RU30226U1 - Calculator of an eight-pulse module of quadrature signals - Google Patents

Description

Eight Pulse Calculator

The utility model relates to electro-radio engineering, in particular, to devices for receiving a quadrature signal module and can be used in radar stations, automation devices and computer technology.

A known amplitude detector containing a phase splitter of the input signal, the first and second outputs of which are connected through the first and second detectors of the components of the input signal to the first and second inputs of the output adder, as well as to the first and second inputs of the signal difference detector, the output of which is connected to the third input of the output adder SU 1249690, 1986, H 03D 1/00.

In this device, the first and second detectors perform the functions of two-half-wave rectifiers, since they perform the operation of rectifying bipolar, phase-shifted by Jc / 2 sinusoidal input voltages, into unipolar voltages without a smoothing filter. A signal difference detector performs the same function. The 3-input circuit of the output adder performs the functions of a multiplier or divider along the third input and the output adder of the three input signals. The multiplier has a scaling factor equal to (l / 2 -1). In the description of the invention, the latter is understood as a divider with a scaling factor,

equal to 2.41. But 2.4} / 2 + / 2-lJ, which corresponds to a scaling factor (/ 2 -1) FOR the multiplier. Thus, the known amplitude detector in a. from. No. 1249690 is, in fact, a calculator of an eight-pulse quadrature signal module (MKS), which contains the first, second, and third half-wave rectifiers, a subtractor, a multiplier, and a 3-input output adder, which can be represented as two 2-series connected in series input adders, which is sometimes more advantageous for digital signal processing. According to the description of the invention, this circuit of the VMI pulse computer calculator allows obtaining a detection error of no worse than 4%. This value is obtained by the formula for calculating the modulation coefficient M:

M (iv-i „/ iv + iv), 96%« 4%.

MPK7 bi03D 1/00 quadrature sigals

for the relative error m determined by the known relation:

where m is usually called the ripple factor.

With the above values of the upper and lower ripple levels, the ripple coefficient of the ISS prototype m is 7.61%. However, its disadvantage is the use of not the full signal power at the output of the multiplier by reducing the signal level by 2.41 times, which reduces the reliability due to internal noise, and also leads to a decrease in the digitization capacity of this signal during digital processing.

The objective of the utility model is to eliminate these drawbacks, as well as expanding the functionality of the device.

This is achieved by the fact that in the known device containing the first, second and third half-wave rectifiers, the first multiplier, subtractor, adder, according to the utility model, series-connected selection circuits for the smaller and second multiplier are introduced, while the inputs of the first and second half-wave rectifiers Ya. devices, the output of the first half-wave rectifier is connected to the first inputs of the subtractor. 11YA and the smaller selection circuit, the output of the second half-wave rectifier is connected to the second inputs of of the subtractor and the smaller selection circuit, the output of the subtractor through the third half-wave rectifier and the first multiplier connected in series to the first input of the adder, the output of the smaller circuit through the second multiplier is connected to the second input of the adder, the output of which is the output of the device.

Introduction to the prototype of series-connected selection schemes of a smaller and a second multiplier instead of the first adder eliminated the aforementioned disadvantages of the prototype, as well as expanding the functionality of the proposed device due to the multivariate choice of optimal pairs of multiplication factors of the first and second multipliers, respectively, Ki and Kg, according to the new formula

while maintaining for all options for calculating the ISS the minimum ripple coefficient w equal to 7.61%.

The utility model is illustrated by drawings. Figure 1 presents the structural diagram of the computer eight pulsating ISS. In FIG. 2-6 shows diagrams of voltage ripples at the outputs of the elements of the structural diagram.

t- (and „-and„ / and „) 100%,

K, K2- (V2 / 2),

switch 3, the smaller circuit 4, the first 6 and second 7 multipliers, the adder 8. The inputs of the first DV1 and second DV2 are the inputs of the device

The first inputs of the subtractor 3 and the smaller circuit 4 are connected to the output of the first DV1 input voltage of a cosine shape. To the output of the second DV2 input voltage, phase shifted by 71/2, the second inputs of the subtractor 3 and the smaller circuit 4 are connected. The output of the subtractor 3 is connected through a third DV5 and the first multiplier 6 connected in series to the first input of the adder 8, and the output of the smaller circuit 4 through the second multiplier 7 is connected to the second input of the adder 8, the output of which is the output of the device. The elements of the calculator device are made according to well-known rules and work according to their functional purpose; see, for example, Tetelbaum I.M., Schneider Yu.R. 400 circuits for computers - M :. Energy, 1978. The claimed device (as well as the prototype) can be performed on elements of both analog and digital technology, for example, on integrated circuits (ICs). In particular, DV1, DV2, DV5 can be implemented on IC type 1533 APZ, 1533 KP11 subtractor 3 and adder 8 on IC type 1533 IPZ; scheme 4 for choosing a smaller one - on an IC type 1533 SP1; 1533 gearbox; 6.7 multipliers - on the IC type 1802VRZ.

