Frequency source module based on double-ring structure

Abstract

The utility model discloses a frequency source module based on a double-ring structure, and relates to the technical field of radio. The frequency source module based on the double-ring structure is characterized by comprising a constant-temperature crystal oscillator, a low-pass filter I, a frequency synthesizer I, a low-pass filter II, a frequency synthesizer II, a numerical control attenuator, a radio frequency switch I and a radio frequency switch II, the constant-temperature crystal oscillator is connected with the input end of the low-pass filter I. The output end of the low-pass filter I is connected with the input end of the frequency synthesizer I. The output end of the frequency synthesizer I is connected with the input end of the low-pass filter II. The output end of the low-pass filter II is connected with the input end of the frequency synthesizer II. The output end of the frequency synthesizer II is connected with the input end of the numerical control attenuator. The output end of the numerical control attenuator is connected with the input end of the radio frequency switch I. The output end of the radio frequency switch I is connected with the input end of the radio frequency switch II, and the output end of the radio frequency switch II outputs signals.

Description

Technical Field

[0001] The utility model relates to the technical field of radio, in particular to a frequency source module based on a double-ring structure. Background Art

[0002] With the rapid development of radio communication and radio monitoring technology, higher and more stringent requirements have been put forward for the performance of the whole system. Frequency range, frequency step, and signal spurious are key indicators of the whole system and directly affect the performance of the whole system. With the traditional single-loop phase-locked technology, integer frequency synthesizers are difficult to achieve small steps, and fractional frequency synthesizers are difficult to avoid integer boundary spurious. The new complex structure frequency synthesizer can achieve ultra-wideband, small steps, and low spurious, but it has the disadvantages of complex structure, large size, high power consumption, and high cost, and can only be applied to special platforms. Utility Model Content

[0003] The purpose of the utility model is to provide a frequency source module based on a dual-ring structure to solve the problems of the prior art.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0005] A frequency source module based on a dual-loop structure includes a constant temperature crystal oscillator, a low-pass filter I, a frequency synthesizer I, a low-pass filter II, a frequency synthesizer II, a digitally controlled attenuator, a radio frequency switch I, and a radio frequency switch II;

[0006] The constant temperature crystal oscillator is connected to the input end of low-pass filter I, the output end of low-pass filter I is connected to the input end of frequency synthesizer I, the output end of frequency synthesizer I is connected to the input end of low-pass filter II, the output end of low-pass filter II is connected to the input end of frequency synthesizer II, the output end of frequency synthesizer II is connected to the input end of digital controlled attenuator, the output end of digital controlled attenuator is connected to the input end of RF switch I, the output end of RF switch I is connected to the input end of RF switch II, and the output end of RF switch II outputs the signal.

[0007] As a preferred technical solution, the model of the constant temperature crystal oscillator U11 is JTM2056B. The VCC pin of the constant temperature crystal oscillator U11 is connected to one end of capacitor C87, one end of capacitor C88, one end of capacitor C89, the positive electrode of polar capacitor C90, and one end of inductor B15; the other end of inductor B15 is connected to a 5V voltage; the other end of C87, the other end of capacitor C88, the other end of capacitor C89, and the negative electrode of polar capacitor C90 are connected and grounded.

[0008] As a preferred technical solution, the low-pass filter I includes a capacitor C91, one end of the capacitor C91 is connected to the OUT pin of the constant temperature crystal oscillator U11 as the input end of the low-pass filter I, and the other end of the capacitor C91 is connected to one end of the capacitor C61 and one end of the inductor L13; the other end of the capacitor C61 is grounded, the other end of the inductor L13 is connected to one end of the capacitor C62 and one end of the inductor L14, and the other end of the capacitor C62 is grounded; the other end of the inductor L14 is connected to one end of the capacitor C63 and serves as the output end of the low-pass filter I, and the other end of the capacitor C63 is grounded.

[0009] As a preferred technical solution, the low-pass filter II includes an inductor L5, one end of the inductor L5 is connected to one end of the capacitor C32 and serves as the input end of the low-pass filter II, the other end of the inductor L5 is connected to one end of the capacitor C33 and one end of the inductor L6, the other end of the inductor L6 is connected to one end of the capacitor C34 and serves as the output end of the low-pass filter II; the other end of the capacitor C32, the other end of the capacitor C33, and the other end of the capacitor C34 are grounded.

