CN216649672U

CN216649672U - 1.8GHz attenuation filtering and amplifying circuit

Info

Publication number: CN216649672U
Application number: CN202220293262.1U
Authority: CN
Inventors: 钱勇; 蒋德龙
Original assignee: Chengdu Haoqi Technology Co ltd
Current assignee: Chengdu Haoqi Technology Co ltd
Priority date: 2022-02-14
Filing date: 2022-02-14
Publication date: 2022-05-31
Anticipated expiration: 2032-02-14

Abstract

The utility model relates to a 1.8GHz attenuation filtering amplification circuit, which comprises a first filter, a numerical control attenuator, a first amplifier, an equalizer, a first temperature compensation attenuator, a second amplifier, a second filter, a second temperature compensation attenuator, a third amplifier and a third filter. The circuit has low power consumption, small volume and no need of independent debugging, and the circuit module has the advantages of good in-band flatness, low cost, high reliability and the like.

Description

1.8GHz attenuation filtering and amplifying circuit

Technical Field

The utility model relates to the technical field of electrical communication, in particular to an L-band receiving and amplifying circuit unit and a 1.8GHz attenuation filtering and amplifying circuit.

Background

In the field of wireless communication such as modern mobile communication, satellite communication, radar communication and the like, a receiver system plays the most critical role and is responsible for amplifying, down-converting and filtering weak radio-frequency signals to intermediate frequency with low noise, so that the signals can be conveniently sent to a digital signal processing part for demodulation and signal processing. In the existing L-band design circuit, the requirements for harmonics, out-of-band rejection and in-band flatness are high, and this is basically achieved by using a scheme of an amplifier and a switch filter bank. The mode has the advantages of high power consumption of the amplifier, large size of the filter, poor flatness in the filter band, high product cost, high debugging difficulty and high batch production cost.

Chinese patent (CN203289418U) discloses a radio frequency sampling receiver, in which the input end of an amplitude limiter in the circuit structure receives an input signal, and the output port of the amplitude limiter is sequentially connected with a low noise amplifier, a broadband filter, a first amplifier, a first low pass filter, a temperature compensation attenuator, an attenuator, a second amplifier, a second low pass filter, and a digital signal processing unit. The signal processing method solves the technical problems that an L-band receiver is poor in processing flexibility, easy to capture and capture signals, large in size and the like. However, the circuit has poor stray index and poor in-band flatness, so that an attenuation filtering amplifying circuit is needed, and the problems of high out-of-band rejection, large dynamic complex circuit, high cost, complex debugging and the like caused by the adoption of the traditional large-size and large-current design scheme with low cost, high stability and reliability are solved.

Furthermore, on the one hand, due to the differences in understanding to the person skilled in the art; on the other hand, since the inventor of the present invention studied a lot of documents and patents at the time of making the present invention, but the space limit did not list all details and content in detail, however, this by no means does the present invention not have these prior art characteristics, but on the contrary the present invention has all the characteristics of the prior art, and the applicant reserves the right to increase the related prior art in the background art.

SUMMERY OF THE UTILITY MODEL

Aiming at the defects of the prior art, the utility model provides a 1.8GHz attenuation filtering and amplifying circuit which comprises a first filter, a numerical control attenuator, a first amplifier, an equalizer, a first temperature compensation attenuator, a second amplifier, a second filter, a second temperature compensation attenuator, a third amplifier and a third filter. In the circuit, after the first filter receives signals, the signals in the circuit are sequentially transmitted to the numerical control attenuator, the first amplifier, the equalizer, the first temperature compensation attenuator, the second amplifier, the second filter, the second temperature compensation attenuator, the third amplifier and the third filter.

According to a preferred embodiment, the parameters of the filter are as follows, the center frequency being 1800 MHz; the central insertion loss is less than 1 dB; the 0.8dB bandwidth is 1000 MHz; the out-of-band inhibition is more than or equal to 45dBc when the frequency is DC-1100 MHz and 2500-6000 MHz; the standing wave ratio in the band is less than 1.5.

According to a preferred embodiment, the first filter is a low-pass filter.

According to a preferred embodiment, the second filter is a high-pass filter.

According to a preferred embodiment, the digitally controlled attenuator is of the type F1958.

According to a preferred embodiment, the first filter has a model number LFCG-2500 +.

According to a preferred embodiment, the second filter has the type HFCG-1100 +.

The utility model has the beneficial technical effects that:

firstly, the utility model can be used for the intermediate frequency processing of the analog front end of the wide bandwidth signal and the wide bandwidth receiving intermediate frequency processing;

secondly, the utility model has good anti-stray interference and in-band flatness;

thirdly, the circuit is widely applied to the intermediate frequency level of the input of the monitoring receiver, has small volume, low power consumption, good product consistency, basically no debugging, low production cost, good temperature stability and high reliability.

Drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Reference numerals in the specification

100-a first filter; 200-a numerical control attenuator; 300-a first amplifier; 400-an equalizer; 500-a first temperature-compensated attenuator; 600-a second amplifier; 700-a second filter; 800-a second temperature-compensating attenuator; 900-a third amplifier; 1000-third filter.

Detailed Description

The following detailed description is made with reference to the accompanying drawings.

