SU1596285A1 - Meter of noise factor - Google Patents

Abstract

The invention can be used in monitoring and diagnosing the technical state of radio engineering systems. The purpose of the invention, an increase in the accuracy of noise figure measurement, is achieved by eliminating the influence of the nonlinearity and instability of the amplitude characteristics of the receiver and amplifier by switching from amplitude to phase measurements. For this, the first 10 1 and second 10 2 mixers are entered into the meter, the first 11 1 and second 11 2 filters, the first 12 1 and second 12 2 analog-to-digital converters, the first 13 1 and the second 13 2 storage units, the first 17 and the second 18 quadrants, serially connected local oscillator 14 and phase shifter 15, as well as block 16 of multipliers and block 19 of adders. During the measurement, the signal from the output of the noise generator 4 or the signal generator 7 is fed to the measured receiver 5, from which output the signal through the amplifier 6 is fed to two chains 8, 9, in which the phase relationships are analyzed. The noise figure is calculated by a computing unit 20, which is synchronized by a control unit 2, consisting of a counter 21 and a trigger 22, the output of which through the modulator 3 controls the noise generator 4. To the input of the counter 21 is connected to the generator 1 pulses. 2 hp f-ly, 4 ill.

Description

onion signals, i.e. possible implementation of a permanent operational avalysis of the technical state of the receiving device in the course of its operation. The device also makes it possible to control the reliability of the measurement results and its operability.

Figure 1 shows the functional diagram of the noise figure meter; figure 2 is a functional block diagram of the multipliers; figure 3 - block diagram adders; in fig. 4 diagram of the output device.

The noise figure meter (Fig. 1): contains a pulse generator 1 connected in series, a control unit 2, a modulator 3, a noise generator 4, the measured receiver 5, an amplifier 6, and a signal generator 7, the output of which is connected to the input of the measured receiver 5, two identical chains 8,9, containing a serially connected mixer 10 (lOg.), A filter P (), an analog-specific converter 12 (12) and a storage unit 13 (13), the inputs of the mixers are connected to the output of the amplifier b, serially connected local oscillator 14 and phase shifter on 90 15, outputs to which are connected respectively to the reference inputs of the first lOf and the second lOg. mixers. The device contains a block 16 of knives, the inputs of which are connected to the outputs of the converters 12, 2 to the storage blocks 13, 13, two identical quadrants 17, 18, the inputs of which are connected to the outputs of the converters 12 and 12, and sequentially connected block 19 adders and computing unit 20, the inputs of block 19 adders connected to the corresponding outputs of the block 16 multipliers and blocks 17,18.

The control unit contains a serially connected pulse divider (counter) 21 and a trigger 22. The output of the pulse divider 2 is the second output of the control unit 2 and is connected to the synchronous input of the computing unit 20.

The multiplier block 16 (Fig. 2) contains four identical multipliers 23, - 234-, whose inputs are the corresponding inputs of the block 16 multipliers.

Adder unit 19 (FIG. 3) contains three identical chains containing successively connected adder 24 and accumulating adder 25, inputs of adders 24 - 24h are the inputs of adder unit 19, and codes of accumulating adders 25;, 253 - outputs of adder unit 19.

Computing unit 20 contains a serially connected block 26 calculating the module of a complex number adder 27, a storage unit 28, a second adder 29, the second input of which is connected to the output of the first adder 27, a divider 30, the second input of which is connected to the output of the storage unit 28, as well as intelligently. resident 31, whose output is the output of the computing unit 20, the second storage unit 32, the output of which is connected to the input of the multiplier 31, and the input is the installation input of the noise figure meter connected in series. divider 33 and arc tangent calculation block 34. Input The recording of the first storage unit 28 is connected to the output of the trigger 22, the synchronous inputs of the modulation module 26, the arctangent 34 and the first adder 27 are the synchronous input of the computing unit

20 and connected to the output of the divider

21 pulses. The output of the pulse generator 1 is connected to the clock inputs of all blocks of digital information processing.

The awnings of the accumulating adders 25 are connected to the output of a 21-pulse divider.

The noise figure meter works as follows.

The pulse generator 1 generates a sequence of clock pulses with a frequency fy, which is divided into a separator of 21 pulses. The pulses generated at the same time nullify the accumulating adders 25 and change the state of the trigger 22. Consider the operation of the device when the state of the trigger 22 is equal to 0. At the same time, the noise generator 4 is turned off. The sinusoidal signal from the signal generator 7 is input to the input of the measured receiver 5. At the output of amplifier 6, an additive mixture of the signal and noise of the measured receiver 5 is observed. This signal goes to the inputs of the mixers 10, the reference inputs of which receive the signal of the local oscillator 14: directly to the first mixer 10, to the second with a phase shift of 90 °. As a result, the outputs of the filters 1 1 The signals are observed:) j U (t :) Acos (+ Cf) n Ug (t) Asin (COnZ + C) + ng (t). These intermediate frequency signals are digitized by analog-to-digital converters 12 controlled by generator 1 and the following pulses: Up. - U. (it;), Ug Ug (ut;), At l / f. These digital samples are memorized in blocks 13, 13, with the digital information being delayed by one clock cycle. Thus, while the outputs Ucj, Ug. Are observed at the output of analog-digital converters 12, 122, the counts Ug are observed at the outputs of blocks 134,132. These values of the samples arrive at the inputs of the block 16 multipliers, the outputs of which are paired products Uc; Uc;.,, Ue; U5 ;,. "with-., ,

