CN205179027U - A high gain amplifier that is used for radio frequency receiver of directly sampling - Google Patents

Abstract

The utility model relates to a high gain amplifier that is used for radio frequency receiver of directly sampling. The high gain amplifier circuit comprises first amplifying unit and second amplifying unit, and first amplifying unit circuit connection is: signal in the working frequency band that the antenna was received loops through LC band pass filter I, broadband low -noise amplifier, PCS -RX I, high frequency triode I, PCS -RX II and is connected with high frequency triode II. The second amplifying unit circuit connection do: signal after the output of first amplifying unit is enlargied loops through LC band pass filter II, high frequency triode III, crystal filter, high frequency triode IV, digital control attenuator, integrated radio frequency amplifier and is connected with LC low pass filter. Two amplifying units set up respectively in two metal cartons, through cable junction. Whole amplifier gain 117dB can have the temperature compensating function in the stable work of wide band section within range, guarantees that the complete machine changes no longer than 3dB - 25 DEG C ~55 DEG C within range gains.

Description

A kind of high-gain amplifier for radio frequency Direct Sampling receiver

Technical field

The utility model relates to a kind of high-gain amplifier for radio frequency Direct Sampling receiver.

Background technology

Along with high-speed a/d, the improving constantly of D/A, DSP device performance, the direct Band-pass Sampling Technology of the radio frequency of receiver is made to have had the platform of putting to good use.The features such as radio frequency Direct Sampling receiver, relative to conventional superheterodyne receiver, has Reconfigurability strong, flexible, open, easily form modularization and standardization.By radio frequency Direct Sampling technology, use filtering and bandpass sampling method along separate routes, the synchronous acquisition to multi-channel rf signal can be realized, synchronous transmission can be carried out to image data.The radio frequency directly technology of adopting must use high-gain radio frequency amplifier, because the signal amplitude that antenna receives is μ V rank, and the minimum resolution of A/D also wants tens of mV, this is amplified to the amplitude of applicable A/D device sampling with regard to needing high-gain amplifier (more than gain 100dB) faint radiofrequency signal, and will the noise factor of step-down amplifier as much as possible, there are enough signal to noise ratios for circuit sampling below and data processing to make the output signal of amplifier.

Summary of the invention

In view of the situation of prior art and the deficiency of existence, the utility model provides a kind of implementation method of the high-gain amplifier for radio frequency Direct Sampling receiver, to tackle the demand that prior art needs high-gain amplifier.

The utility model for achieving the above object, the technical scheme adopted is: a kind of high-gain amplifier for radio frequency Direct Sampling receiver, comprise two metal case, it is characterized in that: also comprise high-gain amplifier circuit, described high-gain amplifier circuit is made up of the first amplifying unit and the second amplifying unit, described first amplifying unit comprises LC band pass filter I, wideband low noise amplifier, Surface Acoustic Wave Filter I, high-frequency triode I, Surface Acoustic Wave Filter II, high-frequency triode II, electronic filter I, electronic filter II, electronic filter III, concrete connection is: the signal in the working band that antenna receives is successively by LC band pass filter I, wideband low noise amplifier, Surface Acoustic Wave Filter I, high-frequency triode I, Surface Acoustic Wave Filter II is connected with high-frequency triode II, the signal after amplifying is exported by radio frequency accessory power outlet, power supply connects wideband low noise amplifier by electronic filter I, and power supply meets high-frequency triode I by electronic filter II, and power supply meets high-frequency triode II by electronic filter III,

Described second amplifying unit comprises LC band pass filter II, high-frequency triode III, crystal filter, high-frequency triode IV, numerical-control attenuator, integrated RF amplifier, LC low pass filter, electronic filter IV, electronic filter V, electronic filter VI, concrete connection is: the signal after the output amplification of the first amplifying unit is successively by LC band pass filter II, high-frequency triode III, crystal filter, high-frequency triode IV, numerical-control attenuator, integrated RF amplifier is connected with LC low pass filter, signal is after filtering added to the radio frequency socket of output, power supply meets high-frequency triode III by electronic filter IV, and power supply meets high-frequency triode IV by electronic filter V, power supply connects integrated RF amplifier by electronic filter VI,

First amplifying unit is placed in a can, and the second amplifying unit is placed in another can, and the first amplifying unit is connected by cable with the second amplifying unit.

The beneficial effects of the utility model are: the utility model and radio frequency Direct Sampling receiver with the use of, the radio frequency Directly solution transfer achieving wireless receiver is received, on sensitivity index, the raising of 3-4dB is had relative to traditional superheterodyne receiver, and the frequency synthesizer eliminated in superheterodyne receiver, it also avoid the problem that synthesizer frequency shift (FS) causes under high and low temperature environment sensitivity declines.

Whole amplifier gain 117dB, can within the scope of wide-band steady operation, there is temperature compensation function, ensure that complete machine change in gain within the scope of-25 DEG C ~ 55 DEG C is no more than 3dB.

Complete machine possesses fabulous low-noise performance.Prime uses ultra-low noise to amplify components and parts and the suitable low loss filter of input makes the noise factor of complete machine be no more than 2dB.

