Review of Experiments on Microwave Beam Steering in Arrays of High-Power Oscillators by the Control of Voltage Rise Time

This paper describes two approaches which have been developed in the past few years for the creation of electronically controlled steering of the microwave beam formed by multichannel auto-oscillators. The first one is based on two- and four-channel gyromagnetic nonlinear transmission lines operating in the generation mode at subgigawatts power level and decimeter wavelengths. The second approach uses Cherenkov superradiance in two and four parallel backward-wave oscillators with centimeter wavelengths. We present the results of several recent experiments and analyze the physical and technical limitations to arrange new radiating arrays.

I. Introduction

The physics of electromagnetic shock wave formation [1], [2] allows producing of radio frequency pulses behind the traveling voltage pulse front. This technique based on the circuits with nonlinear elements and materials has been under development for approximately 25 years [3]–[12]. In past 10 years, the studies of lumped element nonlinear transmission lines (NLTLs) and continuous-medium NLTLs as sources of high-power (10⁸–10⁹ W) radio frequency radiation in the form of nanoseconds duration radio pulses have expanded significantly [8]–[28]. The center frequency of lumped element NLTLs usually lies in the range from 0.05 (with dielectric nonlinearity, [29]) to 1.5 GHz [8], whereas gyromagnetic NLTLs are used for radio frequency generation at frequencies from 0.5 [11] to 5 GHz [18], [19].