SU1415212A1 - Device for automatic measurement of actual sensitivity of radio receivers - Google Patents

Description

11415212

The invention relates to a measurement technique, namely, devices for automatically measuring the real sensitivity of radio receivers, and can be used to automatically measure the parameters of radio receivers,

The aim of the invention is to increase the speed and accuracy of measurements by reducing the number of approximation steps and reducing the aperture error.

Figure 1 shows a block diagram of a device for automatically measuring the real sensitivity of radio receivers; figure 2 - timing charts of the device.

A device for automatically measuring the real sensitivity of radio receivers comprises a signal generator 1, a controlled attenuator 2, a controlled receiver 3, a switch 4, a storage unit. 5, compiler 6, clock generator 7, digital display unit 8, control unit 9, trigger 10, elements 11-11 - 13, counters 14 and 15 whose clock inputs are connected to the outputs of elements 11 and 12 whose first inputs are connected with the generator output 7 clock pulses, the input of which is connected to the output of the control unit 9, another output of which is connected to the input of the switch 4, the first output of which is connected to the first input of KQj napaTOpa 6 through the storage unit 5, and the second output is connected to the second input of the comparator 6, the output of which is connected to the syn trigger trigger 10, with input element I.11 and input element I 13, the output of which is connected to the blocking input of the clock generator 7, the output of the generator 1 of the signals is connected to the input of the controlled attenuator 2, the output of which is connected to the input of the monitored receiver, the output of which connected to the input of switch 4.

In Figure 2, the following notation is taken:

a is the magnitude of the effective voltage at the output of the receiver 3 (for an implied noise voltage, it is assumed to be zero);

b - signal at the second output of control block 9;

in - the output signal of the comparator 6;

y d 12;

the output signal of the trigger 10; element output signal

0

five

0

five

0

five

0

five

0

five

e is the signal at the generator output i 7 clock pulses.

The device works as follows.

At the beginning of the cycle, the command from control unit 9 measures and stores the intrinsic noise level of the monitored receiver, while the storage unit 5 is connected via switch 4 to the output of the receiver.

At time t, the memorized level of the receiver's own noise from the memory unit 5 is fed to the input of the comparator 6, and the output voltage of the receiver is fed to the other input through the switch 4. Counters 14 and 15, trigger 10 reset. At time t, the command of the control unit 9 starts the generator 7 at the same time from the positive differential of the control voltage of the control unit, the counter 15 records the units, the voltage at the input and output of the receiver does not change. The generator 7 begins to generate pulses that pass to the counter of the 14 most significant bits, changing its state. The output voltage of the receiver is rapidly increasing.

At time t, when the output voltage of the receiver exceeds a certain level U, the comparator 6 triggers and translates the 1p trigger into one state. Thus, there was a rough measurement of the sensitivity of the receiver. In this case, the And 11 element blocks the passage of clock pulses to the input of the counter 14, and they begin to pass through the And 12 element to the subtractive input of the low-order counter 15. The counter 15 changes the state of the attenuator 2. The voltage at the receiver output slowly begins to drop to those until it becomes less than a certain level and. Comparator 6 changes its output state and element I 13 produces a signal blocking generator 7. Simultaneously, this signal records information from the outputs of counters 14 and 15 into digital indication block 8, which indicates the measured value

31A152I2

receiver sensitivity and ebnul - with a zero signal from block 9 code

management

em counter 15. Counter 14 zero em

Claims (1)

DEVICE FOR AUTOMATIC MEASUREMENT OF REAL SENSITIVITY OF RADIO RECEIVERS, comprising a signal generator and a controlled attenuator, a switch, a memory unit, a comparator, a clock pulse generator, a digital display unit, a control unit, the first and second outputs of which are connected respectively to the first inputs of the switch and the clock generator , the second input of the switch is connected to the terminal for connecting the output of the monitoring object, the terminal for connecting the input of which is connected with the output of the controlled attenuator, the first output of the switch is connected to the input of the storage unit, the output of which is connected to the first ^ input of the comparator, the second input of which is connected to the second output of the switch, characterized in that, in order to increase the speed and accuracy of measurement, a trigger is inserted into it, three And elements and two counters, the outputs of which are connected to the corresponding inputs of the digital display unit and the control inputs of the controlled attenuator, the first and second inputs of the trigger are connected to the second output of the control unit phenomena, with the installation input of the first counter and the input of zeroing the second counter, the clock inputs of the first and second counters are connected respectively to the outputs of the first and second elements And, the first inputs of which are connected to the output of the clock generator, the blocking input of which is connected to the control input of the digital display unit, with the input of zeroing the first counter and with the output of the third element And, the first input of which is connected to the second input of the first element And and with the output of the trigger, the sync input of which is connected to the output m of the comparator, with the second input of the second element And and with the second input of the third element I.