[0010] As a preferred technical solution, the RF switch I includes a chip U4, and the model of the chip U4 is SIS032SP3; the pin 1 of the chip U4 is connected to the pins 2, 16, and 15 and is grounded; the pin 3 of the chip U4 is connected to the output end of the digital attenuator through the capacitor C85; the pin 4 of the chip U4 is connected to the pins 5 and 6 and is grounded; the pin 7 of the chip U4 is connected to one end of the capacitor C31, the other end of the capacitor C31 is connected to one end of the resistor R5, the other end of the resistor R5 is grounded, and the pin 8 of the chip U4 is connected to the pin 9 and is grounded; the pin 10 of the chip U4 is connected to one end of the resistor R12; the other end of the resistor R12 is the SW pin, which is connected to the main control chip; the pin 11 of the chip U4 is connected to one end of the capacitor C81 and is connected to a 5V voltage; the other end of the capacitor C81 is grounded; the pin 12 of the chip U4 is connected to the pin 13 and is grounded; the pin 14 of the chip U4 is connected to the RF switch II through the capacitor C76;

[0011] The RF switch II includes a chip U3, the model of which is SIS032SP3; the pin 3 of the chip U3 is connected to the pin 14 of the chip U4 through a capacitor C76;

[0012] Pin 1 of chip U3 is connected to pins 2, 16, and 15 and to ground; pin 4 of chip U3 is connected to pins 5 and 6 and to ground; pin 7 of chip U3 is connected to one end of capacitor C86, the other end of capacitor C86 is connected to one end of resistor R47, the other end of resistor R47 is grounded, and pin 8 of chip U3 is connected to pin 9 and to ground; pin 10 of chip U3 is connected to one end of resistor R6; the other end of resistor R6 is the SW pin, which is connected to the main control chip; pin 11 of chip U3 is connected to one end of capacitor C82 and is connected to a 5V voltage; the other end of capacitor C82 is grounded; pin 12 of chip U3 is connected to pin 13 and to ground; pin 14 of chip U3 is connected to one end of capacitor C77, and the other end of capacitor C77 outputs a signal.

[0013] As a preferred technical solution, the frequency synthesizer I includes a chip U2 and its basic circuit, and the model of the chip U2 is HMC832ALP6E; the frequency synthesizer II includes a chip U1 and its basic circuit, and the model of the chip U1 is LMX2594RHAT.

[0014] Compared with the prior art, the utility model has the following beneficial effects:

[0015] The utility model provides a frequency synthesizer, which mainly adopts a dual-loop structure mode, that is, the front-stage frequency synthesizer outputs a frequency signal as a reference signal, which is provided to the second-stage frequency synthesizer, and the second-stage frequency synthesizer outputs a required frequency signal. At the same time, according to the application requirements, the link cascade digital attenuator adjusts the output signal power, and the cascade two-stage radio frequency switch realizes the switch modulation function.

[0016] The output signal of the constant temperature crystal oscillator passes through the low-pass filter I, and the signal spurious and harmonics are suppressed to a certain extent before entering the frequency synthesizer I. The frequency synthesizer I outputs a small-step, low-frequency signal. This signal passes through the low-pass filter II, and the signal spurious and harmonics are suppressed to a certain extent before entering the frequency synthesizer II as a reference signal. The frequency synthesizer II outputs the required frequency signal. The output signal power is adjusted by the digitally controlled attenuator in the later stage, and the switch modulation function is realized through the two-stage RF switch.

[0017] The utility model is a frequency synthesizer with simple circuit structure, ultra-wideband, small step, low spurious, simple circuit structure and few circuit elements, so it has small size, low power consumption and low cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the utility model;

[0019] Figure 2 It is the circuit schematic diagram of the constant temperature crystal oscillator and low-pass filter I;

[0020] Figure 3 is the circuit schematic diagram of frequency synthesizer I;

[0021] Figure 4 This is the circuit schematic diagram of low-pass filter II;

[0022] Figure 5 This is the circuit schematic diagram of frequency synthesizer II;

[0023] Figure 6 This is the circuit schematic diagram of the digital controlled attenuator;

[0024] Figure 7 This is the circuit schematic diagram of RF switch I and RF switch II.

