A multi-gbit/sec electron-beam-semiconductor signal processor

A signal processor has been developed which can multiplex multiple input data lines into a single output (parallel to serial converter) with an output data rate of up to several Gigabit/sec. Among its possible applications, the device is intended for use in digital communications to drive a PIN diode (waveguide) modulator. The specific device to be described consists of a pencil-beam electron gun, a beam rotation system, eight input gates, a beam bending electrostatic Einzel lens, and a single semiconductor target. Operation of the processor is as follows: The beam rotation system launches the pencil e-beam into conical rotation. The conically-rotating beam goes through the gates and is then bent and refocussed by the Einzel lens onto or off the target, depending on the polarity of the input gate signals (ones or zeros). A signal processor output of 0. 8V into 50-Ω has been achieved with a 0. 15 ns-rise-time target at 1. 6 and 2 Gbit/s output data rates. With a 0. 3 ns-rise-time target, the output was 5V into 50-Ω at 1. 6 Gbit/s data rate and can be increased to 10V by doubling the beam current density.