Four channel high power rf source with beam steering based on gyromagnetic nonlinear transmission lines

Abstract

The synchronized operation of four gyromagnetic nonlinear transmission lines (NLTLs) was tested with a pulse repetition frequency up to 1 kHz during 1 s bursts. High voltage pulses with a duration of ∼5 ns from the solid state driver S-500 were split into four 48 Ω channels reaching about -200 kV in each channel with ∼10% variation in the amplitude. The maximum peak voltage at the NLTL output was within 220-235 kV with the maximum modulation depth of decaying oscillations up to 90% at the center frequency near 2.1 GHz. The relative delay between channels reached the half-period of the center frequency of oscillations. The associated beam steering by four element array of conical helical antennas was demonstrated in a horizontal plane at 17°. The effective potential of radiation reached 360 kV at the radiation axis. The effect of ferrite temperature on the shock wave velocity in gyromagnetic NLTL is observed.

A Review of Nonlinear Transmission Line System Design

“…Four coherent gyromagnetic NLTLs produced 2.1 GHz pulses with an effective potential of 360 kV at the radiation axis, at a repetition rate of 1 kHz. A variation of 17° through beam steering was demonstrated in the horizontal plane [119].…”

High-Voltage Drivers Based on Forming Lines with Extended Quasi-Rectangular Pulses for High-Power Microwave Oscillators

“…The matching efficiency can be increased by separating high-voltage pulses into several channels, because the number of channels determines (equals) the factor of decrease in the effective load resistance. For example, such an increase in matching efficiency is provided by pulse separation into two [11,12] and four channels with a pulse sharpener in each of them [36,37]. With phase-controlled parallel channels in shock-excited, nanosecond microwave oscillators [9], one can increase the total power and provide microwave beam control similar to that in active antenna arrays [37].…”

“…For example, such an increase in matching efficiency is provided by pulse separation into two [11,12] and four channels with a pulse sharpener in each of them [36,37]. With phase-controlled parallel channels in shock-excited, nanosecond microwave oscillators [9], one can increase the total power and provide microwave beam control similar to that in active antenna arrays [37].…”

Computer simulation of multi-gigawatt magnetic compression lines

“…The described system of equations is solved using COMSOL Multiphysics numerical simulation software. To couple the system, M from the equation ( 2) is substituted into equation (1) as M in the curl term. Heff in equation ( 2) includes H found from equation (1), as well as Hbias found at the preliminary step.…”

“…Non-linear transmission lines (NLTL) filled with saturated ferrite are promising solid-state sources of high-power microwave radiation. Such NLTLs are usually called gyromagnetic NLTLs (GNLTLs) because their operation principle is based on gyromagnetic precession of magnetization vector M in ferrite, which is magnetized into the state of deep magnetic saturation [1,2]. A GNLTL typically consists of a coaxial transmission line, partially or fully filled with ferrite material, and an external magnetic bias circuit.…”