Accompanying drawing explanation

Fig. 1 is that circuit of the present utility model connects block diagram.

Embodiment

As shown in Figure 1, a kind of high-gain amplifier for radio frequency Direct Sampling receiver, comprise two metal case, also comprise high-gain amplifier circuit, high-gain amplifier circuit is made up of the first amplifying unit and the second amplifying unit, and the first amplifying unit comprises LC band pass filter I, wideband low noise amplifier, Surface Acoustic Wave Filter I, high-frequency triode I, Surface Acoustic Wave Filter II, high-frequency triode II, electronic filter I, electronic filter II, electronic filter III; Concrete connection is: the signal in the working band that antenna receives is connected with high-frequency triode II by LC band pass filter I, wideband low noise amplifier, Surface Acoustic Wave Filter I, high-frequency triode I, Surface Acoustic Wave Filter II successively, exports the signal after amplifying by radio frequency accessory power outlet; Power supply connects wideband low noise amplifier by electronic filter I, and power supply meets high-frequency triode I by electronic filter II, and power supply meets high-frequency triode II by electronic filter III.

Second amplifying unit comprises LC band pass filter II, high-frequency triode III, crystal filter, high-frequency triode IV, numerical-control attenuator, integrated RF amplifier, LC low pass filter, electronic filter IV, electronic filter V, electronic filter VI; Concrete connection is: the signal after the output amplification of the first amplifying unit is connected with LC low pass filter by LC band pass filter II, high-frequency triode III, crystal filter, high-frequency triode IV, numerical-control attenuator, integrated RF amplifier successively, and the signal is after filtering added to the radio frequency socket of output; Power supply meets high-frequency triode III by electronic filter IV, and power supply meets high-frequency triode IV by electronic filter V, power supply connects integrated RF amplifier by electronic filter VI.

First amplifying unit is placed in a can, and the second amplifying unit is placed in another can, and the first amplifying unit is connected by cable with the second amplifying unit.

Because whole amplifying circuit gain is very high, amplifier self-excitation is caused for avoiding coupling between constrained input, first amplifying unit and the second amplifying unit being arranged on independently is had in a can of excellent shielding properties, the radio frequency of two amplifying units connects the rigid cable adopting leakage extremely low, to cut off the coupling between the first amplifying unit and the second amplifying unit input and output, make it can steady operation.

For an implementation method for the high-gain amplifier of radio frequency Direct Sampling receiver, step is as follows: whole high-gain amplifier is divided into 2 amplifying units: the first amplifying unit and the second amplifying unit.

The course of work of the first amplifying unit: first the signal in the working band that antenna receives is accessed by the RF input socket of the first amplifying unit, through LC band pass filter I, the Insertion Loss 2dB of this LC band pass filter I, be added to the gain that wideband low noise amplifier produces 20dB, filtering is carried out afterwards through Surface Acoustic Wave Filter I, about there is the Insertion Loss of 3dB, the gain producing 22dB is amplified again through high-frequency triode I, filtering is carried out through Surface Acoustic Wave Filter II, there is the Insertion Loss of 3dB, amplify through high-frequency triode II again, there is the gain of 22dB, signal after amplification is added to the radio frequency accessory power outlet of the first amplifying unit.

The gain of the first amplifying unit is calculated as follows:

Gain=-the 2dB+20dB-3dB+22dB-3dB+22dB=56dB of the first amplifying unit.

The course of work of the second amplifying unit: the radio frequency of the first amplifying unit exports the radio frequency input of receiving the second amplifying unit, through LC band pass filter II, the Insertion Loss 2dB of this LC band pass filter II, be added to this stage circuit of high-frequency triode III to amplify, there is the gain of 22dB, filtering is carried out afterwards through crystal filter, crystal filter has the Insertion Loss of 3dB, amplify through this stage circuit of high-frequency triode IV again, there is the gain of 22dB, pass through numerical-control attenuator afterwards, the attenuation stepping of numerical-control attenuator is 1dB, its effect is the gain regulating complete machine total, can also compensate as the high/low temperature of complete machine gain, signal through numerical-control attenuator finally delivers to integrated RF amplifier, this grade has the gain of 23dB, the signal exported carries out filtering through low pass filter below, consider except harmonic component, low pass filter has the Insertion Loss of 1dB, signal is after filtering added to the radio frequency socket of output.

The gain of the second amplifying unit is calculated as follows:

Gain=-the 2dB+22dB-3dB+22dB+23dB-1dB=61dB of the second amplifying unit.

Like this, the gain of complete machine just has the gain=117dB of gain+the second amplifying unit of the first amplifying unit.

The activated amplifier of above-mentioned use is all broadband device, and inter-stage is furnished with LC band pass filter or Surface Acoustic Wave Filter or crystal filter, determines the centre frequency of these filters according to receive frequency.The broader bandwidth of LC band pass filter and Surface Acoustic Wave Filter, usually a few MHz is reached to tens MHz, object is the bandwidth in order to reduce high-gain amplifier, thus reduce the signal to noise ratio that noise power improves output signal, the bandwidth of crystal filter is narrower, from a few KHz to hundreds of KHz, crystal filter is used to be to select the signal needing to receive.

