SU661754A1 - Shaper for phase meter - Google Patents

Description

 The invention relates to the field of radio metering technology and can be used to build phase measurement devices and systems operating in a wide amplitude range. At present, trout devices are known that contain an amplifier with adjustable - transfer coefficient, limiting amplifier, shaping grids, a high-pass filter and a delayed automatic gain control circuit. The device of the phase meter closest to the device is The most common of the amplifier-limiting and short-pulse fordarvatel {2. Such forming devices are now very igar use in domestic and foreign phase meters. Not enough, these forming devices have a large error due to the changed signal amplitudes, the so-called phasoses –the accuracy of the error. The purpose of the invention is to reduce the phaso-amplitude error of the forming devices and increase the dynamic range of the input signals. The goal is achieved by the fact that in a forming device containing a series-connected amplifier-limiter and a shaper of short circuits, an additionally adjustable phase shifter, a stroboscopic converter, an amplifier, a synchronous detector and. the first unit, the first inputs of the adjustable phase shifter and the stroboscopic converter are connected to the device input, the output of the short pulse shaper is connected to other inputs of the stroboscopic converter, the output of which through a series-connected additional amplifier, the synchronous detector and the matching unit are connected to the second input of the controlled phase shifter, the output of which connected to the input of the amplifier of the limiter, and the output of the amplifier -og of the strings connected to the second input of the syncron th detector. Ba figl presents a block diagram of the proposed-forming device; on phpg, 2 - stress diagrams.

for those who work with forg- or devices,.

The forming device contains a series-connected regulator phase shifter 1, in which is connected to the device input, an amplifier-limiter 2, a shaper of short impulses 3 and a series-connected stroboscopic converter 4, the first input also connected to the device input, as well. the second - to the output of the formlr ™ bodies of short pulses 3, the amplifier 5, the synchronous detector 6, the second input of which is connected to the output of the amplifier of the limiter 2, the matching unit 7, the output of which is connected to the adjustable phase shifter.

Forming devices in phase meters are designed to form short pulses tied to zero-level transitions of the input signal. During the formation of short pulses associated with zero transitions, errors arise. These errors are caused by different reasons. To eliminate errors due to zero line drift due to changes in ambient temperature, power supply voltage, and other reasons, widespread use of full-wave shaping devices. They use information about zero-level transitions in both half-periods of the input signal. In such formative devices, the error is mainly due to the inertial properties of the helmet, the force of the limiting amplifier.

It is known that due to the inertia of the cascade, when the amplitude changes in the last days, an error occurs

dchgo.zsh-ggsch, where (-O is the operating frequency;

 the time constant of the cascade is inversely proportional to the bandwidth of the cascade.

These errors at higher frequencies are significant.

To reduce the phase-amplitude error at the input of the amplifier cac. 2, the adjustable phase shifter 1 is switched on. When the amplitude of the signal at the input of the amplifier-limiting device 2 changes, the biasing pulse shifts at the output of the short pulse 3 1. A control signal for adjusting the phase difference 1 is generated using a stroboscopic converter 4. Short pulses from the output of the driver 3 are applied to this converter. and short pulses are tied to different levels of the input signal m (as shown in Figure 2) at the output of strobe pulses occur converter 4 to the input frequency (sm.punktir). These pulses are amplified by amplifier 5 (amplifier 5 does not have strict bandwidth requirements) and are fed to a synchronous detector. The synchronous detector, in addition to detecting the amplified signal, also represents the sign of the mismatch. For this, rectangular pulses are fed directly to the synchronous detector directly from the output of amplifier-limiter 2.

The constant voltage from the output of the synchronous detector 6 through the matching unit 7 is supplied to the control of the phase shifter 1. The matching unit 7 may include a low-pass filter that enhances the noise immunity of the shaping device, an amplifier of direct current. The signal from the output of the matching device changes the phase of the signal at the output of the amplifier-limiter 2 until the snapping pulses at the output of the driver of short pulses 3 are strictly attached to the same level, which is possible without error.

The application of the proposed device leads to a significant reduction in the phase-amplitude error of the phase-measuring devices and systems and the expansion of their dynamic diapason. The reduction in phase errors of phase meters, the expansion of their dynamic range nx is currently an important task, as it leads to a significant improvement in the metrological characteristics of the devices and to an improvement in the technical characteristics of various phase systems. For example, in phase radionavigation systems, an improvement in the characteristics of forming devices leads to an increase in the accuracy of determining the coordinates of objects and an increase in the range of operation of the systems in detail.

Claims (2)

1. Author's Certificate USSR No. 312210, cl. G 01 R 25/00, .1971. 2. Galanova O.P. and etc. The basics of phase metering, L., Energie, 1976, p.141.