CN209088926U

CN209088926U - One kind being based on DDS high-performance broadband signal source

Info

Publication number: CN209088926U
Application number: CN201822189598.XU
Authority: CN
Inventors: 邹金强; 李显富
Original assignee: Chengdu Chiffo Electronics Instruments Co Ltd
Current assignee: Chengdu Chiffo Electronics Instruments Co Ltd
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2019-07-09
Anticipated expiration: 2028-12-25

Abstract

One kind being based on DDS high-performance broadband signal source, including audio generation circuitry, Audio processing circuit, Digital Frequency Synthesize circuit, mixting circuit, quadruplicated frequency circuit；The audio generation circuitry generates audio signal according to SPI signal, then pass through the conditioning of the Audio processing circuit, the Digital Frequency Synthesize circuit generates a signal according to the audio signal after conditioning and is mixed into the mixting circuit, then exports broadband signal after quadruplicated frequency circuit processing；Based on DDS technology, the anharmonic wave for reducing output signal is spuious, improves the purity of frequency spectrum of output signal, generates the high-performance broadband signal source that a kind of anharmonic wave index is maintained at -70dBc.

Description

One kind being based on DDS high-performance broadband signal source

Technical field

The utility model relates to a kind of instrument-landing-systems, in particular to a kind of to be based on DDS high-performance broadband signal source.

Background technique

Instrument-landing-system (Instrument Landing System, ILS) is translated into instrument landing system, blind landing system again System, is the aircraft precision approach and Landing Guidance System being most widely used, including localizer (LOC) system, glide-path localizer (GS) system, marker beacon (MB) system three parts.Its effect is to realize course by two beam radio signals of ground launch Road and glide path guide establish one and are directed toward aerial virtual glissade by runway, and aircraft is determined certainly by airborne receiving equipment The relative position of body and the path makes aircraft fly to runway along correct direction and steadily declines, finally realizes safe landing.It is existing Have in technology, the spuious height of signal anharmonic wave of ground launch output, the purity of frequency spectrum is low, and performance is to be improved.

Utility model content

The purpose of the utility model is to overcome the above-mentioned deficiencies in the presence of the prior art, provide a kind of based on DDS high Performance broadband signal source

In order to realize above-mentioned purpose of utility model, the utility model provides following technical scheme:

One kind being based on DDS high-performance broadband signal source, including audio generation circuitry, Audio processing circuit, numerical frequency are closed At circuit, mixting circuit, quadruplicated frequency circuit；The audio generation circuitry generates audio signal according to SPI signal, then passes through institute The conditioning of Audio processing circuit is stated, the Digital Frequency Synthesize circuit generates a signal according to the audio signal after conditioning and enters The mixting circuit is mixed, and then exports broadband signal after quadruplicated frequency circuit processing.

The audio generation circuitry includes field programmable gate array, D/A converter, operational amplifier, and filter circuit is opened Powered-down road；Field programmable gate array generates digital signal according to SPI signal, and then digital signal passes through the D/A converter It is converted into analog signal, analog signal successively enters after the operational amplifier operation amplifier, filter circuit filtering The switching circuit, the switching circuit on-off control output audio signal.

The Audio processing circuit includes operational amplifier, D/A converter, analog switch, analog-digital converter；Audio signal By being sent into D/A converter after operational amplifier, after exporting audio analog signals using analog switch switch control later.

The Digital Frequency Synthesize circuit includes Direct Digital Frequency Synthesizers, analog-digital converter, field-programmable gate array Column and filter；Audio analog signals are sent to analog-digital converter, obtained audio digital signals, and audio digital signals are sent into existing Field programmable gate array controls Direct Digital Frequency Synthesizers and generates signal, and filters.

