the other end of the choke inductor is connected with the ground bypass capacitor to the ground and is also connected to the drain electrode voltage.

The output matching circuit adopts an L-shaped network, and the drain electrode of the power amplifying tube is connected with the series matching inductor and then connected with the parallel matching capacitor to the ground.

The output device is a radio frequency coaxial connector.

Compared with the prior art, the invention has the advantages that:

the power-adjustable solid-state radio frequency source adopts the signal generator as the radio frequency source, the signal generator comprises an active crystal oscillator, the voltage input end of the active crystal oscillator is communicated with a continuously adjustable power supply voltage, in the adjusting process, the power supply voltage can be continuously adjusted, so that the signal generator generates continuously adjustable power of a crystal oscillator signal source, the power amplifier amplifies the continuously adjustable power of the crystal oscillator signal source and outputs the amplified radio frequency power through the output device, and finally the power of the solid-state radio frequency source can be continuously adjusted.

In the setting mode of the invention, an adjustable gain amplifier or an electrically adjustable attenuator does not need to be additionally arranged, thereby avoiding unnecessary input cost and effectively simplifying the circuit structure. The grid voltage or the drain voltage of the power amplifier does not need to be adjusted, so that the power amplifier works at a fixed static working point, the complexity of adjusting the drain voltage and the grid voltage is avoided, and the stability of the circuit is greatly improved. The function of continuously adjusting the power can be realized under the condition of not adopting the complicated adjustment through simple setting, the technology is easier to realize, and the power adjusting device is suitable for various devices.

Drawings

Fig. 1 to 4 illustrate the output regulation of a conventional solid-state rf source;

FIG. 5 is a schematic diagram of a power tunable solid state RF source of the present invention;

fig. 6 is a circuit schematic of the power tunable solid state rf source of the present invention.

Illustration of the drawings: 1. a signal generator; 2. an output device; 3. a power amplifier; 31. an input matching circuit; 32. a gate feed circuit; 33. a drain feed circuit; 34. and an output matching circuit.

Detailed Description

In order to facilitate understanding of the invention, the invention will be described more fully and in detail with reference to the accompanying drawings and preferred embodiments, but the scope of the invention is not limited to the specific embodiments below.

Example (b):

as shown in fig. 5 and fig. 6, the power tunable solid-state rf source of the present embodiment includes a signal generator 1, an output device 2, and at least one stage of power amplifier 3, where the power amplifier 3 is connected between an output terminal of the signal generator 1 and an input terminal of the output device 2, and the signal generator 1 includes an active crystal oscillator, as shown in the diagram CX1, whose rated operating voltage is generally 5V, 3.3V, or other lower dc voltage value. The voltage input end Vcc of the active crystal oscillator is communicated with a continuously adjustable power supply voltage, the signal generator 1 outputs the continuously adjustable power of the crystal oscillator signal source to the power amplifier 3 by the continuously adjustable power supply voltage, the power amplifier 3 amplifies the continuously adjustable power of the crystal oscillator signal source and outputs the amplified radio frequency power through the output device 2. The output device 2 is a radio frequency coaxial connector. In the embodiment, the output power of the signal generator 1 is continuously adjusted by continuously adjusting the supply voltage of the active crystal oscillator, so that the power of the solid-state radio frequency source can be continuously adjusted finally.

Because the regulation power range of the crystal oscillator is small, the supply voltage reaches a certain value, the crystal oscillator does not output, and the crystal oscillator is generally regarded as constant-voltage power supply in the radio frequency field, so the technical concept of regulating the voltage of the crystal oscillator is lacked in the radio frequency field. The scheme of this embodiment adopts the mode that adjusts active crystal oscillator supply voltage and adjusts output, not only provides new thinking for the regulation mode in the radio frequency source field, still further reduces the radio frequency source cost in industry and consumption field.

