Multi-channel multi-frequency-point radio frequency signal generation circuit

Abstract

The utility model discloses a multi-channel multi-frequency-point radio frequency signal generating circuit, which comprises N radio frequency circuit input channels, an N-channel radio frequency circuit and a multi-band transmitting antenna, n is smaller than or equal to 8; the N radio frequency circuit input channels are used for receiving at most N channels of parallel intermediate frequency signals transmitted by a preceding-stage intermediate frequency circuit and transmitting the received N channels of parallel intermediate frequency signals to the N channels of radio frequency circuit; and the N-channel radio frequency circuit converts the received N-channel parallel intermediate frequency signal into a multi-frequency-point satellite radio frequency signal, and the multi-frequency-band transmitting antenna transmits the multi-frequency-point satellite radio frequency signal. The satellite signal simulator is a radio frequency circuit capable of generating multiple GNSS satellite system signals at the same time, and aims to solve the problems that signals generated by an existing satellite signal simulator are single in frequency point, low in carrier-to-noise ratio and poor in signal real-time performance.

Description

Technical Field

[0001] The utility model relates to a radio frequency signal generating circuit, in particular to a multi-channel and multi-frequency radio frequency signal generating circuit. Background Art

[0002] The GPS global satellite positioning system (Global Positioning System) is an all-round, all-time, all-weather, high-precision satellite navigation system established by the United States. After decades of development, GPS has played a vital role in the military and civilian fields. At present, the GPS global navigation and positioning system has become inseparable from people's lives, but because satellite signals are affected by ionospheric interference, multipath effects, short satellite visibility time and other factors, it is difficult to stably and continuously receive high carrier-to-noise ratio interference-free satellite signals at the same location in real life. Therefore, the research and development of satellite signal simulators has become more and more frequent. However, the current satellite signal simulators generally have shortcomings such as poor signal phase continuity, low carrier-to-noise ratio, few simulation frequencies and poor signal real-time performance. Utility Model Content

[0003] The purpose of the utility model is to provide a multi-channel and multi-frequency radio frequency signal generating circuit, which is a radio frequency circuit capable of simultaneously generating multiple GNSS (Global Navigation Satellite System) satellite system signals, and aims to solve the problems of the existing satellite signal simulator generating a single signal frequency, a low carrier-to-noise ratio and poor signal real-time performance.

[0004] The technical solution of the utility model is: a multi-channel multi-frequency radio frequency signal generating circuit, comprising N radio frequency circuit input channels, an N-channel radio frequency circuit and a multi-band transmitting antenna; the N is less than or equal to 8;

[0005] The N-channel RF circuit input channels are used to receive a maximum of N-channel parallel intermediate frequency signals transmitted from the previous intermediate frequency circuit, and transmit the received N-channel parallel intermediate frequency signals to the N-channel RF circuit;

[0006] The N-channel radio frequency circuit converts the received N-channel parallel intermediate frequency signals into multi-frequency satellite radio frequency signals, and transmits them through the multi-band transmitting antenna.

[0007] Furthermore, N is equal to 8.

[0008] Furthermore, the RF circuit input channel is respectively provided with a first pull-up resistor and a corresponding RC filter circuit on the basis of the metal wire direct connection; the pull-up resistor is connected in parallel with the first capacitor in the corresponding RC filter circuit and then grounded.

[0009] Further, the radio frequency circuit includes a second capacitor, a third capacitor, a frequency multiplication chip, a fourth capacitor, a first-level amplifier, a fifth capacitor, a first inductor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a third resistor, a filter chip, a mixing chip, a fourth resistor, a pull-down resistor, a second-level amplifier, a tenth capacitor, a second inductor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixth resistor, and an SMA interface;

[0010] The second capacitor and the third capacitor are used as input and grounding capacitors respectively, and the other ends are connected to the input pin of the frequency multiplication chip; the frequency multiplication chip up-converts the input 10M sinusoidal signal into a radio frequency local oscillator signal, and the output signal is input to the first-stage amplifier through the fourth capacitor, and the local oscillator signal is amplified and sent to the filter chip after passing through the impedance matching circuit composed of the first inductor and the fifth capacitor, the sixth capacitor, the seventh capacitor, the eighth capacitor and the third resistor. The filter chip filters the local oscillator signal and then inputs it to the mixing chip; the mixing chip mixes the input N-channel intermediate frequency signal and the radio frequency local oscillator signal to obtain the corresponding radio frequency satellite signal, and inputs it to the second-stage amplifier after passing through the fourth resistor and the pull-down resistor. The second-stage amplifier amplifies the gain of the previous-stage satellite signal and then performs impedance matching through the impedance matching circuit composed of the tenth capacitor, the second inductor, the thirteenth capacitor, the fourteenth capacitor, the fifteenth capacitor and the sixth resistor, and is filtered by the eleventh capacitor and the twelfth capacitor before inputting it to the SMA interface. Finally, the generated satellite signal is transmitted by the multi-band transmitting antenna connected to the SMA interface.