The mixting circuit include the first bandpass filter, the second bandpass filter, a local oscillation circuit, two local oscillation circuits, First frequency mixer, the second frequency mixer, low-pass filter；The signal that the Digital Frequency Synthesize circuit generates passes through the first band After bandpass filter, the signal generated with a local oscillation circuit is mixed in first frequency mixer, then electric with two local oscillator The signal that road generates is mixed in second frequency mixer, and obtained signal enters second bandpass filter, using institute It states low-pass filter and obtains fundamental wave segment signal.

The quadruplicated frequency circuit includes two frequency multiplier circuits of first time, second of two frequency multiplier circuit；Fundamental wave segment signal passes through institute It states for the first time after two frequency multiplier circuits using being exported after second of two frequency multiplier circuit.

Compared with prior art, the utility model has the beneficial effects that audio generation circuitry generates audio letter according to SPI signal Number, then by conditioning, the Digital Frequency Synthesize circuit generates a signal according to the audio signal after conditioning and enters mixing Circuit is mixed, and then exports broadband signal after quadruplicated frequency circuit is handled, and is based on DDS technology, is reduced output signal Anharmonic wave is spuious, improves the purity of frequency spectrum of output signal, generates the high-performance broadband that a kind of anharmonic wave index is maintained at -70dBc Signal source.

Detailed description of the invention:

Fig. 1 is the structural block diagram of the utility model.

Fig. 2 is the circuit connection diagram of field programmable gate array.

Fig. 3 is D/A converter, the first amplifier, the second amplifier, the first filter circuit, the circuit connection of the second filter circuit Schematic diagram.

Fig. 4 is the circuit connection diagram of switching circuit.

The circuit connection diagram of the position Fig. 5 Audio processing circuit.

Fig. 6 is the circuit connection diagram of digital frequency synthesizer.

Fig. 7 is the circuit connection diagram of a local oscillation circuit.

Fig. 8 is the circuit connection diagram of two local oscillation circuits.

Fig. 9 is the circuit connection diagram of the first frequency mixer.

Figure 10 is the circuit connection diagram of the second frequency mixer.

Figure 11 is the circuit connection diagram of two frequency multiplier circuits for the first time.

Figure 12 is the circuit connection diagram of second of two frequency multiplier circuit.

Specific embodiment

The utility model is described in further detail below with reference to test example and specific embodiment.But it should not be by this The range for being interpreted as the above-mentioned theme of the utility model is only limitted to embodiment below, all to be realized based on the content of the present invention Technology belongs to the scope of the utility model.

One kind is based on DDS high-performance broadband signal source, such as Fig. 1, including field programmable gate array, D/A converter, and first Amplifier, the second amplifier, the first filter circuit, the second filter circuit, switching circuit；Such as Fig. 2, the field programmable gate array D8 Two ways of digital signals is generated according to SPI signal, then, such as Fig. 3, two ways of digital signals is converted by the D/A converter N703 At two-way analog signal, the first via analog signal is successively by the first amplifier N704 operation amplifier, first filter Enter the switching circuit after wave circuit filtering, second analog signal is successively put by the second amplifier N706 operation Greatly, enter the switching circuit after the second filter circuit filtering, first filter circuit is the second order Bezier of 20kHz For complex conjugate poles to low-pass filter circuit, including amplifier N705 and peripheral circuit, second filter circuit is the two of 300kHz Rank Bezier complex conjugate poles are to low-pass filter circuit, including amplifier N707 and peripheral circuit；Such as Fig. 4, the switching circuit packet Three switches N906, N907, N908 are included, the switching circuit on-off control send signal to the Audio processing circuit, described Audio processing circuit output modulated signal, modulated signal pass through the Audio processing circuit, such as Fig. 5, by operational amplifier (N30) afterwards be sent into DA (D13), later using analog switch ADG1421 (D14) after, be sent to analog-digital converter N3.N3 is one The analog-digital converter of a 14bit, by sampling to audio signal, obtained digital signal is sent into FPGA (D15), in FPGA The digital signal of internal modulation is added with frequency control word, and the data of output are sent into data port.

