CN205105200U - Portable sonde receiver radio frequency front end circuit - Google Patents

Abstract

The utility model provides a radio frequency front-end circuit of a portable radiosonde receiver, comprising: a low noise amplifier, a radio frequency filter, a mixer, an intermediate frequency filter, a controllable gain amplifier, a wave detector and an operational amplifier electrically connected in sequence. The utility model improves the power consumption of the radiosonde receiver, has higher sensitivity, can receive and process weaker meteorological signals, and improves the detection distance; it has high integration, small size and light weight, and is suitable for people to carry. It is used together with the air instrument and has good portability.

Description

Portable radiosonde receiver radio frequency front-end circuit

technical field

The invention relates to the field of radio frequency front-end circuits of receivers, in particular to the receiving and processing of radiosonde signals in UHF meteorological frequency bands.

Background technique

In recent years, the rapid economic development has also brought some environmental issues worthy of attention, among which the issue of climate and environmental change has attracted widespread attention from all parties. Global warming, off-season weather, local sudden disasters and other weather conditions have brought a huge impact on people's daily life, not only causing serious economic losses, but also threatening the safety of human life and property. In order to reduce the impact of meteorological disasters, it is very important to take protective measures in advance, which requires accurate weather forecasting. The data information of high-altitude meteorological detection not only affects daily weather forecast and climate analysis, but also plays an important role in national defense, military and national economic construction. Nowadays, my country's ground detection equipment is mainly fixed-station and vehicle-mounted. Most of the equipment is large-scale equipment such as weather radar and radio theodolite. The cost of developing and updating such equipment is higher than that of radiosondes. a lot of. The continuous development of radiosonde technology puts forward higher requirements on the performance of ground receiving equipment. The performance of the receiving system is related to whether the meteorological data can be effectively received, and the accuracy of the meteorological data will directly affect the quality of related application services. Compared with station-type and vehicle-mounted equipment, the development cost of portable receivers is relatively small, and it is suitable for people to carry. It has incomparable mobility compared with station-type and vehicle-mounted equipment. It is suitable for artificial rainfall, missile launching and mountain disaster relief. Wait for some special occasions.

The existing portable radiosonde receiver is used in conjunction with the L-band digital radiosonde, the detection distance is not far enough, and the accuracy is not high. With the successful development and gradual promotion and use of domestic GPS radiosondes, the detection distance has become farther after GPS positioning is adopted, and the sensitivity, power consumption, gain and other performance of the receiver also need to be further improved.

Contents of the invention

The purpose of the present invention is to provide a radio frequency front-end circuit system with high integration, small size, better sensitivity and power consumption, which can be used in conjunction with the latest domestic GPS radiosonde, and the detection distance is longer and the accuracy is higher.

The present invention provides following technical scheme:

A radio frequency front-end circuit of a portable radiosonde receiver, comprising: a low noise amplifier, a radio frequency filter, a mixer, an intermediate frequency filter, a controllable gain amplifier, a wave detector and an operational amplifier electrically connected in sequence.

The noise figure of the low noise amplifier is less than 1.5dB, and the gain reaches 22dB.

The radio frequency filter is a high-Q band-pass filter.

The mixer is an active mixer capable of providing 10dB of gain.

The intermediate frequency filter is an intermediate frequency bandpass filter.

The controllable gain control amplifier, wave detector and operational amplifier form an automatic gain control circuit, and the automatic gain control circuit can provide a gain of 35dB for a weak input signal level.

The beneficial effects of the present invention are: the power consumption of the radiosonde receiver is improved, the sensitivity is higher, and weaker meteorological signals can be received and processed, and the detection distance is improved; the integration degree is high, the volume is small and the weight is light, and it is suitable for people to carry, and it is compatible with The latest GPS radiosonde is used in conjunction with it, and the portability is good.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the embodiments of the present invention to explain the present invention, and do not constitute a limitation to the present invention. In the attached picture:

Figure 1 is a structural diagram of the radio frequency front end;

Figure 2 is a gain-to-noise performance diagram of the RF front-end;

Fig. 3 is the input signal of the third-order intermodulation test;

Figure 4 is the output signal of the third-order intermodulation test;

Figure 5 shows the results of higher harmonic analysis.

detailed description

As shown in Figures 1-5, the present invention discloses a radio frequency front-end circuit of a portable sonde receiver, comprising: a low noise amplifier 1, a radio frequency filter 2, a mixer 3, an intermediate frequency filter 4, a controllable Gain amplifier 5, detector 6 and operational amplifier 7.

