CN210183288U

CN210183288U - High-power radio frequency VCO circuit

Info

Publication number: CN210183288U
Application number: CN201920948031.8U
Authority: CN
Inventors: Huai Gao; 高怀; Haijian Shi; 施海健; Wenwei Zhang; 张文伟; Ying Chang; 常颖; Kaihang Wang; 王凯航
Original assignee: Suzhou Hua Shi Wireless Tech Co Ltd
Current assignee: Suzhou Hua Shi Wireless Tech Co Ltd
Priority date: 2019-06-24
Filing date: 2019-06-24
Publication date: 2020-03-24
Anticipated expiration: 2029-06-24

Abstract

The utility model discloses a high-power radio frequency VCO circuit, which comprises a frequency-selecting oscillation starting unit, an interstage matching unit and a power amplifying unit which are connected in sequence; the frequency-selecting oscillation starting unit inputs an external tuning signal through a VT end and generates an oscillation starting signal; the interstage matching unit is used for carrying out primary matching on the oscillation starting signal generated by the frequency-selecting oscillation starting unit and then outputting the oscillation starting signal to the power amplifying unit; and the power amplification unit is used for further power amplifying the oscillation starting signal processed by the interstage matching unit and performing secondary matching on the amplified signal. The utility model discloses an adopt the electric capacity bikini oscillating structure of high stability, the microstrip line oscillating inductance of high Q value and the radio frequency oscillation pipe of high cut-off frequency ft produce stable oscillating signal, then carry out oscillating signal's enlargies through stage-to-stage matching and effectual isolation means, optimize amplifying signal once more at last, realized effectual design of integrating, the wholeness can be more reliable and more stable.

Description

High-power radio frequency VCO circuit

Technical Field

The utility model relates to a circuit field, concretely relates to high-power radio frequency VCO circuit.

Background

A VCO, i.e., a voltage controlled oscillator, is an important component of a radio frequency circuit, and the VCO plays an important role in the fields of communications, electronics, and the like since its birth, and has a wide range of applications. In the early days of radio technology development, it was used in transmitters to generate high frequency carrier voltages and in superheterodyne receivers as local oscillators, which became essential components of transmitting and receiving equipment. With the development of communication technology, new devices gradually popularize various signal modulation modes such as frequency division multiplexing, frequency hopping and the like, so that the VCO circuit has an increasingly important role in the field of electronic communication. In addition, in the field of information security, the VCO is also used to generate interference signals in various frequency bands, and is widely used in important places and environments such as examination rooms, government offices, national defense and the like.

At present, with the continuous upgrade of wireless communication technology and the gradual start-up of a 5.8GHz radio frequency communication frequency band, a high-power VCO capable of working in the 5.8GHz frequency band is required in the market, and particularly, a 20dBm power level VCO can save a rear-stage power amplification part, thereby being beneficial to the miniaturization and integration application of products.

SUMMERY OF THE UTILITY MODEL

The utility model discloses the purpose is: the high-power radio frequency VCO circuit is characterized in that an oscillating circuit, an interstage matching circuit, a power amplifying circuit and a peripheral power supply circuit are designed in an integrated mode, the VCO circuit with high frequency, high isolation and high power is provided, and the VCO circuit is applied to the communication field including 5.8GHz and the information safety field, can be generally used for the existing communication frequency band and effectively reduces the size of the whole VCO circuit. The whole machine equipment works stably, and the failure rate is low.

The technical scheme of the utility model is that:

a high-power radio frequency VCO circuit comprises a frequency-selecting oscillation starting unit, an interstage matching unit and a power amplifying unit which are sequentially connected, and further comprises a direct current power supply unit;

the frequency-selecting oscillation starting unit inputs an external tuning signal through a VT end and generates an oscillation starting signal;

the interstage matching unit is used for carrying out primary matching on the oscillation starting signal generated by the frequency-selecting oscillation starting unit and then outputting the oscillation starting signal to the power amplifying unit;

the power amplification unit is used for further power amplifying the oscillation starting signal processed by the interstage matching unit and performing secondary matching on the amplified signal;

and the direct current power supply unit provides working voltage for the frequency-selecting oscillation starting unit and the power amplification unit.

Preferably, the frequency-selecting oscillation starting unit comprises a filter circuit and an oscillation starting core circuit which are sequentially connected, wherein the oscillation starting core circuit comprises a varactor diode, a two-stage access capacitor and a capacitor three-point oscillation circuit, the varactor diode is reversely connected between an output end of the filter circuit and the ground, and the two access capacitors are sequentially arranged between the output end of the filter circuit and an input end of the capacitor three-point oscillation circuit.

Preferably, the capacitance three-point type oscillating circuit comprises an oscillating transistor, two oscillating capacitors, an oscillating inductor in the form of a microstrip line and a radio frequency choke inductor; the two oscillation capacitors are connected in series and then connected in parallel with the grounded oscillation inductor, three end points of the series oscillation capacitor are connected with three electrodes of the oscillation transistor, and the radio frequency choke inductor is connected in parallel with the grounded oscillation capacitor.