It further include Digital Frequency Synthesize circuit, bandpass filter, a local oscillation circuit, two local oscillation circuits, the first frequency mixer, Two frequency mixers, low-pass filter, two frequency multiplier circuits of first time, second of two frequency multiplier circuit；

The 427MHz signal that the Digital Frequency Synthesize circuit generates is after the bandpass filter, with a local oscillator Circuit generate signal be mixed in the first frequency mixer N16 after by switching be three road signals, such as Fig. 9, the first via Intermediate frequency is that the 940MHz local oscillation signal that a local oscillation circuit generates is mixed to obtain with 427MHz signal 1367MHz signal, second Road intermediate frequency is that the 1210MHz local oscillation signal that a local oscillation circuit generates is mixed to obtain 1637MHz signal with 427MHz signal, the Three road intermediate frequencies are that the 1460MHz local oscillation signal that a local oscillation circuit generates is mixed to obtain 1887MHz signal with 427MHz signal； Three road signals pass through the signal generated after switching with two local oscillation circuit and are mixed in the second frequency mixer N20, such as Figure 10, First via intermediate frequency is that 2117~2637MHz local oscillation signal that two local oscillation circuit generates is mixed to obtain 750 with 1367MHz signal ~1000MHz signal, the second road intermediate frequency are the 2637~2887MHz local oscillation signal and 1637MHz that a local oscillation circuit generates Signal is mixed to obtain 1000~1250MHz signal, and third road intermediate frequency is 3137~3387MHz sheet that a local oscillation circuit generates Vibration signal is mixed to obtain 1250~1500MHz signal with 1887MHz signal；It then is three road signals by switching, respectively By the bandpass filter of the 750~1000MHz of bandpass filter, 1000~1250MHz and 1250~1500MHz, obtain To 750~1500MHz signal, using the fundamental wave segment signal for obtaining 750~1500MHz after the low-pass filter；750~ The fundamental wave segment signal of 1500MHz obtains 1500~3000MHz signal by two frequency multiplier circuit of first time and exports, Huo Zhetong It crosses after two frequency multiplier circuit of first time and obtains 3000~6000MHz signal and defeated using second of two frequency multiplier circuit Out, or by the frequency-halving circuit and the divide by four circuit it obtains 200~750MHz signal and exports.

Such as Fig. 6, the Digital Frequency Synthesize circuit includes Direct Digital Frequency Synthesizers D1, using chip AD9914, mould Number converter N3, field programmable gate array D15 and loop filter (including C51, C52, R17).

Such as Fig. 7, a local oscillation circuit includes frequency synthesis chip HMC830 (D4), loop filter (including R47, R48, R4), power circuit HMC1060 (N7), frequency divider HMC905 (U1), amplifier ERA-3SM (N5), output switch HMC536 (D2, D3) and low-pass filter (including Z1, Z2, Z3, Z4)；HMC830 is one and is integrated with the frequency synthesis chip of VCO, defeated Frequency of phase locking out is up to 3GHz.Frequency synthesis chip D4 exports 1880MHz, 2420MHz, 2920MHz signal respectively, then After frequency divider U1 carries out 2 frequency dividings, the local oscillation signal that frequency is 940MHz, 1210MHz and 1460MHz is obtained；Amplification Device N5 completes the amplification to a local oscillation signal, can provide the gain of 20dB or so；Exporting switch D2, D3 is that local oscillator output is logical Road selection, a local oscillation signal selects different filter paths by switch, to filter out harmonic wave and clutter.

Such as Fig. 8, two local oscillation circuit include frequency synthesis chip HMC704 (U2) and loop filter (including N10, R65, C156, C142, R10, C154, R62, L10, R63, C153, R61), VCO (N11), power circuit HMC1060 (N12), put Big device ERA-3SM (N9, N13), output switch HMC536 (N8, N14) and low-pass filter (including Z6, Z7, Z8, Z9)；Frequently Rate synthesis chip U2 has lower background phase noise and lesser spurious signal.Built-in decimal frequency divider cooperates external The higher frequency synthesized signal of the available purity of VCO；Amplifier N9, N13 complete the amplification to two local oscillation signals, can provide The gain of 20dB or so；Switch N8, N14 are exported as the selection of two local oscillator output channels, two local oscillation signals are different by switch selection Filter path, to filter out harmonic wave and clutter.