In this embodiment, in the radio frequency front end of the receiver, the noise figure of the low noise amplifier 1 is less than 1.5dB, and the gain reaches 22dB. The RF filter 2 is a band-pass filter with high Q value, which requires small insertion loss and large out-of-band suppression with steep edges, which can sufficiently suppress the image frequency. The mixer 3 plays the role of down-conversion, is an active mixer, and can provide a gain of 10dB. The intermediate frequency filter 4 is an intermediate frequency bandpass filter with small insertion loss and good out-of-band suppression performance.

The automatic gain control amplifier 5, the wave detector 6 and the operational amplifier 7 form an automatic gain control circuit. For the weak input signal level, the automatic gain control circuit can provide a gain of 35dB. When the input signal level is high, in order to make the output level not exceed the rated value of the back-end circuit, the automatic gain control circuit plays a certain role in the gain. the compression effect. The gain of the controllable gain amplifier 5 is controlled by the output voltage of the operational amplifier 7. The wave detector 6 detects the output signal of the controllable gain amplifier 5 and outputs a DC voltage. For comparison, the output voltage of the operational amplifier 7 controls the gain of the controllable gain amplifier. The automatic gain control circuit composed of the automatic gain control amplifier 5, the wave detector 6 and the operational amplifier 7 keeps the output power of the intermediate frequency within a stable range.

The radio frequency front end of the receiver of the present invention, the received signal is first amplified and denoised by the low noise amplifier 1, and then filtered by the radio frequency filter 2, and the mixer 3 performs down-conversion processing on the signal and provides partial gain, and then passes through The intermediate frequency filter 4 filters to obtain the intermediate frequency signal. When the output signal of the intermediate frequency filter 4 is small, the self-controlled gain control part provides a full gain of 35dB. When the output signal of the intermediate frequency filter 4 is large, the gain of the final automatic gain control circuit is compressed so that the output power of the intermediate frequency is stable at about 0dBm .

As shown in Figure 2, it shows the RF front-end path, the gain, output power and noise figure of each part of the circuit under different input signal power conditions.

As shown in Figure 3, it is the input signal situation when testing the third-order intermodulation characteristics of the entire front-end circuit.

As shown in Figure 4, it is the input signal situation when testing the third-order intermodulation characteristics of the entire front-end circuit.

As shown in Figure 55, it is the analysis result of the high-order harmonics of the front-end circuit. It can be seen that except for the required intermediate frequency frequency, the suppression of other harmonics is very good.

In summary, the present invention improves the power consumption of the radiosonde receiver, has higher sensitivity, can receive and process weaker meteorological signals, and improves the detection distance; it has high integration, small size and light weight, and is suitable for people to carry. It is used together with GPS radiosonde and has good portability.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still understand the foregoing embodiments The recorded technical solutions are modified, or some of the technical features are equivalently replaced. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. A portable radiosonde receiver radio frequency front-end circuit, is characterized in that, comprises: the low noise amplifier, radio frequency filter, mixer, intermediate frequency filter, controllable gain amplifier, wave detector and operational amplifier electrically connected successively . 2. portable sonde receiver radio frequency front-end circuit according to claim 1, is characterized in that, the noise figure of described low noise amplifier is less than 1.5dB, and gain reaches 22dB. 3. The radio frequency front-end circuit of the portable radiosonde receiver according to claim 1, wherein the radio frequency filter is a high-Q band-pass filter. 4. The radio frequency front-end circuit of the portable radiosonde receiver according to claim 1, wherein the mixer is an active mixer capable of providing a gain of 10dB. 5. The radio frequency front-end circuit of the portable radiosonde receiver according to claim 1, wherein the intermediate frequency filter is an intermediate frequency bandpass filter. 6. portable sonde receiver radio frequency front-end circuit according to claim 1, is characterized in that, described controllable gain control amplifier, detector and operational amplifier have formed automatic gain control circuit, for weak input signal level , The automatic gain control circuit can provide a gain of 35dB.