The claimed computer eight-pulsation module of quadrature signals works by the equation.

C Ki | (ia-lbl) | + K2-mm (| aUb |), (1)

where C is the signal of the eight pulsation module. for the output of the adder 8;

KI and Ka are the multiplication factors, respectively, of the first 6 and second 7 multipliers,

and Cosa is a signal with a unit amplitude at the input of the first DW1;

b Sina - - signal with a unit amplitude at the input of the second DW2;

a - oscillation phase;

I a I and I b I - the signal of the two-pulse modules, respectively, at the outputs of the first and second DW;

(| a | - | b |) - the output signal of the subtractor 3;

| (| a | - | b |) | - four-pulsation module of the difference of two modules at the output of the third DV5;

min (| a |, | b |) is the signal of the four-pulse module at the output of the smaller circuit 4.

on l / 2 and having a sinusoidal shape, enter the input of the second DW2. As a result of half-wave rectification, at the outputs of the first I and second 2 DW, unipolar signals are distinguished — modules (“bumps”) with two pulsations during the cosine wave (sinusoid) period. They have a 100% ripple with zero low and a high level of 1.0.

The signals from the outputs of the DV 1 and DV2 are received, respectively, at the first and second inputs of the subtractor 3 and circuit 4, the choice of the smaller one. The subtractor has 3 modules | aj | Cosa | and | b | | Sina | (dashed lines in the diagram of Fig. 2) are subtracted from one another and an output of a differential bipolar signal of approximately sawtooth shape is highlighted (Fig. 2 solid lines). This signal is in the third DV5, where, as a result of half-wave rectification, the sawtooth shape is also converted into a unipolar four-pulse module (Fig. 3). It has a ripple factor with a zero low and an upper level of 1.0. Then, passing through the first multiplier 6, this signal is fed to the first input of the adder 8. In the circuit 4, the choice of the smaller of the two two-pulse modules coming from the outputs of the first 1 and second 2 LWs (in the diagram of Fig. 4 they are shown in dashed lines), the smaller ones are selected levels and thus formed, a four-pulsation sawtooth module with 100% ripple at zero lower level and with an upper level equal to l / 2/2 at a 71/4 (Fig. 4 solid lines). After passing through the second multiplier 7, this signal is fed to the second input of the adder 8. Here, both four-pulse modules multiplied by the coefficients Ki and K2, respectively (for example, KI 1,0 and Кз V2), are summed and an eight-pulse module of quadrature signals is extracted at the output of adder 8 (Fig. 6). Plots 1, 2, 3, 4 in FIG. 6 depict:

1-four-pulsation module at the first input of the adder 8 with a multiplication factor KI 1,0 of the first multiplier 6;

2- four-pulsation module at the output of the smaller selection circuit 4 with the upper level equal to 0.707;

3-four-pulsation module at the output of the second multiplier 7 with a multiplication factor KI 2 with the upper level equal to 1.0;

A 4-eight pulsation module at the output of the adder 8 with the upper level equal to 1,082 (“humps, solid lines). adder 8, the formula linking Ki and K2, has the form:

At the same time, the eight-pulsation module will have a minimum ripple coefficient m equal to 7.61%, and the time diagram - “the hump will be symmetrical with respect to a 22.5 ° at a frequency of 7C / 4 (Fig. 5, Fig. 6). In what follows, we will call Kl and Kr the optimal if they are calculated by formula (2). Otherwise, the timing diagram is asymmetric, and the ripple coefficient w is greater than 7.61%.

Let us prove the formula KI K2 (V2 / 2) from the condition that the lower levels of the eight-pulsation module are equal at a 0 ° and. Then, either Ki (CosO-SinO) K2min (Cos45 °, Sin45 °), or KI K2 (2/2), as required. Further, to calculate the value of m, we derive formulas for the lower UH and upper UB levels of the eight-pulse module, respectively, for and, 5.

and „Ki (CosO ° -SinO °) + K2min (CosO °, SinO KI.

5 Ki (Cos22.5 ° -Sin22.5 °) + K2min (Cos22.5 °, Sin22.5 °) Ki-0.541196 + Ki-V2-0.38268 Ki-1.0823.

Let us prove that, 5 corresponds to an extremum (i.e., the maximum or minimum of the eight-pulse module diagram). To do this, find the first derivative C (a) and equate it to zero.

C (a) K, (- Sina-Cosa) + KrV2min (-Sina, Cosa)

Ki (-Sina-Cosa) + KrV2 (-Sina) 0.

After rearrangement, we obtain Tg a - (V2-l) -0.4142, then 5 °, which was to be proved. The minus sign in front of 22.5 ° appeared due to the differentiation of the non-continuous broken function C (a) at 5 °. Let us prove that the negative derivative C (a) at, 5 ° corresponds to the maximum of the function C (a), i.e. corresponds to the upper level of the diagram (Fig. 6, diagram 4) of the eight-pulse ISS:

C (a) Ki (-Cos22.5 ° + Sin22.5 °) + K2min (-Cos22.5 °, Sin22.5 °) 0, as required.