Such as Figure 11, two frequency multiplier circuit of first time includes line transformer T1, diode V18；Frequency multiplier circuit uses Diode's balanced circuit avoids the interference of active circuit, while balancing circuitry can preferably offset higher hamonic wave, and T1 is responsible for Differential signal, which is converted, by single-ended signal gives diode V18.

Such as Figure 12, second of two frequency multiplier circuit include line transformer T2, diode V38；Frequency multiplier circuit uses Diode's balanced circuit avoids the interference of active circuit, while balancing circuitry can preferably offset higher hamonic wave, and T2 is responsible for Differential signal, which is converted, by single-ended signal gives diode V38.

The above, the only detailed description of specific embodiment of the present invention, rather than limitations of the present invention. Those skilled in the technology concerned in the case where not departing from the principle and range of the utility model, the various replacements made, Modification and improvement should be included within the scope of protection of this utility model.

Claims

1. one kind is based on DDS high-performance broadband signal source, which is characterized in that including audio generation circuitry, Audio processing circuit, number Word frequency combiner circuit, mixting circuit, quadruplicated frequency circuit；The audio generation circuitry generates audio signal according to SPI signal, so Afterwards by the conditioning of the Audio processing circuit, the Digital Frequency Synthesize circuit generates one according to the audio signal after conditioning Signal enters the mixting circuit and is mixed, and then exports broadband signal after quadruplicated frequency circuit processing.

2. according to claim 1 be based on DDS high-performance broadband signal source, which is characterized in that the audio generation circuitry Including field programmable gate array, D/A converter, operational amplifier, filter circuit, switching circuit；Field programmable gate array Digital signal is generated according to SPI signal, then digital signal is converted into analog signal, analog signal by the D/A converter Successively enter the switching circuit, the switch electricity after the operational amplifier operation amplifier, filter circuit filtering Road on-off controls output audio signal.

3. according to claim 1 be based on DDS high-performance broadband signal source, which is characterized in that the Audio processing circuit Including operational amplifier, D/A converter, analog switch, analog-digital converter；Audio signal is sent into D/A after passing through operational amplifier Converter, after exporting audio analog signals using analog switch switch control later.

4. according to claim 1 be based on DDS high-performance broadband signal source, which is characterized in that the Digital Frequency Synthesize Circuit includes Direct Digital Frequency Synthesizers, analog-digital converter, field programmable gate array and filter；Audio analog signals are sent Enter to analog-digital converter, obtained audio digital signals, audio digital signals are sent into field programmable gate array control directly number Word frequency synthesizer generates signal, and filters.

5. according to claim 1 be based on DDS high-performance broadband signal source, which is characterized in that the mixting circuit includes First bandpass filter, the second bandpass filter, a local oscillation circuit, two local oscillation circuits, the first frequency mixer, the second frequency mixer are low Bandpass filter；The signal that the Digital Frequency Synthesize circuit generates is after first bandpass filter, with a local oscillator The signal that circuit generates is mixed in first frequency mixer, then the signal generated with two local oscillation circuit is mixed described second It is mixed in frequency device, obtained signal enters second bandpass filter, obtains fundamental wave section letter using the low-pass filter Number.

6. according to claim 1 be based on DDS high-performance broadband signal source, which is characterized in that the quadruplicated frequency circuit packet Include two frequency multiplier circuits for the first time, second of two frequency multiplier circuit；Fundamental wave segment signal passes through again after passing through two frequency multiplier circuit of first time It is exported after crossing second of two frequency multiplier circuit.