[0025] The reference numerals are as follows:

[0026] 1- constant temperature crystal oscillator, 2- low pass filter I, 3- frequency synthesizer I, 4- low pass filter II, 5- frequency synthesizer II, 6- digital controlled attenuator, 7- radio frequency switch I, 8- radio frequency switch II. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] On the contrary, the present application covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present application as defined by the claims. Further, in order to make the public have a better understanding of the present application, some specific details are described in detail in the detailed description of the present application below. Those skilled in the art can fully understand the present application without the description of these details.

[0029] Example

[0030] like Figure 1 As shown, a frequency source module based on a dual-loop structure includes a constant temperature crystal oscillator, a low-pass filter I, a frequency synthesizer I, a low-pass filter II, a frequency synthesizer II, a digitally controlled attenuator, a radio frequency switch I, and a radio frequency switch II;

[0031] The constant temperature crystal oscillator is connected to the input end of low-pass filter I, the output end of low-pass filter I is connected to the input end of frequency synthesizer I, the output end of frequency synthesizer I is connected to the input end of low-pass filter II, the output end of low-pass filter II is connected to the input end of frequency synthesizer II, the output end of frequency synthesizer II is connected to the input end of digital controlled attenuator, the output end of digital controlled attenuator is connected to the input end of RF switch I, the output end of RF switch I is connected to the input end of RF switch II, and the output end of RF switch II outputs the signal.

[0032] In the utility model, a 120MHz constant temperature crystal oscillator outputs a 120MHz signal, and the signal passes through a 120MHz low-pass filter I, and after the 120MHz signal spurious and harmonics are suppressed to a certain extent, it enters a frequency synthesizer I, and the frequency synthesizer I outputs a small-step, low-frequency signal according to a software algorithm, and the signal passes through a 150MHz low-pass filter II, and after the spurious and harmonics of the signal are suppressed to a certain extent, it enters a frequency synthesizer II as a reference signal, and the frequency synthesizer II outputs a required frequency signal, and the output signal power is adjusted by a digitally controlled attenuator at the rear stage (the output signal of the frequency synthesizer II is digitally attenuated, and power control is performed, and the attenuation step of the digitally controlled attenuator is 0.25dB, and the maximum attenuation is 31.75dB), and the switch modulation function is realized through a two-stage radio frequency switch.

[0033] like Figure 2 As shown, the circuit structure of the constant temperature crystal oscillator and the low-pass filter I is shown.

[0034] The model of the constant temperature crystal oscillator U11 is JTM2056B. The VCC pin of the constant temperature crystal oscillator U11 is connected to one end of capacitor C87, one end of capacitor C88, one end of capacitor C89, the positive electrode of polar capacitor C90, and one end of inductor B15; the other end of inductor B15 is connected to a 5V voltage; the other end of C87, the other end of capacitor C88, the other end of capacitor C89, and the negative electrode of polar capacitor C90 are connected and grounded.

[0035] The low-pass filter I includes a capacitor C91, one end of which is connected to the OUT pin of the constant temperature crystal oscillator U11 as an input end of the low-pass filter I, and the other end of the capacitor C91 is connected to one end of the capacitor C61 and one end of the inductor L13; the other end of the capacitor C61 is grounded, the other end of the inductor L13 is connected to one end of the capacitor C62 and one end of the inductor L14, and the other end of the capacitor C62 is grounded; the other end of the inductor L14 is connected to one end of the capacitor C63 and serves as the output end of the low-pass filter I, and the other end of the capacitor C63 is grounded.

[0036] like Figure 3 As shown, the circuit structure of the frequency synthesizer I is shown. The frequency synthesizer I includes a chip U2 and its basic circuit. The model of the chip U2 is HMC832ALP6E.