and

C

s; - At the same time, samples from the outputs of analog-digital converters 12 p 1-2 are fed to the inputs of quadrants 17, 18, at the outputs of which are formed: and, I, and. These values of the samples are fed to the inputs of the block 19 adders, so that at the outputs of the adders 24 The values are formed: s; Uc; ATS, +%; . A cosCOnAt + SUxnj + + Ps; Ps; -, +%; Front ;,; Us; -.,: A sinGD flt + + Pv; Ps; -, - Ps; P5 {, J

and;

, - with;

2 + 5U

Js3 / l |

s |

/ S,

2G

26

26

Claims (3)

where 2 C is the noise power of the measured receiver 5; The subtraction is implemented by the summation result of the addition in the additional (inverse) code. In accumulating adders 25 during the observation interval, the values are generated: H: S.u; A + 26; and cosCO At} A sinG3..ut. S T The division is realized by cooning the shift of binary numbers, for example, by switching the input buses, 2 (5 is the noise dispersion (power). When the next control pulse arrives, the divider 21 passes the outputs from the accumulating adders 25 to the computing unit 20 and zeroing the accumulating adders 25 for the next measurement cycle, while the trigger 22 is set to state 1. Computing unit 20 (FIG. 4) works as follows. Module calculation unit 26 implements calculation of set modules The xs number: The adder 27 implements the operation of subtracting (adding in the additional code) numbers:; S, - / S2 + jSj / 20. At this time, the trigger 22 is already set to state 1. This signal goes to the recording of Block 28, allowing recording value 2 (j in block 28. The same signal blocks the operation of the next four numbers D:: blocks.: When trigger 22 is set to state I, noise generator 4 is turned on, signal processing is repeated as described above before the next control impulse with divider 21 pulses. With this on you during the adder 27 of the computing unit 20, as before, the dispersion estimate is formed, which has the form: 2 (5 p is the noise power of the noise generator 4). This value arrives at the input of the second adder 29, the second input of which receives the value 20 at the previous step. As a result of the summation in the additional code, a difference of 2 C - 2 is formed (Y, received at the input of the division unit 30, to the second input of which 2 b is from the output of the first storage unit 28. At the output of the division unit 30, the result of division (GjC) is formed, which in the mind of the knife 31 is multiplied by the value that is recorded in the second storage unit 32 before the measurement (app; 1t constant), the result those that form an estimate of the noise figure of the measured receiver 5. ITg - f; TO + Trr rle T (5 is the standard temperature; Tr and T (tp is the temperature of the noise generator 4. and the measured receiver, respectively 5. The following ratios are used: + T р p); 2C T р p), where Kg is a constant determined by a number of characteristics, in particular, the signal power, bandwidth, etc. Thus, the device allows to measure the noise figure of the receiving device for two work cycle with the standard noise generator turned on and off. Serially connected divider 33 and block 34 calculate arktan 1ensa computing unit 20 Normalizes the value of the control parameter: §z Wt We - Or „- This parameter is determined by the frequency of the signal CC f-, r-r« i, IOr clock generator and and myco c. The control of the reliability of the measurement results and the operability of the measurement of the bodies is carried out by the operator by comparing the measured value of the parameter P | with the calculated value at known frequencies 03, 63 O g i. At () 5, the decision about the unreliability of the assessment is made. Claim 1. A noise figure meter comprising a pulse generator connected in series, a control unit, a modulator, a noise generator, terminals for connecting the measured receiver and an amplifier, as well as a computing unit, the synchronization input of which is connected to the second output of the control unit, that, in order to improve the accuracy of noise figure measurement, a signal generator was introduced, two identical chains containing a series-connected mixer, a filter, an analog-to-digital converter and a storage unit, serially connected local oscillator and phase shifter by 90 °, a multiplier unit, two quadrants, an adder unit, the inputs of which are connected to the outputs of the multiplier unit and quadrants, and the outputs to the inputs of the computing unit, while the output of the signal generator is connected to the terminals the measured receiver, the signal inputs of the first and second mixers are connected to the output of the amplifier, and the reference inputs are connected to the output of the phase shifter and the local oscillator, respectively, the corresponding inputs of the multiplier unit are connected to Exit storage units and analog-converters, the outputs of analog-converters are connected to inputs of the quad. 2. The coefficient meter according to claim 1, characterized in that the computing unit comprises serially connected module calculating module, adder, storage unit, second adder, divider, multiplier and second storage unit, the input of the second adder is connected to the output of the first adder. 3. The coefficient meter according to claim 2, characterized in that, with the accuracy of the control and: 1ST9159628510 Simulation information, a computational vena divider and a calculating unit, the unit contains sequentially connectors. j Fig r . / -N -one -. D. ZTZ Fog. / tJ