An antenna system that generates radiation similar to that generated by a relativistic charged particle is provided. The antenna system includes a conducting wire carrying a current pulse with a net charge, called a quasi charged particle, which propagates near the speed of light and emits radiation. Preferably, the quasi charged particle is generated by using a pulsed laser to knock out electrons from the conducting wire. While propagating on the conducting wire near the speed of light, the quasi charged particle generates a synchrotron like radiation from a bent of the wire, an undulator like radiation from a sinusoidal or helical structure of the wire, a diffraction like radiation from an aperture transmitting the wire, a Smith-Purcell like radiation from a corrugated grating surface next to the wire, and a greatly wavelength-contracted undulator like radiation from an undulator with the wire aligned along the undulator axis. |