[0037] like Figure 4 As shown, the circuit structure of the low-pass filter II is shown. The low-pass filter II includes an inductor L5, one end of the inductor L5 is connected to one end of the capacitor C32 and serves as the input end of the low-pass filter II, the other end of the inductor L5 is connected to one end of the capacitor C33 and one end of the inductor L6, the other end of the inductor L6 is connected to one end of the capacitor C34 and serves as the output end of the low-pass filter II; the other end of the capacitor C32, the other end of the capacitor C33, and the other end of the capacitor C34 are grounded.

[0038] like Figure 5 As shown, the circuit structure of the frequency synthesizer II is shown. The frequency synthesizer II includes a chip U1 and its basic circuit. The model of the chip U1 is LMX2594RHAT.

[0039] like Figure 6 As shown, the circuit structure of the digital controlled attenuator is shown. The digital controlled attenuator includes a chip U5 and its basic circuit. The model of the chip U5 is SIAT116ASP5.

[0040] like Figure 7 As shown, the circuit structure of RF switch I and RF switch II.

[0041] The RF switch I includes a chip U4, and the model of the chip U4 is SIS032SP3; the pin 1 of the chip U4 is connected to the pins 2, 16, and 15 and is grounded; the pin 3 of the chip U4 is connected to the output end of the digital controlled attenuator through a capacitor C85; the pin 4 of the chip U4 is connected to the pins 5 and 6 and is grounded; the pin 7 of the chip U4 is connected to one end of the capacitor C31, the other end of the capacitor C31 is connected to one end of the resistor R5, the other end of the resistor R5 is grounded, the pin 8 of the chip U4 is connected to the pin 9 and is grounded; the pin 10 of the chip U4 is connected to one end of the resistor R12; the other end of the resistor R12 is the SW pin, which is connected to the main control chip; the pin 11 of the chip U4 is connected to one end of the capacitor C81 and is connected to a 5V voltage; the other end of the capacitor C81 is grounded; the pin 12 of the chip U4 is connected to the pin 13 and is grounded; the pin 14 of the chip U4 is connected to the RF switch II through a capacitor C76;

[0042] Specifically, the RF switch II includes a chip U3, the model of which is SIS032SP3; the pin 3 of the chip U3 is connected to the pin 14 of the chip U4 through a capacitor C76;

[0043] Pin 1 of chip U3 is connected to pins 2, 16 and 15 and grounded; pin 4 of chip U3 is connected to pins 5 and 6 and grounded; pin 7 of chip U3 is connected to one end of capacitor C86, the other end of capacitor C86 is connected to one end of resistor R47, the other end of resistor R47 is grounded, and pin 8 of chip U3 is connected to pin 9 and grounded; pin 10 of chip U3 is connected to one end of resistor R6; the other end of resistor R6 is the SW pin, which is connected to the main control chip; pin 11 of chip U3 is connected to one end of capacitor C82 and connected to 5V voltage; the other end of capacitor C82 is grounded; pin 12 of chip U3 is connected to pin 13 and grounded; pin 14 of chip U3 is connected to one end of capacitor C77, and the other end of capacitor C77 outputs a signal;

[0044] It is worth noting that, based on the above structural design, in order to solve the same technical problem, even if some insubstantial improvements are made on the present invention, they also fall within the protection scope of the present invention.

Claims

1. A frequency source module based on a dual-loop structure, characterized in that it includes a constant temperature crystal oscillator, a low-pass filter I, a frequency synthesizer I, a low-pass filter II, a frequency synthesizer II, a digitally controlled attenuator, a radio frequency switch I, and a radio frequency switch II; The constant temperature crystal oscillator is connected to the input end of low-pass filter I, the output end of low-pass filter I is connected to the input end of frequency synthesizer I, the output end of frequency synthesizer I is connected to the input end of low-pass filter II, the output end of low-pass filter II is connected to the input end of frequency synthesizer II, the output end of frequency synthesizer II is connected to the input end of digital controlled attenuator, the output end of digital controlled attenuator is connected to the input end of RF switch I, the output end of RF switch I is connected to the input end of RF switch II, and the output end of RF switch II outputs the signal.