Preferably, the inter-stage matching unit comprises an oscillating transistor matching circuit, a first blocking capacitor, a T-shaped attenuation network and a second blocking capacitor which are sequentially cascaded; the oscillating transistor matching circuit comprises a capacitor and an inductor, wherein one end of the capacitor is connected with the output end of the frequency-selecting oscillation starting unit, and the other end of the capacitor is connected with the inductor in series and is grounded.

Preferably, the power amplification unit comprises a power amplification tube, the power amplification tube is connected in series to the dc power supply unit through a matching inductor, is connected in parallel to the ground through a matching capacitor, and outputs a power amplification signal through a third blocking capacitor.

Preferably, the dc power supply unit includes two step-down resistors connected to the VCC terminal, two filter capacitors connected to the ground with the other end of the step-down resistors, a radio frequency choke inductor of the collector of the oscillation transistor, and four voltage dividing resistors for supplying power to the bases of the oscillation transistor and the power amplifier tube, respectively.

Preferably, the frequency-selecting oscillation starting unit realizes the oscillation frequency from 50MHz to 6GHz by adjusting the value of the oscillation component, and the relative bandwidth of 20% is realized in any frequency band from 50MHz to 6 GHz.

Preferably, the power level of the oscillation signal amplified by the power amplification unit is greater than 20dBm in the frequency range of 50MHz-2.7GHz, greater than 12dBm in the frequency range of 2.7GHz-4.5GHz, and greater than 8dBm in the frequency range of 4.5GHz-6 GHz.

The utility model has the advantages that: by adopting a high-stability capacitance three-point oscillation structure, a high-Q-value microstrip line oscillation inductor and a high-cut-off frequency ft radio frequency oscillation tube generate stable oscillation signals, then the oscillation signals are amplified through interstage matching and an effective isolation means, and finally the amplified signals are optimized again, so that the output impedance of the whole circuit is matched with the impedance of a real part of 50 omega. The whole circuit integrates three parts of an oscillation unit, an isolation unit and an amplification unit, so that the effective integrated design is realized, and meanwhile, a high-gain radio frequency triode device is used, so that the overall performance is more stable and reliable.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required to be used in the description of the embodiments are briefly introduced below, the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a high-power rf VCO circuit according to an embodiment of the present invention;

wherein:

1. a frequency-selecting oscillation starting unit;

2. an interstage matching unit;

3. a power amplifying unit;

4. a DC power supply unit.

Detailed Description

The above-described scheme is further illustrated below with reference to specific examples. It should be understood that these examples are for illustrative purposes and are not intended to limit the scope of the present invention. The conditions used in the examples may be further adjusted according to the conditions of the particular manufacturer, and the conditions not specified are generally the conditions in routine experiments.

Referring to a schematic structural diagram of a high-power radio frequency VCO circuit shown in fig. 1, the high-power radio frequency VCO circuit includes a frequency-selective oscillation starting unit 1, an inter-stage matching unit 2, a power amplification module 3, and a dc power supply unit 4 for supplying power to the whole circuit.

The frequency-selecting oscillation starting unit 1 comprises a tuning signal processing part and an oscillation starting core part, an external tuning signal enters a circuit through a VT end, then the external tuning signal is processed by an LC filter circuit consisting of an inductor L1 and a capacitor C1, and then the processed signal is loaded on a variable capacitance diode D1 which is reversely connected, so that the variable capacitance diode D1 presents certain capacitance, and the capacitive reactance which changes along with tuning voltage enters the capacitance three-point oscillation starting core part through two-stage access capacitors C2 and C5 to generate an oscillation starting signal with certain frequency. The capacitance three-point type oscillation starting core part comprises an oscillation inductor L2, oscillation capacitors C3 and C4, an oscillation tube U1 and a radio frequency choke inductor L3.

The interstage matching unit 2 performs first matching on the generated oscillation starting signal through a capacitor C6 and an inductor L4, primarily adjusts the signal flatness and inhibits second and third harmonics of the oscillation starting signal, then the influence of a second-stage amplifying circuit on a first-stage oscillating circuit is isolated through a first-stage T-shaped attenuation network R3, R4 and R5, the capacitor C7 serves as a collector blocking capacitor of an oscillating tube U1, and the capacitor C8 serves as a base blocking capacitor of a next-stage amplifying tube U2.

The power amplification unit 3 further amplifies the oscillation starting signal processed by the interstage matching unit 2 through an amplification tube U2, and can be used as a buffer to weaken the influence of output impedance mismatch on a first-stage oscillation circuit, an LC matching circuit with an output end composed of an inductor L6 and a capacitor C9 performs second matching on the amplified signal, the flatness is optimized, the output impedance is matched to 50 omega, and the capacitor C10 is used as a collector blocking capacitor of the amplification tube U2.

