Intense electron beam microwave switch

DETAILED DESCRIPTION OF THE INVENTION Referring to FIG.
1, the switch includes a superconducting resonator 1, such as a lead-plated copper cylindrical resonator, adapted to be pumped to a high energy state by a low power microwave source 2.
The source frequency, as is customary, corresponds to the resonant frequency .
omega.
of the resonator and it may be either a CW or a pulsed signal.
Coupled to the resonator by way of a suitable aperture 3 is a waveguide 4 having a main rectangular waveguide section or cavity 6 formed by top and bottom walls of 7 and 8, end walls 9 and 11 and side walls 12 and 13.
A branch or T-section 14 extends laterally of side wall 12 in open communication with the rectangular main cavity.
T-section 14 normally is terminated in a matched load (not shown) which, for example, may be an antenna.
For descriptive purposes, it can be considered that the main waveguide section 6 is formed of two continuous arms A and B, arm A extending from input end wall 9 to the longitudinal center of T-section 14, designated line C, and arm B extending from terminal wall 11 to line C.
Terminal end 11 is, in effect, a short circuit capable of reflecting incident microwave energy in the form of a standing wave 16.
As shown in FIG.
2, this wave which is produced by the incident and reflected traveling waves has the usual nodes and antinodes or, in other words, points of minimum and maximum electrical field intensity.
In what will be referred to as an `open` state, short circuit 11 is spaced from center line C to produce a nodal condition at line C.
To achieve this `open` state, the length of arm B is a quarter wavelength of the microwave signal (.
lambda.
g/4) or an even multiple of (.
lambda.
g/4).
The node at center line C then prevents coupling of electromagnetic energy from the main waveguide cavity to external load 15 and the load consequently is isolated from the resonator and its microwave source.
Substantially all of the power supplied to the resonator remains stored permitting it to charge to a high microwave energy state