We calculate the ripple coefficient m for the eight-pulse module using the formulas for UB and UH

m ((K, -l, 0823-Ki) / (Ki-l, 0823)), 61.

K, K2 (l / 2/2). (2)

compared with other m calculated from non-optimal pairs. For example, consider two non-optimal pairs, as well, i.e. in the first pair K; less than the optimal value of K2 2, and in the second pair - more. For the first pair we have: C (0 °) 1; C (22.5 °) 0.9239; C (45 °) 0.7071. Moreover, 3%, i.e. the eight-pulse module becomes a four-pulse module with a minimum at and with a frequency of 90 °. Similarly, we get the same bad result for the second non-optimal pair KI and Ka:

C (0 °) 1; C (22.5 °) 1.3065; C (45 °) V2, and, therefore, 3% (received a four-pulse module with a maximum at and with a frequency of 90 °).

From the two examples considered, we can conclude that, 61% is the minimum and optimal when the ratio of the multiplication factors, respectively, of the first 6 and second 7 multipliers, K | K2 (V2 / 2). From FIG. 5,6 it is seen that the first “hump, as well as all the others, is absolutely symmetrical with respect to the phase, 5 °. You can also see the symmetry of both plots of the four pulsation modules formed in accordance with the formulas Cosa-Sina and / 2Sina. Bearing in mind this symmetry, the last expression can be rewritten as Cosa-Sina V2Sin (45 ° -a). Let us prove the existence of this symmetry by converting the right side of the equation to the left using the well-known trigonometry formula:

Sin (p-a) Sinp-Cosa-Cosp-Sina, then V2 (Sin45 ° Cosa-Cos45 ° Sina) Cosa-Sina; .

Thus, the diagrams of both four-pulsation modules forming the first “head” (as well as the other seven) are symmetrical about the vertical axis passing through, 5 °. This means that the plot of the “pink” is also symmetrical, since it is the sum of the symmetrical diagrams of the four-pulsation modules. This proved symmetry once again confirms that the formula KI K2 (v2 / 2) was deduced reasonably for the symmetry conditions, i.e. equality of the lower levels in (0 °) in (45 °). Otherwise, the asymmetry of the "pinkies, as well as the modules, undoubtedly leads to a non-minimum ripple coefficient of 61%. Let us prove the complete symmetry of the eight-pulsation module “coils on the interval from to, substituting the optimality conditions KI K2 V2 in the formula for C (a):

C (a) Ki-Cosa- KrSina + KI V2-Sina Ki Cosa + (V2-l) -Sina

(Ki / Cos22.5 °) (Cosa-Cos22.5 ° + Sina-Sin22.5 °) KKi / Cos22.5 °) -Cosa-22.5 ° 6

the table shows the results of calculations of calculation options (1, 2, 3, any, prototype) and parameters of calculators of an eight-pulse ISS according to the above formulas for optimal pairs Ki and K2 corresponding to the formula (V2 / 2).

From the table of analytical calculations of parameters, as well as from graphical calculations of time diagrams, we can conclude about the following advantages of the proposed calculator;

1. The multivariance of the choice of values of pairs of coefficients KI and K2, calculated by the proposed formula (V2 / 2), compared with the univariate prototype. Of the many pairs KI and K2, the most preferred are pairs in which one of the coefficients (Ki or K2) is 0.25; 0.5; 1; 2; 4 etc. It does not require a complex IC of the multiplier (for example, type 1802 VRZ), which can be replaced by a simpler IC of the shift register. Due to the multivariance, the functionality of the calculator is expanded.

2. The ability to choose to avoid an undesirable decrease in the signal level at the output of the first multiplier, as is the case in the prototype 2.41 times. Such a decrease in the signal level leads to a decrease in the dynamic range of signals, a decrease in the reliability of operation under internal noise, and also to a decrease in the accuracy of calculating the eight-pulse module due to a decrease in the bit capacity of the quantized (2.41 times smaller) signal at the output of the first multiplier. The latter can be compensated, but due to an undesirable complex increase in the bit depth of quantization of both input signals of the device.

Claims (1)

The calculator of the eight-pulse module of quadrature signals, characterized in that it contains the first, second and third half-wave rectifiers, a subtractor, a circuit for selecting a smaller one, the first and second multipliers and an adder, while the inputs of the first and second half-wave rectifiers are the inputs of the device, the output of the first half-wave rectifier is connected with the first inputs of the subtractor and the smaller selection circuit, the output of the second half-wave rectifier is connected to the second inputs of the subtractor and the smaller selection circuit it, to the output of the subtractor connected in series within the third full-wave rectifier and a first multiplier, whose output is connected to a first input of an adder, to the output selection circuit connected to the smaller second multiplier, whose output is connected to the second input of the adder whose output is an output device.