The high-power radio frequency VCO circuit further comprises a direct current power supply unit 4, the direct current power supply unit 4 supplies power to the base electrode and the collector electrode of the oscillating tube U1 and the amplifying tube U2 through voltage reduction resistors R8 and R9 and voltage division resistors R1, R2, R6 and R7 respectively, C11 and C12 are alternating current filter capacitors on a direct current path, and an inductor L5 is a radio frequency choke inductor of the oscillating tube U1.

Preferably, in the above embodiment, the overall quality factor of the VCO circuit can be changed by optimizing the Q value of the microstrip line oscillation inductor L2, optimizing the values of the access capacitors C2 and C5, and optimizing the proportions of the oscillation capacitors C3 and C4 in the frequency-selective oscillation start unit 1, so as to significantly reduce the phase noise of the VCO circuit.

Preferably, in the above embodiment, the values of the dc blocking capacitors C7 and C8 described in the inter-stage matching unit 2 have a large influence on the oscillation condition and the inter-stage isolation, the value of the dc blocking capacitor C7 may be appropriately adjusted to relax the oscillation starting condition, so that the circuit is more stable, and the value of the dc blocking capacitor C8 may be appropriately adjusted to increase the inter-stage isolation.

Preferably, in the above embodiment, the resonant point of the LC matching circuit composed of the inductor L6 and the capacitor C9 in the power amplifying unit 3 should be near the oscillation frequency, so that the reflected power caused by the mismatch of the output impedance of the circuit can be effectively absorbed.

Further preferably, in the above embodiment, the oscillating tube U1 in the frequency-selective oscillation starting unit 1 and the amplifying tube U2 in the power amplifying unit 3 may be chip type innuoxun YG380, and the chip of the innuoxun YG380 has the characteristics of 20dB high gain, 22dBm high power and 40GHz high cut-off frequency, and is suitable for being used as the oscillating tube U1 and the amplifying tube U2 of the present embodiment.

It is to be emphasized that: the above embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form, and any simple modifications, equivalent changes and modifications made by the technical spirit of the present invention to the above embodiments are all within the scope of the technical solution of the present invention.

Claims

1. A high-power radio frequency VCO circuit is characterized by comprising a frequency-selecting oscillation starting unit, an interstage matching unit and a power amplifying unit which are sequentially connected, and further comprising a direct current power supply unit;

2. The high power RF VCO circuit according to claim 1, wherein said frequency-selective oscillation start unit comprises a filter circuit, an oscillation start core circuit, and a varactor diode, a two-stage access capacitor and a three-point capacitor oscillation circuit, which are connected in sequence, wherein said varactor diode is connected in reverse between an output terminal of said filter circuit and ground, and two access capacitors are connected in sequence between an output terminal of said filter circuit and an input terminal of said three-point capacitor oscillation circuit.

3. The high power radio frequency VCO circuit according to claim 2, wherein the capacitance three-point oscillating circuit comprises an oscillating transistor, two oscillating capacitors, an oscillating inductor in the form of a microstrip line, and a radio frequency choke inductor; the two oscillation capacitors are connected in series and then connected in parallel with the grounded oscillation inductor, three end points of the series oscillation capacitor are connected with three electrodes of the oscillation transistor, and the radio frequency choke inductor is connected in parallel with the grounded oscillation capacitor.

4. The high-power radio frequency VCO circuit according to claim 3, wherein said inter-stage matching unit comprises an oscillating transistor matching circuit, a first blocking capacitor, a T-shaped attenuation network and a second blocking capacitor which are cascaded in sequence; the oscillating transistor matching circuit comprises a capacitor and an inductor, wherein one end of the capacitor is connected with the output end of the frequency-selecting oscillation starting unit, and the other end of the capacitor is connected with the inductor in series and is grounded.

5. The high power RF VCO circuit according to claim 4, wherein said power amplification unit comprises a power amplification tube, said power amplification tube is connected in series to said DC power supply unit through a matching inductor, connected in parallel to ground through a matching capacitor, and outputs a power amplified signal through a third blocking capacitor.

6. The high power RF VCO circuit of claim 5, wherein said DC power supply unit comprises two voltage dropping resistors connected to VCC end, two filtering capacitors connected to ground respectively to the other end of said voltage dropping resistors, a RF choke inductor at the collector of said oscillating transistor, and four voltage dividing resistors for respectively supplying power to the bases of said oscillating transistor and said power amplifier transistor.

7. The high-power radio frequency VCO circuit of claim 1, wherein said frequency-selective oscillation start unit realizes an oscillation frequency of 50MHz to 6GHz by adjusting values of oscillation elements, and a relative bandwidth of 20% is realized in any frequency band of the oscillation frequency of 50MHz to 6 GHz.

8. The high power radio frequency VCO circuit of claim 1, wherein the power level of the oscillating signal amplified by the power amplifying unit is greater than 20dBm in a frequency range of 50MHz-2.7GHz, greater than 12dBm in a frequency range of 2.7GHz-4.5GHz, and greater than 8dBm in a frequency range of 4.5GHz-6 GHz.