A.S. Velichkina1, A.E. Elfimov2, G.K. Uskov3, A.M. Bobreshov4

1-4 Voronezh State University (Voronezh, Russia)

1 velichkina@phys.vsu.ru; 2 elfimov@phys.vsu.ru; 3 uskov@phys.vsu.ru; 4 bobreshov@phys.vsu.ru

The paper proposes an algorithm for independent accumulation and resorption of charge in a step recovery diode (SRD), which makes it possible to improve the shape of the resulting pulse and reduce the level of subsequent distortion, also called ringing. This turns out to be especially important when forming a Gaussian monocycle and doublet using adders of the Wilkinson design. The proposed solution is based on the ability to control the duration of the processes of accumulation and resorption of charges in the structure of the DNC, which ultimately affects the shape of the generator pulse. The control algorithm includes changing the duration of the triggering pulses and their start time relative to each other.

The proposed electrical circuit diagram includes two field-effect transistors: one for each control channel. Rectangular pulse generators are connected to the gates of the transistors, which generate trigger signals. Pumping and absorption pulses for diodes are formed at the sources of field-effect transistors; constant power sources of different polarities are connected to the drains of the transistors: 5 V to generate the absorption current and -3 V in the pump channel. The circuit uses two series-connected diodes to increase the amplitude of the generated pulse and an inductance to accumulate the energy of the generated pulse.

A full-scale experiment was conducted to test the operation of the described video pulse generator circuit. A sample of the pulse generator was manufactured; Rogers RO4350D textolite with a dielectric constant of 3.48 and a dielectric thickness of 0.76 mm was used as the substrate material. During installation, unpackaged transistors from Ampleon model BLF574 and charge storage diodes Macom-MAVR-044769-12790T were used. The measurements were carried out using an Agilent DCA-X 86100D four-channel stroboscopic oscilloscope. Two Agilent 81104A were used as trigger pulse generators.

The study confirmed the effectiveness of the proposed circuit solution. At the output of the generator, a bell video pulse with an amplitude of 38 V and a half-maximum duration of 200 ps was obtained. A comparison was made of the level of after-effect distortion with pulses received from generators using one control channel. The “ringing” level, calculated as the ratio of the peak-to-peak interference after the end of the pulse, is about 4.2% of the pulse amplitude. This indicator improved three times relative to the solutions with which the comparison was made.

The ability to control the shape of the resulting bell video pulse was also demonstrated. The dependence of the amplitude and duration of the pulse pulse on the delay time between pumping pulses and charge resorption in the discrepancy zone was shown. The duration tuning range was 160-315 ns, and the amplitude tuning range was 36-52.7 V. Thus, the possible tuning range for duration was 97%, for amplitude 46%. This property can be used to modulate a signal.

Velichkina A.S., Elfimov A.E., Uskov G.K., Bobreshov A.M. Gaussian pulse generator with independent control of charge accumulation and dissolution time. Radiotekhnika. 2024. V. 88. № 12. P. 83−88. DOI: https://doi.org/10.18127/j00338486-202412-07 (In Russian)

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