The utility model provides a 1.8GHz attenuation filtering amplification circuit, which comprises a first filter 100, a numerical control attenuator 200, a first amplifier 300, an equalizer 400, a first temperature compensation attenuator 500, a second amplifier 600, a second filter 700, a second temperature compensation attenuator 800, a third amplifier 900 and a filter 1000, wherein after the circuit receives signals by the first filter 100 such as a low-pass filter, the signals in the circuit are transmitted to the numerical control attenuator 200, the first amplifier 300, the equalizer 400, the first temperature compensation attenuator 500, the second amplifier 600, the second filter 700, the second temperature compensation attenuator 800, the third amplifier 900 and the third filter 1000 in sequence. For example, in the process of inputting a radio frequency signal of 1.8GHz ± 500MHz, the radio frequency signal is subjected to filtering processing by the first filter 100, then enters the digitally controlled attenuator 200 to dynamically adjust the input signal, then the first amplifier 300 amplifies the attenuated signal, compensates for the in-band flatness by the equalizer 400(LC) matched together, performs compensation processing for different temperature gains by the first temperature compensation attenuator 500, then amplifies the signal by the second amplifier 600, performs filtering processing by the second filter 700 set, for example, a high-pass filter, passes through the second temperature compensation attenuator 800, enters the third amplifier 900 to perform signal amplification, and finally performs filtering processing on the signal by the third filter 1000.

Wherein the attenuation of the first temperature-compensated attenuator 500 and the second temperature-compensated attenuator 800 is 3 dB.

The numerical control attenuator 200 is F1958 of IDT, is controlled by SPI, and has the characteristic that the flatness of 1.3-2.3GHz is better than 0.15 dB; inserting loss: 1.4dBm @3 GHz; P0.1dB: 35dB @2 GHz; IP 3: 60dBm @2.2 GHz; the adoption of the numerical control attenuator is beneficial to reducing the volume of the whole circuit, and the flatness of the broadband is excellent.

The first filter 100 and the second filter 700 are LFCG-2500+ and HFCG-1100+ which are MINI, respectively, have excellent rectangular coefficients, and are ultra-small-sized.

The third filter 1000 is an LC filter, and the center frequency of the third filter 1000 is 1800 MHz; central insertion loss: less than 1 dB; 0.8dB bandwidth: 1000MHz (1300MHz to 2300 MHz); out-of-band suppression: more than or equal to 45dBc @ DC-1100 MHz, more than or equal to 45dBc @ 2500-6000 MHz; and (3) internal standing-wave ratio: is less than 1.5.

The technical indexes of the attenuation filtering amplifying circuit are as follows:

1. inputting a signal:

1) and the working frequency: 1.3 GHz-2.3 GHz;

2) and input level: < -10 dBm;

3) input harmonic suppression: > 50 dB.

2. Outputting a signal:

1) and the working frequency: 1.3 GHz-2.3 GHz;

2) and gain: 40 plus or minus 0.5 dB;

3) p1 dB: > 18, typical values: 19 dB;

4) harmonic suppression: when the @ output is more than 55dB, and is 5 dBm;

5) and out-of-band inhibition:

≥45dBc@DC～1100MHz

≥45dBc@2500～6000MHz

6) in-band flatness: < 1.5 dB.

3. Power supply characteristics:

1) and working power supply voltage: 5V of direct current;

2) and working current: 200mA (typical value) < 250 mA.

4. Working temperature: minus 40 ℃ to plus 85 ℃.

5. The external dimension of the PCB is as follows: < 50X 50 (mm).

It should be noted that the above-mentioned embodiments are exemplary, and that those skilled in the art, having benefit of the present disclosure, may devise various arrangements that are within the scope of the present disclosure and that fall within the scope of the utility model. It should be understood by those skilled in the art that the present specification and figures are illustrative only and are not limiting upon the claims. The scope of the utility model is defined by the claims and their equivalents.

Claims

1. A1.8 GHz attenuation filtering amplification circuit comprises a first filter (100), a first amplifier (300), a first temperature-compensated attenuator (500), a second amplifier (600), a second filter (700), a second temperature-compensated attenuator (800), a third amplifier (900) and a third filter (1000), the circuit also comprises a numerical control attenuator (200) and an equalizer (400), and after the circuit receives signals by the first filter (100), the signal in the circuit is transmitted to the numerical control attenuator (200), the first amplifier (300), the equalizer (400), the first temperature-compensated attenuator (500), the second amplifier (600), the second filter (700), the second temperature-compensated attenuator (800), the third amplifier (900) and the third filter (1000) in sequence.

2. Attenuating filter amplifying circuit according to claim 1, characterised in that the parameters of the filter (1000) are such that the centre frequency is 1800 MHz; the central insertion loss is less than 1 dB; the 0.8dB bandwidth is 1000 MHz; the out-of-band inhibition is more than or equal to 45dBc when the frequency is DC-1100 MHz and 2500-6000 MHz; the standing wave ratio in the band is less than 1.5.

3. Attenuating, filtering and amplifying circuit according to claim 2, characterised in that the first filter (100) is a low-pass filter.

4. Attenuating filter amplifying circuit according to claim 3, characterized in that the second filter (700) is a high-pass filter.

5. Attenuating, filtering and amplifying circuit according to claim 4, characterised in that the digitally controlled attenuator (200) is of type F1958.

6. Attenuating-filtering amplification circuit according to claim 5, characterized in that the first filter (100) is of the type LFCG-2500 +.

7. The attenuate-filter amplifier circuit according to claim 5, wherein the second filter (700) is of type HFCG-1100 +.