[0011] Furthermore, the model of the frequency multiplier chip is SI4133-BT.

[0012] Furthermore, the models of the first-stage amplifier and the second-stage amplifier are HMC474.

[0013] Furthermore, the model of the filter chip is TA0224A.

[0014] Furthermore, the model of the mixing chip is LT5521EUF.

[0015] The beneficial effects of the utility model are: providing a multi-channel and multi-frequency radio frequency signal generating circuit, using the most reasonable way to design a multi-channel implementation circuit of a satellite signal simulator, and innovatively using an 8-channel parallel design to improve the phase continuity of the radio frequency signal generated by the circuit system in high dynamic and high resolution scenarios, reduce the circuit response time, and improve the real-time performance of generating satellite signals. In addition, through systematic design, multi-stage filtering processing is added to places that have a great impact on signal quality, thereby reducing systematic noise and improving the carrier-to-noise ratio of the output satellite signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is an 8-channel multi-frequency RF circuit, its position in the entire system circuit, circuit layout and connection method;

[0017] Figure 2 It is an 8-channel multi-frequency RF circuit;

[0018] Figure 3 For radio frequency circuits. DETAILED DESCRIPTION

[0019] The utility model is further described below in conjunction with the accompanying drawings.

[0020] This embodiment provides an 8-channel multi-frequency radio frequency circuit, and its position, circuit layout and connection method in the entire system circuit are as follows: Figure 1 Among them, the 8-channel RF circuit receives a maximum of 8-channel parallel intermediate frequency signals transmitted from the previous intermediate frequency circuit, and outputs the multi-frequency satellite RF signals as designed, which are finally transmitted by the multi-band transmitting antenna.

[0021] In detail, Figure 2 As shown in the figure, channel0~channel7 are 8 parallel intermediate frequency signals output to the RF circuit input channel. The RF circuit input channel adds pull-up resistors R27~R34 and corresponding RC filter circuits on the basis of classic metal wire direct connection; specifically, R35~R42 are connected in parallel with C13~C20 and then grounded.

[0022] The function of the 8-channel RF circuit is to up-convert the parallel satellite intermediate frequency signals (tens of MHz) sent by the intermediate frequency circuit to the corresponding satellite signal frequency (about 1 GHz, such as the GPS L1 satellite signal frequency is 1575.42 MHz, the GPSL2C frequency is 1127.60 MHz, and the GPS L5 frequency is 1176.45 MHz).

[0023] In detail, Figure 3As shown, the 8-channel RF circuit includes integrated chips A7, A8, A9, A10, A11 and peripheral circuits thereof, the second capacitor C22 and the third capacitor C23 are used as input and grounding capacitors respectively, and the other ends are connected to the input pin of the frequency multiplication chip A7; the frequency multiplication chip A7 up-converts the input 10M sinusoidal signal into a RF local oscillator signal, and the output signal is input to the first-stage amplifier A8 through the fourth capacitor C24, and the local oscillator signal is amplified and then sent to the filter chip A9 after passing through the impedance matching circuit composed of the first inductor L3 and the fifth capacitor C25, the sixth capacitor C26, the seventh capacitor C27, the eighth capacitor C28 and the third resistor R3, and the filter chip A9 filters the local oscillator signal and outputs it. The mixed chip A10 mixes the input 8-channel intermediate frequency signal and the RF local oscillator signal to obtain the corresponding RF satellite signal, which is input into the secondary amplifier A11 after passing through the fourth resistor R4 and the pull-down resistor R5. The secondary amplifier A11 amplifies the gain of the previous satellite signal and then performs impedance matching by the impedance matching circuit composed of the tenth capacitor C30, the second inductor L4, the thirteenth capacitor C33, the fourteenth capacitor C34, the fifteenth capacitor C35 and the sixth resistor R6, and the eleventh capacitor C31 and the twelfth capacitor C32 filtering, and then inputs it to the SMA interface P3, and finally the satellite signal generated is transmitted by the multi-band transmitting antenna connected to the SMA interface P3. The multi-band transmitting antenna is used to transmit the multi-channel RF navigation signal finally generated by this circuit.

[0024] The model of the frequency multiplication chip is SI4133-BT. The model of the first-stage amplifier and the second-stage amplifier is HMC474. The model of the filter chip is TA0224A. The model of the frequency mixing chip is LT5521EUF.

