CN203368401U - Multifunctional frequency multiplier - Google Patents

Abstract

The utility model discloses a multifunctional frequency multiplier. The multifunctional frequency multiplier comprises an input low pass filter, two schottky diode pairs which are homonymously connected in series, an output band pass filter, two 1/4 wavelength open-circuit lines which are connected in series, a high-frequency choke circuit, a first phase modulation transmission line, a second phase modulation transmission line and a third phase modulation transmission line. The multifunctional frequency multiplier provided by the utility model has the advantages of simple circuit structure and small frequency multiplication stray, and can be used in a miniaturized and highly-integrated broadband frequency synthesizer or multimode transceiver.

Description

A multifunctional frequency multiplier

technical field

The utility model relates to a frequency multiplier applied to microwave and millimeter wave frequency bands. The frequency multiplier can simultaneously realize low spurious secondary and tertiary frequency multipliers, and is especially suitable for frequency sources in the field of communication or electronic countermeasures.

Background technique

The frequency source is the heart of communication and radar systems. With the blowout development of data capacity in modern communication systems, the signal bandwidth is often as high as several gigahertz; in addition, in order to realize the miniaturization of the communication system, the transceivers of multiple frequency bands will be integrated into one design. For example, in an electronic countermeasure system, the bandwidth of the frequency synthesizer often covers one or more radar frequency bands, and the frequency multiplier is widely used in the frequency source system of electronic countermeasures, and sometimes it is often necessary to realize the dual frequency of a certain reference frequency at the same time. second and third multipliers. For another example, in a multi-mode satellite communication system, if the Ka-band transmitter (local oscillator is about 28GHz) and the EHF band transmitter (local oscillator is about 42GHz) are integrated together, the 14GHz dielectric resonant oscillator can be passed through Double frequency multiplier and triple frequency multiplier are obtained.

Usually, the second frequency multiplication and the third frequency multiplication are respectively implemented by two balanced frequency multipliers. This balanced frequency multiplier has the advantages of high frequency multiplication efficiency, simple idle circuit and high spurious suppression. For example, for a balanced frequency tripler, even harmonics can be suppressed by using the structural characteristics of the circuit itself, so that the design of idle circuits can be simplified. But this kind of frequency multiplier can only generate one usable harmonic component (secondary or third), if a reference frequency source is to be doubled or tripled at the same time, two balanced frequency doublers are often required and frequency tripler.

Utility model content

Purpose of the invention: In order to overcome the deficiencies in the prior art, the utility model provides a multifunctional frequency multiplier with simple structure and capable of generating low spurious second and third harmonics at the same time.

Technical scheme: in order to achieve the above object, the technical scheme adopted in the utility model is:

A multifunctional frequency multiplier, including a low-pass filter, a high-frequency choke circuit, a band-pass filter, a first phase adjustment transmission line, a second phase adjustment transmission line, a third phase adjustment transmission line, a first Schottky diode, a second Schottky diode, a first open line and a second open line;

The first Schottky diode and the second Schottky diode are connected in series in the same direction, and the common end of the first Schottky diode and the second Schottky diode is a contact point, and the anode of the second Schottky diode is grounded; The first open line and the second open line are connected in series, and the common end of the first open line and the second open line is the b contact;

The input end of the low-pass filter is used as the input end of the frequency multiplier, and the output end is connected to the a contact point through the first phase adjustment transmission line;

The output end of the bandpass filter is used as the frequency tripler output end of the frequency multiplier, and the input end is connected to the a contact point through the third phase adjustment transmission line;

The cathode of the first Schottky diode is connected to the b contact and one end of the second phase adjustment transmission line, the other end of the second phase adjustment transmission line is used as the double frequency output end of the frequency multiplier, and the second phase The other end of the adjusted transmission line is also connected to the output end of the high frequency choke circuit.

Specifically, the low-pass filter allows the fundamental wave signal to pass, but the third harmonic signal cannot pass; the band-pass filter allows the third harmonic signal to pass, but the fundamental wave signal cannot pass; the first open The wavelength of the input signal of the line and the second open line is a quarter of the wavelength of the fundamental wave signal.