The existing solid-state radio frequency source technology is all from the basic architecture of communication products, the radio frequency source for communication is generally high frequency above 1GHz and is realized through a circuit with a complex structure, so that the radio frequency source has the condition that the voltage cannot be adjusted, and the power adjustment is realized by adding an attenuator, an adjustable gain amplifier or the voltage of an adjusting and amplifying circuit at the later stage. However, in the field of the industrial solid-state radio frequency source below 100MH, the active crystal oscillator can be used to replace the radio frequency source formed by the traditional complex circuit, and an adjustable gain amplifier or an electrically-tuned attenuator is not required to be additionally arranged, so that unnecessary investment cost is avoided, and the circuit structure can be effectively simplified. The grid voltage or the drain voltage of the power amplifier 3 does not need to be adjusted, so that the power amplifier 3 works at a fixed static working point, the complexity of adjusting the drain voltage and the grid voltage is avoided, and the stability of the circuit is greatly improved. The function of continuously adjusting the power can be realized under the condition of not adopting the complicated adjustment through simple setting, the technology is easier to realize, and the power adjusting device is suitable for various devices. The solid-state radio frequency source is particularly suitable for the field of ISM solid-state radio frequency sources with the working frequency of less than 100MHz, including solid-state radio frequency sources in VHF frequency bands of 2MHz, 13.56MHz, 27.12MHz, 40.68MHz and the like. And the existing solid-state radio frequency source is applied to the industrial or consumer field, and the requirement of communication products is not so high, so the signal generator 1 can be adopted as the radio frequency source.

In this embodiment, the power-adjustable solid-state rf source includes two stages of power amplifiers 3, a first dc blocking capacitor C1 is disposed between the output end of the signal generator 1 and the power amplifier 3, a second dc blocking capacitor C2 is disposed between the power amplifier 3 and the input end of the output device 2, and a third dc blocking capacitor C3 is disposed between two adjacent stages of power amplifiers 3. In this embodiment, the solid-state rf source formed by the single-stage power amplifier 3 or the power amplifiers 3 with more than two stages may also be used in combination with other power adjustment methods to adjust the output power of the solid-state rf source.

In this embodiment, the power amplifier 3 includes a power amplifier tube, an input matching circuit 31, a gate feed circuit 32, a drain feed circuit 33, and an output matching circuit 34; the grid of the power amplifier tube is communicated with the output end of the signal generator 1/the upper-stage power amplifier 3 through the input matching circuit 31, and is communicated with grid power supply voltage through the grid feed circuit 32; the drain electrode of the power amplifier tube is communicated with the input end of the output device 2/the next-stage power amplifier 3 through an output matching circuit 34, and is communicated with the drain electrode power supply voltage through a drain electrode feed circuit 33; the source electrode of the power amplifier tube is grounded.

In this embodiment, the input matching circuit 31 includes a capacitor and an inductor, and a single-stage L-type network is adopted, and the output end of the signal generator 1/the previous-stage power amplifier 3 is connected to the parallel matching capacitor to the ground, and then connected to the series matching inductor to the gate input of the power amplifier tube.

The primary power amplifier 3 includes a first power amplifier transistor Q1, the capacitance of the input matching circuit 31 is a fourth capacitance C4, and the inductance is a first inductance L1; the secondary power amplifier 3 includes a second power amplifier Q2 with a rated operating rf power of 150W, and the input matching circuit 31 has a fifth capacitor C5 and an inductor L2.

In this embodiment, the gate feeding circuit 32 includes a feeding resistor and a ground bypass capacitor, the feeding resistor is connected to the gate of the power amplifier tube at one end, and the other end of the feeding resistor is connected to the ground bypass capacitor to ground and further connected to the gate feeding voltage.

In a gate feed circuit 32 of the primary power amplifier 3, a ground bypass capacitor is a sixth capacitor C6 and a seventh capacitor C7 which are connected in parallel, a feed resistor is a first resistor R1, and a gate supply voltage is Vgs 1; in the gate feed circuit 32 of the secondary power amplifier 3, the shunt capacitance to ground is an eighth capacitance C8 and a ninth capacitance C9, a third inductance L3 is further connected in series between the eighth capacitance C8 and the gate supply voltage, the feed resistance is a second resistance R2 and a third resistance R3 which are connected in parallel, and the gate supply voltage is Vgs 2.

In this embodiment, the drain feed circuit 33 includes a ground bypass capacitor and a choke inductor, one end of the choke inductor is connected to the drain of the power amplifier tube, and the other end of the choke inductor is connected to the ground bypass capacitor and the ground, and is also connected to the drain voltage.

