Generation of high-power RF pulses by means of a nonlinear magnetic coupling network

Abstract

In many navigation and communication systems it is required to generate high-power RF pulses at a relatively low duty cycle. In conventional systems the active devices (tubes, transistors) that generate these pulses must handle the peak RF power. In this paper a new method of generating RF pulses is described in which the active devices need handle only the average power. The key element in this new method is a magnetic coupling network that consists of a balanced interconnection of four nonlinear inductors. This coupling network is termed the variable mutual coupling network (VMCN). High-power RF pulses are generated by ac charging of a high- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</tex> circuit called the RF storage tank. This storage tank is coupled to the load by means of the VMCN. During charging the VMCN is balanced such that no mutual coupling exists between the storage tank and the load. When the storage tank is fully charged, control currents are applied to the VMCN causing an unbalance to occur because of the non-linear <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B-H</tex> characteristics of the inductors, and thereby introducing a mutual coupling between the storage tank and the load. The energy in the storage tank is thus transferred to the load in the form of an RF pulse.