Specifically, the high-frequency choke circuit only allows DC signals to pass through, and provides bias for the first Schottky diode and the second Schottky diode.

The low-pass filter can pass the fundamental wave signal and suppress the third harmonic signal; adjusting the length and width of the first phase adjustment transmission line connected to the low-pass filter can realize the impedance matching of the input signal.

The cathode of the second Schottky diode is connected between the first open line and the second open line which are quarter wavelengths at the frequency of the fundamental wave signal, which makes all The odd harmonic component is equivalent to ground, and the even harmonic component is equivalent to open circuit; this circuit structure makes the input signal equal amplitude and same direction respectively added to the first Schottky diode and the second Schottky diode.

At the triple frequency output terminal, since several harmonic components generated by diode nonlinearity are superimposed and output in the same direction, while the even harmonic components are superimposed and canceled in the same amplitude and reverse direction, so the triple frequency output terminal can be used without a filter Better suppression of even harmonic components is obtained; the output bandpass filter allows the third harmonic to pass, while the fundamental wave component with a larger power amplitude is transmitted back to the first Schottky diode and the second Schottky diode, been reused. By adjusting the third phase to adjust the length and width of the transmission line, the output impedance matching of the triple frequency multiplication is realized.

At the cathode of the first Schottky diode, the even-order harmonic signal can be output, and then output through the second phase adjustment transmission line for impedance matching.

In order to further improve the frequency multiplication efficiency of the frequency multiplier, a DC bias circuit is added to the branch of the double frequency output, and the frequency multiplication efficiency of the frequency multiplier can be optimized by adjusting the bias voltage.

Beneficial effects: the multifunctional frequency multiplier provided by the utility model has a simple circuit structure and small frequency multiplication spurs, and can be used in miniaturized and highly integrated broadband frequency synthesizers or multi-mode transceivers.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is the simulation result of the double frequency output terminal;

Fig. 3 is the simulation result of the frequency tripled output.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described further.

As shown in Figure 1, it is a multifunctional frequency multiplier, including a low-pass filter 1, a high-frequency choke circuit 8, a band-pass filter 10, a first phase adjustment transmission line 2, a second phase adjustment transmission line 7, a third Phase adjustment transmission line 9 , first Schottky diode 3 , second Schottky diode 4 , first open line 5 and second open line 6 .

The first Schottky diode 3 and the second Schottky diode 4 are connected in series in the same direction, and the common end of the first Schottky diode 3 and the second Schottky diode 4 is a contact point, and the second Schottky diode The anode of 4 is grounded; the first open line 5 and the second open line 6 are connected in series, and the common end of the first open line 5 and the second open line 6 is the b contact.

The input end of the low-pass filter 1 is used as the input end of the frequency multiplier, and the output end is connected to the a node through the first phase adjustment transmission line 2 .

The output end of the band-pass filter 10 is used as the frequency tripler output end of the frequency multiplier, and the input end is connected to the a node through the third phase adjustment transmission line 9 .

The cathode of the first Schottky diode 3 is connected to the b contact and one end of the second phase adjustment transmission line 7, and the other end of the second phase adjustment transmission line 7 is used as the double frequency output end of the frequency multiplier, and at the same time The other end of the second phase adjustment transmission line 7 is also connected to the output end of the high frequency choke circuit 8 .

The low-pass filter 1 allows the fundamental signal to pass, but the third harmonic signal cannot pass; the band-pass filter 10 allows the third harmonic signal to pass, but the fundamental signal cannot pass; the first open line The input signal wavelength of 5 and the second open line 6 is a quarter of the wavelength of the fundamental signal.

The high-frequency choke circuit 8 only allows DC signals to pass through, and provides bias for the first Schottky diode 3 and the second Schottky diode 4 .

The cut-off frequency of the input low-pass filter 1 is designed between f ₀ and 3f ₀ , which can suppress the third harmonic signal frequency 3f ₀ through the input fundamental wave signal frequency f ₀ and prevent the generated third harmonic signal from being fed back to the input.

The length of the first open line 5 and the second open line 6 is a quarter wavelength at the fundamental frequency f ₀ , thereby forming at the cathode of the first Schottky diode 3 at the fundamental frequency The equivalent grounding of f ₀ , 3f ₀ , 5f ₀ , ... on odd multiples, and the equivalent open circuit of 2f ₀ , 4f ₀ , 6f ₀ , ... on even multiples of the fundamental frequency.