In the drain feed circuit 33 of the primary power amplifier 3, the ground bypass capacitors comprise a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12 and a first electrolytic capacitor EC1 which are connected in parallel, the choke inductor is a fourth inductor L4, and the drain supply voltage is Vds 1; in the drain feed circuit 33 of the two-stage power amplifier 3, the ground bypass capacitors are a thirteenth capacitor C13, a fourteenth capacitor C14 and a second electrolytic capacitor EC2 which are connected in parallel, the choke inductor is a fifth inductor L5, and the drain supply voltage is Vds 2.

In this embodiment, the output matching circuit 34 includes a capacitor and an inductor, and adopts an L-type network form, and the drain of the power amplifier tube is connected to the series matching inductor, and then connected to the parallel matching capacitor to ground. Namely, the inductor is connected in series between the drain of the power amplifier tube and the input end of the output device 2/the next-stage power amplifier 3, and the capacitor is connected between the inductor and the input end of the output device 2/the connection end of the next-stage power amplifier 3 and the ground.

In the output matching circuit 34 of the primary power amplifier 3, the capacitor is a fifteenth capacitor C15, and the inductor is a sixth inductor L6; in the output matching circuit 34 of the secondary power amplifier 3, the capacitor is a sixteenth capacitor C16, and the inductor is a seventh inductor L7.

In this embodiment, the power-adjustable solid-state rf source has a working frequency of 40.68MHz, a combined gain of the two stages of power amplification circuits 3 is about 45dB, and an efficiency is about 80% under a 150W output condition. The gain of the amplifying circuit is kept unadjusted, and the power of the crystal oscillator signal source is adjusted by adjusting the power supply voltage Vcc of the active crystal oscillator, so that the output power of the solid-state radio frequency source is adjusted.

Taking an active crystal oscillator powered by 5V as an example, the adjustment data of the output power of the crystal oscillator signal source and the power supply voltage Vcc are shown in the following table:

table 1: regulating data of output power and supply voltage Vcc of crystal oscillator signal source

Supply voltage Vcc/V	Signal source output power/dBm	Output power of signal source/mW
			1	-4.74	0.34
1.2	-1.47	0.71
			1.4	0.94	1.24
1.6	2.93	1.96
			1.8	4.56	2.86
2.0	5.94	3.93
			2.2	7.14	5.18
2.4	8.21	6.62
			2.6	9.15	8.22
2.8	10	10.00
			3	10.8	12.02
3.2	11.5	14.13
			3.4	12.16	16.44
3.6	12.78	18.97
			3.8	13.36	21.68
4.0	13.9	24.55
			4.2	14.42	27.67
4.4	14.9	30.90
			4.6	15.36	34.36
4.8	15.79	37.93
			5.0	16.2	41.69

Therefore, the supply voltage of the crystal oscillator is adjusted from 1V to 5V, and the output power adjustment range of the signal source can reach about 21 dB.

In the solid-state radio frequency source of the 150W two-stage power amplifying circuit, the crystal oscillator power supply voltage Vcc and the radio frequency output power regulation data are shown in the following table:

table 2: crystal oscillator supply voltage Vcc and RF output power regulation data

Supply voltage Vcc/V	Solid state source output power/dBm	Solid state source output power/W
			1.00	37.21	5.26
1.20	42.12	16.29
			1.40	45.30	33.88
1.60	47.69	58.75
			1.80	49.44	87.90
2.00	50.44	110.66
			2.20	51.04	127.06
2.40	51.42	138.68
			2.60	51.66	146.55
2.80	51.80	151.36
			3.00	51.88	154.17
3.20	51.94	156.31
			3.40	51.98	157.76
3.60	52.01	158.85
			3.80	52.03	159.59
4.00	52.03	159.59
			4.20	52.04	159.96
4.40	52.04	159.96
			4.60	52.04	159.96
4.80	52.05	160.32
			5.00	52.07	161.06

Therefore, the supply voltage of the crystal oscillator is adjusted from 1V to 5V, the output power of the solid-state radio frequency source can be adjusted from 5W to 161W, and the power adjustment application requirement of the solid-state radio frequency source in the ISM field is met.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. It should be apparent to those skilled in the art that modifications and variations can be made without departing from the technical spirit of the present invention.