This high-gain amplifier is owing to there being very high gain, and wherein amplifier at different levels is very easily because coupling causes positive feedback self-excitation, therefore the power supply circuits of every grade of amplifier have all added electronic filter, makes every grade of Power supply all using " pure ".

For making complete machine reliably working, improving the isolation exported between input, taking measures from circuit and structure two aspect.The measure that circuit is taked has, and the power supply circuits of amplifier at different levels adopt electronic filter, increases filter effect, follows input and output and to be coupled minimum principle, make output to greatest extent away from input during circuit fabric swatch.

Structurally adopt shielding measure, the first amplifying unit and the second amplifying unit are placed in two independently in can respectively, realize the electromagnetic shielding of complete machine.

The first order adopts the wideband low noise amplifier WHM02AE of ultra-low noise, and its key property is:

Noise: 0.7dB

Export IP3:27dBm

Gain: 13 ~ 22dB

Export 1dB compression point: 14dBm

Bandwidth of operation: 100KHz ~ 3GHz.

Adopt the high-frequency triode BFG425W of high-gain, its key property is:

Noise: 0.8dB

Export IP3:22dBm

Gain: 20 ~ 26dB

Export 1dB compression point: 12dBm

Cut-off operating frequency: 25GHz.

Adopt the LC band pass filter of filter with low insertion loss, which kind of filter of input termination of amplifier has vital effect to amplifier performance, if use narrow band filter (just meeting bandwidth of operation), Insertion Loss is larger, the noise factor of whole amplifier certainly will be caused too high, if do not use filter, the noise factor of complete machine can be lower, but Clogging indicator is poor, the outer strong signal disturbing of easy tape.This case adopts the LC band pass filter of filter with low insertion loss, noise factor institute both can have been made influenced little, significantly can suppress again the interference signal beyond bandwidth of operation.The leading indicator of the LC band pass filter of this filter with low insertion loss is:

Insertion Loss: lower than 1.5dB

Three dB bandwidth: 5 ~ 10MHz

Unevenness: 0.5dB in band.

Adopt crystal filter, this amplifier is used in narrow-band receiver, although may receive the signal of multiple channel simultaneously, multiple receive channel is all arrowband (bandwidth 25KHz), and the interval between each channel is no more than 100KHz.Therefore the bandwidth of operation of amplifier should be narrower, namely uses narrow band filter, to improve the signal to noise ratio of output signal.The crystal filter index that this case uses is:

Centre frequency: 162MHz

Three dB bandwidth: 100KHz

Insertion Loss :≤3dB

Stopband attenuation: >=60dB

Input and output impedance: 50 Ω.

Power supply adopt electronic filter, because the amplifier gain of this case is very high, thus to pay special attention to remove at different levels between coupling, to avoid self-excitation.The coupling of each inter-stage is very likely realized by power supply, so decoupling in power supply is strengthened in this case.Electronic filter can exceed more than 10dB than the filter effect of common LC filter.

Adopt numerical-control attenuator, the gain of amplifier is higher, so the absolute change amount of gain that variation of ambient temperature causes is comparatively large, is compensating gain change, uses numerical-control attenuator, can with temperature sensing circuit with the use of, realize the temperature-compensating of gain.

Integrated RF amplifier model is MGA-62563.

Claims (1)

1. the high-gain amplifier for radio frequency Direct Sampling receiver, comprise two metal case, it is characterized in that: also comprise high-gain amplifier circuit, described high-gain amplifier circuit is made up of the first amplifying unit and the second amplifying unit, described first amplifying unit comprises LC band pass filter I, wideband low noise amplifier, Surface Acoustic Wave Filter I, high-frequency triode I, Surface Acoustic Wave Filter II, high-frequency triode II, electronic filter I, electronic filter II, electronic filter III, concrete connection is: the signal in the working band that antenna receives is successively by LC band pass filter I, wideband low noise amplifier, Surface Acoustic Wave Filter I, high-frequency triode I, Surface Acoustic Wave Filter II is connected with high-frequency triode II, the signal after amplifying is exported by radio frequency accessory power outlet, power supply connects wideband low noise amplifier by electronic filter I, and power supply meets high-frequency triode I by electronic filter II, and power supply meets high-frequency triode II by electronic filter III,

Described second amplifying unit comprises LC band pass filter II, high-frequency triode III, crystal filter, high-frequency triode IV, numerical-control attenuator, integrated RF amplifier, LC low pass filter, electronic filter IV, electronic filter V, electronic filter VI, concrete connection is: the signal after the output amplification of the first amplifying unit is successively by LC band pass filter II, high-frequency triode III, crystal filter, high-frequency triode IV, numerical-control attenuator, integrated RF amplifier is connected with LC low pass filter, signal is after filtering added to the radio frequency socket of output, power supply meets high-frequency triode III by electronic filter IV, and power supply meets high-frequency triode IV by electronic filter V, power supply connects integrated RF amplifier by electronic filter VI,

First amplifying unit is placed in a can, and the second amplifying unit is placed in another can, and the first amplifying unit is connected by cable with the second amplifying unit.