Focusing properties of a microwave radiator utilizing a slotted rectangular waveguide

A microwave radiator, utilizing a slotted rectangular waveguide that is bent into an equiangular spiral, for focusing leaky microwaves radiated from a continuous longitudinal slot is presented. The radiation fields near the focus are derived by setting up a magnetic current on the slot. Some of the fundamental focusing properties of this spiral slotted rectangular waveguide (SSRW) radiator, such as the radiated power distribution and the phase behavior near the focus, are also discussed numerically. The power distribution near the focus in the form of intensity contours is compared with preliminary measurement of the prototype operating at 10 GHz. >