The first Schottky diode 3 and the second Schottky diode 4 are connected in series in the same direction to form a Schottky series diode pair, the anode of the second Schottky diode 4 is grounded, and the cathode of the first Schottky diode 3 is connected to the ground. Equivalent ground on odd harmonics of input frequency. This structure makes the odd harmonics at the triple frequency output end superimpose in the same direction, and the even harmonics superimpose in the opposite direction, so that only odd harmonics exist at the triple frequency output end; at the double frequency output The odd harmonics at the end are superimposed with the same amplitude and reverse, while only the even harmonics exist.

The bandpass filter 10 is located in the triple frequency output channel, and is used to select the third harmonic, and reflect the fundamental wave signal back to the pair of Schottky series diodes to participate in frequency multiplication again.

Although there are multiple even harmonics at the second harmonic output port, since the second harmonic is significantly larger than other even harmonics, there is no need to select the second harmonic through a band-pass filter.

The first phase adjustment transmission line 2 , the second phase adjustment transmission line 7 and the third phase adjustment transmission line 9 are used to realize the input and output matching of the frequency multiplier and improve the frequency multiplication efficiency of the frequency multiplier.

In order to verify the effectiveness of the present utility model, we simulate the frequency multiplier circuit in the ADS software of Agilent Company. During the simulation, it is assumed that the input fundamental frequency is 5GHz, and the fundamental signal power is 13dBm. The simulation results are shown in Figure 2 and Figure 3 Shown (where the abscissa is the output frequency, and the ordinate is the output power).

Figure 2 shows the harmonic components of the output port of the second frequency multiplication. It can be seen from the figure that the power value of the second harmonic component is significantly higher than the fundamental and third harmonic power values.

Figure 3 shows the harmonic components of the triple frequency multiplier output port. It can be seen from the figure that the power value of the third harmonic component is significantly higher than that of the even harmonic component.

The above is only a preferred embodiment of the utility model, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the utility model, some improvements and modifications can also be made. Retouching should also be regarded as the scope of protection of the present utility model.

Claims (3)

1. a multi-functional frequency multiplier, is characterized in that: comprise low pass filter (1), high frequency choke circuit (8), band pass filter (10), the first phase adjusted transmission line (2), the second phase adjusted transmission line (7), third phase position adjusting transmission line (9), the first Schottky diode (3), the second Schottky diode (4), the first open-circuit line (5) and the second open-circuit line (6);

Described the first Schottky diode (3) and the second Schottky diode (4) series aiding connection, remember that the common port of the first Schottky diode (3) and the second Schottky diode (4) is a contact, the plus earth of the second Schottky diode (4); Described the first open-circuit line (5) and the second open-circuit line (6) series connection, remember that the common port of the first open-circuit line (5) and the second open-circuit line (6) is the b contact;

The input of described low pass filter (1) is connected with a contact by the first phase adjusted transmission line (2) as input, the output of this frequency multiplier;

The output of described band pass filter (10) is regulated transmission line (9) as frequency tripling output, the input of this frequency multiplier by the third phase position and is connected with a contact;

The negative electrode of described the first Schottky diode (3) is connected with an end of the second phase adjusted transmission line (7) with the b contact, the other end of described the second phase adjusted transmission line (7) is as two frequency multiplication outputs of this frequency multiplier, and the other end of the second phase adjusted transmission line (7) also is connected with the output of high frequency choke circuit (8) simultaneously.

2. multi-functional frequency multiplier according to claim 1, it is characterized in that: described low pass filter (1) makes fundamental signal to pass through, and harmonic signal can not be passed through; Described band pass filter (10) makes harmonic signal to pass through, and fundamental signal can not pass through; The input signal wavelength of described the first open-circuit line (5) and the second open-circuit line (6) is 1/4th of fundamental signal wavelength.

3. multi-functional frequency multiplier according to claim 1, it is characterized in that: described high frequency choke circuit (8) only allows direct current signal to pass through, and is that the first Schottky diode (3) and the second Schottky diode (4) provide biasing.

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