[0025] In this embodiment, the 8-channel multi-frequency RF circuit is used in the most reasonable way, and a multi-channel implementation circuit of the satellite signal simulator is designed. The innovative use of 8-channel parallel design improves the phase continuity of the circuit system in generating RF signals in high dynamic and high-resolution scenarios, reduces the circuit response time, and improves the real-time performance of generating satellite signals. In addition, through systematic design, multi-stage filtering processing is added in places that have a great impact on signal quality, thereby reducing systematic noise and improving the carrier-to-noise ratio of the output satellite signal.

[0026] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A multi-channel multi-frequency radio frequency signal generating circuit, characterized in that: It includes N radio frequency circuit input channels, an N-channel radio frequency circuit and a multi-band transmitting antenna; The N is less than or equal to 8; The N-channel RF circuit input channels are used to receive a maximum of N-channel parallel intermediate frequency signals transmitted from the previous intermediate frequency circuit, and transmit the received N-channel parallel intermediate frequency signals to the N-channel RF circuit; The N-channel radio frequency circuit converts the received N-channel parallel intermediate frequency signals into multi-frequency satellite radio frequency signals, and transmits them through the multi-band transmitting antenna.

2. The multi-channel multi-frequency radio frequency signal generating circuit according to claim 1, characterized in that: The N is equal to 8.

3. The multi-channel multi-frequency radio frequency signal generating circuit according to claim 1, characterized in that: The RF circuit input channel is respectively provided with a first pull-up resistor and a corresponding RC filter circuit on the basis of a metal wire direct connection; the pull-up resistor is connected in parallel with a first capacitor in the corresponding RC filter circuit and then grounded.

4. The multi-channel multi-frequency radio frequency signal generating circuit according to claim 1, characterized in that: The radio frequency circuit includes a second capacitor (C22), a third capacitor (C23), a frequency multiplication chip (A7), a fourth capacitor (C24), a first-level amplifier (A8), a fifth capacitor (C25), a first inductor (L3), a sixth capacitor (C26), a seventh capacitor (C27), an eighth capacitor (C28), a third resistor (R3), a filter chip (A9), a mixer chip (A10), a fourth resistor (R4), a pull-down resistor (R5), a second-level amplifier (A11), a tenth capacitor (C30), a second inductor (L4), an eleventh capacitor (C31), a twelfth capacitor (C32), a thirteenth capacitor (C33), a fourteenth capacitor (C34), a fifteenth capacitor (C35), a sixth resistor (R6) and an SMA interface (P3); The second capacitor (C22) and the third capacitor (C23) are used as input and grounding capacitors respectively, and the other ends are connected to the input pin of the frequency multiplication chip (A7); the frequency multiplication chip (A7) up-converts the input 10M sinusoidal signal into a radio frequency local oscillator signal, and the output signal is input to the first-stage amplifier (A8) through the fourth capacitor (C24); the local oscillator signal is amplified and then sent to the filter chip (A9) after passing through the impedance matching circuit composed of the first inductor (L3) and the fifth capacitor (C25), the sixth capacitor (C26), the seventh capacitor (C27), the eighth capacitor (C28) and the third resistor (R3); the filter chip (A9) filters the local oscillator signal and then inputs it into the mixing chip (A10); The mixing chip (A10) mixes the input N-channel intermediate frequency signal and the radio frequency local oscillator signal to obtain the corresponding radio frequency satellite signal, and then inputs the mixed signal into the secondary amplifier (A11) after passing through the fourth resistor (R4) and the pull-down resistor (R5). The secondary amplifier (A11) amplifies the gain of the previous stage satellite signal, and then performs impedance matching through an impedance matching circuit composed of a tenth capacitor (C30), a second inductor (L4), a thirteenth capacitor (C33), a fourteenth capacitor (C34), a fifteenth capacitor (C35) and a sixth resistor (R6), and filtering through an eleventh capacitor (C31) and a twelfth capacitor (C32), and then inputs the mixed signal into the SMA interface (P3). Finally, the generated satellite signal is transmitted by a multi-band transmitting antenna connected to the SMA interface (P3).

5. The multi-channel multi-frequency radio frequency signal generating circuit according to claim 4, characterized in that: The model of the frequency multiplier chip (A7) is SI4133-BT.

6. The multi-channel multi-frequency radio frequency signal generating circuit according to claim 4, characterized in that: The models of the first-stage amplifier (A8) and the second-stage amplifier (A11) are HMC474.

7. The multi-channel multi-frequency radio frequency signal generating circuit according to claim 4, characterized in that: The model of the filter chip (A9) is TA0224A.

8. The multi-channel multi-frequency radio frequency signal generating circuit according to claim 4, characterized in that: The model of the mixing chip (A10) is LT5521EUF.

Images