2. A frequency source module based on a dual-ring structure according to claim 1, characterized in that: The model of the constant temperature crystal oscillator U11 is JTM2056B. The VCC pin of the constant temperature crystal oscillator U11 is connected to one end of capacitor C87, one end of capacitor C88, one end of capacitor C89, the positive electrode of polar capacitor C90, and one end of inductor B15; the other end of inductor B15 is connected to a 5V voltage; the other end of C87, the other end of capacitor C88, the other end of capacitor C89, and the negative electrode of polar capacitor C90 are connected and grounded.

3. The frequency source module based on the dual-ring structure according to claim 1, characterized in that: The low-pass filter I includes a capacitor C91, one end of which is connected to the OUT pin of the constant temperature crystal oscillator U11 as an input end of the low-pass filter I, and the other end of the capacitor C91 is connected to one end of the capacitor C61 and one end of the inductor L13; the other end of the capacitor C61 is grounded, the other end of the inductor L13 is connected to one end of the capacitor C62 and one end of the inductor L14, and the other end of the capacitor C62 is grounded; the other end of the inductor L14 is connected to one end of the capacitor C63 and serves as the output end of the low-pass filter I, and the other end of the capacitor C63 is grounded.

4. The frequency source module based on a dual-ring structure according to claim 1, characterized in that: The low-pass filter II includes an inductor L5, one end of the inductor L5 is connected to one end of the capacitor C32 and serves as the input end of the low-pass filter II, the other end of the inductor L5 is connected to one end of the capacitor C33 and one end of the inductor L6, the other end of the inductor L6 is connected to one end of the capacitor C34 and serves as the output end of the low-pass filter II; the other end of the capacitor C32, the other end of the capacitor C33, and the other end of the capacitor C34 are grounded.

5. The frequency source module based on a dual-ring structure according to claim 1, characterized in that: The radio frequency switch I includes a chip U4, the model of which is SIS032SP3; the pin 1 of the chip U4 is connected to the pins 2, 16, and 15 and is grounded; the pin 3 of the chip U4 is connected to the output end of the digital controlled attenuator through a capacitor C85; Pin 4 of chip U4 is connected to pins 5 and 6 and grounded; pin 7 of chip U4 is connected to one end of capacitor C31, the other end of capacitor C31 is connected to one end of resistor R5, the other end of resistor R5 is grounded, pin 8 of chip U4 is connected to pin 9 and grounded; pin 10 of chip U4 is connected to one end of resistor R12; the other end of resistor R12 is SW pin, connected to main control chip; pin 11 of chip U4 is connected to one end of capacitor C81 and connected to 5V voltage; the other end of capacitor C81 is grounded; pin 12 of chip U4 is connected to pin 13 and grounded; pin 14 of chip U4 is connected to RF switch II through capacitor C76; The RF switch II includes a chip U3, the model of which is SIS032SP3; the pin 3 of the chip U3 is connected to the pin 14 of the chip U4 through a capacitor C76; Pin 1 of chip U3 is connected to pins 2, 16, and 15 and to ground; pin 4 of chip U3 is connected to pins 5 and 6 and to ground; pin 7 of chip U3 is connected to one end of capacitor C86, the other end of capacitor C86 is connected to one end of resistor R47, the other end of resistor R47 is grounded, and pin 8 of chip U3 is connected to pin 9 and to ground; pin 10 of chip U3 is connected to one end of resistor R6; the other end of resistor R6 is the SW pin, which is connected to the main control chip; pin 11 of chip U3 is connected to one end of capacitor C82 and is connected to a 5V voltage; the other end of capacitor C82 is grounded; pin 12 of chip U3 is connected to pin 13 and to ground; pin 14 of chip U3 is connected to one end of capacitor C77, and the other end of capacitor C77 outputs a signal.

6. The frequency source module based on a dual-ring structure according to claim 1, characterized in that: The frequency synthesizer I includes a chip U2 and a basic circuit thereof, and the model of the chip U2 is HMC832ALP6E; the frequency synthesizer II includes a chip U1 and a basic circuit thereof, and the model of the chip U1 is LMX2594RHAT.

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